https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=Djbrasier&feedformat=atomexplain xkcd - User contributions [en]2024-03-28T17:04:26ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=2489:_Bad_Map_Projection:_The_Greenland_Special&diff=2150902489: Bad Map Projection: The Greenland Special2021-07-15T13:14:54Z<p>Djbrasier: /* Transcript */ Put link to Tobler hyperelliptical projection</p>
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<div>{{comic<br />
| number = 2489<br />
| date = July 14, 2021<br />
| title = Bad Map Projection: The Greenland Special<br />
| image = bad_map_projection_the_greenland_special.png<br />
| titletext = The projection for those who think the Mercator projection gives people a distorted idea of how big Greenland is, but a very accurate idea of how big it SHOULD be.<br />
}}<br />
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==Explanation==<br />
{{incomplete|Created by a AFRICA SIZED NOT AFRICA SIZED ISLAND. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
Map projections are different methods of representing the curved surface of the Earth on a two-dimensional map. Because the Earth is not flat,{{Citation needed}} any method of representing it will unavoidably contain some inaccuracies, but some projections are more noticeably inaccurate than others. Typically a projection can represent only distances, areas ''or'' angles correctly, or at best imperfectly compromise two of these. The map choice should reflect the purpose you need to put it to, as it will necessarily distort (perhaps by twisting, skewing and/or resizing) those aspects it was not designed to show intact. <br />
<br />
One such projection is the {{w|Mercator projection}}, which is designed so that all north-south lines of longitude are parallel to each other and all {{w|Rhumb line}}s are consistent, which is most important in the time of map-based navigation. In reality, these imaginary lines eventually meet at the poles and this also expands the apparent distance between lines of latitude at the more extreme latitudes. This means that Mercator maps will show geographic features with larger areas and distances than they should if they are near the poles, compared to those more equatorial. It is not possible to accurately compare the sizes of features across the globe using this projection, although the distortions do not significantly affect more local maps (other than ''very'' close to the poles, historically not an issue) or comparisons along or between similar latitudes away from the equator.<br />
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Greenland is a large island in the Arctic ocean and one of the nearest pieces of land to the north pole. The Mercator projection shows it to be significantly larger than it really is, compared to equator-straddling features such as Africa. It is therefore one of the most obvious inaccuracies of Mercator's map, if used (e.g.) in the classroom to teach physical geography (which perhaps would best use a representation that was consistent to area) rather than navigation.<br />
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This comic's projection has retained this singular inaccuracy as a deliberate feature, though avoiding all other such inaccuracies of the Mercator projection by using a different projection elsewhere that is designed explicitly to avoid them. For example, a traditional Mercator map would show other polar areas such as Antarctica, southern South America, or even New Zealand as larger, but this map does not.<br />
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The title text suggests that this map was created by people who believe Greenland should be larger. Whether these people believe it should be physically increased in size in some manner or should simply receive a greater share of the attention is unclear. One method for increasing its size would be to increase the coverage of its ice cap, which is currently decreasing in size due to increases in temperature. However, increasing Greenland's ice coverage to the size it appears on a Mercator map would involve covering the entire island and surrounding ocean with ice, which would be very problematic for Greenland's population.<br />
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==Transcript==<br />
:Bad Map Projection #299:<br />
:<big>The Greenland Special</big><br />
:Equal-area map preserves size everywhere except Greenland, which uses the Mercator projection.<br />
:[A drawn world map, apparently approximating the {{w|Tobler hyperelliptical projection}}, except for Greenland which is of a typical Mercator (non-)skew and sized at almost the size of Africa, to almost entirely fill the space between Canada and Iceland, extending up well beyond the nominal location of the North Pole and its southern tip comparable to that of Spain/the central states of the US.]<br />
{{comic discussion}}<br />
[[Category:Bad Map Projections]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:2489:_Bad_Map_Projection:_The_Greenland_Special&diff=215089Talk:2489: Bad Map Projection: The Greenland Special2021-07-15T13:10:37Z<p>Djbrasier: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
I want this map, but s/Greenland/Alaska (because that is how big Alaska ''should'' be) [[User:Orion205|Orion205]] ([[User talk:Orion205|talk]]) 05:38, 15 July 2021 (UTC)<br />
:What are you trying to say? <span style="text-shadow:0 0 6px black">[[User:Beanie|<span style="font-size:11pt;color:#dddddd">Beanie</span>]]</span> <sup><span style="text-shadow:0 0 3px #000000">[[User talk:Beanie|<span style="font-size:8pt;color:#dddddd">talk</span>]]</span></sup> 09:50, 15 July 2021 (UTC)<br />
Hi, [[User:Beanie]], sorry I've been messing with your well-intentioned Transcript edits, with my own well-intentioned ones. I seem to have difficulty with the Edit Conflict page not being very helpful (on this wide but short small screen, and a browser that wants me to resubmit things and lose newer stuff if I even ''think'' of switching windows mid-edit), especially when it seems we're each pushing little changes in very short intervals (often takes longer to tap in the edit-Summary!), and I'm formally not changing that any more. Except that it's so descriptive, I absolutely wouldn't object to some ''other'' way of describing the 'Supertitle', like a Subtitle but above the in-comic main title-scrawl, for example. (I only 'reverted' that back over because it was easier than trying to snipe in all the other retweaks it looked at one point that I needed to reapply when I couldn't work out why it was submitting so 'wrong'.) You've probably safely and sanely un-nuked my 'nuke' by the time I've added this comment, of course, but I can't know for sure yet... ;) [[Special:Contributions/141.101.99.177|141.101.99.177]] 10:24, 15 July 2021 (UTC)<br />
:Ah well, I'm trying to conform to the usual style of transcripts. I will compare this to other examples of 'Bad Map Projections', in hope of styling the transcript right :). <span style="text-shadow:0 0 6px black">[[User:Beanie|<span style="font-size:11pt;color:#dddddd">Beanie</span>]]</span> <sup><span style="text-shadow:0 0 3px #000000">[[User talk:Beanie|<span style="font-size:8pt;color:#dddddd">talk</span>]]</span></sup> 10:35, 15 July 2021 (UTC)<br />
The non-Greenland map projection is very close to Kavrayskiy 5 (not 7) except the South Pole is rounded like Mollweide. - [[User:Frankie|Frankie]] ([[User talk:Frankie|talk]]) 12:09, 15 July 2021 (UTC)<br />
Does anyone know which projection the rest of the map is? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 13:10, 15 July 2021 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:2446:_Spike_Proteins&diff=209840Talk:2446: Spike Proteins2021-04-07T01:28:18Z<p>Djbrasier: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
I got my 1st dose today. My apartment is swarming with spike proteins. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 01:17, 6 April 2021 (UTC)<br />
:My Dad got his second dose on Thursday & got allll the usual symptoms. He's not on antibiotics, but his breath smells like the taste of antibiotics to me. I swear, dogs aren't the only ones that can smell a body's reaction to coronavirus (and also, for reference, cancer ''stinks''). <br />
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 16:39, 6 April 2021 (UTC)<br />
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Can someone here create a "COVID-19 vaccine" category (as a subcategory of COVID-19)? Randall has been posting a lot of vaccine-related comics recently. [[Special:Contributions/172.69.35.113|172.69.35.113]] 02:11, 6 April 2021 (UTC)<br />
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I don't think the description as it is right now is very accurate. It seems to be stating that the spike protein is a normal protein normally produced by humans, rather than a protein used by SARS-CoV-2 (and likely other similar viruses (virii?) to aid in their infection. In this case, beret guy has gotten an MRNA vaccine (either Moderna or Pfizer), so has given his cells the recipe to make this spike protein for themselves, until the immune system realizes it shouldn't be there. [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 07:08, 6 April 2021 (UTC)<br />
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== Off topic ==<br />
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I'm a bit suprised there was no Ever Given comic... [[Special:Contributions/162.158.111.161|162.158.111.161]] 13:45, 6 April 2021 (UTC)<br />
:It's been delayed by two weeks, by having been sent round Africa...<br />
:(Srsly, though, if the sufficient dose of inspiration hasn't happened - and it's not his usual geek-out topic - then it's no more likely to be mentioned than (say) Brexit issues seriously messing with exports, especially of foodstuffs. And I think the US is largely proof from Suez (or Channel) cargo movements, so may not be on the radar. Chip shortages, etc, are likely from C19 disruptions, not from the otherwise unaffected trans-Pacific shipping.) [[Special:Contributions/162.158.159.108|162.158.159.108]] 22:28, 6 April 2021 (UTC)<br />
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== Moist Corona ==<br />
As a new 'image' of the Corona virus has recently been used in a scientific publication (as discussed in https://www.snopes.com/fact-check/moist-coronavirus-image/ ), showing a 'moist' Corona virus, I got the impression that the "Why is it so wet?" part of the comic refers to this. (Otherwise it seems like a remark coming out of nowhere.) Of course, at the normal scale of a virus, 'wet' and 'dry' don't really mean anything, but as 'images' of the virus are mostly artistic representations anyway, there's no reason not to show them as 'moist'. (Unsigned addition by 162.158.92.102)<br />
:That article has the odd assertion that "it’s important to remember that art is objective." I think they mean "subjective". [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 17:25, 6 April 2021 (UTC)<br />
:I subject to such a misuse of terms! [[Special:Contributions/141.101.98.218|141.101.98.218]] 22:31, 6 April 2021 (UTC)<br />
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== Does anyone know why this is incomplete? ==<br />
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Without information, nobody knows which part needs fixing. If anyone knows why this is incomplete, please post the reason here or, even better, in the incomplete tag. If nobody can provide a satisfactory answer, maybe we should consider removing the incomplete tag. '''Note that I am posting this exact same text on other comics of questionable incompleteness. It's not spamming, it's a conscious attempt to clean this category up.''' [[User talk:Quillathe Siannodel|<sup>{)|(}</sup>]][[User:Quillathe_Siannodel|Quill]][[User talk:Quillathe Siannodel|<sub>{)|(}</sub>]] 18:15, 6 April 2021 (UTC)<br />
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:It's marked as "incomplete" because it's new and still under active revision. I don't know if there's a formal criterion set down anywhere, but I don't think it would be appropriate to remove that tag from any page that's been repeatedly edited in the previous ten days or so. [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 18:33, 6 April 2021 (UTC) EDIT: I find it especially eyebrow-raising when someone edits a page ''and'' removes that tag at the same time. If I edit a page, I ''want'' at least one more pair of eyeballs to check what I've done. As opposed to the implied "Now that I have made my changes, the page is in its final form."<br />
:Agree with the above user. This text is always placed when a comic is new and is not usually removed for a few days (or even longer). Also, although you say that "this is not spamming", it feels like spamming if you place this exact same text on multiple comics, without even having a real discussion on why a comic is incomplete. [[Special:Contributions/172.69.33.249|172.69.33.249]] 22:59, 6 April 2021 (UTC)<br />
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== Beret Guy superpowers? ==<br />
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Sorry, I don't know if this is the right format for this, but it seems that not only does Beret Guy often misunderstand, he also has superpowers. Making a life-sized spike protein would classify as that to me. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 01:28, 7 April 2021 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:2335:_Photo_Deposit&diff=194923Talk:2335: Photo Deposit2020-07-21T19:01:42Z<p>Djbrasier: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
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Depositing cash through a smartphone app was one of the silliest and most useful features in GTA V. Unfortunately, depositing money would not duplicate it. Presumably the characters in the game are very honest and trustworthy, destroying any cash instantly after scanning it in. This honesty is to be expected from thieving killers such as these.<br />
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You can also withdraw cash via the app. How that works is beyond me.<br />
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--[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 23:38, 20 July 2020 (UTC)<br />
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A frequent joke in "The Goon Show" on 1950s British radio was the offer of a printed photograph of usually a small sum of money, treated as the photograph actually having value itself. Sometimes it's a phonograph disc. And sometimes the money represented turns out to be a forgery. In a less silly context, the photograph might be considered as an I.O.U., as evidence that the money exists and will be paid... which is what a banknote is, really. But in practice someone influencing you with pictures of money might be dishonest. Bank advertising for instance.<br />
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Wikipedia's article on "The Goon Show running jokes" (!) doesn't mention money photographs, although there is a reference to handing out pictures of Queen Victoria, especially in historical stories. Pictures of Queen Victoria may be on older money, but these ones don't seem to be.<br />
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Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.98.26|141.101.98.26]] 08:18, 21 July 2020 (UTC)<br />
: Search for "photo"(graph) in http://www.thegoonshow.net/scripts_show.asp?title=s06e07_foiled_by_president_fred for the instant(s) that came straight to my mind, being recently broadcast. (I assume you're familiar with LSD?) [[Special:Contributions/162.158.159.14|162.158.159.14]] 09:38, 21 July 2020 (UTC)<br />
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"Other nations ... have started introducing plastic banknotes" Lol. Australia had *finished* introducing plastic bank notes 30 years ago. [https://csiropedia.csiro.au/polymer-banknotes/] [[User:Boatster|Boatster]] ([[User talk:Boatster|talk]]) 01:43, 21 July 2020 (UTC)<br />
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Hmm. How much money would that be? Say each photo is 4MB and your upload speed is 25 or so Mb/s. Each upload would take about 1.3 secs. We'll round up to 1.5. To keep it simple, we'll say that they have a stack of bills, and are able to scan each new bill within those 1.5 seconds. Now, if the bank allows you to upload $100 bills, without any rate limiting, you'd be able to make $400/min (the same as the what if article, weird). Which means that in six hours, they could make $144,000 dollars! Of course, this is mostly guesswork, but it should be somewhere in the ballpark. <br />
Could be a little more: Smaller photos, better network.<br />
Or a lot less: Most people don't have $144,000 in cash ready at a moment's notice, and scanning could take more than 1.5 secs. <br />
Of course, if this was a feature that was announced, and they had time to prepare....<br />
[[Special:Contributions/108.162.245.102|108.162.245.102]] 04:11, 21 July 2020 (UTC)<br />
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The feature of depositing check is this new or old... Is it something from before or after the Corona outbreak? It is a smart feature to avoid visits to banks during the pandemic - also the money thing, which of course is not realistic irl. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:19, 21 July 2020 (UTC)<br />
:depositing checks by smartphone is old, going back to 2018 if not earlier, and the depositing of currency could be realistic if bills used blockchain ledger entries instead of easily guessed serial numbers and everyone verified every currency transaction against the blockchain every time (this would end counterfeiting as a side effect). [[Special:Contributions/162.158.63.172|162.158.63.172]] 09:53, 21 July 2020 (UTC)<br />
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Is it by the way illegal to even take a picture of banknote? I know printing one out is... Even if only one side and not very good quality. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:27, 21 July 2020 (UTC)<br />
:if taking pictures of banknotes is illegal then bank security cameras (and security cameras in many retail establishments and casinos) are routinely breaking the law. Also, aren’t change machines taking a picture as part of their anti-counterfeiting circuits? [[Special:Contributions/162.158.63.172|162.158.63.172]] 09:58, 21 July 2020 (UTC)<br />
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I know it's acceptable in the 'colonial' idiom, but seeing "cheques" spelt as "checks" always confuses me for a micromoment. As well as imagining a test/verification being somehow a bartered service, I'm only just getting past it also being a bill-of-fare (in the UK we may pay a bill with a cheque, over there you can pay a check with a bill). But carry on carrying on! I'll get my coat. (If I can find the coat-check.) [[Special:Contributions/162.158.159.100|162.158.159.100]] 10:01, 21 July 2020 (UTC)<br />
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Why is cryptocurrency in there, it seems tangential at best? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 19:01, 21 July 2020 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=2322:_ISO_Paper_Size_Golden_Spiral&diff=1936762322: ISO Paper Size Golden Spiral2020-06-20T15:07:39Z<p>Djbrasier: /* Explanation */ Corrected relationship between radians, gradians, and degrees</p>
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<div>{{comic<br />
| number = 2322<br />
| date = June 19, 2020<br />
| title = ISO Paper Size Golden Spiral<br />
| image = iso_paper_size_golden_spiral.png<br />
| titletext = The ISO 216 standard ratio is cos(45°), but American letter paper is 8.5x11 because it uses radians, and 11/8.5 = pi/4.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a GRAPHICS DESIGNER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This comic strip is about how to annoy graphics designers and mathematicians, much like [[590: Papyrus]] and [[1015: Kerning]].<br />
<br />
The {{w|Golden Spiral}} is a figure made by concatenating squares whose side lengths shrink according to the golden ratio. One can make a similar shape with the {{w|Paper_size#A_series|A Series}} of standard paper sizes, but the figures are rectangles whose side lengths shrink by a factor of the square root of 2, not squares whose side lengths shrink by a factor of the golden ratio. This is meant to parody the numerous questionable examples of the golden ratio in everyday life.<br />
<br />
(The difference between the two is approximately either .2038 (for sqrt(2)-1.6180etc) or .08907 ((1/sqrt(2))-1.6180etc), depending on which way you're counting. Either way, the difference would be very noticeable.)<br />
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The spiral shown is a logarithmic spiral with a growth factor of sqrt(2), and if the center of the spiral is at the origin, it may be graphed with r = C*2^(θ/π), for any positive constant C.<br />
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The title text is a joke, based partly on the fact that the US uses imperial units while much of the rest of the world uses SI units. The 11/8.5 ratio is the length/width ratio of {{w|Letter (paper size)|US Letter}} paper, which is 11 inches by 8.5 inches (another common size in the United States is US Legal, which is 14" by 8.5"). The value of pi/4 radians is indeed equal to 45 degrees, although Randall takes the cosine in one case and uses the raw angle in the other case in order to get a close coincidence of values. The width/length ratio of A Series paper ({{w|ISO 216}}) is exactly cos(45°), which is 1/sqrt(2). As for US Letter paper, 11/8.5 is not in fact close to pi/4, but it’s possible that Randall meant to write 8.5/11 instead of 11/8.5. To 4 decimal places, 8.5/11 = 0.7727 and pi/4 = 0.7854.<br />
<br />
In reality, the usage of radians vs. degrees is not a geographic or political decision, but generally is delineated by profession. Most engineering and science fields measure angles in degrees or fractions of degrees (arcseconds, or even milliarcseconds in fields like astronomy), while mathematicians and physicists generally use radians. Civil engineers may refer to the slope of a road by its {{w|Grade (slope)|grade}}, which is commonly expressed in terms of the tangent of the angle to the horizontal (either as a percentage or a ratio); 1 gradian = 0.9 degrees ~= 0.0157 radian.<br />
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==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Caption inside panel:]<br />
:The golden ratio is everywhere!<br />
<br />
:[Picture of the ISO standard paper sizes (i.e. A1, A2, etc.) placed so that they fit together perfectly, overlaid with a spiral resembling that of the golden ratio]<br />
<br />
:[Caption below panel:]<br /><br />
:How to annoy both graphic designers and mathematicians<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Comics with color]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=2322:_ISO_Paper_Size_Golden_Spiral&diff=1936752322: ISO Paper Size Golden Spiral2020-06-20T15:04:20Z<p>Djbrasier: /* Explanation */ Previous version read like a correction of an error and didn't meet style guidelines</p>
<hr />
<div>{{comic<br />
| number = 2322<br />
| date = June 19, 2020<br />
| title = ISO Paper Size Golden Spiral<br />
| image = iso_paper_size_golden_spiral.png<br />
| titletext = The ISO 216 standard ratio is cos(45°), but American letter paper is 8.5x11 because it uses radians, and 11/8.5 = pi/4.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a GRAPHICS DESIGNER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
This comic strip is about how to annoy graphics designers and mathematicians, much like [[590: Papyrus]] and [[1015: Kerning]].<br />
<br />
The {{w|Golden Spiral}} is a figure made by concatenating squares whose side lengths shrink according to the golden ratio. One can make a similar shape with the {{w|Paper_size#A_series|A Series}} of standard paper sizes, but the figures are rectangles whose side lengths shrink by a factor of the square root of 2, not squares whose side lengths shrink by a factor of the golden ratio. This is meant to parody the numerous questionable examples of the golden ratio in everyday life.<br />
<br />
(The difference between the two is approximately either .2038 (for sqrt(2)-1.6180etc) or .08907 ((1/sqrt(2))-1.6180etc), depending on which way you're counting. Either way, the difference would be very noticeable.)<br />
<br />
The spiral shown is a logarithmic spiral with a growth factor of sqrt(2), and if the center of the spiral is at the origin, it may be graphed with r = C*2^(θ/π), for any positive constant C.<br />
<br />
The title text is a joke, based partly on the fact that the US uses imperial units while much of the rest of the world uses SI units. The 11/8.5 ratio is the length/width ratio of {{w|Letter (paper size)|US Letter}} paper, which is 11 inches by 8.5 inches (another common size in the United States is US Legal, which is 14" by 8.5"). The value of pi/4 radians is indeed equal to 45 degrees, although Randall takes the cosine in one case and uses the raw angle in the other case in order to get a close coincidence of values. The width/length ratio of A Series paper ({{w|ISO 216}}) is exactly cos(45°), which is 1/sqrt(2). As for US Letter paper, 11/8.5 is not in fact close to pi/4, but it’s possible that Randall meant to write 8.5/11 instead of 11/8.5. To 4 decimal places, 8.5/11 = 0.7727 and pi/4 = 0.7854.<br />
<br />
In reality, the usage of radians vs. degrees is not a geographic or political decision, but generally is delineated by profession. Most engineering and science fields measure angles in degrees or fractions of degrees (arcseconds, or even milliarcseconds in fields like astronomy), while mathematicians and physicists generally use radians. Civil engineers may refer to the slope of a road by its {{w|Grade (slope)|grade}}, which is commonly expressed in terms of the tangent of the angle to the horizontal (either as a percentage or a ratio); for angles up to ~10 degrees, this is close to the value of the angle in radians.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Caption inside panel:]<br />
:The golden ratio is everywhere!<br />
<br />
:[Picture of the ISO standard paper sizes (i.e. A1, A2, etc.) placed so that they fit together perfectly, overlaid with a spiral resembling that of the golden ratio]<br />
<br />
:[Caption below panel:]<br /><br />
:How to annoy both graphic designers and mathematicians<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Comics with color]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:2322:_ISO_Paper_Size_Golden_Spiral&diff=193674Talk:2322: ISO Paper Size Golden Spiral2020-06-20T15:03:02Z<p>Djbrasier: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
It annoys me that the hover text says 11/8.5 = pi/4, when 8.5/11≈0.77272727272 and pi/4≈0.78539816339. Claiming 8.5/11 equals pi/4 would be a much more beleiveable lie. [[Special:Contributions/162.158.79.37|162.158.79.37]] 15:29, 19 June 2020 (UTC)<br />
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The explanation says that the A series "side lengths shrink by a factor of the square root of two" but that's not true. The width of A(n+1) is half the length of A(n) as depicted. The sqrt(2) ratio referenced is between the length and width of any one piece of paper.[[Special:Contributions/172.69.62.124|172.69.62.124]] 15:35, 19 June 2020 (UTC)<br />
:The side lengths do shrink by a factor of sqrt(2): the width of A(n) is sqrt(2) times the width of A(n+1), the length of A(n) is sqrt(2) times the length of A(n+1). Your statement that "the width of A(n+1) is half the length of A(n)" is also true, but it does not contradict that each step in the A-series shrinks the sides by a factor of sqrt(2). [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 16:09, 19 June 2020 (UTC)<br />
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Fixed it [[Special:Contributions/162.158.74.61|162.158.74.61]] 15:43, 19 June 2020 (UTC)<br />
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Hi ! How come 11/8.5 = Pi/4 ? First one is more thant 1, second one is less than one... Although Pi/4 and 8.5/11 (or the reverse) are pretty similar, as usual in "let's annoy mathematicians" Randall's style...<br />
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https://xkcd.com/spiral/ --[[Special:Contributions/188.114.103.233|188.114.103.233]] 17:22, 19 June 2020 (UTC)<br />
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I understand why it annoys mathematicians (it's not the golden ratio), but why does it annoy graphics designers? Please add explanation!<br />
<br />
It should be noted that the logarithmic spiral this comic implies it is would actually go outside the bounds of the paper. The leftmost point of the spiral would be about 6.4mm to the left of the left edge of the A1 sheet. [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 18:39, 19 June 2020 (UTC)<br />
:This drawing (as opposed to the singular mathematical formula behind the idealised spiral for the partitioning used) basically takes a simple quarter-oval across each distinct sheet size (with, as essentially mentioned elsewhere, the root(2) ratio between sides) alternating x/y and y/x as major and minor axes respectively. Even if it is not obviously discontinuous (x and y inflection transitions occur subtly) any derivative of the curve (as polar, say) would show jumps in gradient at each stage - probably an inclined-stepped/saw-toothy pattern whereas the true logarithmic line would demonstrate itself as a continuous function at any such level of derivation. The true spiral line followed from origin outwards would ''almost'' (not quite, because of the polar gradient) hit the 'outer edge' first in line with the ultimately recursive centre-point then withdraw again to hit the next transition slightly 'inward' of the next level out. The Golden Spiral approximation uses squares for each quarter, which therefore does not switch major and minor axes, but still changes the curve <!-- (stepped, but 'flat' treads between the abrupt risers) --> and thus has the same not-quite-Golden nature. Although it's hard to describe, as you can see from my poor attempt that's probably inadvertently fallen foul of more specialised Pure Mathematics terminology due to the Pedant's Curse... ;) [[Special:Contributions/162.158.155.240|162.158.155.240]] 22:23, 19 June 2020 (UTC)<br />
<br />
Mathematicians get annoyed by the claim that the golden ratio is everywhere. I love Disney's "Donald in Mathmagic Land" but they make some outrageous claims about the golden ratio's place in art and architecture. BTW, the ISO system of paper sizes is awesome! You can photocopy two A4 pages side-by-side, reduced to fit exactly on a single A4 page.<br />
<br />
Isn't grade closer to degrees than to radians? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 15:03, 20 June 2020 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=2295:_Garbage_Math&diff=1909142295: Garbage Math2020-04-18T18:50:11Z<p>Djbrasier: /* Explanation */ Citation needed</p>
<hr />
<div>{{comic<br />
| number = 2295<br />
| date = April 17, 2020<br />
| title = Garbage Math<br />
| image = garbage_math.png<br />
| titletext = 'Garbage In, Garbage Out' should not be taken to imply any sort of conservation law limiting the amount of garbage produced.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a ZILOG Z80. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
This comic explains the "{{w|garbage in, garbage out}}" concept using arithmetical expressions. Just like the comic says, if you get garbage in any part of your workflow, you get garbage as a result. Except when you multiply by zero. That one always fixes everything.<br />
<br />
Some of these rules correspond to the rules of {{w|floating point arithmetic}}, while others may be inspired by the rules of {{w|Propagation_of_uncertainty#Example_formulae| propagation of uncertainty}} where a "garbage" number would correspond to an estimate with a high degree of uncertainty, and the uncertainty of the result of arithmetic operations will tend to be dominated by the term with the highest uncertainty. The rule about N pieces of independent garbage reflects the {{w|central limit theorem}} and how it predicts that the uncertainty (or {{w|standard error}}) of an estimate will be reduced when independent estimates are averaged. The comic oddly omits raising garbage to the 0th power, which transforms even NaN, the platonic ideal of garbage, to exactly 1{{Citation needed}}.<br />
<br />
This comic is about the propagation of errors in numerical analysis and statistics, but described in much more colloquial terms. Numbers with low precision are termed "garbage" and numbers with high precision are labeled "precise".<br />
<br />
This comic is not related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}, breaking the streak of comics preceding this on [[:Category:COVID-19|topics relating to COVID-19]], after (rather appropriately) 19 comics (not counting the [[2288: Collector's Edition|April Fools' comic]]).<br />
<br />
{| class="wikitable"<br />
!Formula<br />
!Statistical Expression<br />
!Explanation<br />
|-<br />
|Precise number + Precise number = Slightly less precise number<br />
|<math>\mathop\sigma(X+Y)=\sqrt{(\mathop\sigma(X))^2+(\mathop\sigma(Y))^2}</math><br />
|If we know absolute error bars, then adding two precise numbers will at worst add the sizes of the two error bars. For example, if our precise numbers are 1 (±10<sup>-6</sup>) and 1 (±10<sup>-6</sup>), then our sum is 2 (±2·10<sup>-6</sup>). It is possible to lose a lot of relative precision, if the resultant sum is close to zero as a result of adding a number and then close to its inverse. This phenomenon is known as catastrophic cancellation. Therefore, it is likely that all numbers referred here are positive numbers, which does not exhibit this phenomenon.<br />
|-<br />
|Precise number × Precise number = Slightly less precise number<br />
|<math>\mathop\sigma(X\times Y)=\sqrt{(\mathop\sigma(X)\times Y)^2+(\mathop\sigma(Y)\times X)^2}</math><br />
|Here, instead of absolute error, relative error will be added. For example, if our precise numbers are 1 (±10<sup>-6</sup>) and 1 (±10<sup>-6</sup>), then our product is 1 (±2·10<sup>-6</sup>).<br />
|-<br />
|Precise number + Garbage = Garbage<br />
|<math>\mathop\sigma(X+Y)=\sqrt{(\mathop\sigma(X))^2+(\mathop\sigma(Y))^2}</math><br />
|If one of the numbers has a high absolute error, and the numbers being added are of comparable size, then this error will be propagated to the sum. <br />
|-<br />
|Precise number × Garbage = Garbage<br />
|<math>\mathop\sigma(X\times Y)=\sqrt{(\mathop\sigma(X)\times Y)^2+(\mathop\sigma(Y)\times X)^2}</math><br />
|Likewise, if one of the numbers has a high relative error, then this error will be propagated to the product. Here, this is independent of the sizes of the numbers.<br />
|-<br />
|<math>\sqrt{\text{Garbage}} = \text{Less bad garbage}</math><br />
|<math>\mathop\sigma(\sqrt X)=\frac{\mathop\sigma(X)}{2\times\sqrt X} </math><br />
| When the square root of a number is computed, its relative error will be halved. Depending on the application, this might not be all that much ''better'', but it's at least ''less bad''.<br />
|-<br />
|Garbage<sup>2</sup> = Worse garbage<br />
|<math>\mathop\sigma(X^2)=2\times X\times\mathop\sigma(X)</math><br />
|Likewise, when a number is squared, its relative error will be doubled. This is a corollary to multiplication adding relative errors.<br />
|-<br />
|<math>\frac{1}{N}\sum(\text{N pieces of statistically independent garbage}) = \text{Better garbage}</math><br />
|<br />
|By aggregating many pieces of statistically independent observations (for instance, surveying many individuals), it is possible to reduce relative error. This is the basis of statistical sampling.<br />
|-<br />
|Precise number<sup>Garbage</sup> = Much worse garbage<br />
|<math>\mathop\sigma(b^X)=b^{2\times X}\times\mathop{\mathrm{ln}}b\times\sigma(X)</math><br />
|The exponent is very sensitive to changes, which may also magnify the effect based on the magnitude of the precise number.<br />
|-<br />
|Garbage – Garbage = Much worse garbage<br />
|<math>\mathop\sigma(X-Y)=\sqrt{(\mathop\sigma(X))^2+(\mathop\sigma(Y))^2}</math><br />
|This line involves catastrophic cancellation. If both pieces of garbage are about the same (e.g. if their error bars overlap), then it is possible that the answer is positive, zero, or negative.<br />
|-<br />
|<math>\frac{\text{Precise number}}{\text{Garbage}-\text{Garbage}}</math> = Much worse garbage, possible division by zero<br />
|<math>\mathop\sigma(\frac{a}{X-Y})=|\frac a{X-Y}|\times\sqrt{(\mathop\sigma(X))^2+(\mathop\sigma(Y))^2}</math><br />
|Indeed, as with above, if error bars overlap then we might end up dividing by zero.<br />
|-<br />
|Garbage × 0 = Precise number<br />
|<math>\mathop\sigma(0)=0</math><br />
|Multiplying anything by 0 results in 0, an extremely precise number in the sense that it has no error whatsoever since we supply the 0 ourselves. This is equivalent to discarding garbage data from a statistical analysis.<br />
|}<br />
<br />
The title text refers to the computer science maxim of "garbage in, garbage out," which states that when it comes to computer code, supplying incorrect initial data will produce incorrect results, even if the code itself accurately does what it is supposed to do. As we can see above, however, when plugging data into mathematical formulas, this can possibly magnify the error of our input data, though there are ways to reduce this error (such as aggregating data). Therefore, the quantity of garbage is not necessarily conserved.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
[A series of mathematical equations are written from top to bottom]<br />
<br />
Precise number + Precise number = Slightly less precise number<br />
<br />
Precise number × Precise number = Slightly less precise number<br />
<br />
Precise number + Garbage = Garbage<br />
<br />
Precise number × Garbage = Garbage<br />
<br />
√<span style="border-top:1px solid; padding:0 0.1em;">Garbage</span> = Less bad garbage<br />
<br />
1/N Σ (N pieces of statistically independent garbage) = Better garbage<br />
<br />
(Precise number)<sup>Garbage</sup> = Much worse garbage<br />
<br />
Garbage – Garbage = Much worse garbage<br />
<br />
Precise number / ( Garbage – Garbage ) = Much worse garbage, possible division by zero<br />
<br />
Garbage × 0 = Precise number<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:2295:_Garbage_Math&diff=190913Talk:2295: Garbage Math2020-04-18T18:46:20Z<p>Djbrasier: NaN^0???</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
== Inclusion in Series ==<br />
<br />
This is not a Covid19 comic. One could think that this is a comment on the difficulties of modeling the corona virus outbreak, but since discussions of exponential functions are only a small part in the comic I believe it is just a general comment on floating point arithmetic mixed in with statistical considerations. --[[Special:Contributions/108.162.229.242|108.162.229.242]] 17:28, 17 April 2020 (UTC) <br />
:I disagree that this is not a COVID-19 comic. I also believe the one about visualizing large numbers was COVID-19 related. On the other hand, I like the idea that Randall might produce exactly 19 comics related to SARS CoViD 2019, so I'm prepared to concede the point for the sake of arbitrary numerological appeal. <br />
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 18:42, 17 April 2020 (UTC)<br />
::I think Exa-Exabyte was a real stretch (the virus doesn't even have DNA), but there is a tenuous link so whatever. The idea that ''this'' comic is related, on the other hand, stretches past the breaking point. There's hardly anything that can't be linked to global events if we try hard enough, but that doesn't mean there's an actual link. Sometimes a comic about garbage math is just a comic about garbage math. [[Special:Contributions/172.69.71.58|172.69.71.58]] 19:33, 17 April 2020 (UTC)<br />
:::I think this one's much more likely to be a coronavirus comic than Exa-Exabyte was. There's an awful lot of COVID data, much of it either very imprecise or outright garbage; and the comic directly before this one ([[2294]]) involved bad modeling of said COVID data, so clearly COVID data (and its limitations) is something Randall's currently thinking of and drawing comics about. [[User:Pelosujamo|Pelosujamo]] ([[User talk:Pelosujamo|talk]]) 20:25, 17 April 2020 (UTC)<br />
::::Exa-Exabyte was centered around biology, which gives reason to believe it was covid19 related. This one seems much more uncertain. Any conclusion that it is related is based on garbage. Jokes aside, It seems like much more of a stretch to me. Randall thinking in those terms is a reasonable argument, but personally I am going to assume this is the chain breaker unless a direct reference is made in the next couple comics since ending at 19 is would be appropriate. [[Special:Contributions/172.69.70.209|172.69.70.209]]<br />
:: While this comic has no ''direct'' reference to Covid-19 it does appear that the math might be related. At this point we can't know if the series has ended. As such I've edited the paragraph in the explanation to identify the known ambiguities. And now I realize I've made an explanatory paragraph about "knowledge error bars" in the explanation of a comic about numerical error bars.[[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 14:42, 18 April 2020 (UTC)<br />
:::No. The reason it appears the math might be related is ''because the math relates to everything, everywhere''. That's not enough of a connection. During this pandemic, there will be a lot of comics related to the coronavirus, many of them in a row, but that doesn't mean that every comic that could be tangentially related if you squint just right should qualify as a COVID-19 comic (I ''still'' think Exa-Exabyte doesn't). There needs to be a real link, because just about ''anything'' could be twisted into a relation if you try hard enough. As a test, I hit [[Special:Random]] and got [[346: Diet Coke+Mentos]]. Wouldn't you know, that's a coronavirus comic! The father, you see, actually had COVID-19 and died, but Diet Coke and Mentos has brought him back! No. The line should be drawn here. The streak has ended. [[Special:Contributions/172.69.68.197|172.69.68.197]] 17:02, 18 April 2020 (UTC)<br />
<br />
== Math and Error bars ==<br />
<br />
Well this is surprising came here thinking I understood it just to see what the discussion looked like. Ended up learning something new. I was able to understand intuitively the comic. But this is my first exposure to actually doing math on the error bars. I think I was supposed to do that in college but I don't remember anyone ever explaining how it should work. --[[Special:Contributions/162.158.63.208|162.158.63.208]] 18:14, 17 April 2020 (UTC)<br />
<br />
In recent days, there have been a number of math "quizzes" in this same type of format, albeit generally with only addition and maybe multiplication, appearing on Facebook. Should the explanation include a reference to this as a possible contributing reason for Randall's comic? One could also argue that those quizzes have been appearing on Facebook as a way to spend/waste time during the coronavirus pandemic lock-down, making he comic at least tangentially related to Covid19 LIES.<br />
:: Unsigned vandalism? /\ [https://www.explainxkcd.com/wiki/index.php?title=Talk:2295:_Garbage_Math&diff=190866&oldid=190856 change history] @user Please feel free to move your discussion to an appropriate forum and remove both the edit and this comment at such time. [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]])<br />
<br />
What's the difference between relative error and absolute error? I don't understand these terms. Maybe add?<br />
: Absolute error is the amount of uncertainty in a value measured as a given number. e.g. 5.7 &plusmn; 1.2 means that actual value lies somewhere between 5.7 - 1.2 and 5.7 + 1.2 = 4.5 to 6.9. If you change the 5.7 to another value, you still get the same absolute difference of maximum and minimum values. Relative error depends on the value you are comparing to. e.g. 5.7 &plusmn; 10% would be between 5.7 - 0.57 and 5.7 + 0.57 = 5.13 to 6.27. The absolute difference of maximum and minimum would change if the main number changes. e.g. 11.3 &plusmn; 10% would be between 10.17 and 12.43, which has a greater absolute difference of maximum and minimum than the previous example. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 01:54, 18 April 2020 (UTC)<br />
<br />
Are all of these equations consistent with garbage = infinity?<br />
: Unfortunately, as written, these equations would not make sense by defining Garbage as an infinity. Infinity is not a number you can count to or measure in between integers. Infinity is the idea of unending-ness. Trying to use infinity as if it a finite number yields all sorts of invalid results. In this case Garbage is defined as an arbitrary finite number with a large amount of uncertainty in its value. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 01:40, 18 April 2020 (UTC)<br />
::: That's a pretty good definition of 'garbage' in ''any'' case, plus or minus 10%. ( See also [https://www.weforum.org/agenda/2017/06/landfill-mining-recycling-eurelco/ valuable garbage]) [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 14:19, 18 April 2020 (UTC)<br />
<br />
Would the summation divided by ''n'' just give you the arithmatic mean of the data set? [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 01:55, 18 April 2020 (UTC)<br />
:Pretty much, but the point is probably more that (without consistent bias across the set, just 'random' errors for each item) it suppresses the degree of garbagicity as outliers are increasingly nullified by the greater number of more competently accurate values and (if it's a symmetric error) opposing outliers. [[Special:Contributions/162.158.34.222|162.158.34.222]] 09:29, 18 April 2020 (UTC)<br />
<br />
The statement that NaN^0 isn't fully justified and I'm not clear it belongs. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 18:46, 18 April 2020 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570461991: Research Areas by Size and Countedness2018-05-14T16:00:11Z<p>Djbrasier: /* Lower right quadrant */ # of gods</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|{{w|Drugs}}, including {{w|medications}} and {{w|recreational drug use|illegal and recreational drugs}} are molecules which are sub-microscopic (in the range of nanometers).<br />
|Although it is possible to tally all the known drugs, this is at the extreme low end of the pile because the number of possible organic compounds is nearly infinite and the fraction of those are bioactive is completely unknown.<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|It has been estimated that the number of black holes in the {{w|Milky Way}} is around 100 million ([http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html]), although there is uncertainty in that estimate and the total number in the universe depends on the size of the universe (see "cosmology", above).<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|The comic puts this in the size range of paleontology, which can include many sizes (see above), and also marine mammology, which tends to have individuals that are in the range of tens of centimeters to several meters. However, {{w|life|life as we know it}} is dominated in numbers by {{w|microbes}}, and {{w|Evolutionary history of life|life on Earth}} began {{w|Abiogenesis|microscopic}}, leading most {{w|Astrobiology|Astrobiologists}} to hypothesize that life on other planets would necessarily include microbes and only possibly include macroscopic life (https://en.wikipedia.org/wiki/Fermi_paradox#No_other_intelligent_species_have_arisen).<br />
|The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000; additionally, multiple moons (https://en.wikipedia.org/wiki/Habitability_of_natural_satellites#In_the_Solar_System) are believed to potentially habitable for some forms of in our own solar system. However, the number of bodies apart from Earth confirmed to have life is currently zero. Even more uncertain than the number of potentially habitable exoplanets is the {{w|Rare Earth Hypothesis|huge uncertainty}} in the likelihood of life arising on a habitable planet.<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The uncertainty about how many planets have life in the Milky Way relates to the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|Some religions have one (or {{w|athiesm|zero}}) god. Other religions have hundreds of gods. It is also conceivable to have a religion with an infinite number of gods. Thus, the possible number is completely unknown (ranging from 0 to infinity).<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570451991: Research Areas by Size and Countedness2018-05-14T15:58:07Z<p>Djbrasier: /* Lower left quadrant */ Update # of pharmacology</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|{{w|Drugs}}, including {{w|medications}} and {{w|recreational drug use|illegal and recreational drugs}} are molecules which are sub-microscopic (in the range of nanometers).<br />
|Although it is possible to tally all the known drugs, this is at the extreme low end of the pile because the number of possible organic compounds is nearly infinite and the fraction of those are bioactive is completely unknown.<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|It has been estimated that the number of black holes in the {{w|Milky Way}} is around 100 million ([http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html]), although there is uncertainty in that estimate and the total number in the universe depends on the size of the universe (see "cosmology", above).<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|The comic puts this in the size range of paleontology, which can include many sizes (see above), and also marine mammology, which tends to have individuals that are in the range of tens of centimeters to several meters. However, {{w|life|life as we know it}} is dominated in numbers by {{w|microbes}}, and {{w|Evolutionary history of life|life on Earth}} began {{w|Abiogenesis|microscopic}}, leading most {{w|Astrobiology|Astrobiologists}} to hypothesize that life on other planets would necessarily include microbes and only possibly include macroscopic life (https://en.wikipedia.org/wiki/Fermi_paradox#No_other_intelligent_species_have_arisen).<br />
|The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000; additionally, multiple moons (https://en.wikipedia.org/wiki/Habitability_of_natural_satellites#In_the_Solar_System) are believed to potentially habitable for some forms of in our own solar system. However, the number of bodies apart from Earth confirmed to have life is currently zero. Even more uncertain than the number of potentially habitable exoplanets is the {{w|Rare Earth Hypothesis|huge uncertainty}} in the likelihood of life arising on a habitable planet.<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The uncertainty about how many planets have life in the Milky Way relates to the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570101991: Research Areas by Size and Countedness2018-05-13T16:51:17Z<p>Djbrasier: /* Lower right quadrant */ fix links</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|{{w|Drugs}}, including {{w|medications}} and {{w|recreational drug use|illegal and recreational drugs}} are molecules which are sub-microscopic (in the range of nanometers).<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|It has been estimated that the number of black holes in the {{w|Milky Way}} is around 100 million ([http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html]), although there is uncertainty in that estimate and the total number in the universe depends on the size of the universe (see "cosmology", above).<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|The comic puts this in the size range of paleontology, which can include many sizes (see above), and also marine mammology, which tends to have individuals that are in the range of tens of centimeters to several meters. However, {{w|life|life as we know it}} is dominated in numbers by {{w|microbes}}, and {{w|Evolutionary history of life|life on Earth}} began {{w|Abiogenesis|microscopic}}, leading most {{w|Astrobiology|Astrobiologists}} to hypothesize that life on other planets would necessarily include microbes and only possibly include macroscopic life (https://en.wikipedia.org/wiki/Fermi_paradox#No_other_intelligent_species_have_arisen).<br />
|The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000; additionally, multiple moons (https://en.wikipedia.org/wiki/Habitability_of_natural_satellites#In_the_Solar_System) are believed to potentially habitable for some forms of in our own solar system. However, the number of bodies apart from Earth confirmed to have life is currently zero. Even more uncertain than the number of potentially habitable exoplanets is the {{w|Rare Earth Hypothesis|huge uncertainty}} in the likelihood of life arising on a habitable planet.<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The uncertainty about how many planets have life in the Milky Way relates to the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570091991: Research Areas by Size and Countedness2018-05-13T16:48:04Z<p>Djbrasier: /* Lower right quadrant */ Fill out black holes and exobiology</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|{{w|Drugs}}, including {{w|medications}} and {{w|recreational drug use|illegal and recreational drugs}} are molecules which are sub-microscopic (in the range of nanometers).<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|It has been estimated that the number of black holes in the {{w|Milky Way}} is around 100 million ([http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html]), although there is uncertainty in that estimate and the total number in the universe depends on the size of the universe (see "cosmology", above).<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|The comic puts this in the size range of paleontology, which can include many sizes (see above), and also marine mammology, which tends to have individuals that are in the range of tens of centimeters to several meters. However, {{w|life as we know it|life}} is dominated in numbers by {{w|microbes}}, and {{w|life on Earth|Evolutionary history of life}} began {{w|microscopic|Abiogenesis}}, leading most {{w|Astrobiologists|Astrobiology}} to hypothesize that life on other planets would necessarily include microbes and only possibly include macroscopic life (https://en.wikipedia.org/wiki/Fermi_paradox#No_other_intelligent_species_have_arisen).<br />
|The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000; additionally, multiple moons (https://en.wikipedia.org/wiki/Habitability_of_natural_satellites#In_the_Solar_System) are believed to potentially habitable for some forms of in our own solar system. However, the number of bodies apart from Earth confirmed to have life is currently zero. Even more uncertain than the number of potentially habitable exoplanets is the {{w|huge uncertainty|Rare Earth Hypothesis}} in the likelihood of life arising on a habitable planet.<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The uncertainty about how many planets have life in the Milky Way relates to the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570081991: Research Areas by Size and Countedness2018-05-13T16:28:56Z<p>Djbrasier: /* Lower left quadrant */ Size of drugs</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|{{w|Drugs}}, including {{w|medications}} and {{w|recreational drug use|illegal and recreational drugs}} are molecules which are sub-microscopic (in the range of nanometers).<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570071991: Research Areas by Size and Countedness2018-05-13T16:23:47Z<p>Djbrasier: /* Upper right quadrant */ Link universe</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the {{w|universe}} we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570061991: Research Areas by Size and Countedness2018-05-13T16:23:06Z<p>Djbrasier: /* Upper right quadrant */ Link Earth</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The {{w|Earth}} is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the universe we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570051991: Research Areas by Size and Countedness2018-05-13T16:22:18Z<p>Djbrasier: /* Upper right quadrant */ Fill out Geology</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|The Earth is larger, by far, than everything else on the chart except the universe (Cosmology), Black Holes, and God (at least under some conceptions, see "Theology" below).<br />
|There is only one Earth (at least if you set aside the possibility of multiverses, see below in Cosmology).<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the universe we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570041991: Research Areas by Size and Countedness2018-05-13T16:19:17Z<p>Djbrasier: /* Upper left quadrant */ Fill out Ancient literature</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|As above, with Shakespeare plays, original or print reproductions would be the size of a book, typically. Although ancient {{w|scrolls}} may have different dimensions with similar total volume.<br />
|Because of the high number of {{w|lost work}}, it is hard to have a solid estimate of the number, although rough lists have been made (e.g. https://en.wikipedia.org/wiki/Ancient_literature#List_of_ancient_texts).<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|<br />
|<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the universe we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1991:_Research_Areas_by_Size_and_Countedness&diff=1570031991: Research Areas by Size and Countedness2018-05-13T16:14:42Z<p>Djbrasier: /* Upper left quadrant */ Shakespeare, reorganize & fill out.</p>
<hr />
<div>{{comic<br />
| number = 1991<br />
| date = May 9, 2018<br />
| title = Research Areas by Size and Countedness<br />
| image = research_areas_by_size_and_countedness.png<br />
| titletext = Mathematicians give a third answer on the vertical axis, "That question is poorly defined, but we have a sub-field devoted to every plausible version of it."<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|The tables needs to be filled in. And I think the title text has been explained already... Do NOT delete this tag too soon.}}<br />
<br />
This comic is a [[:Category:Scatter plots|scatter plot]] that ranks different research fields according to the precision of the knowledge of the number of the studied object (vertical axis) vs. how large (the size of) the studied object is on the horizontal axis. <br />
<br />
For instance the number of United States presidents is well known, so the study of their history is at the top of the Y-axis. This study is placed close to the Y-axis as the size of a president is about midway in size between the two extremes of the X-axis, elementary particles to the left (small) and the entire cosmos (cosmology) to the right (big). <br />
<br />
On the X-axis Presidents are close to the middle. Both presidents and other larger life forms (as a research area) including extinct animals (paleontology) and exobiology are all close to the the same central position just right of the Y-axis, with smaller animals like birds and insects just to the left of the Y-axis. But where the number of presidents is well known, then the number of exoplanet life forms (exobiology) is completely unknown and thus it will be found at the very bottom of the Y-axis, since we have no idea if there are life elsewhere and if so how many places will it be and how varied.<br />
<br />
The 19 research areas are listed and explained in the [[#Tables of research areas|tables]] below.<br />
<br />
In the title text mathematicians may give a third answer that the concept of counting the things being studied is not reasonable, because the things are abstract or otherwise not discrete. There are many different types of math that blend into each other, and many have turned into separate sub-disciplines based on different interpretations of fundamental rules. As a specific example in geometry, different interpretations of how many lines you may draw parallel to another line through a given point has lead to hyperbolic (infinite parallel lines) and spherical (0 parallel lines) geometric systems that are just as valid (and valuable, in some contexts) as the more commonly known Cartesian (1 parallel line) geometry. As a specific example of the blending, number theory and set theory and topology all interrelate and it is difficult to concretely say whether many theorems belong to one branch of math or another.<br />
<br />
==Tables of research areas==<br />
*For a table with the coordinates given in percentage for each research field, see the [[#Table with coordinates|table]] in the trivia section<br />
<br />
===Upper left quadrant===<br />
*This is the section with the small items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size of the thing<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Elementary particle physics}}<br />
| The smallest subjects that we have actually detected are the {{w|elementary particles}}. In the {{w|Standard Model}} of particle physics, they are considered point masses (i.e. to have zero width). They may be made of smaller {{w|String theory|strings}} but if so these have still not been detected.<br />
| We think we have a fairly good estimate of how many elementary particles that are known. There could be some uncertainty though, so it is not at the very top.<br />
|Elementary particle physics is concerned with the study of subatomic particles (the smallest things that we know of), of which there are 17. Most notably, until recently it was uncertain whether the {{w|Higgs boson}} was one of the elementary particles, but scientists have a "pretty good estimate" because the mathematical models don't predict the existence of many other particles<br />
|-<br />
|{{w|Dentistry}}<br />
|Several mm to several centimeters<br />
|Most teeth are visible to the naked eye, and dentists have x-ray technology to see what's not visible, so counting them is pretty straightforward.<br />
|Dentistry is the study of teeth (pretty small, both in size as well as in quantity). Humans adults grow 32 teeth, which is a "pretty good estimate" since it is very rare for {{w|Hyperdontia|more than 32 teeth to grow}} and it is rather common for {{w|wisdom teeth}} to be surgically extracted or in some cases never to develop. Children may only have 20 teeth before they start falling out, but each tooth that falls out is because another tooth is growing underneath, so a child might have as many as 52 teeth, counting the child teeth that haven't fallen out yet plus the adult teeth that are starting to form. So while a dentist will usually have a good idea how many teeth will be in a patient's mouth, they won't know for sure until they look or consult dental records.<br />
|-<br />
|{{w|Shakespeare}} studies<br />
|Most are the size of typical book. In printed form, they would be in the range of tens of centimeters in height and width and ~1 centimeter in depth. Although, if stored in digial form, they could be much smaller than a tooth, so it seems to refer to print or handwritten originals.<br />
|Generally, 36 plays are attributed to him, but between 1 and 3 additional plays are considered "lost" (i.e. at some point between being first published or performed and scholars seriously studying Shakespeare, all known copies, references, and fragments were destroyed, making it impossible to determine whether Shakespeare actually wrote them or whether they actually existed as separate plays), and {{w|Shakespeare apocrypha|some 20 more}} are believed to have been written by him, but not signed. To make matters worse, some plays that ''were'' published or performed under Shakespeare's name are believed to have been written as collaborations (not fully by him) or mis-attributed (we don't know who wrote them but, everyone says it was him).<br />
|Shakespeare studies is concerned with the works of William Shakespeare. <br />
|-<br />
|{{w|Ornithology}}<br />
|<br />
|<br />
|Ornithology studies birds (birds tend to be small; even the largest known flying bird, the {{w|Condor}}, stands smaller than the average human, with non-flying avians such as the {{w|ostrich}} being larger, but not that large). As with all animal classifications, we aren't really certain how many species there are, and are [https://www.amnh.org/about-the-museum/press-center/new-study-doubles-the-estimate-of-bird-species-in-the-world constantly revising the figure], but all estimates remain in the low thousands, so we do have a "pretty good estimate"<br />
|-<br />
|Ancient {{w|literature}}<br />
|<br />
|<br />
|While it is fairly straightforward to look up how many books [http://www.proquest.com/products-services/Books-in-Print.html are currently in print], or how many books [https://mashable.com/2010/08/05/number-of-books-in-the-world/ all currently printed information would fit into if bound into equal-length volumes], and then limiting those estimates to those that date before a specific year, counting how many books from the period of interest haven't survived to the present day (books that were "{{w|lost work|lost}}" either by deliberate discontinuation, or accidental destruction such as in the {{w|Destruction of the Library of Alexandria|Library of Alexandria}}) is a bit more difficult. However, because we know the work existed (it is mentioned by name in some other text), we have "pretty good estimate" that the number of lost works is "only" in the tens of thousands, as is the number of surviving works.<br />
|}<br />
<br />
===Upper right quadrant===<br />
*This is the section with the big items with count known.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Marine mammal|Marine}} {{w|Mammalogy|Mammology}}<br />
|<br />
|<br />
|Marine mammals are the largest extant animals. The US Government [http://www.nmfs.noaa.gov/pr/species/mammals/ recognizes] 119 marine mammals. However, what constitutes each species is [https://www.marinemammalscience.org/species-information/list-marine-mammal-species-subspecies/ constantly being revised], with new studies indicating either that what used to be considered a subspecies is actually a separate species, or that what used to be considered a separate species is actually a subspecies. As the depths of the ocean are further explored, species that were outright unknown are spotted and need to be classified. However, since marine mammals breathe air, they have to come to the surface where we can see them, so we're pretty sure that we've spotted all species. Note that RAndall has misspelled Mammalogy with o instead of a in the middle.<br />
|-<br />
|{{w|List_of_Presidents_of_the_United_States|Presidential History}}<br />
|<br />
|<br />
|Presidents are generally considered "big" men in history. Therefore, each one is fairly well known and documented. There is, however, some discussion on how many presidents there have been in the history of the United States, since prior to the {{w|Twenty-fifth Amendment to the United States Constitution|25th amendment}}, it was unspecified whether vice presidents counted as presidents during the President's absence. Most notably, this ambiguity is the reason {{w|David Rice Atchison}}'s tombstone is inscribed with the words "President of the United States for one day". <br />
|-<br />
|{{w|Railway engineering}}<br />
|<br />
|<br />
|A railway can span anywhere from a few hundred feet, to thousands of miles, so they're pretty big. The type of a railway is generally given by its {{w|track gauge}}, which are defined as "standard" (whatever you're currently using), "narrow" (rails closer together than whatever you're using) and "broad" (rails farther apart than whatever you're using). Since what is standard varies from country to country, and indeed from line to line, how many kinds of "narrow" gauge and "broad" gauge exist depend on who you ask.<br />
|-<br />
|{{w|Geology}}<br />
|<br />
|<br />
|Geology is generally considered the study of rocks (small rocks being considered fragments of mountain layers, so what counts as a "rock" for a geologist can be pretty big). There is no universally agreed upon number to how many {{w|List of rock types|types of rock}} there are, but all geologists agree they can be grouped into igneous, metamorphic, and sedimentary rock. Alternatively, geology can be construed as the study of the planet Earth's composition ( *geo*- meaning "Earth" ), and geologists are confident that the planet Earth is big and there is only one of it.<br />
|-<br />
|{{w|Cosmology}}<br />
| As this encompasses (at least) all of the visible parts of the universe we live in, there can be no other "items" to study that would be larger.<br />
| There is only one visible universe, but there could be multiverses/parallel universes, and also an infinite universe beyond the borders of our own part of this universe's event horizon. So it depends on who you ask if they say there is one of and infinite number of universes to study, thus it is placed close to the middle of the two extremes,<br />
|Cosmology is the study of the universe. There is an asterisk with the note "Depends on who you ask", relating to the estimate of how many universes there are. While it might seem obvious that there is only one universe, some branches of physics believe that our universe is part of a {{w|multiverse}}, and this remains an open and contested subject in the field.<br />
|}<br />
<br />
===Lower left quadrant===<br />
*This is the section with the small items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Mycology}}<br />
| microscopic to a few miles<br />
|<br />
|Mycology is the study of fungi (since fungi tend to grow flat -- excepting for mushrooms, which are their sexual organs, and do not exceed a foot in height (see [http://www.isciencetimes.com/articles/5740/20130729/giant-fungus-china-mushroom-world-s-largest-size.htm World's Largest mushrooms] -- mushrooms are generally considered small). Many fungi are microscopic, but some get to be a few miles in diameter.[http://www.nationalgeographic.com.au/nature/the-worlds-largest-living-organism.aspx The World's largest living organism.] It is a lot harder to discern which species a fungus is, and therefore classify it, so we "have no idea" how many kinds of fungi there are. Studies [https://www.ncbi.nlm.nih.gov/pubmed/21613136 vary wildly] between about 70,000 to over 5,000,000. There is a comic named after this study: [[1664: Mycology]].<br />
|-<br />
|[[1012: Wrong Superhero|Entymology]]<br />
|<br />
|<br />
|It is unclear whether [[Randall]] means {{w|entomology}} or {{w|etymology}} (probably neither; it's likely that this wasn't a mistake and it is possibly a direct reference to [[1012: Wrong Superhero]]). In either case, [https://www.ncbi.nlm.nih.gov/pubmed/28938083 estimates for insects] (entomology) vary from less than 1,000,000 to 30,000,000; and [https://www.quora.com/How-many-root-words-are-there-in-the-English-language estimates for root words] (etymology) reaching hundreds of thousands. Entomology was mentioned in the title text of [[1610: Fire Ants]].<br />
|-<br />
|-<br />
|{{w|Microbiology}}<br />
|<br />
|<br />
|Microbiology studies microscopic (too small to see) organisms, of which some 1,400 are known and "estimates for the total number of microbial species vary wildly, from as low as 120,000 to tens of millions and higher", according to [https://www.quora.com/How-many-root-words-are-there-in-the-English-language Nature magazine]. <br />
|-<br />
|{{w|Pharmacology}}<br />
|<br />
|<br />
|The number of drugs (pharmaceuticals) discovered and synthesized is not tallied, according to [https://www.raps.org/regulatory-focus%E2%84%A2/news-articles/2014/10/how-many-drugs-has-fda-approved-in-its-entire-history-new-paper-explains recent studies], but an estimate can be obtained by seeing how many have passed through the {{w|Food and Drug Administration|U.S. FDA}} (1,453). Many home remedies, which might technically qualify as drugs, have not been approved because {{w|Novelty (patent)|"everybody knows that"}}, as well as many solely recreational drugs since regulation might result in outlawing. Because of this, "we have no idea" how many drugs truly exist. Since drugs are extremely powerful molecules that are only administered in choice amounts, they are generally perceived as small.<br />
|}<br />
<br />
===Lower right quadrant===<br />
*This is the section with the big items with count unknown.<br />
<br />
{| class = "wikitable"<br />
! Research field<br />
! Size<br />
! Knowledge of #<br />
! Explanation<br />
|-<br />
|{{w|Botany}}<br />
|<br />
|<br />
|Botany studies plants, which can reach {{w|List of superlative trees|hundreds of feet by any measure}}. Some {{w|Pando (tree)|clonal colonies of trees}} spread for miles. However, plant tend to clump together in forests and jungles, which makes it hard to get to them and document them. Every year, thousands of new plants are discovered, with the best estimate being that there are [https://news.mongabay.com/2016/05/many-plants-world-scientists-may-now-answer/ nearly 400,000 vascular plants] and an additional [https://www.britannica.com/topic-browse/Plants/Nonvascular-Plants 12,000 non-vascular plants]. However, the rate of discovery doesn't appear to be slowing down significantly, so we truly "have no idea."<br />
|-<br />
|{{w|Paleontology}}<br />
|Paleontologists study fossils, which range in size from very small to very large. When most people think of paleontologists though, they tend to think of them as studying large animals such as dinosaurs.<br />
|<br />
|Paleontology studies fossils, particularly those of extinct animals, which can reach {{w|Largest prehistoric animals|huge sizes}}. However, since fossils form under very special circumstances, if the animal did not die under those special circumstances, there will be no record of their existence. Therefore, the number of extinct animals can never truly be known, but we've found [http://scienceblogs.com/authority/2010/01/12/how-do-we-know-that-most-of-th/ around 250,000]<br />
|-<br />
|{{w|Black Hole}} {{w|Astronomy}}<br />
|Compared to most astronomical objects, black holes are fairly small. However, most of them (that we are able to detect) are still larger than the Earth, so they would still fall on the "big" end of this chart. Alternatively, Randall may be referring to their mass, which is on the scale of stars.<br />
|<br />
|"Most stellar black holes [...] are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone." ([https://science.nasa.gov/astrophysics/focus-areas/black-holes NASA Black Hole information page])<br />
|-<br />
|{{w|Exobiology}}<br />
|<br />
|<br />
|Exobiology refers to the study of life outside Earth, which requires {{w|SETI|scanning the entire universe for life}}. Currently, exobiology seeks to find a planet or similar body with life (and, {{w|definition of planet|to qualify as a planet}}, bodies capable of sustaining life are big). The estimate of {{w|List of potentially habitable exoplanets|how many planets with life there are}} varies from 16 to 40,000,000,000. However, the number of bodies apart from Earth confirmed to have life is currently zero. This is known as the {{w|Fermi Paradox}}. For life, of the type we know, to exist outside of the Solar system there need to be planets around other stars. Such planets are called Exoplanets, and they have been a [[:Category:Exoplanets|recurrent subject]] on xkcd.<br />
|-<br />
|{{w|Theology}}<br />
|It is placed at a scale as large as the universe (cosmology) as it should encompass the entire creation. For those not believing in gods it could also be seen as studying something as small as the human brain that has created all the gods. But Randall has chosen to place it in the big section. <br />
|As no one really can know anything about theology as it is a study covering a wide range of beliefs from a wide range of religions.<br />
|Theology is concerned with the study of God(s), which, by some definitions, is a hypothetical being greater than the universe itself. In particular, theologists study the question of whether {{w|theism|a god could exist}} (there is &ge;1 god) {{w|astheism|or not}} (there are 0 gods) and, in the former case, whether there could be {{w|polytheism|multiple gods}} (there are ''n''>1 gods) or {{w|monotheism|just one}} (there is exactly 1 god) or indeed whether there is {{w|animism|one god for each living thing}} (''n''≫1 gods). I.e., the very definition of the field is the fact that "we have no idea" how many there are. This quantitative uncertainty is also mentioned in [[900: Religions]].<br />
|}<br />
<br />
==Transcript==<br />
:[An X-Y scatter plot of research areas, written in gray font, where both axes have arrows in both ends. At the end of each arrow is a label. Above the left part of the X-axis there is a line which goes to a text about the meaning of the X-axis. Similarly there is a line to from the top of the Y-axis to a questions “asked” to those that study the given subject, their answers being somewhere between the two labels on the Y axis.] <br />
<br />
:[The X-axis from left to right, text first and then labels:]<br />
:Size of the thing you study<br />
:Small<br />
:Big<br />
<br />
:[The Y-axis from top to bottom, question first and then labels:]<br />
:"That thing you study - how many of them are there?"<br />
:"We have a pretty good estimate."<br />
:"We have no idea"<br />
<br />
:[The research areas names are listed here below by sorting them into the four quadrants from top left to bottom right. In each quadrant the areas are listed after most left first, and then top to bottom for those at the same x position.]<br />
<br />
:[Upper left quadrant (Small & count known):]<br />
:Elementary particle physics <br />
:Dentistry <br />
:Shakespeare studies<br />
:Ornithology<br />
:Ancient Literature<br />
<br />
:[Upper right quadrant (Big & count known):]<br />
:Presidential History <br />
:Marine Mammology <br />
:Railway Engineering <br />
:Geology <br />
:Cosmology*<br />
:<small>(*Depends who you ask)</small><br />
<br />
:[Lower left quadrant (Small & count unknown):]<br />
:Pharmacology<br />
:Microbiology<br />
:Entymology<br />
:Mycology<br />
<br />
:[Upper right quadrant (Big & count unknown):]<br />
:Botany <br />
:Paleontology <br />
:Exobiology <br />
:Black Hole Astronomy <br />
:Theology<br />
<br />
==Trivia==<br />
===Table with coordinates===<br />
*Here is a sortable table with the coordinates in percentage given.<br />
**They have been taken from the discussion where "Zetfr" states that<br />
***I have determined the exact position of each science on both axes. <br />
***I computed the center of the smallest rectangle that encloses each name. <br />
***Here they are, expressed as percentages, assuming 0% and 100% correspond to the arrow tips on each axis.<br />
****It could be argued that cosmology size should be at 100% and Theology knowledge 0 %, etc. but that is just semantics. <br />
****The interesting here is what order Randall seems to have put the different fields and object sizes.<br />
**To begin with they are sorted after the size of the ting the research are studies, with the smallest first.<br />
{|class="wikitable sortable"<br />
! Research area<br />
! Size (%)<br />
! Estimate (%)<br />
|-<br />
|Elementary Particle Physics ||7 ||72<br />
|-<br />
|Pharmacology ||12 ||6<br />
|-<br />
|Microbiology ||15 ||13<br />
|-<br />
|Dentistry ||21 ||84<br />
|-<br />
|Entymology ||24 ||25<br />
|-<br />
|Mycology ||29 ||38<br />
|-<br />
|Ornithology ||34 ||62<br />
|-<br />
|Shakespeare Studies ||37 ||88<br />
|-<br />
|Ancient Literature ||38 ||53<br />
|-<br />
|Botany ||60 ||40<br />
|-<br />
|Presidential History ||62 ||89<br />
|-<br />
|Marine Mammology ||66 ||68<br />
|-<br />
|Paleontology ||68 ||31<br />
|-<br />
|Exobiology ||68 ||5<br />
|-<br />
|Railway Engineering ||79 ||81<br />
|-<br />
|Geology ||90 ||90<br />
|-<br />
|Theology ||91 ||5<br />
|-<br />
|Black Hole Astronomy ||92 ||26<br />
|-<br />
|Cosmology ||94 ||62<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Scatter plots]]<br />
[[Category:Rankings]]<br />
[[Category:Science]]<br />
[[Category:Physics]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]] <!--Title text --><br />
[[Category:Fiction]] <!--Shakespeare/Theology --><br />
[[Category:Religion]] <!--Theology --><br />
[[Category:Animals]] <!-- Several studies --><br />
[[Category:Exoplanets]] <!--Exo biology --><br />
[[Category:Politics]] <!--President --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1992:_SafetySat&diff=1569691992: SafetySat2018-05-12T01:38:30Z<p>Djbrasier: /* Explanation */ Citations and/or explanations needed on the laser pointer.</p>
<hr />
<div>{{comic<br />
| number = 1992<br />
| date = May 11, 2018<br />
| title = SafetySat<br />
| image = safetysat.png<br />
| titletext = During launch, in the event of an unexpected sensor reading, SafetySat will extend prongs in all directions to secure itself and any other cubesats safely in the launch vehicle until the source of the problem can be determined.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a CubeSat so dangerous, I corrupted the image file and crashed the server (the first image upload was corrupt)- Maybe expand it a little? Some of the individual items need more explaining. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Cubesat}} is a standard format for small satellites that can fit in a 10&times;10&times;10&nbsp;cm format with a mass of less than 1.3&nbsp;kg. They have been widely used by academics for research satellites, and by both small and large companies.<br />
<br />
Cubesats are normally launched as a secondary payload often beside a deployment to the international space station. There are multiple safety rules to ensure that the cubesat cannot damage the primary payload. However, the joke in this comic is that [[Randall]]'s design seeks to break as many rules as possible.<br />
<br />
(from bottom left)<br />
<br />
;Americium corners: {{w|Americium}} is a very dense, highly radioactive substance. Depending on the amount of Americium involved, this alone could shoot the mass over the 1.3 kg mass limit.<br />
;Gun cotton: A form of nitrocellulose; it is explosive.<br />
;Crude Oil: {{w|Exxon Valdez oil spill}}, {{w|Deepwater Horizon explosion}}... need we say more? Of course the leakable volume would not be near those levels, but plenty dangerous nonetheless if it were to leak though a faulty seal... And this is not helped by the fact that it is in orbit or if it leaks during launch...<br />
;Volatile Epoxy Seal: When this goes, everything gets coated in flammable crude oil.<br />
;Celebratory Firework: Explosive Fire Source that can hit other satellites in the vicinity.<br />
;CFCs/Ozone-depleting CFC Spritzer: {{w|Chlorofluorocarbons}} ({{w|CFCs}}) are fully halogenated paraffin hydrocarbons that contain only carbon, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. {{w|Freon}} is a common example of a CFC, and the use of CFCs has been linked to a depletion of the Earth's {{w|ozone layer}} leading many countries to ban their use. So spritzing CFCs in an area closer to the Ozone layer sounds like a good idea?<br />
;Laser Pointer (Hubble-Seeking): Aiming a red laser at a visible light telescope is really bad for the telescope in question and its optics{{Citation needed|reason=Not obvious to non-experts why visible-light laser is damaging to a telescope designed to read visible spectrum, disruptive perhaps?|date=May 2018}}.<br />
;Laser Pointers (Fixed): Theses three laser points will effectively point in 3 different random directions, which is not safe for other object around this Cubesat{{Citation needed|reason=Why is a laser pointer dangerous?|date=May 2018}}.<br />
;SDR/{{w|Software-Defined Radio}} (Code Editable via Public Wiki): Radio which can be programmed to broadcast and receive in a range of frequencies, and formats. Since anyone could change the radio's instructions, the radio could interfere with other satellites, or with the launch vehicle. This counts as a huge security risk, as ''anyone'' could edit it.<br />
;BIC Mini-Lighter: Fire source, resting on the can of crude oil. The pressurized butane could also make the lighter burst, allowing the sparkplug to ignite the volatile butane gas.<br />
;Rare Earth Magnets: Very powerful magnets that have a high likelihood of messing up the electronics on nearby electronics, like other Cubesats. Might also stick to other satellites.<br />
;Wet Sand Dispenser: possibly a reference to the {{w|Kessler syndrome}}.<br />
;Batteries (eBay): The quality of batteries bought on the auction site can vary widely, and certain batteries exposed to conditions outside their design specifications can {{w|Battery_(electricity)#Explosion|explode or leak corrosive acids}}. These batteries might also be connected to the adjacent spark plug.<br />
;Solar Panel (Found): The quality of the solar panel and the power it produces would have to be investigated thoroughly before being cleared for space flight.<br />
;Spark Plug: Fire Source, if it was connected to electricity. Excess mass if not.<br />
;Prongs: Prongs that extend in the event of an unexpected sensor reading at launch could damage the rocket and/or nearby cubsats/payloads. Along with this, it is not unlikely that this cubesat might be the source of any internal problem that might arise; in such a situation, having such a dangerous cubesat further secure itself would be counterproductive.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[A prototype for a small cube-shaped "CubeSat"satellite, with labels on various components.]<br />
<br />
<br />
[Labelled on top:]<br />
<br />
Rare-Earth Magnets<br />
<br />
Bic Mini Lighter<br />
<br />
Software-Defined Radio (code editable via a public wiki)<br />
<br />
<br />
[Labelled on right:]<br />
<br />
Laser Pointers (fixed)<br />
<br />
Laser Pointer (Hubble-seeking)<br />
<br />
Ozone-Depleting CFC Spritzer<br />
<br />
<br />
[Labelled on bottom:]<br />
<br />
Celebratory Firework<br />
<br />
Volatile Epoxy Seal<br />
<br />
Filler (Guncotton)<br />
<br />
<br />
[Labelled on left:]<br />
<br />
Americium Corners<br />
<br />
Spark Plug<br />
<br />
Solar Panel (found)<br />
<br />
Batteries (eBay)<br />
<br />
Wet Sand Dispenser<br />
<br />
<br />
[Labelled from within drawing in white text on top of a black rectangle:] <br />
<br />
Crude Oil<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1969:_Not_Available&diff=1545511969: Not Available2018-03-20T01:38:24Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1969<br />
| date = 19 March, 2018<br />
| title = Not Available<br />
| image = not_available.png<br />
| titletext = If my country ever picks a new national flag, this is on my shortlist for designs to argue for, but I think in the end I'll go with the green puzzle piece or broken image thumbnail.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Update content a little bit further. What is a "broken image icon", please provide examples. <small>Do not remove this tag too soon.</small>}}<br />
<br />
A very common, yet frustrating issue on the {{w|internet}} is finding a broken link, taking you to an "{{w|HTTP 404|Error 404}}" page. The purpose of the page is to tell the user that the content they were looking for has been either moved, or deleted. Randall suggested replacing the standard "page not found" text, to "This content is not available in your country". This could fool the user into thinking the media they are looking for is actually there, but is {{w|Regional lockout|region locked}}. Using a {{w|VPN}} and/or {{w|Tor (anonymity network)|TOR}} to try and access the content from another country wouldn't work, because it isn't actually region locked; it is just an error 404 page, wasting even more time, most likely frustrating the user a great deal in the process.<br />
<br />
The title text suggests setting the picture as a national flag. This would be very ironic, as it would suggest that the country's flag itself, something that is used to represent the country across the globe, is region locked. The country in the title text likely does not refer to the United States, but rather to the new country featured in [[1815: Flag]]. The first flag of this country included a phone notification bar, so changing it to a "page not found" icon would continue with a trend of technology imagery. Instead he argues for a green puzzle piece, which is Firefox's and Chrome's "plugin is missing" icon. Although, Chrome's "plugin is missing" puzzle piece icon is gray. He also argues for an equally frustrating broken image icon (which is used in lieu of a photo that is either missing or incompatible with the browser).<br />
<br />
==Transcript==<br />
:[A gray box shown on a black background says "This content is not available in your country."]<br />
:Caption: If you ever ''really'' want to make people mad, set this as your 404/"Not Found" page.<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1966:_Smart_Home_Security&diff=154205Talk:1966: Smart Home Security2018-03-12T15:50:53Z<p>Djbrasier: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
When I went to explainxkcd right after the comic posted, I saw this in the incomplete tag: "Created by ORGANIZED CRIME". Today is the day this website has officially swallowed its own tail. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 15:50, 12 March 2018 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1874:_Geologic_Faults&diff=1438771874: Geologic Faults2017-08-09T15:41:39Z<p>Djbrasier: </p>
<hr />
<div>{{comic<br />
| number = 1874<br />
| date = August 9, 2017<br />
| title = Geologic Faults<br />
| image = geologic_faults.png<br />
| titletext = I live on a torn-bag-of-potato-chips-where-the-tear-is-rapidly-growing fault, which is terrifying.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a fool with no knowledge of faults. Do NOT delete this tag too soon. Also, title text not explained.}}<br />
<br />
This comic appears to be a successor to [[1714: Volcano Types]]. Similar to its predecessor, the comic explores several phenomena (in this case, geologic faults), both real phenomena and several made up for the point of a joke.<br />
<br />
A fault is a geologic feature that involves the boundaries of two tectonic plates.<br />
<br />
The items are:<br />
;Normal fault<br />
A real-life fault in Geology. In a Normal fault, the hanging wall (the upper wall) moves downward relative to the footwall (the lower wall). The Earth's crust is extended in this type of fault. <br />
;Reverse fault<br />
Another real-life type of fault. A Reverse fault is basically the opposite of a Normal fault. The hanging wall moves upward relative to the footwall, and the Earth's crust is compressed.<br />
;Transverse fault<br />
The third real-life fault in this comic. A Transverse fault, also known as a Transform fault, is where the two plates move parallel to each other, but in opposite directions.<br />
;Thrust fault<br />
The fourth and final real-life fault in this comic. a Thrust fault is when older rocks are pushed (or thrust) on top of younger rocks.<br />
;Taffy fault<br />
A fictional type of fault. It appears to involve one tectonic plate, that is being stretched out like a piece of taffy.<br />
;Splinted fault<br />
Another fictional fault. This appears to be a Normal of Reverse fault to which someone has attached a large splint.<br />
;Squeezed-bar-of-soap-fault<br />
The third fictional fault type. Two plates seem to be moving towards each other, while a third smaller plate is squeezed between them and pushed upwards.<br />
;Apple power cable fault<br />
The fourth fictional fault. The plate appears to have been twisted and bent so many times that parts of it are fraying, similar to the power cable of an Apple phone.<br />
;Brio fault<br />
The final fictional fault. The Brio fault seems to be two tectonic plates which join together like the Brio train track pieces do. {{w|Brio (company)|BRIO}} is a company from Sweden that makes wooden toys.<br />
<br />
Thrust faults were previously mentioned in [[1082: Geology]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon. Lacks small description for each item.}}<br />
:[The comic shows nine different schematic views to present geographic faults and some more.]<br />
<br />
:[Two planes with a slip fault drifting away to the left and right.]<br />
:Normal fault<br />
:[Two planes with a slip fault drifting against each other from left and right.]<br />
:Reverse fault<br />
:[Two planes moving sidewards.]<br />
:Transverse fault<br />
<br />
:[The left plane moves above the other to the right.]<br />
:Thrust fault<br />
:[Two planes drifting away and the connection between them gets smaller.]<br />
:Taffy fault<br />
:[On top of both planes a small piece with splints holds them together.]<br />
:Splinted fault<br />
<br />
:[The two planes pressing together with a piece in the middle moving topwards.]<br />
:Squeezed-bar-of-soap-fault<br />
:[The right plane is connected to the left and swinging up and down.]<br />
:Apple power cable fault<br />
:[One side with a thin connector and the other with an evenly spaced hole connecting the planes together.]<br />
:Brio fault<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1860:_Communicating&diff=142385Talk:1860: Communicating2017-07-07T19:44:51Z<p>Djbrasier: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and not delete this comment.--><br />
<br />
Isn't this [[Science Girl]], and not necessarily "Alice"? Although they could be one and the same, in this comic and all comics? [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 16:45, 7 July 2017 (UTC)<br />
*I agree that this is [[Science Girl]], but she could be playing the role of Alice, or alternatively she could be merely visiting the Looking Glass world as Alice also did. --[[Special:Contributions/108.162.216.94|108.162.216.94]] 17:13, 7 July 2017 (UTC)<br />
<br />
I've heard that the nursery rhyme never makes explicit that Humpty is an egg. [[Special:Contributions/108.162.212.83|108.162.212.83]] 18:36, 7 July 2017 (UTC)<br />
<br />
I took this to mean politicians stating false things then equivocating by saying the words they used mean something different from what the traditional meaning the listeners assumed they meant were. Maybe I just watch too much late night TV tho. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 19:44, 7 July 2017 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1845:_State_Word_Map&diff=1406821845: State Word Map2017-06-02T16:23:51Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1845<br />
| date = June 2, 2017<br />
| title = State Word Map<br />
| image = state_word_map.png<br />
| titletext = The top search for every state is PORN, except Florida, where it's SEX PORN.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Almost there...}}<br />
<br />
This is another of the many comics where [[Randall]] used a map of the United States for his joke (see below for examples).<br />
<br />
Similar in spirit to [[1138: Heatmap]], this comic pokes fun at many maps that attempt to use data to discern unique characteristics about various sub-regions, in this case {{w|U.S. state|American states}}. This map may have been inspired by [https://twitter.com/GoogleTrends/status/869624196921303040 this map] posted on Twitter by Google Trends the day before the comic was posted. Many web companies use maps like this in viral marketing, but the methodology behind them is pretty weak. The random noise in the data will mean that there will be variations between states even if there is no underlying pattern - and this can be further boosted by statistical tricks. A common one is to show the "most characteristic" or "most distinctive" term for each state. For instance, [http://www.businessinsider.com/most-common-causes-of-death-in-each-state-2014-6?IR=T the most common cause of death is heart disease or cancer] in every US state, but this makes for a boring map. Looking at the [https://www.cdc.gov/pcd/issues/2015/14_0395.htm most distinctive cause of death] produces a more interesting map, but it highlights very minor trends - Lousiana is marked as having syphilis as its most distinctive cause of death, even though [https://www.cdc.gov/nchhstp/stateprofiles/pdf/louisiana_profile.pdf only 15 Louisianans in every 100,000 have the disease] and there were only 22 syphilis deaths in the state over a whole decade. These maps can give a misleading impression of huge variation between states that doesn't really exist.<br />
<br />
This map does not say anything real, but says: <br />
:You can make these maps say whatever you want by adjusting the methodology. Half of the time you're just amplifying random noise because the underlying data doesn't change that much from one state to another. But whatever. Nobody checks this stuff. Just pick whatever normalization lets you make fun of Florida.<br />
<br />
The primary joke is that the likelihood of these being the words used most often by the inhabitants of each state is low, rather than accurately representing the most used words Randall has just done exactly what he says he can do (make fun of Florida by putting whatever he wants). He also has not obtained the data from anywhere, just 'Something Something'. <br />
<br />
The joke about Florida is that the most used word in Florida is "Florida", which would make people in Florida very self-centered. <br />
<br />
The comic continues to make fun of Florida in the title text by saying that Florida searches for ''sex porn'' instead of ''porn'', which is not needed since porn means images and film of people having sex. This is also probably a reference to PornHub's [https://www.pornhub.com/insights/united-states-top-searches data-farming] exercises, where they have periodically released the most frequently searched term by state.<br />
<br />
{{w|Florida}} is often the butt of many jokes, including the {{w|Florida Man}} meme and many mocking jibes regarding its {{w|2000 United States presidential election recount in Florida|messy electoral history}}. {{tvtropes|OnlyInFlorida|"Only in Florida" phenomenon}}<br />
<br />
Randall previously used a map of the United States as the basis for his comics in [[1767: US State Names]], [[1653: United States Map]], [[1509: Scenery Cheat Sheet]] and in [[1079: United Shapes]].<br />
<br />
==Transcript==<br />
:[Caption above the map, with sub caption:]<br />
:<big>Most-Used Word in Each State</big><br />
:Based on Something Something Search Data<br />
<br />
:[Beneath the captions are a colorful map of the United States of America. Each state has one color, but the colors do not change from state to state, but rather between rows of states. The top "row" is purple, the second row is gray-blue, but only goes half across. Where it stops a pink row of states begins. Beneath this runs a yellow row, except it does not take California with it, since it belongs to the next purple line beneath this yellow line. Finally the two states not in the contiguous states as well as the southern states from Texas to Florida are again pink. Inside each state is written one, and only one word (or for small states the word is outside and if needed a line indicates which state it belongs to). The words size depends on the size of the state and the word. If it can fit inside the state it will be written in a font large enough to fill the entire state if possible (in one case a hyphen is used). So a short word, like "lets" in huge Texas becomes huge, but a word like "noise" which has been fitted inside small Massachusets becomes small.]<br />
<br />
:[Here is the 50 words written in lines resembling the colors on the map (from left to right). Purple, gray-blue, pink, yellow, purple and pink:]<br />
:You can make these maps say whatever you want <br />
:by adjusting the methodology. <br />
:Half the time you're just amplifying random noise. <br />
:Because the underlying data doesn't vary that much from one state to another. <br />
:But whatever. Nobody checks this stuff. Just pick<br />
:whatever normal-ization lets you make fun of Florida.<br />
<br />
==Trivia==<br />
*The state line between New Hampshire and Maine is missing in the map, but each state has a word assigned, so it is only the line that has been left out.<br />
**Thus there are indeed 50 single words on the map.<br />
{{comic discussion}}<br />
<br />
[[Category:Comics with color]]<br />
[[Category:Maps]]<br />
[[Category:Geography]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1835:_Random_Obsessions&diff=139765Talk:1835: Random Obsessions2017-05-13T02:24:35Z<p>Djbrasier: </p>
<hr />
<div>I feel like it's worth noting that the internet fixations mentioned on the chart - robot, monkeys, pirate, ninja, zombies, bacon - were all mentioned in #856 Trochee fixation https://xkcd.com/856/ and that sandwich is also a trochee. [[User:Necroleopard|Necroleopard]] ([[User talk:Necroleopard|talk]]) 20:01, 12 May 2017 (UTC)<br />
<br />
I'm clearly behind on some things here. I know about all of these except "sandwiches" and "bacon". [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 04:51, 12 May 2017 (UTC)<br />
:Some reference to a rise in "sandwich debate" online (Google trends or something) would be very helpful. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 04:53, 12 May 2017 (UTC)<br />
http://knowyourmeme.com/memes/is-a-hot-dog-a-sandwich is one of the threads of this meme but the meme does go further than just hotdogs --[[Special:Contributions/162.158.2.4|162.158.2.4]] 07:36, 12 May 2017 (UTC)<br />
<br />
I added some description of the bacon fad, I wasn't sure if/where the Know Your Meme entry fits but here it is (http://knowyourmeme.com/memes/cultures/bacon) in case some other editor wants to put it in[[Special:Contributions/108.162.238.11|108.162.238.11]] 13:09, 12 May 2017 (UTC)<br />
:Bacon is never a fad though. It has always been and will always be. [[User:OldCorps|OldCorps]] ([[User talk:OldCorps|talk]]) 16:30, 12 May 2017 (UTC)<br />
<br />
The current incomplete explanation asking about the bacon.... Are you kidding? This was the one I was most comfortable with! It's the quite current trend of singing the praises of bacon, memes shared around Facebook that say things like "Everything's better with bacon", "When in doubt, bacon", "Like if you love bacon, Comment if you love bacon, Share if you love bacon, ignore if you hate puppies". I even have a Facebook friend who put their middle name as "bacon", LOL! - NiceGuy1 [[Special:Contributions/108.162.219.16|108.162.219.16]] 21:42, 12 May 2017 (UTC)<br />
:I added that tag. The question is what about bacon started to rise in 2010 and is peaking now? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 02:24, 13 May 2017 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1835:_Random_Obsessions&diff=139669Talk:1835: Random Obsessions2017-05-12T04:53:57Z<p>Djbrasier: </p>
<hr />
<div>I'm clearly behind on some things here. I know about all of these except "sandwiches" and "bacon". [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 04:51, 12 May 2017 (UTC)<br />
:Some reference to a rise in "sandwich debate" online (Google trends or something) would be very helpful. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 04:53, 12 May 2017 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1835:_Random_Obsessions&diff=1396681835: Random Obsessions2017-05-12T04:52:25Z<p>Djbrasier: </p>
<hr />
<div>{{comic<br />
| number = 1835<br />
| date = May 10, 2017<br />
| title = Random Obsessions<br />
| image = random obsessions.png<br />
| titletext = I take the view that "open-faced sandwiches" are not sandwiches, but all other physical objects are.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|New page, what sandwich debate? What is "bacon" referring to?}}<br />
<br />
This comic is formatted as a graph showing various internet trends over the years. The caption states that these "random obsessions," as stated in the title, have 9-10 year cycles, and so predicts that the sandwich debate will be over by around 2024.<br />
<br />
The title text a joke on the debate over the definition of a sandwich, first starting with a common topic in the said debate - whether or not open-faced sandwiches are, in fact, sandwiches - and makes an absurd argument by stating that "I," presumably Randall Munroe, believes that open-faced sandwiches are the only physical objects that would not be considered sandwiches.<br />
<br />
The other obsessions mentioned are, in order: robot monkeys, pirates vs ninjas, zombies, and bacon.<br />
<br />
==Transcript==<br />
{{incomplete transcript}}<br />
<br />
{{comic discussion}}<br />
<!-- Include any categories below this line. --></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1835:_Random_Obsessions&diff=139667Talk:1835: Random Obsessions2017-05-12T04:51:46Z<p>Djbrasier: Created page with "I'm clearly behind on some things here. I know about all of these except "sandwiches" and "bacon". ~~~~"</p>
<hr />
<div>I'm clearly behind on some things here. I know about all of these except "sandwiches" and "bacon". [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 04:51, 12 May 2017 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:114:_Computational_Linguists&diff=136198Talk:114: Computational Linguists2017-03-01T02:55:39Z<p>Djbrasier: </p>
<hr />
<div>Why {{w|Ryan North}}? [[Special:Contributions/108.233.253.211|108.233.253.211]] 21:49, 8 January 2013 (UTC)<br />
<br />
First of all, Ryan North happened to specialize in computational linguistics in his masters degree. He was mentioned because he was a computational linguist. On a side note, Ryan North's father was called Randall (though he was not the Randall whose comics this wiki explains).<br />
<br />
This may have somehow influenced Ryan's name appearing on this list.--[[User:Commarchinin|Commarchinin]] ([[User talk:Commarchinin|talk]]) 12:44, 30 August 2013 (UTC)<br />
<br />
It may also be a joke on Ryan's webcomic name: "Dinosaur Comics" [[Special:Contributions/121.44.164.207|121.44.164.207]] 09:52, 20 October 2013 (UTC)<br />
<br />
Don't particle physicists have the same issue: string theorists, Bohmians, Many-worldsians, Copenhagen-interpretians, all-possible-pathians, etc.? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 02:55, 1 March 2017 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311941761: Blame2016-11-18T15:05:29Z<p>Djbrasier: /* Title text */ Expansion, related to likely connection to recent US election</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events {{Citation needed}}. (Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking {{Citation needed}}, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reasons for bad events (for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 United States presidential election. One read on this is that, many people, including [http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it| some news sources], have pointed out that social media forms an echo chamber, and some sources have claimed that this is responsible both for political polarization (see [https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s| this video]) and even [http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html| for the recent victory of Donald Trump]. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends echoing his ideas back to him as causing (partially) Clinton's loss; thus they are (partially) at fault for his presumed sadness over her loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually, users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run. Additionally, "yelling" on social media would likely only increase the influx of: 1) political posts reminding Cueball of his sadness, 2) angry messages back at him, 3) reminders of the reason he's sad, including possibly "rubbing in" the sad feelings, and 4) posts design to offend Cueball, including posts design to offend his political sensibilities; all of these would make him feel worse, potentially in relatively short order.<br />
<br />
==Transcript==<br />
:Cueball (Thinking): I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}<br />
==Citations==<br />
<references/></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311931761: Blame2016-11-18T15:01:13Z<p>Djbrasier: /* Explanation */ format, sorry!</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events {{Citation needed}}. (Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking {{Citation needed}}, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reasons for bad events (for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 United States presidential election. One read on this is that, many people, including [http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it| some news sources], have pointed out that social media forms an echo chamber, and some sources have claimed that this is responsible both for political polarization (see [https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s| this video]) and even [http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html| for the recent victory of Donald Trump]. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends echoing his ideas back to him as causing (partially) Clinton's loss; thus they are (partially) at fault for his presumed sadness over her loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually, users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball (Thinking): I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}<br />
==Citations==<br />
<references/></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311921761: Blame2016-11-18T14:59:45Z<p>Djbrasier: /* Explanation */ Incomplete flag removed: too vague.</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events {{Citation needed}}. (Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking {{Citation needed}}, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reasons for bad events (for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 United States presidential election. One read on this is that, many people, including [http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it|some news sources], have pointed out that social media forms an echo chamber, and some sources have claimed that this is responsible both for political polarization (see [https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s|this video] and even [http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html|for the recent victory of Donald Trump]. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends echoing his ideas back to him as causing (partially) Clinton's loss; thus they are (partially) at fault for his presumed sadness over her loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually, users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball (Thinking): I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}<br />
==Citations==<br />
<references/></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311911761: Blame2016-11-18T14:59:12Z<p>Djbrasier: /* Explanation */ format refs</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
{{incomplete|There needs to be more}}<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events {{Citation needed}}. (Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking {{Citation needed}}, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reasons for bad events (for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 United States presidential election. One read on this is that, many people, including [http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it|some news sources], have pointed out that social media forms an echo chamber, and some sources have claimed that this is responsible both for political polarization (see [https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s|this video] and even [http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html|for the recent victory of Donald Trump]. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends echoing his ideas back to him as causing (partially) Clinton's loss; thus they are (partially) at fault for his presumed sadness over her loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually, users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball (Thinking): I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}<br />
==Citations==<br />
<references/></div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311831761: Blame2016-11-18T14:16:10Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
{{incomplete|There needs to be more}}<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events. {{Citation needed}}(Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reason for bad events(for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 election. One read on this is that, many people, including news sources have pointed out that social media forms an echo chamber<ref>http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it</ref>, and some sources have claimed that this is responsible both for political polarization<ref>https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s</ref> and even for the recent victory of Donald Trump<ref>http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html</ref>. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends echoing his ideas back to him as causing (partially) Clinton's loss; thus they are (partially) at fault for his presumed sadness over her loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball: I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311821761: Blame2016-11-18T14:14:53Z<p>Djbrasier: /* Explanation */ Added third read taken from comments section.</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
{{incomplete|There needs to be more}}<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events. {{Citation needed}}(Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reason for bad events(for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 election. One read on this is that, many people, including news sources have pointed out that social media forms an echo chamber<ref>http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it</ref>, and some sources have claimed that this is responsible both for political polarization<ref>https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s</ref> and even for the recent victory of Donald Trump<ref>http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html</ref>. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends for his presumed sadness over Clinton's loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts. A third read would be that friends with whom Cueball/Randall disagrees are posting things that he finds unpleasant to read, either ideas that he finds offensive or posts "rubbing in" the victory of the candidate Randall opposed.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball: I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1761:_Blame&diff=131181Talk:1761: Blame2016-11-18T14:13:02Z<p>Djbrasier: </p>
<hr />
<div>It seems like he's talking about all of the bad things that have happened in 2016 so far making fun of Facebook posts that blame everyone for the things that are happening <br />
[[Special:Contributions/173.245.52.119|173.245.52.119]] 05:21, 18 November 2016 (UTC)<br />
: In particular the recent election[[Special:Contributions/108.162.215.224|108.162.215.224]] 08:16, 18 November 2016 (UTC)<br />
Is this a reference to the "echo chamber" issue raised in recent US election? I.e. blaming my friends on facebook for only sharing stories that reinforce my biases and thus my failure to be fully informed about why people who disagree with me do disagree and only blaming them for being dumb isn't a failing on *my* part, but on my friends' parts for only sharing echo-chamber-y material. [[Special:Contributions/108.162.237.87|108.162.237.87]] 10:03, 18 November 2016 (UTC)<br />
<br />
I definitely think it's worth mentioning that this comic is, while written to be timeless, clearly a reaction to the election. (Randall has endorsed both Obama in 2008 and Clinton this year, and judging by #500, cares more than a little, so it's hard to conceive that this *wouldn't* be about the election.) <br />
<br />
There are two types of Facebook activity that may be the target of this satire: 1) engaging in angry arguments with Facebook friends with *differing* political opinions, and 2) making numerous angry posts and comments against the other side, despite the fact that they’ll mainly be seen by *like-minded* people in your social media echo chamber. I expect that this comic is aimed at both: 1) the futility of internet arguments has been a topic before, while 2) the title text specifying “scared friends” clearly indicates like-minded people. [[Special:Contributions/162.158.89.54|162.158.89.54]] 10:22, 18 November 2016 (UTC)<br />
: Just added the "friends who disagree" to it.<br />
By focusing on blame he has cleverly shifted thinking to Q:"are your friends on Facebook to blame?" A:"probably not as they are almost all likely to have similar views to you" Q:"So why vent anger on Facebook to people who aren't to blame and you don't want to change?" A:"errrrrr...." {{unsigned ip|141.101.98.224}}<br />
<br />
There are 3 references in my recent edit. If you go into the source code, you can see the links, but I lack the wikipedia knowledge to get them to properly link out. Help? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 14:13, 18 November 2016 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311801761: Blame2016-11-18T14:10:31Z<p>Djbrasier: /* Explanation */ Secondary interpretation, meant to capture presumed original intent of earlier author of the paragraph I just edited.</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
{{incomplete|There needs to be more}}<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events. {{Citation needed}}(Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reason for bad events(for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 election. One read on this is that, many people, including news sources have pointed out that social media forms an echo chamber<ref>http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it</ref>, and some sources have claimed that this is responsible both for political polarization<ref>https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s</ref> and even for the recent victory of Donald Trump<ref>http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html</ref>. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends for his presumed sadness over Clinton's loss in the election. A second read on this would be that constant reminders of Clinton's loss only serve to make Randall sadder: again the proximal cause being his friends' posts.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball: I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1761:_Blame&diff=1311791761: Blame2016-11-18T14:08:27Z<p>Djbrasier: /* Explanation */ Social media, echo chamber.</p>
<hr />
<div>{{comic<br />
| number = 1761<br />
| date = November 18, 2016<br />
| title = Blame<br />
| image = blame.png<br />
| titletext = I bet if I yell at my scared friends I will feel better.<br />
}}<br />
<br />
==Explanation==<br />
<br />
{{incomplete|There needs to be more}}<br />
<br />
Cueball states that he feels sad and links it with his observation that bad things are happening. Sadness is a normal human reaction to perceived bad events. {{Citation needed}}(Other emotions that might be felt at such times include anger and guilt.)<br />
<br />
He then reasons that it must be someone's fault. If the "bad things" in question are not natural calamities or accidents, it is usually logical to surmise that someone is responsible for them taking place.<br />
<br />
After some thinking, he has an idea. Ideas are usually the result of thinking, although it might not always be conscious thinking like Cueball is doing.<br />
<br />
He then blames his friends on Facebook, an online website that helps people communicate with other people through their computers and handheld electronic devices. While they could be possible reason for bad events(for example if the bad event was nobody wishing him a happy birthday or someone posting compromising pictures)his friends would not be a likely source for bad events extending beyond a personal or local scope. Most people have a few hundred (or thousand) friends (or "friends") on Facebook, most of whom do not have enough influence to cause bad events on a national or global level.{{Citation needed}}<br />
<br />
This is probably a reference to people ranting on social media sites (like Facebook) about various things which are blamed on certain people (or sometimes everyone), but the person doing the ranting never thinks that the problem might be with themselves.<br />
<br />
It probably also a reference to how an individual's Facebook news feed has probably been inundated by political posts due to the results of the 2016 election. In particular, many people, including news sources have pointed out that social media forms an echo chamber<ref>http://www.npr.org/sections/alltechconsidered/2016/07/24/486941582/the-reason-your-feed-became-an-echo-chamber-and-what-to-do-about-it</ref>, and some sources have claimed that this is responsible both for political polarization<ref>https://www.youtube.com/watch?v=rE3j_RHkqJc&t=2s</ref> and even for the recent victory of Donald Trump<ref>http://www.independent.co.uk/voices/donald-trump-president-social-media-echo-chamber-hypernormalisation-adam-curtis-protests-blame-a7409481.html</ref>. Notably, Randall [[1756|publicly supported Trump's rival, Hillary Clinton in a recent comic]]. Therefore, blaming social media for the election can be read as blaming his friends for his presumed sadness over Clinton's loss in the election.<br />
<br />
===Title text===<br />
<br />
The title text refers to people venting, usually in all caps and with exclamation points. Usually users do this when they are mad. The (humorous) assumption here is that one will feel better after doing so. While some amount of venting might help to relieve immediate stress caused by bad events, alienating people you know by blaming them for bad events usually causes more stress in the long run.<br />
<br />
==Transcript==<br />
:Cueball: I feel sad.<br />
:Bad things are happening.<br />
:They must be someone's fault.<br />
:But whose?<br />
:[A light bulb, indicating he has an idea]<br />
:My friends on Facebook.<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1725:_Linear_Regression&diff=125817Talk:1725: Linear Regression2016-08-26T21:00:38Z<p>Djbrasier: /* Teapot */</p>
<hr />
<div><!--Please sign your posts with ~~~~--><br />
<br />
== Teapot ==<br />
<br />
It also seems likely that the teapot refers to the Utah Teapot (https://en.wikipedia.org/wiki/Utah_teapot). It was one of the first complex 3D objects defined for CGI rendering, and has seen countless uses since. Notably in the Pipes screensaver, and early SIGGRAPH papers where it was rendered along side the 5 platonic solids as if it belonged with them.<br />
[[User:Dkfenger|Dkfenger]] ([[User talk:Dkfenger|talk]]) 17:10, 26 August 2016 (UTC)<br />
: I'm not sure I follow. How do you reach that conclusion? Given that the concept of constellations (and thus stars) is clearly shown in the comic, it seems much more likely to me that he was referring to Russell's Teapot and not to a computer rendering (if there was any reference at all). The fact that that shape could abstractly resemble a teapot may be all that there is to it. :) [[User:KieferSkunk|KieferSkunk]] ([[User talk:KieferSkunk|talk]]) 18:06, 26 August 2016 (UTC)<br />
<br />
I think that the teapot is a reference to the constellation Sagittarius. This seems most likely to me as the reference is to a constellation that looks like a teapot despite ostensibly being something else. Sagittarius is a constellation that is supposed to be an archer, but many people see it as a teapot instead. (http://www.space.com/30274-constellation-sagittarius-archer-dipper-teapot.html) [[User:Harperska|Harperska]] ([[User talk:Harperska|talk]]) 19:27, 26 August 2016 (UTC)<br />
<br />
Based on what is an R^2 value of 0.06 significant??? I'm removing that. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 20:59, 26 August 2016 (UTC)<br />
: Oops, misread it! I read "insignificant" as "significant". [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 21:00, 26 August 2016 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1725:_Linear_Regression&diff=125816Talk:1725: Linear Regression2016-08-26T20:59:32Z<p>Djbrasier: </p>
<hr />
<div><!--Please sign your posts with ~~~~--><br />
<br />
== Teapot ==<br />
<br />
It also seems likely that the teapot refers to the Utah Teapot (https://en.wikipedia.org/wiki/Utah_teapot). It was one of the first complex 3D objects defined for CGI rendering, and has seen countless uses since. Notably in the Pipes screensaver, and early SIGGRAPH papers where it was rendered along side the 5 platonic solids as if it belonged with them.<br />
[[User:Dkfenger|Dkfenger]] ([[User talk:Dkfenger|talk]]) 17:10, 26 August 2016 (UTC)<br />
: I'm not sure I follow. How do you reach that conclusion? Given that the concept of constellations (and thus stars) is clearly shown in the comic, it seems much more likely to me that he was referring to Russell's Teapot and not to a computer rendering (if there was any reference at all). The fact that that shape could abstractly resemble a teapot may be all that there is to it. :) [[User:KieferSkunk|KieferSkunk]] ([[User talk:KieferSkunk|talk]]) 18:06, 26 August 2016 (UTC)<br />
<br />
I think that the teapot is a reference to the constellation Sagittarius. This seems most likely to me as the reference is to a constellation that looks like a teapot despite ostensibly being something else. Sagittarius is a constellation that is supposed to be an archer, but many people see it as a teapot instead. (http://www.space.com/30274-constellation-sagittarius-archer-dipper-teapot.html) [[User:Harperska|Harperska]] ([[User talk:Harperska|talk]]) 19:27, 26 August 2016 (UTC)<br />
<br />
Based on what is an R^2 value of 0.06 significant??? I'm removing that. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 20:59, 26 August 2016 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1691:_Optimization&diff=1215711691: Optimization2016-06-08T18:55:26Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1691<br />
| date = June 8, 2016<br />
| title = Optimization<br />
| image = optimization.png<br />
| titletext = Premature optimization is the root of all evil, so to start this project I'd better come up with a system that can determine whether a possible optimization is premature or not.<br />
}}<br />
<br />
==Explanation==<br />
This comic is a flowchart making fun of the difference between prematurely optimizing and just doing things right. Since you're consulting a flowchart to find the answer, you're prematurely optimizing.<br />
<br />
Apart from this main point - do not optimize prematurely - the flowchart in it self is a joke as the question in the first box only result in one arrow, with no options/labels, and by reaching the next box there can only be one answer to that question as you have to be consulting this flowchart to get to that question. The conclusion is that anyone actually trying to find out if they are using ''premature optimization'' are already ''prematurely optimizing''!<br />
<br />
In addition, the minimalism of the flowchart suggests that the the flowchart ''itself'' has been highly (prematurely?) optimized adding extra layers to the joke.<br />
<br />
The title text's ''root of all evil'' refers to {{w|Donald Knuth}}'s paper "Structured Programming with Goto statements" (1974) in which he wrote:<br />
<blockquote><br />
"There is no doubt that the grail of efficiency leads to abuse. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: '''premature optimization is the root of all evil'''. Yet we should not pass up our opportunities in that critical 3%."<br />
</blockquote><br />
*Source: http://web.archive.org/web/20130731202547/http://pplab.snu.ac.kr/courses/adv_pl05/papers/p261-knuth.pdf (Computing Surveys, Vol 6, No 4, December 1974) <br />
<br />
The title text then just takes the problem one step further back, by spending time trying to determine when you are too soon out for optimization, which is actually just another way of making premature optimization. This time-wasting behavior is common in obsessively perfectionist coders: developing tools to analyze aspects, such as performance, of the software actually required. In some fields, such as compilers or database design for instance, such tools are useful and productive (the 3% mentioned by Knuth?), but the usage suggested here is more appropriately covered by instinct and common sense.<br />
<br />
Flowcharts are [[:Category:Flowcharts|often used in xkcd]] including the (mostly) non-farcical [[1688: Map Age Guide]] one week prior to this comic. Inefficiency (another xkcd theme) was featured in the [[1690: Time-Tracking Software|comic prior to this one]].<br />
<br />
==Transcript==<br />
:[A flow chart is shown with three boxes connected with two arrows. The first box is rectangular:] <br />
:Are you '''''prematurely optimizing''''' or just '''''taking time to do things right?'''''<br />
<br />
:[From the first box there is a short arrow straight down to a diamond shaped box:]<br />
:Are you consulting a flowchart to answer this question?<br />
<br />
:[A labeled arrow continues down.]<br />
:Yes<br />
<br />
:[The arrow connects to the final rectangular box.]<br />
:You are prematurely optimizing<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Flowcharts]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1691:_Optimization&diff=1215701691: Optimization2016-06-08T17:57:59Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1691<br />
| date = June 8, 2016<br />
| title = Optimization<br />
| image = optimization.png<br />
| titletext = Premature optimization is the root of all evil, so to start this project I'd better come up with a system that can determine whether a possible optimization is premature or not.<br />
}}<br />
<br />
==Explanation==<br />
This comic is a flowchart making fun of the difference between prematurely optimizing and just doing things right. Since you're consulting a flowchart to find the answer, you're prematurely optimizing.<br />
<br />
Apart from this main point - do not optimize prematurely - the flowchart in it self is a joke as the question in the first box only result in one arrow, with no options/labels, and by reaching the next box there can only be one answer to that question as you have to be consulting this flowchart to get to that question. The conclusion is that anyone actually trying to find out if they are using ''premature optimization'' are already ''prematurely optimizing''!<br />
<br />
In addition, the minimalism of the flowchart suggests that the the flowchart ''itself'' has been highly (prematurely?) optimized adding extra layers to the joke.<br />
<br />
The title text's ''root of all evil'' refers to {{w|Donald Knuth}}'s paper "Structured Programming with Goto statements" (1974) in which he wrote:<br />
<blockquote><br />
"There is no doubt that the grail of efficiency leads to abuse. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: '''premature optimization is the root of all evil'''. Yet we should not pass up our opportunities in that critical 3%."<br />
</blockquote><br />
*Source: http://web.archive.org/web/20130731202547/http://pplab.snu.ac.kr/courses/adv_pl05/papers/p261-knuth.pdf (Computing Surveys, Vol 6, No 4, December 1974) <br />
<br />
The title text then just takes the problem one step further back, by spending time trying to determine when you are too soon out for optimization, which is actually just another way of making premature optimization. This time-wasting behavior is common in obsessively perfectionist coders: developing tools to analyze aspects, such as performance, of the software actually required. In some fields, such as compilers or database design for instance, such tools are useful and productive (the 3% mentioned by Knuth?), but the usage suggested here is more appropriately covered by instinct and common sense.<br />
<br />
Flowcharts are [[:Category:Flowcharts|often used in xkcd]] including the (mostly) non-farcical [[1688: Map Age Guide]] one week prior to this comic.<br />
<br />
==Transcript==<br />
:[A flow chart is shown with three boxes connected with two arrows. The first box is rectangular:] <br />
:Are you '''''prematurely optimizing''''' or just '''''taking time to do things right?'''''<br />
<br />
:[From the first box there is a short arrow straight down to a diamond shaped box:]<br />
:Are you consulting a flowchart to answer this question?<br />
<br />
:[A labeled arrow continues down.]<br />
:Yes<br />
<br />
:[The arrow connects to the final rectangular box.]<br />
:You are prematurely optimizing<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Flowcharts]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1079:_United_Shapes&diff=1210231079: United Shapes2016-05-31T02:40:54Z<p>Djbrasier: Criteria in "incomplete" tag appear to have been satisfied.</p>
<hr />
<div>{{comic<br />
| number = 1079<br />
| date = July 9, 2012<br />
| title = United Shapes<br />
| image = united_shapes.png<br />
| imagesize = 800px<br />
| titletext = That eggplant is in something of a flaccid state.<br />
}}<br />
The large version is here: [http://xkcd.com/1079/large/ http://xkcd.com/1079/large/]<br />
==Explanation==<br />
In this comic, each state of the United States of America has been filled-in with an object of similar shape. Due to the size range of the states, some states are too small to clearly make-out in the normal size image. Click [http://xkcd.com/1079/large/ here] to see the large version, which makes every state perfectly clear. Several years later Randall made a new map of the US mainland [[1653: United States Map]], where he shuffled the positions of the states but filled out the outline. Also in this map Michigan has been split into two separate parts. (Here it is the glove and the eagle). <br />
<br />
Very few, if any, of the shapes used are stereotypes of the state; they are merely objects that look like the state. Some of the objects are those which the states are widely known to resemble. For example, Michigan is represented by a glove and an Eagle, and a pot with handle takes the place of Oklahoma (with the panhandle region of the state filled with a literal handle). Others, however, are more creative. Few would have likely pictured Texas as a dog or Alaska as a bear with a jet pack and laser gun. There are several incredibly simple objects filling some states. Kentucky is filled by a cloud, which conceivably could have been used for any state, and Wyoming, one of the nearly rectangular states, is simply an envelope. There are three pairs of states that are related. Georgia and Missouri each contain an image of the other, drawing attention to their similar shapes, North and South Dakota are the top and bottom halves of an amp, and Alabama and Mississippi are {{w|moai}} facing in opposite directions.)<br />
<br />
Colorado contains what looks like a Wikipedia article. A close-up of the fake article is provided [http://xkcd.com/1079/colorado/]. The following references are made in the Colorado article:<br />
<br />
*The pronunciation is not that for Colorado, but for {{w|Eyjafjallajökull}}, a volcano in Iceland that erupted in April 2010.<br />
*The way it has a demilitarized zone towards Wyoming resembles {{W|North Korea}} and {{W|South Korea}}.<br />
*Eleven dimensions refers to {{w|string theory}}.<br />
*A {{w|wormhole}} is a theoretical relative of the {{w|black hole}}. This is a reference to the television series {{w|Stargate SG-1}} where a device capable of creating wormholes is located in the {{w|Cheyenne Mountain nuclear bunker}} in Colorado.<br />
*A {{w|Horcrux}} is a type of magical object in the world of {{W|Harry Potter}}.<br />
*The radiation zones around Longmont are caused by {{w|Radioactive contamination from the Rocky Flats Plant|radioactive contamination from the Rocky Flats Plant}}.<br />
*The fake motto ''Si parare possis, vivere septem'' can be roughly translated as "With preparation, survival is possible for over a week."<br />
<br />
New Mexico according to Randall's transcript is "A liquid container labeled for something of unusual and silly danger". The labeling is upside down and it refers to the nuclear testing facility White Sands Missile Range located in New Mexico for the nuclear bomb.<br />
:This end up<br />
:Property of White Sands Missile Range<br />
:??? [Followed by a [https://en.wikipedia.org/wiki/NFPA_704 NFPA 704] Diamond with all divisions at severe risk, and a radiation symbol in the special notice division]<br />
:Contains White Sand<br />
:FLAMMABLE<br />
:Warning: <br />
:This product contains chemicals known <br />
:only to the state of Nevada. <br />
:Contents under pressure from parents<br />
:If swallowed, induce labor<br />
:56 fluid ounces <br />
:and 14 other ounces<br />
<br />
The title text makes fun of Florida which is sometimes called "The penis of America". Obviously, this penis is somewhat flaccid (not erect). The use of the word "state" is a pun, as it means some particular condition (flaccid state) as well as a political entity (The State of Florida).<br />
<br />
==Chart==<br />
{|class=wikitable<br />
!State!!Contained Picture!!Comments<br />
|-<br />
|Alabama ||A moai head facing east.||{{w|Moai}} are Easter Island stone statues<br />
|-<br />
|Alaska ||A teddy bear with a jetpack and a ray gun||The ray gun and jetpack are fixtures of science fiction during the Cold War era, and the Russian Bear is an often-used personification of the country Russia in political cartoonage; the "teddy bear" image may be related to Alaska's former Russian heritage. The USA acquired Alaska from Russia in the Alaska Purchase of 1867 and it became a state in 1959, during the Cold War. The Cold War often featured worries of a potential Russian invasion of Alaska due to their geographical proximity across the Bering Sea and Bering Strait, which persisted through the 1980s; Alaska was the location of a large number of interceptor missiles as part of Ronald Reagan's "Star Wars Defense Initiative" intended to shoot down missiles that might be launched from the USSR. The ray gun is pointed across the Bering Strait at Russia, consistent with Alaska's often being described as the "first line of defense" against Russian aggression. The teddy bear is similar in appearance to {{w|Winnie the Pooh}}.||<br />
|-<br />
|Arizona ||A refrigerated shelf containing milk, bread, and pastries.||<br />
|-<br />
|Arkansas ||A measuring cup.||<br />
|-<br />
|California ||A vacuum.||An old-fashioned upright vacuum cleaner (lying down to the right), green with a yellow bag.<br />
|-<br />
|Colorado ||The wikipedia article on Colorado.||A fake Wikipedia article on Colorado. Below the text as seen in the provided close up:<br />
:[web address:]<br />
::en.wikipedia.org/wiki/colorado<br />
:[Headers]<br />
::Wikipedia<br />
::Article Talk<br />
::Colorado<br />
:[Main article {note that Randall forgot the closing parentheses ')' after the pronunciation}]<br />
::Colorado (Pronounced [ˈeːijaˌfjatlaˌjœːkʏtl̥] is a US State encompassing portions of the Rocky<br />
::Mountains and the Great Plains. The region has been inhabited since at least 11,000 BCE, and <br />
::some archaeological evidence suggest the state – with roughly its current borders – has literally<br />
::always existed. Colorado is separated from Wyoming by a 28-mile demilitarized zone, and <br />
::has at times exercised substantial regional <br />
::power via the installation of puppet governments<br />
::in neighboring states<br />
::Geographically, Colorado is eleven-dimensional,<br />
::though seven of those dimensions are tightly<br />
::compacted and difficult to detect in most areas<br />
::of the state. Colorado is home to the nation's<br />
::oldest continually-operated wormhole and two<br />
::of President Lincoln's horcruxes.<br />
::The wildlife in Colorado is commonly characterized <br />
::as "erratic", particularly in the radiation zones <br />
::around Longmont. The State's timber wolf<br />
::population is largely bipedal; the Park Service<br />
::has expressed "concern" at their attempts to enroll in<br />
:[Fact box with correct State flag and emblem and fake motto:]<br />
::State of Colorado<br />
::Motto:<br />
::"Si parare possis, vivere septem."<br />
::(With preparation, survival is<br />
::possible for over a week.)<br />
|-<br />
|Connecticut ||A train conductor's hat.||<br />
|-<br />
|Delaware ||A meerkat.||<br />
|-<br />
|Florida ||An eggplant.||The title text mentions the eggplant being in a flaccid state, which might be a reference to the sexual use of the eggplant emoji.<br />
|-<br />
|Georgia ||Missouri.||The outline of the state of Missouri, with the {{w|Gateway Arch}} in St. Louis.<br />
|-<br />
|Hawaii ||The island of Hawaii is a snowball. The smaller islands are small bits of snow.||<br />
|-<br />
|Idaho ||A garden gnome, sitting down.||<br />
|-<br />
|Illinois ||A gangster with a guitar case, upside down.||<br />
|-<br />
|Indiana ||The brush of a paintbrush.||<br />
|-<br />
|Iowa ||A tomato, lettuce, cold cut and cheese sandwich.||<br />
|-<br />
|Kansas ||A stand-up piano.||<br />
|-<br />
|Kentucky ||A cloud.||<br />
|-<br />
|Louisiana ||A boot with some gum stuck to the bottom of it.||<br />
|-<br />
|Maine ||A Vulcan salute.||Maine's camp sunshine has had Star Trek related events in the past, including the opportunity to appear in a film.<br />
|-<br />
|Maryland ||A wolf howling to the moon, upside down.||<br />
|-<br />
|Massachusetts ||An elephant, being ridden by a man, carrying tea.||Might be a reference to the Boston Tea Party, which occurred in Massachusetts, and the Republican political party. The man seems to be wearing a tricorn hat.<br />
|-<br />
|Michigan ||A mitten for the lower portion, an eagle for the {{w|Upper Peninsula of Michigan}}.||<br />
|-<br />
|Minnesota ||$160 in $20 USD bills. It is tied together.||<br />
|-<br />
|Mississippi ||A moai head facing west.||<br />
|-<br />
|Missouri ||Georgia.||The outline of the state of Georgia, with a pair of {{w|Georgia Peach|Georgia peaches}}.<br />
|-<br />
|Montana ||One half of a muffin, sideways.||<br />
|-<br />
|Nebraska ||A blue VW type 2 with mattresses sticking out the back.||<br />
|-<br />
|Nevada ||A clothes iron.||<br />
|-<br />
|New Hampshire ||A tall brick factory building.||<br />
|-<br />
|New Jersey ||A bent-over old person. He is carrying a cane.||<br />
|-<br />
|New Mexico ||A liquid container labeled for something of unusual and silly danger.||A yellow liquid container with upside-down labeling.<br />
::This end up!!<br />
::Property of White Sands Missile Range<br />
::Contains White Sand<br />
:[Written inside a hazardous-materials diamond with the ? very large, and the three '4' in the three top part of a diamond shape divided in four these three sections being blue, red, yellow. The lower part has a radioactive sign on the same grey background as the large rectangle.]<br />
::??? 4 4 4 <br />
::Flammable<br />
::Warning<br />
::This product contains chemicals known<br />
::Only to the State of Nevada.<br />
::Contents under pressure from parents<br />
::If swallowed, induce labor<br />
::56 fluid ounces<br />
::and 14 other ounces<br />
|-<br />
|New York ||A hybrid transmission with standard manual-style gears and a torque converter sliced in half.||<br />
|-<br />
|North Carolina ||A bouquet of flowers. They appear similar to {w|Galium Palustre|marsh bedstraws}.||<br />
|-<br />
|North Dakota ||The top half of an amp.||<br />
|-<br />
|Ohio ||Underwear (Briefs).||<br />
|-<br />
|Oklahoma ||A covered pot, dripping with boil-over.||<br />
|-<br />
|Oregon ||A locomotive.||<br />
|-<br />
|Pennsylvania ||A very thick book with a bookmark.||<br />
|-<br />
|Rhode Island ||The bow half of a boat's hull.||<br />
|-<br />
|South Carolina ||A slice of pizza.||<br />
|-<br />
|South Dakota ||The bottom half of an amp.||<br />
|-<br />
|Tennessee ||A number of children's books, placed in a slightly askew pile.|| Possibly a reference to Dolly Parton's Imagination Library. The books are {{w|Where's Waldo?}}, {{w|The Wreck of the Zephyr}}, {{w|The Way Things Work}}, Free Fall, {{w|Paddle-to-the-Sea}}, What It Feels Like to Be a Building, and {{w|The Crab with the Golden Claws}}.<br />
|-<br />
|Texas ||A dog sitting in a bowl.||<br />
|-<br />
|Utah ||An oven.||<br />
|-<br />
|Vermont ||A microscope, upside down.||<br />
|-<br />
|Virginia ||A {{w|stegosaurus}}.||<br />
|-<br />
|Washington ||A whale.|| The Puget Sound is well known for whale watching<br />
|-<br />
|Washington DC ||A star.||On most maps, capitals are shown as stars. Washington DC is the capital of the United States.<br />
|-<br />
|West Virginia ||A {{w|frog}}.||<br />
|-<br />
|Wisconsin ||A skull.||<br />
|-<br />
|Wyoming ||An envelope.||The back side of a white envelope, sealed with red wax, with a black heart next to a signature (lower left corner).<br />
|}<br />
<br />
==Transcript==<br />
:The '''United Shapes'''<br />
:A map of things states are shaped like <br />
:[Each state has some item wedged to stay inside its borders]<br />
<br />
{|class=wikitable<br />
!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text!!State!!Official Transcript!!Text<br />
|-<br />
|WA||whale||<br />
|MT||half muffin||<br />
|ND and SD||top and bottom halves of an amp||<br />
|MN||$160 in $20 USD bills||<br />
|WI||skull||<br />
|MI||mitten for the lower portion, eagle for the {{w|Upper Peninsula of Michigan}}||<br />
|NY||hybrid transmission with standard manual-style gears and a torque converter sliced in half||<br />
|VT||microscope, upside down||<br />
|NH||tall brick factory building||<br />
|ME||Vulcan salute||<br />
|MA||elephant, being ridden by a man, carrying tea||<br />
|CT||train conductor's hat||<br />
|RI||bow half of a boat's hull||<br />
|-<br />
|OR||locomotive||<br />
|ID||garden gnome, sitting down||<br />
|WY||envelope.||The envelope is marked with a signature, possibly Randal's<br />
|NE||blue VW type 2 with mattresses sticking out the back||<br />
|IA||tomato, lettuce, cold cut and cheese sandwich||<br />
|IL||gangster with a guitar case, upside down||<br />
|IN||brush of a paintbrush||<br />
|OH||underwear (Briefs)||<br />
|PA||very thick book with a bookmark||<br />
|NJ||bent-over old person||<br />
|-<br />
|NV||clothes iron||<br />
|UT||oven||<br />
|CO||Wikipedia article on Colorado||See Link Above<br />
|KS||stand-up piano||<br />
|MO||Georgia||Georgia<br />
|KY||cloud||<br />
|WV||{{w|frog}}||<br />
|VA||{{w|stegosaurus}}||<br />
|DC||star.||<br />
|MD||wolf howling to the moon, upside down||<br />
|DE||meerkat||<br />
|-<br />
|CA||vacuum cleaner||<br />
|AZ||refrigerated shelf containing milk, bread, and pastries||<br />
|NM||liquid container with warning label||<br />
:This end up!!<br />
: <br />
:Property of White Sands Missile Range<br />
:Contains White Sand<br />
: <br />
:???<br />
: <br />
:FLAMMABLE<br />
: <br />
:Warning: This product contains chemicals known<br />
:Only to the state of Nevada.<br />
:Contents under pressure from parents.<br />
:If swallowed, induce labor.<br />
: <br />
:56 Fluid Ounces<br />
:and 14 other ounces.<br />
|OK||covered pot, dripping with boil-over||<br />
|AR||measuring cup||<br />
|TN||children's books, placed in a slightly askew pile||<br />
:Handford / WHERE'S WALDO / or wally<br />
:The Wreck of the Zephyr / Chris Van Allsburg<br />
:The Way Things Work / DAVID MACAULRY<br />
:Weisner / FREE FALL<br />
:PADDLE-TO-THE-SEA / HCH(?)<br />
:WHAT IT FEELS LIKE TO BE A BUILDING / Wilson<br />
:TINTIN / The Crab with the Golden Claws / Hergé<br />
|NC||flower bouquet||<br />
|-<br />
|AK||teddy bear with a jetpack and a ray gun||<br />
|HI||snowball||<br />
|TX||dog sitting in a bowl||<br />
|LA||boot with some gum stuck to the bottom||<br />
|MS||moai head facing west||<br />
|AL||moai head facing east||<br />
|GA||Missouri.||Missouri<br />
|SC||pizza slice||<br />
|FL||eggplant||<br />
|}<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Large drawings]]<br />
[[Category:Comics with color]]<br />
[[Category:Maps]]<br />
[[Category:Food]]<br />
[[Category:Animals]]<br />
[[Category:Dinosaurs]]<br />
[[Category:Wikipedia]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=Talk:1684:_Rainbow&diff=120680Talk:1684: Rainbow2016-05-23T19:54:34Z<p>Djbrasier: </p>
<hr />
<div><!--Please sign your posts with ~~~~--><br />
How do I find the official transcript?[[User:Transuranium|Transuranium]] ([[User talk:Transuranium|talk]]) 11:00, 23 May 2016 (UTC)Transuranium<br />
:Most recent comics do not have official transcripts. {{User:17jiangz1/signature|11:13, 23 May 2016}}<br />
::But now there is one here ;-) [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:38, 23 May 2016 (UTC)<br />
<br />
Religion... geez. It's some weird stuff, huh. [[Special:Contributions/108.162.219.10|108.162.219.10]] 17:05, 23 May 2016 (UTC)<br />
<br />
Now that XKCD adopts the voice of God, it's time to write him off and move elsewhere. [[Special:Contributions/141.101.70.109|141.101.70.109]] 11:56, 23 May 2016 (UTC)<br />
: Nice of you to decide for everyone. Just like god would do, right? [[Special:Contributions/141.101.80.27|141.101.80.27]] 13:38, 23 May 2016 (UTC)<br />
:Word of God has appered before, as in Comic 224 or 258. [[Special:Contributions/162.158.86.161|162.158.86.161]] 17:09, 23 May 2016 (UTC)<br />
<br />
For the sake of doctrinal accuracy, God (assuming the comic is in fact referring to the Jewish God who set his war bow in the cloud after the Flood) never promised not to destroy the earth by fire. Christian theology (2 Peter 3:10) implies God fully intends to destroy the earth by fire - or at least by unprecedented universal nuclear fission. [[Special:Contributions/108.162.221.87|108.162.221.87]] 11:59, 23 May 2016 (UTC)<br />
<br />
: Good point, but for universal respect you should capitalise His pronouns. [[Special:Contributions/141.101.70.109|141.101.70.109]] 12:16, 23 May 2016 (UTC)<br />
<br />
:: Ok, really? So the bible says "I will destroy the earth by '''universal nuclear fission'''" ? I must have missed something on the first reading -- could you tell me the page number? [[Special:Contributions/162.158.255.219|162.158.255.219]] 19:20, 23 May 2016 (UTC)<br />
<br />
<br />
When the conditions are right, various types of [[wikipedia:Rainbow#Variations|multiple rainbow]] may be visible. [[User:Rhubbarb|Rhubbarb]] ([[User talk:Rhubbarb|talk]]) 12:03, 23 May 2016 (UTC)<br />
<br />
: [https://en.wikipedia.org/wiki/User:Drabkikker Atmospheric optics enthusiast] signing in. That's right. Although the "third faint bow near the sun" Cueball mentions might indeed refer to the 22° halo, another possibility is that he means the (very rare) ''tertiary'' or ''third-order'' rainbow. See [[wikipedia:Rainbow#Higher-order_rainbows]]. [https://www.sciencedaily.com/releases/2011/10/111005111001.htm Here]'s a picture of one. [[Special:Contributions/141.101.104.78|141.101.104.78]] 13:03, 23 May 2016 (UTC)<br />
<br />
Should we mention multiple rainbow discussion in [http://what-if.xkcd.com/150/ today's What If?]? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 19:54, 23 May 2016 (UTC)</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1681:_Laser_Products&diff=1201901681: Laser Products2016-05-16T19:28:56Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1681<br />
| date = May 16, 2016<br />
| title = Laser Products<br />
| image = laser_products.png<br />
| titletext = ERRORS: HAIR JAM. COLOR-SAFE CONDITIONER CARTRIDGE RUNNING LOW. LEGAL-SIZE HAIR TRAY EMPTY, USING LETTER-SIZE HAIR ONLY.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Initial draft outline. Please explain each technology, and elaborate on each combination. Include wiki links}}<br />
This comic takes three laser-based technologies - laser eye surgery, laserjet printers, and laser hair removal - and conflates them, with humourous results. These are illustrated through reviews by users of the resulting combinations. For the original combinations, the reviews are highly positive. For the new combinations, most are negative, because most of these new "technologies" are ill-conceived and possibly harmful.<br />
<br />
"Laser eye surgery" gets a positive review, since it has successfully corrected the reviewer's vision, no longer requiring them to use glasses. However, "laser eye removal" would be very painful, and thus the review is negative, stating that the review had read the description incorrectly, likely believing it to be one of the real combinations on the chart. "Laser eye printer" refers to printing on (or possibly ''of'') an eyeball, which gets an "eww" response.<br />
<br />
"Laser jet surgery" makes the reviewer nervous, as performing maintenance on a jet with lasers is potentially dangerous and could easily be done incorrectly. Alternatively, "laser jet surgery" could mean laser surgery done on a human from a laser-mounted jet aircraft (unspecified whether the human being operated on is aboard that aircraft as well, another aircraft, or on land: in any case, not a safe idea. "Laser jet removal" implies the destruction of jets with lasers, which works, but angers the Federal Aviation Administration, and probably resulted in legal consequences for the reviewer. "Laserjet printing" gets a positive review, as it is legitimate printing technology that works well for the reviewer.<br />
<br />
"Laser hair surgery" is rated negatively, noting how bizarre the phrase is and claiming that it was a very unpleasant haircut with the aftermath being the smell of burning hair. "Laser hair removal" is reviewed well, as it is a real process that effectively removes unwanted hair. "Laser hair printer" is negatively reviewed for being disgusting, the printer jamming, and the machine being unable to stop printing the hair. The title text expands on this, displaying a standard printer error message, replacing "paper" with "hair". It also replaces "ink" with "color-safe conditioner". <br />
<br />
===Laser eye surgery===<br />
<br />
[Explanation of how laser eye surgery works]<br />
<br />
<br />
===Laserjet printing===<br />
<br />
Laserjet printing, or more commonly known as laser printing, is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially-charged image. The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated in order to permanently fuse the text and/or imagery. As with digital photocopiers and multifunction/all-in-one inkjet printers, laser printers employ a xerographic printing process. However, laser printing differs from analog photocopiers in that the image is produced by the direct scanning of the medium across the printer's photoreceptor. This enables laser printing to copy images more quickly than most photocopiers.<br />
<br />
===Laser hair removal===<br />
<br />
Laser hair removal is the process of removing unwanted hair by means of exposure to pulses of laser light that destroy the hair follicle. It had been performed experimentally for about twenty years before becoming commercially available in the mid-1990s. One of the first published articles describing laser hair removal was authored by the group at Massachusetts General Hospital in 1998.The efficacy of laser hair removal is now generally accepted in the dermatology community,[citation needed] and laser hair removal is widely practiced in clinics, and even in homes using devices designed and priced for consumer self-treatment. Many reviews of laser hair removal methods, safety, and efficacy have been published in the dermatology literature.<br />
<br />
<br />
[[https://en.wikipedia.org/wiki/Laser_Weapon_System Laser Jet Removal]] (Although it's primarily meant to be used against jet ''missiles'' not jet planes (as the FAA quip suggests)<br />
<br />
==Transcript==<br />
{{incomplete transcript}}<br />
{| class="wikitable"<br />
|+ Combinations<br />
! Second word<br />
! Surgery<br />
! Removal<br />
! Printer<br />
|-<br />
! Eye<br />
| (4 1/2 stars) "I don't need glasses anymore!" || (1/2 star) "Aaaaaaa! Misread the description! Aaaaaaaaaaaa!" || (1 star) "Eww."<br />
|-<br />
! Jet<br />
| (1 1/2 stars) "Too nervous to try it." || (2 1/2 stars) "Effective, but the FAA got ''really mad''." || (4 stars) "Prints great!"<br />
|-<br />
! Hair<br />
| (2 1/2 stars) "Confusing word for haircut. Burning smell." || (4 stars) "Great results!" || (1/2 star) "Disgusting, won't turn off, jams constantly."<br />
|-<br />
|}<br />
<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1678:_Recent_Searches&diff=1199781678: Recent Searches2016-05-12T02:27:44Z<p>Djbrasier: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1678<br />
| date = May 9, 2016<br />
| title = Recent Searches<br />
| image = recent_searches.png<br />
| titletext = autoexec code posted by verified twitter users<br />
}}<br />
<br />
==Explanation==<br />
People often find answers to computer problems by searching on {{w|Google}}, which shows you recent search terms in a drop-down box when you go to search it. Here we see a list of search queries, each of which suggests the author is perversely misusing or overextending some computer technology. The overall impression is of someone technically sophisticated enough to shoot themselves in the foot, and who does not learn any larger lessons despite doing so repeatedly. The title text is another possible entry in this list.<br />
<br />
The caption implies that from Randall's perspective, every computer he uses seems to be broken; he doesn't seem to realise this is because he's the one using them, not because the computers actually start off broken. (For similar themes see also these comics: [[349: Success]], [[1084: Server Problem]], [[1316: Inexplicable]] and [[1586: Keyboard Problems]]).<br />
<br />
([[979|Dear people from the future]], if Google directed you here because it is the most popular result for a problem you are experiencing, this is not the page you were looking for). <br />
<br />
===Table of searches===<br />
{| class="wikitable" border="1" cellpadding="4" style="border-collapse: collapse;"<br />
|-<br />
! width=20% | Search<br />
! Explanation<br />
|-<br />
| [https://www.google.com/search?q=Google+translate+syntax+highlighting Google translate syntax highlighting]<br />
| {{w|Syntax highlighting}} can be used when editing {{w|source code}} to make the code more readable and easier to understand. It is not generally used for natural languages, but {{w|sentence diagram}}s of brief passages are used in language education. {{w|Google Translate}} is used to translate text from one {{w|natural language}} to another. It uses {{w|JavaScript}} <tt>mouseover()</tt> to highlight words as an aid in matching phrases in the source with their translations, but does not apply different highlighting dependent on syntax.<br />
<br />
Alternatively, this could imply that Randall is attempting to translate code from one programming language to another using Google Translate. Success would be unlikely, since the service is not intended for this, {{Citation needed}} and syntactically valid output might further break the computer executing it.<br />
|-<br />
| Autodetect mixed bash zsh<br />
| {{w|bash}} and {{w|Z_shell|zsh}} are two {{w|Command-line_interface|command line interfaces}} for {{w|Unix-like}} OSes. The way to execute commands is almost identical, making detecting a script that contains a mixed syntax nearly impossible.<br />
|-<br />
| CPU temperature sensor limits<br />
| The CPU's temperature sensors exist to tell you when your CPU is becoming dangerously overheated (normally because of a faulty fan or overclocking). Someone who searches for information about the limits of those sensors is presumably expecting to misuse their CPU. Probably also a reference to [[1172: Workflow]].<br />
|-<br />
| GIF to XLS<br />
| .GIF (Graphic Interchange Format) is a file extension used to store images and sequences of images to be displayed as an animation. .XLS is the file extension for Microsoft Excel spreadsheets. The joke is that the two file types are used for different purposes - it's quite normal for someone to want to convert between .GIF, .JPG, .PNG, .BMP files, as these are all image files; or between .XLS, .CSV, and .ODS files, as these all record tabulated information. However, for some reason Randall wants to convert an image file to a spreadsheet. (This is actually possible, because a digital image is essentially an array of colour and brightness values; it just wouldn't be particularly useful for most people. [http://www.think-maths.co.uk/spreadsheet Here] is a webpage with an online converter.) Matt Parker has done a [https://www.youtube.com/watch?v=UBX2QQHlQ_I stand up routine] about converting these two file types.<br />
<br />
An alternate way to convert an image file, such as a .GIF file, into a text-based file like an .XLS file, is through {{w|optical character recognition}} (OCR). This is only effective if the image is a copy (i.e. a scan or reasonably clear photograph) of a document containing letters and words, and neither .GIF nor .XLS are file formats anyone would usually use in that case.<br />
|-<br />
| Clock speed jumper sample rate<br />
| A jumper is an intentional short circuit used for selecting options for an electronic circuit. They are usually used where it is not feasible to use programming (such as outputting a byte or word through a port) to alter the selection, such as before the processor even begins executing. A common example would be, on some motherboards, jumpers can be used to alter the clock speeds of various motherboard functions (such as the CPU or the front side bus). These jumpers should ordinarily be modified when the computer is off. However, this search is asking how often the motherboard checks the status of the clock speed jumpers, implying that they intend to change these jumpers while the computer is powered on, and often enough that the sample rate matters (change cpu speed several times a second, by moving jumpers on the motherboard.). That is, of course, a little silly.<br />
|-<br />
| [https://www.google.com/search?q=clean+reinstall+keybinding Clean reinstall keybinding]<br />
| This refers to keybinding, the practice of mapping (binding) a certain key to a certain function (e.g., pressing PRTSC will take a screenshot). Most keyboards do not output characters directly, but only codes for which keys have been pressed (or released). Keybindings translate the pressing of the "A" key on your keyboard into the letter "A" being sent to a program which is reading keyboard input. A "clean reinstall" of keybindings is something that would almost never be necessary - it means Randall has modified his default keybindings to such an extent that his [[1031:_s/keyboard/leopard/|leopard]] has become unusable (similar to [[1284: Improved Keyboard]]), necessitating a "clean reinstall" of the bindings. Alternatively, he might be doing clean reinstalls so often that he wants a keybinding to execute them with minimal loss of time.<br />
|-<br />
| Cron job to update crontab<br />
| {{w|Cron}} is a utility that allows you to schedule commands or scripts to be run periodically. These scheduled jobs are read from a ''crontab'' file. A job that updates the crontab (therefore creating new jobs, removing old ones or editing existing ones) is paramount to a {{w|job scheduler}}, and trying to use cron for such functionality could result in highly unstable functionality (although a crontab could be sensibly regenerated periodically by a set of machines from a master crontab file annotated with per-host directives). This is similar to {{w|self-modifying code}}.<br />
|-<br />
| [https://www.google.com/search?q=fsck+chrome+extension fsck Chrome extension]<br />
| <br />
This is a search for an interface to the Unix '''f'''ile'''s'''ystem che'''ck'''er {{w|fsck}} via third-party software added to Chrome. fsck is a program for checking your filesystem for corruption. Repairing a filesystem this way would be inadvisable. {{Citation needed}} This might indicate confusion about the meaning of the term "online filesystem repair", in which "online" means "while the filesystem is in use" rather than "over the Internet". Alternatively, Randall might want to repair an installation of the operating system Chromium, in a manner less drastic than the {{w|factory reset}} preferred by Google.<br />
|-<br />
| Recursive font<br />
| An idiosyncratic mix of {{w|recursion}} and the font style ''{{w|cursive}}'', referring especially to text handwritten in a flowing manner. {{w|PostScript}} (the language in which {{w|PostScript fonts|some fonts}} are written) is capable of recursion and PostScript Type 3 fonts are able to use the full language. This could create effects like fonts with complicated fractal borders and fill patterns - but the increase in processing time would contribute to seeming brokenness of the computer (or printer) rendering the font.<br />
<br />
A true recursive font would be a form of {{w|fractal}}s.<br />
|-<br />
| Regex matching valid EBNF<br />
| EBNF refers to {{w|Extended Backus–Naur Form}}, which is used to define {{w|formal language}}s. EBNF specifies recursive patterns that are impossible for a {{w|Regular_Expression|regular expression}} (regex) to determine whether it is valid or not. There is some irony in using regex to test the validity of something which ''defines'' the validity of things like regex.<br />
|-<br />
| [https://www.google.com/search?q=Hardlinks+Turing+complete Hardlinks Turing complete]<br />
| In some filesystems, for example {{w|ext4}} and {{w|NTFS}}, a single file may be referenced by different names anywhere in the filesystem. These filenames are termed "hard links" to the file because they are automatically resolved by the operating system to the file metadata. "Soft" or "symbolic" links are resolved indirectly via a pathname, which may reside anywhere. A file is deleted when the last hard link to it is unlinked; a soft link exists independently of its target. In fact, the target need not exist, in which case this is often called a dangling symbolic link.<br />
<br />
{{w|Turing completeness}} is the {{w|computational complexity}} required to simulate any {{w|computable function}} (given an infinite amount of memory). Recently there have been cases where [http://beza1e1.tuxen.de/articles/accidentally_turing_complete.html unexpected mechanisms] from card games to text parsers were proved to be Turing complete. Hardlinks being Turing complete would imply that creating and deleting hardlinks alone is enough to satisfy the requirements of Turing completeness.<br />
|-<br />
| Opposite of safe mode<br />
| {{w|Safe mode}} is a diagnostic mode of an operating system or application which allows the user to troubleshoot problems by disabling unnecessary functionality. The "opposite of safe mode" implies a "dangerous" mode where the purpose is to allow uselessly dangerous action, like {{w|sudo}}.<br />
<br />
It's also possible that Randall sees safe mode so often that he sees regular mode as an unusual and unique state and needs help navigating back to it.<br />
|-<br />
| Predictive touchpad<br />
| {{w|Predictive text}} is a feature of many smartphone keyboards that predicts the most likely word the user wishes to type, and then gives the user the option to place the word in the sentence without typing the whole word. A {{w|touchpad}} is a computer pointing device, similar to a {{w|computer mouse}}. The idea of a "predictive touchpad" seems absurd because, as opposed to typed words, there are not a limited number of swipe combinations that are possible on a touchpad. A "predictive touchpad" implies that a computer could predict where the user was going to move the mouse or click, which in this case would seem to defeat the purpose of a user input device. {{Citation needed}}.<br />
<br />
Interestingly, a version of Linux {{Citation needed}} had a predictive cursor option, where the cursor jumped to the nearest button (like window close) when it moved near to but didn't quite reach that button.<br />
|-<br />
| Google docs from bootloader<br />
| Google docs relies on programs and libraries much more complex than a {{w|bootloader}} (a very small program running immediately after boot, mainly for loading the OS) could run.<br />
|-<br />
| Hardware acceleration red channel only<br />
| {{w|Hardware acceleration}} means that certain calculations are not performed by the computer's {{w|CPU}} but by a "specialized" processor, e.g. a {{w|GPU}} which is part of the graphics adapter. This speeds up output, especially if complex 3D calculations are required and reduces CPU load. To use this function only on a single color channel seems pretty useless, but one may want to troubleshoot a program that displays only red when hardware acceleration is enabled.<br />
<br />
While graphics cards are most commonly used with three or four channels (red, green, blue, and sometimes alpha), they do support two-channel or single-channel images. An 8-bit single-channel image would use the format '[https://www.opengl.org/wiki/Image_Load_Store#Format_qualifiers R8]', which is indeed 'red channel only'. This type of image could be used to store monochrome images or non-image data.<br />
|-<br />
| autoexec code posted by verified twitter users. ('''Title text''')<br />
| Automatically executing code from the Internet is generally a terrible idea, because it could be written by someone with malicious intent and harm your computer. The joke here is that the code would only be executed if written by someone who has been "verified" on Twitter. Twitter's verification service only serves to show that a user is who they claim to be, not whether or not their code can be trusted, so this would provide little protection. Usually, twitter verification is used by celebrities so they can be distinguished from people claiming to be them. The line implies that Randall is only interested in running code posted by celebrities.<br />
<br />
Most code downloaded from authentic sources, such as Windows and Linux, is verified by a cryptographic signature -- such packages signed by a true trusted source authenticating the origin of the software, and the are frequently executed on your computer automatically and it forms the basis for auto-updates of for example your Chrome browser, any automatically updated linux package, and everything automatically updated by Windows 10. The joke here is that "verified" have different meaning for twitter and cryptography.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
:[Coloured and styled as the real logo:]<br />
:<big><font color="blue">G</font color><font color="red">o</font color><font color="orange">o</font color><font color="blue">g</font color><font color="green">l</font color><font color="red">e</font color></big><br />
<br />
:[Google Search bar, with a drop down box with faded text, implying recent searches]<br />
:Google translate syntax highlighting<br />
:Autodetect mixed bash zsh<br />
:CPU temperature sensor limits<br />
:GIF to XLS<br />
:Clock speed jumper sample rate<br />
:Clean reinstall keybinding<br />
:Cron job to update crontab<br />
:fsck Chrome extension<br />
:Recursive font<br />
:Regex matching valid EBNF<br />
:Hardlinks Turing complete<br />
:Opposite of safe mode<br />
:Predictive touchpad<br />
:Google docs from bootloader<br />
:Hardware acceleration red channel only<br />
<br />
:[Caption below the panel:]<br />
:'''I have no idea why my computers are always broken.'''<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics with color]]<br />
[[Category:Google Search]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1678:_Recent_Searches&diff=1197261678: Recent Searches2016-05-10T20:09:47Z<p>Djbrasier: /* Table of searches */</p>
<hr />
<div>{{comic<br />
| number = 1678<br />
| date = May 9, 2016<br />
| title = Recent Searches<br />
| image = recent_searches.png<br />
| titletext = autoexec code posted by verified twitter users<br />
}}<br />
<br />
==Explanation==<br />
People often find answers to computer problems by searching on {{w|Google}}, which shows you recent search terms in a drop-down box when you go to search it. Here we see a list of search queries, each of which suggests the author is perversely misusing or overextending some computer technology. The overall impression is of someone technically sophisticated enough to shoot themselves in the foot, and who does not learn any larger lessons despite doing so repeatedly. The title text is another possible entry in this list.<br />
<br />
The caption implies that from Randall's perspective, every computer he uses seems to be broken; he doesn't seem to realise this is because he's the one using them, not because the computers actually start off broken. (For similar themes see also these comics: [[349: Success]], [[1084: Server Problem]], [[1316: Inexplicable]] and [[1586: Keyboard Problems]]).<br />
<br />
([[979|Dear people from the future]], if Google directed you here because it is the most popular result for a problem you are experiencing, this is not the page you were looking for). <br />
<br />
===Table of searches===<br />
{| class="wikitable" border="1" cellpadding="4" style="border-collapse: collapse;"<br />
|-<br />
! width=20% | Search<br />
! Explanation<br />
|-<br />
| [https://www.google.com/search?q=Google+translate+syntax+highlighting Google translate syntax highlighting]<br />
| {{w|Syntax highlighting}} can be used when editing {{w|source code}} to make the code more readable and easier to understand. It is not generally used for natural languages, but {{w|sentence diagram}}s of brief passages are used in language education. {{w|Google Translate}} is used to translate text from one {{w|natural language}} to another. It uses {{w|Javascript}} <tt>mouseover()</tt> to highlight words as an aid in matching phrases in the source with their translations, but does not apply different highlighting dependent on syntax.<br />
<br />
Alternatively, this could imply that the user is attempting to translate code from one programming language to another using Google Translate. Success would be unlikely, since the service is not intended for this, {{Citation needed}} and syntactically valid output might further break the computer executing it.<br />
|-<br />
| Autodetect mixed bash zsh<br />
| {{w|bash}} and {{w|Z_shell|zsh}} are two {{w|Command-line_interface|command line interfaces}} for {{w|Unix-like}} OSes. The way to execute commands is almost identical, making detecting a script that contains a mixed syntax nearly impossible.<br />
|-<br />
| CPU temperature sensor limits<br />
| The CPU's temperature sensors exist to tell you when your CPU is becoming dangerously overheated (normally because of a faulty fan or overclocking). Someone who searches for information about the limits of those sensors is presumably expecting to misuse their CPU. Probably also a reference to [[1172: Workflow]].<br />
|-<br />
| GIF to XLS<br />
| .GIF (Graphic Interchange Format) is a file extension used to store images and sequences of images to be displayed as an animation. .XLS is the file extension for Microsoft Excel spreadsheets. The joke is that the complete difference between the two types of file makes any kind of conversion seemingly impossible. However, since a pixel graphic can be thought of as a rectangular array of numerical values, a conversion is technically possible. [http://www.think-maths.co.uk/spreadsheet Here] is a webpage with an online converter.<br />
<br />
Matt Parker has done a [https://www.youtube.com/watch?v=UBX2QQHlQ_I stand up routine] about converting these two file types.<br />
|-<br />
| Clock speed jumper sample rate<br />
| Jumper wire is a short circuit used for switching a certain function on an electronic circuit. On a motherboard, jumpers can be used to alter the clock speeds of various motherboard functions (such as the CPU or the front side bus). These jumpers should be modified when the computer is off. However, this search is asking how often the motherboard checks the status of the clock speed jumpers, implying that they intend to change these jumpers while the computer is powered on.<br />
|-<br />
| [https://www.google.com/search?q=clean+reinstall+keybinding Clean reinstall keybinding]<br />
| This refers to keybinding, the practice of mapping a certain key to a certain function (e.g., pressing PRTSC will take a screenshot). Creating a keybinding for a task usually implies that the task is repeated often. A "clean reinstall" (presumably of an operating system) is however not generally something that should be repeated often, implying that the user is regularly breaking the OS with their tinkering. Alternatively, the user may have modified their default keybindings to such an extent that their [[1031|leopard]] has become unusable (similar to [[1284: Improved Keyboard]]), necessitating a "clean reinstall" of the bindings.<br />
|-<br />
| Cron job to update crontab<br />
| {{w|Cron}} is a utility that allows you to schedule commands or scripts to be run periodically. These scheduled jobs are read from a ''crontab'' file. A job that updates the crontab (therefore creating new jobs, removing old ones or editing existing ones) is paramount to a {{w|Job scheduler}}, and trying to use cron for such functionality could result in highly unstable functionality (although a crontab could be sensibly regenerated periodically by a set of machines from a master crontab file annotated with per-host directives).<br />
|-<br />
| [https://www.google.com/search?q=fsck+chrome+extension fsck Chrome extension]<br />
| <br />
This is probably a search for an interface to the Unix '''f'''ile'''s'''ystem che'''ck'''er {{w|fsck}} via third-party software added to Chrome. Repairing a filesystem this way would be inadvisable. {{Citation needed}} This might indicate confusion about the meaning of the term "online filesystem repair", in which "online" means "while the filesystem is in use" rather than "over the internet". Alternatively, the user might want to repair an installation of the operating system Chromium, in a manner less drastic than the {{w|factory reset}} preferred by Google.<br />
|-<br />
| Recursive font<br />
| An idiosyncratic mix of {{w|Recursion}} and the font style ''{{w|cursive}}'', referring especially to text handwritten in a flowing manner. {{w|PostScript}} (the language {{w|PostScript fonts|some fonts}} are written in) is capable of recursion and PostScript Type 3 fonts are able to use the full language. This could create effects like fonts with complicated fractal borders and fill patterns - but the increase in processing time would contribute to seeming brokenness of the computer (or printer) rendering the font.<br />
<br />
A true recursive font would be a form of {{w|Fractals}}.<br />
|-<br />
| Regex matching valid EBNF<br />
| EBNF refers to {{w|Extended Backus–Naur Form}}, which is used to define {{w|Formal Language|formal languages}}. EBNF specifies recursive patterns that are impossible for a {{w|Regular_Expression|regular expression}} to determine whether it is valid or not. There is some irony in using regex to test the validity of something which ''defines'' the validity of things like regex.<br />
|-<br />
| [https://www.google.com/search?q=Hardlinks+Turing+complete Hardlinks Turing complete]<br />
| In some filesystems, for example {{w|ext4}} and {{w|NTFS}}, a single file may be referenced by different names anywhere in the filesystem. These filenames are termed "hard links" to the file because they are automatically resolved by the operating system to the file metadata. "Soft" or "symbolic" links are resolved indirectly via a filename, which may reside anywhere. A file is deleted when the last hard link to it is unlinked; a soft link exists independently of its target.<br />
<br />
{{w|Turing completeness}} is the {{w|computational complexity}} required to simulate any {{w|computable function}} (given an infinite amount of memory). Recently there have been cases where [http://beza1e1.tuxen.de/articles/accidentally_turing_complete.html unexpected mechanisms] from card games to text parsers were proved to be Turing complete. Hardlinks being Turing complete would imply that creating and deleting hardlinks alone is enough to satisfy the requirements of Turing completeness.<br />
|-<br />
| Opposite of safe mode<br />
| {{w|Safe mode}} is a diagnostic mode of an operating system or application which allows the user to troubleshoot problems by disabling unnecessary functionality. The "opposite of safe mode" implies a "dangerous" mode where the purpose is to allow uselessly dangerous action, and even encourages you do so.<br />
<br />
Alternatively, the user have somehow been dropped into safemode and is searching for how to get back to normal operation, which in itself is ridiculous as safemode is intended for the user to resolve the problem, and the user clearly does not understand why the system have been put in the state it has.<br />
|-<br />
| Predictive touchpad<br />
| {{w|Predictive text}} is a feature of many smartphone keyboards that predicts the most likely word the user wishes to type, and then gives the user the option to place the word in the sentence without typing the whole word. A {{w|touchpad}} is a computer pointing device, similar to a {{w|computer mouse}}. The idea of a "predictive touchpad" seems absurd because, as opposed to typed words, there are not a limited number of swipe combinations that are possible on a touchpad. A "predictive touchpad" implies that a computer could predict where the user was going to move the mouse or click, which is clearly unreasonable. {{Citation needed}} - Beside all this it's a simple word play on techonlogies/names used for touchpads. Resistive or capacitive touchpads are quite common, while inductive touchpads are only used with special pens for drawing.<br />
<br />
Interestingly, a version of Linux {{Citation needed}} had a predictive cursor option, where the cursor jumped to the nearest button (like window close) when it got moved near but not quite reached that button.<br />
|-<br />
| Google docs from bootloader<br />
| Google docs relies on programs and libraries much more complex than a {{w|bootloader}} (a very small program running immediately after boot, mainly for loading the OS) could run.<br />
|-<br />
| Hardware acceleration red channel only<br />
| {{w|Hardware acceleration}} means that certain calculations are not performed by the computer's {{w|CPU}} but by a "specialized" processor, e.g. a {{w|GPU}} which is part of the graphics adapter. This speeds up output, especially if complex 3D calculations are required and reduces CPU load. To use this function only on a single color channel seems pretty useless, but one may want to troubleshoot a program that displays only red when hardware acceleration is enabled.<br />
|-<br />
| autoexec code posted by verified twitter users. ('''Title text''')<br />
| Automatically executing code from the internet is generally a terrible idea, because it could be written by someone with malicious intent and harm your computer. The joke here is that the code would only be executed if written by someone who has been "verified" on Twitter. Twitter's verification service only serves to show that a user is who they claim to be, not whether or not their code can be trusted, so this would provide little protection. Usually, twitter verification matters so that celebrities can identify themselves, so this line implies that Randall is only interested in running code posted by celebrities. It might also refer to autoexec.bat, the script that is automatically executed when a DOS computer boots up.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
:[Coloured and styled as the real logo:]<br />
:<big><font color="blue">G</font color><font color="red">o</font color><font color="orange">o</font color><font color="blue">g</font color><font color="green">l</font color><font color="red">e</font color></big><br />
<br />
:[Google Search bar, with a drop down box with faded text, implying recent searches]<br />
:Google translate syntax highlighting<br />
:Autodetect mixed bash zsh<br />
:CPU temperature sensor limits<br />
:GIF to XLS<br />
:Clock speed jumper sample rate<br />
:Clean reinstall keybinding<br />
:Cron job to update crontab<br />
:fsck Chrome extension<br />
:Recursive font<br />
:Regex matching valid EBNF<br />
:Hardlinks Turing complete<br />
:Opposite of safe mode<br />
:Predictive touchpad<br />
:Google docs from bootloader<br />
:Hardware acceleration red channel only<br />
<br />
:[Caption below the panel:]<br />
:'''I have no idea why my computers are always broken.'''<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics with color]]<br />
[[Category:Google Search]]</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=1678:_Recent_Searches&diff=1195951678: Recent Searches2016-05-09T16:39:32Z<p>Djbrasier: /* Explanation */ Computer code can be written, but is a formal language as opposed to natural.</p>
<hr />
<div>{{comic<br />
| number = 1678<br />
| date = May 9, 2016<br />
| title = Recent Searches<br />
| image = recent_searches.png<br />
| titletext = autoexec code posted by verified twitter users<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Needs an explanation for the individual queries.}}<br />
<br />
The comic refers to the practice of finding answers to computer problems using {{w|Google}}. It shows a list of search queries, each of which suggests the author is perversely misusuing or overextending some computer technology or technologies. The overall impression is of someone technically sophisticated enough to shoot themselves in the foot, and who does not learn any larger lessons despite doing so repeatedly. It is unlikely any of the searches would give useful answers, because no two people would be perverse in these extremely specific ways. The title text is another possible entry in this list. A complication in attempting to solve computer problems this way would be presented by Google's search term autocorrection, which for several years has replaced technical terms with unrelated language from recent popular culture.<br />
<br />
{| class="wikitable" border="1" cellpadding="4" style="border-collapse: collapse;"<br />
|-<br />
! width=20% | Search<br />
! Explanation<br />
|-<br />
| Google translate syntax highlighting<br />
| {{w|Syntax highlighting}} can be used when editing source code to make the code more readable and easier to understand. {{w|Google Translate}} is used to translate text from one {{w|natural language}} to another. The joke here is that syntax highlighting doesn't make sense in the context of translating natural languages.<br />
|-<br />
| Autodetect mixed bash zsh<br />
| {{w|bash}} and {{w|Z_shell|zsh}} are two {{w|Command-line_interface|command line interfaces}} for {{w|Linux}}. The way to execute commands are almost identical, making detecting a script that contains a mixed syntax nearly impossible.<br />
|-<br />
| CPU temperature sensor limits<br />
| The CPU's temperature sensors exist to tell you when your CPU is becoming dangerously overheated (presumably as a result of overuse). Someone who searches for information about the limits of those sensors is presumably expecting to misuse their CPU.<br />
|-<br />
| GIF to XLS<br />
| .GIF (Graphic Interchange Format) is a file extension used to store images and sequences of images to be displayed as an animation. .XLS is the file extension for Microsoft Excel spreadsheets. The joke is that the complete difference between the two types of file makes any kind of conversion all but impossible, so the search is useless.<br />
|-<br />
| Clock speed jumper sample rate<br />
| On a motherboard, jumpers can be used to alter the clock speeds of various motherboard functions (such as the CPU or the front side bus). These jumpers should be modified when the computer is off. However, this search is asking how often the motherboard checks the status of the clock speed jumpers, implying that they intend to change these jumpers while the computer is powered on.<br />
|-<br />
| [https://www.google.com/search?q=clean+reinstall+keybinding Clean reinstall keybinding]<br />
| This refers to keybinding, the practice of mapping a certain key to a certain function (e.g., pressing PRTSC will take a screenshot). Creating a keybinding for an task usually implies that the task is repeated often. A "clean reinstall" (presumably of an operating system) is however not generally something that should be repeated often, implying that the user is regularly breaking the OS with their tinkering. Searching for (any) default keybinding suggests they are having severe problems with their [[1031|leopard]].<br />
|-<br />
| Cron job to update crontab<br />
| {{w|Cron}} is a utility that allows you to schedule commands or scripts to be run periodically. These scheduled jobs are read from a ''crontab'' file. A job that updates the crontab (therefore creating new jobs, removing old ones or editing existing ones) is highly unusual and unlikely to be what you actually want to do.<br />
|-<br />
| [https://www.google.com/search?q=fsck+chrome+extension fsck Chrome extension]<br />
| <br />
Google suggests "fleck" instead of "fsck". Fleck is a recent {{w|web annotation}} service; an extension to Chrome would make it accessible from that web browser. However, it would be extremely implausible that "fleck" had been mistyped as "fsck".<br />
<br />
In context, this is probably a search for a interface to the Unix '''f'''ile'''s'''ystem che'''ck'''er {{w|fsck}} via third-party software added to Chrome. Repairing a filesystem this way would be inadvisable. {{Citation needed}}<br />
<br />
This might indicate confusion about the meaning of the term "online filesystem repair", in which "online" means "while the filesystem is in use" rather than "over the internet".<br />
<br />
Alternatively, the user might want to repair an installation of the operating system Chromium, in a manner less drastic than the {{w|factory reset}} preferred by Google.<br />
|-<br />
| Recursive font<br />
| An idiosyncratic mix of {{w|Recursion}} and the font style ''{{w|cursive}}'', referring especially to text handwritten in a flowing manner. If you could recursively create characters, the result would most likely be quite illegible and not useful as a font.<br />
|-<br />
| Regex matching valid EBNF<br />
| EBNF refers to {{w|Extended Backus–Naur Form}}, which is used to define {{w|Formal Language|formal languages}}. It is far too complex for a {{w|Regular_Expression|regular expression}} to determine whether it is valid or not. There is some irony in using regex to test the validity of something which ''defines'' the validity of things like regex.<br />
|-<br />
| Hardlinks Turing complete<br />
| Hardlinks are features of filesystems where two or more files point to the same data structures in the filesystem. Deleting one file will result in the deletion of the other file due to the sharing of data. Turning complete is when a computer (given an infinite amount of memory) can simulate every other type of computer. Recently there have been cases where unexpected mechanisms from card games to text parsers were proved to be Turing complete. Hardlinks being Turing complete would imply that creating and deleting hardlinks alone is enough to statisfy the requirements of Turing completeness.<br />
|-<br />
| Opposite of safe mode<br />
| {{w|Safe mode}} is a diagnostic mode of an operating system or application which allows the user to troubleshoot problems by disabling unnecessary functionality. The "opposite of safe mode" implies a "dangerous" mode where the purpose is to cause problems rather than fix them.<br />
|-<br />
| Predictive touchpad<br />
| {{w|Predictive text}} is a feature of many smartphone keyboards that predicts the most likely word the user wishes to type, and then gives the user the option to place the word in the sentence without typing the whole word. A {{w|touchpad}} is a computer pointing device, similar to a {{w|computer mouse}}. The idea of a "predictive touchpad" seems absurd because, as opposed to typed words, there are not a limited number of swipe combinations that are possible on a touchpad. A "predictive touchpad" implies that a computer could predict where the use was going to move the mouse or click, which is clearly unreasonable.<br />
|-<br />
| Google docs from bootloader<br />
| Google docs relies on programs and libraries much more complex than a bootloader could run.<br />
|-<br />
| Hardware acceleration red channel only<br />
| {{w|Hardware acceleration}} means that certain calculations are not performed by the computer's {{w|CPU}} but by a "specialized" processor, e.g. a {{w|GPU}} which is part of the graphics adapter. This speeds up output, especially if complex 3D calculations are required and reduces CPU load. To use this function only on a single color channel seems pretty useless.<br />
|-<br />
| autoexec code posted by verified twitter users<br />
| Automatically executing code from the internet is generally a terrible idea, because it could be written by someone with malicious intent and harm your computer. The joke here is that the code would only be executed if written by someone who has been "verified" on Twitter. Twitter's verification service only serves to show that a user is who they claim to be, not whether or not their code can be trusted, so this would provide little protection.<br />
|-<br />
|}<br />
<br />
==Transcript==<br />
:[Coloured and styled as the logo]<br />
:Google<br />
<br />
:[Drop down box, implying recent searches]<br />
:Google translate syntax highlighting<br />
:Autodetect mixed bash zsh<br />
:CPU temperature sensor limits<br />
:GIF to XLS<br />
:Clock speed jumper sample rate<br />
:Clean reinstall keybinding<br />
:Cron job to update crontab<br />
:fsck Chrome extension<br />
:Recursive font<br />
:Regex matching valid EBNF<br />
:Hardlinks Turing complete<br />
:Opposite of safe mode<br />
:Predictive touchpad<br />
:Google docs from bootloader<br />
:Hardware acceleration red channel only<br />
<br />
:[Bold, below page outline]<br />
:I have no idea why my computers are always broken<br />
<br />
{{comic discussion}}</div>Djbrasierhttps://www.explainxkcd.com/wiki/index.php?title=893:_65_Years&diff=111859893: 65 Years2016-02-15T20:16:24Z<p>Djbrasier: /* Explanation */ links to astraunat's</p>
<hr />
<div>{{comic<br />
| number = 893<br />
| date = May 2, 2011<br />
| title = 65 Years<br />
| image = 65 years.png<br />
| titletext = The universe is probably littered with the one-planet graves of cultures which made the sensible economic decision that there's no good reason to go into space--each discovered, studied, and remembered by the ones who made the irrational decision.<br />
}}<br />
==Explanation==<br />
[[Randall]] is showing the number of still living humans who have walked on another world for the 65 year period that begins in 1969 (when a human first walked on the moon). Up to 2011 (when the comic was drawn), he has drawn a single line for the actual figures.<br />
<br />
For the subsequent years, he has drawn three lines using {{w|actuarial table}}s or life tables (such tables show, for each age, the probability that a certain person will die within the next year).<br />
<br />
The line marked "5TH PERCENTILE" indicates that there is a 95% probability that the number alive in a given year will be above that line and a 5% probability that the number alive will be below that line. For example, this line indicates a 5% chance that all Apollo moon walkers will be dead by 2023, and a 95% chance that at least one will still be alive by that year.<br />
<br />
The line marked "95TH PERCENTILE" indicates that there is a 5% probability that the number alive in a given year will be above that line and a 95% probability that the number alive will be below that line. For example, this line indicates a 95% chance that all Apollo moon walkers will be dead by 2035, and a 5% chance that at least one will still be alive by that year.<br />
<br />
The middle line is not identified, but is probably the "50TH PERCENTILE" (see [http://blog.xkcd.com/2012/07/12/a-morbid-python-script/ these tables]). If so, it indicates that there is a 50% probability that the number alive in a given year will be above that line and a 50% probability that the number alive will be below that line. For example, this line indicates a 50% chance that all Apollo moon walkers will be dead by 2028 (see previous link), and a 50% chance that at least one will still be alive by that year.<br />
<br />
Although the term ''other world'' would include all other worlds on which humans have walked, there is currently only one other world on which humans have walked, which is the moon. The humans that have walked there are the 12 {{w|List of Apollo astronauts#Apollo astronauts who walked on the Moon|Apollo astronauts}} who landed on the Moon between 1969 and 1972.<br />
<br />
In particular, {{w|Neil Armstrong}} and {{w|Buzz Aldrin}} landed in July 1969. {{w|Pete Conrad}} and {{w|Alan Bean}} landed in November. {{w|Alan Shepard}} and {{w|Edgar Mitchell}}: February 1971. {{w|David Scott}} and {{w|James Irwin}}: July 1971. {{w|John Young (astronaut)|John Young}} and {{w|Charles Duke}}: April 1972. {{w|Eugene Cernan}} and {{w|Harrison Schmitt}}: December 1972.<br />
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Irwin died in 1991. Shepard and Conrad died in 1998 and 1999 respectively, making the total 9 as of the date this comic was published. Armstrong died in 2012 and Mitchell in 2016, so the current number is 7. The oldest living person to have landed on the moon is Aldrin, 86. There is one 86-year-old, one 85, two 83s, one 81 and two 80s.<br />
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The chart assumes that no other humans will go to walk on another world within the time-frame plotted and the title text implies that this is primarily an economically determined decision. While noting that not exploring space is a justifiable and sensible decision which may also be made by many hypothetical cultures on other worlds, the text implies a grandness to a civilization that would be given the opportunity to discover, study and memorialize the 'one-world graves' of other civilizations by choosing to explore space despite the economic difficulty. High five for exoplanet archaeology.<br />
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==Transcript==<br />
:[A graph titled 'Number of Living Humans Who Have Walked on Another World' - its y-axis is numbered 5, 10, 15, its x-axis increments every ten years from 1960-2040. The line of the graph has a bracket above it that says '65 Years', starting at 1969, ending in 2034.<br />
:The line starts at 1969 and increases steeply to 12 by 1972. It then plateaus until the early nineties declines gradually to 9 between 1991-1999, and then plateaus again.<br />
:From 2011-2035, which is labeled 'Projected Actuarial Tables', the line branches into three and begins to decline more steeply to zero. The area between the first and second branch is shaded and labeled '5th percentile' and the area between the second and third branch is shaded and labeled '95th percentile.']<br />
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==Trivia==<br />
*The theme of actuarial projections was explored earlier in [[493: Actuarial]]; Randall's morbid python script for both was given in [http://blog.xkcd.com/2012/07/12/a-morbid-python-script/ the blag].<br />
{| class="wikitable"<br />
|+Table of men who walked the moon<br />
|- style="background:#ccc;"<br />
| style="width:20px;"|<br />
| '''Name'''<br />
| '''Born'''<br />
| '''Died'''<br />
| '''Age at<br>first step'''<br />
| '''Mission'''<br />
| '''Lunar dates'''<br />
| '''Service'''<br />
| '''Alma Mater'''<br />
|- style="background:#def;"<br />
| 1. || {{w|Neil Armstrong}}|| 1930-08-05 || 2012-08-25 || 38y&nbsp;11m&nbsp;15d<br />
|rowspan="2"| {{w|Apollo&nbsp;11}} ||rowspan="2"| July&nbsp;21,&nbsp;1969 || {{w|NASA}} || {{w|Purdue University}}, {{w|University of Southern California}}<br />
|- style="background:#def;"<br />
| 2. || {{w|Buzz Aldrin}}|| 1930-01-20 || || 39y 6m 0d || {{w|United States Air Force|Air Force}} || {{w|United States Military Academy}}, {{w|MIT}}<br />
|- style="background:#ffe8e8;"<br />
| 3. || {{w|Pete Conrad}} || 1930-06-02 || 1999-07-08 || 39y 5m 17d<br />
|rowspan="2"| {{w|Apollo 12}} ||rowspan="2"| November&nbsp;19–20,&nbsp;1969 || {{w|United States Navy|Navy}} || {{w|Princeton University}}<br />
|- style="background:#ffe8e8;"<br />
| 4. || {{w|Alan Bean}}|| 1932-03-15 || || 37y 8m 4d || {{w|United States Navy|Navy}} || {{w|University of Texas, Austin}}<br />
|- style="background:#def;"<br />
| 5. || {{w|Alan Shepard}} || 1923-11-18 || 1998-07-21 || 47y 2m 18d<br />
|rowspan="2"| {{w|Apollo 14}} ||rowspan="2"| February 5–6, 1971 || {{w|United States Navy|Navy}} || {{w|United States Naval Academy}}<br />
|- style="background:#def;"<br />
| 6. || {{w|Edgar Mitchell}}|| 1930-09-07 || 2016-02-04 || 40y 4m 19d || {{w|United States Navy|Navy}} || {{w|Carnegie Mellon University}}, {{w|Naval Postgraduate School}}, {{w|MIT}}<br />
|- style="background:#ffe8e8;"<br />
| 7. || {{w|David Scott}} || 1932-06-06 || || 39y 1m 25d<br />
|rowspan="2"| {{w|Apollo 15}} ||rowspan="2"| July&nbsp;31&nbsp;-&nbsp;August&nbsp;2,&nbsp;1971 || {{w|United States Air Force|Air Force}} || {{w|University of Michigan}} (freshman year, and later, an honorary doctorate), {{w|United States Military Academy}}, {{w|MIT}}<br />
|- style="background:#ffe8e8;"<br />
| 8. || {{w|James Irwin}} || 1930-03-17 || 1991-08-08 || 41y 4m 14d || {{w|United States Air Force|Air Force}} || {{w|United States Naval Academy}}, {{w|University of Michigan}}<br />
|- style="background:#def;"<br />
| 9. || {{w|John Young (astronaut)|John W. Young}}|| 1930-09-24 || || 41y 6m 28d<br />
|rowspan="2"| {{w|Apollo 16}} ||rowspan="2"| April 21–23, 1972 || {{w|United States Navy|Navy}} || {{w|Georgia Institute of Technology}}<br />
|- style="background:#def;"<br />
| 10. || {{w|Charles Duke}} || 1935-10-03 || || 36y 6m 18d || {{w|United States Air Force|Air Force}} || {{w|United States Naval Academy}}, {{w|MIT}}<br />
|- style="background:#ffe8e8;"<br />
| 11. || {{w|Eugene Cernan}} || 1934-03-14 || || 38y 9m 7d<br />
|rowspan="2"| {{w|Apollo 17}} ||rowspan="2"| December 11–14, 1972 || {{w|United States Navy|Navy}} || {{w|Purdue University}}, {{w|Naval Postgraduate School}}<br />
|- style="background:#ffe8e8;"<br />
| 12. || {{w|Harrison Schmitt}} || 1935-07-03 || || 37y 5m 8d || {{w|NASA}} || {{w|Caltech}}, {{w|University of Oslo}} (exchange), {{w|Harvard University}}<br />
|}<br />
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{{comic discussion}}<br />
[[Category:Charts]]<br />
[[Category:Math]]<br />
[[Category:Science]]<br />
[[Category:Comics to make one feel old]]</div>Djbrasier