explain xkcd - User contributions [en]

User:Xkcdjerry

2025-11-19T08:04:28Z

Xkcdjerry:

I checked the Pages to Delete category and 42.book.addict was behind every one I checked.
This should count for recent activity so you don't add it right back in.
Also, reason for doing this?

User:Xkcdjerry

2025-11-19T06:08:30Z

Xkcdjerry:

I checked the Pages to Delete category and 42.book.addict was behind every one I checked.
This should count for recent activity so you don't add it right back in.
Also, reason for doing this?

3168: Beam Dump

2025-11-18T16:01:45Z

Xkcdjerry: Transcript "physicist" typo fix

{{comic
| number = 3168
| date = November 14, 2025
| title = Beam Dump
| image = beam_dump_2x.png
| imagesize = 309x346px
| noexpand = true
| titletext = We're adding some industrial flypaper to minimize reflection or scattering of customers who might complain.
}}

==Explanation==
{{incomplete|This page was created by a SAFELY DECELERATING BOT. Don't remove this notice too soon.}}
Experimental {{w|particle physics}} and {{w|amusement park}}s both involve moving objects at speed, and both require provisions to be made to safely handle those objects if something goes wrong. However, the considerations in each situation are quite different, largely due to the fact that in one case the objects are people which we would not want to damage, and a solution from one field is therefore unlikely to be suitable in the other.

In the comic, [[Cueball]], [[Megan]], and [[White Hat]] have apparently hired an accelerator physicist, portrayed as [[Ponytail]], to design a water park. Ponytail has decided that, in the event that an emergency stop is activated on a large {{w|waterslide}}, the riders would be diverted to a "{{w|beam dump}}", a large block of {{w|graphite}}, which Ponytail believes would safely slow the momentum of the riders. However, unlike in Ponytail's former field of work, the subsequent fate of the visitors should be a major concern, and collisions into heavy solid blocks is a physical health risk.

In the context of a {{w|particle accelerator}}, beam dumps are indeed formed of large blocks of graphite, which safely slow the unwanted particles without having them release large amounts of energy in a more uncontrolled manner. It could be argued that since this measure is intended for the safety of the operators, and not the particles (customers) it would technically be effective at the original purpose if the blocks are sufficiently large, protecting the operators from high velocity customers — if not from the lawsuits of any survivors/next-of-kin.

Reflection and scattering, mentioned in the title text, are effects that occur as a result of particle collisions in a particle accelerator. In the context of this amusement park, though, it could mean customers worrying about the "beam dump" solution and heading off to find someone to complain to about it. Alternatively, it could mean the messy after-effects of them striking the graphite. Either way, Ponytail proposes to use {{w|flypaper}} to prevent it by trapping the patrons.

The word "industrial", applied to a product, can have a number of meanings. It can imply "more powerful than the versions usually used at home": "industrial-strength" chemicals are more concentrated than their home versions; "industrial-strength" tools tolerate more and heavier use than those used occasionally by amateurs before breaking or wearing out. Such products are usually considerably more expensive than the usual versions, because of higher costs of manufacturing and lower demand. Alternatively, it can mean things produced, often at lower unit cost, in larger quantities or sizes than would be practical for domestic consumption. Both would be useful in this case, since it would need to be large enough, with strong enough glue, to trap humans — even wet humans. Flypaper produced and marketed for use on commercial premises, which could be termed "industrial flypaper", does exist, but is unlikely to meet the specifications required for this use case in either respect.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Ponytail is standing in front of a diagram on the wall, pointing at it with a pointer. The diagram has a picture of a waterslide and some untelligible text. The waterslide has two paths at the bottom; one returns to the base of the entrance tower, the other goes to a large black block. On the right stand Cueball, Megan, and White Hat facing her.]
:Ponytail: If the emergency stop is activated, any riders on the waterslide will be diverted into the beam dump, a large graphite block which will safely absorb their momentum.

:[Caption below panel:]
:We regretted hiring an accelerator physicist to design our water park.

{{comic discussion}}<noinclude>
[[Category:Physics]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]

Talk:3120: Geologic Periods

2025-08-20T12:13:11Z

Xkcdjerry: added comment

Discovered this explanation fresh off the griddle. The transcript doesn't even exist yet wow. Also, hi! This is my first time commenting! Did I do it right? [[User:Giraffequeries|Giraffequeries]] ([[User talk:Giraffequeries|talk]]) 22:54, 25 July 2025 (UTC)
:(Yes, looks like you did.)
:A couple of hours on, and nobody's attempted the Transcript yet. If you're still around right now-ish and you've got more time than everyone elses seems to have (including me, sorry), that could be your next thing.
:Check prior Transcripts for the right kind of way (and a few wrongs, but hey?), and imagine the words+'markup' being read through the hypothetical screen-readers. That might not know how to 'audible' a table, may at best shout/stress '''bold-strong'''/''italics-emphasis'', but perhaps not correctly.
:But just getting the words down helps the next soul with a few more minutes at hand. Any normal weekend, I'd be happy to do it right now, but I've got to be up in five hours, and I mildly regret just checking right now to see if I might have missed the latest comic popping up when it was a bit earlier and I was prepping my weekend bags. :) [[Special:Contributions/82.132.236.123|82.132.236.123]] 01:49, 26 July 2025 (UTC)
:Darn, forgot to say my intended actual personal comment I was just going to add. i.e.: Looks like Randall hasn't forgotten about Raptors! Anyway, goodnight/early-morning (my time).... [[Special:Contributions/82.132.236.123|82.132.236.123]] 01:53, 26 July 2025 (UTC)

I've done my part. Also, Raptors [[User:TPS|TPS]] ([[User talk:TPS|talk]]) 02:20, 26 July 2025 (UTC)

Did anyone else google "The Great Dying"? How about "Manicouagan"? How about "Picture of a dinosaur eating a burrito" (just to prove Randall wrong)?
: Ask and you shall receive (shitty AI pic made in five seconds): https://imgur.com/a/4lVKoqD [[Special:Contributions/2A02:2455:1960:4000:1972:32FB:7958:52D3|2A02:2455:1960:4000:1972:32FB:7958:52D3]] 18:30, 26 July 2025 (UTC)

Who wrote this? Tanystropheus wasn't a dinosaur!
[[Special:Contributions/70.115.234.146|70.115.234.146]] 03:28, 26 July 2025 (UTC)

Given that this wiki doesn't really like tables, and this one is formatted rather simply, maybe we should just transfer its content to the transcript and retain only explanations in the main part, as separate paragraphs? [[User:Cock|The Rooster]] ([[User talk:Cock|talk]]) 08:41, 26 July 2025 (UTC)
:What are you talking about. This wiki loves tables! And it is used extensively. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:07, 28 July 2025 (UTC)

Yeah I'm not sure what to do for transcript, comic 2627 is in similar style but not sure if we necessarily want it like that.--[[User:Darth Vader|Darth Vader]] ([[User talk:Darth Vader|talk]]) 09:18, 26 July 2025 (UTC)

Just a small explanation to the Quarternary/Tertiary naming issue because this has become rather obscure and is seldomly spelled out in newer geology textbooks: When the first geologists came up with a table of geologic epochs it consisted of four parts: "Primary", "Secondary", "Tertiary" and "Quarternary". Only the last two names have survived into our time, because the first two parts became split up into the systems that we still use today rather quickly. This is also the main reason that most stratigraphers want to get rid of the terms Tertiary and Quarternary and why Paleogene/Neogene were invented instead. [[Special:Contributions/2003:DD:472A:5500:35F8:1CD8:D274:E286|2003:DD:472A:5500:35F8:1CD8:D274:E286]] 14:46, 26 July 2025 (UTC)

Burrito? Surely not, everyone knows its "soft toilet tissue"
[[Special:Contributions/2A00:23C8:252D:A301:B573:A9F2:E80C:711B|2A00:23C8:252D:A301:B573:A9F2:E80C:711B]] 10:08, 27 July 2025 (UTC)

I don't know why he doesn't like the Zanclean flood. It would have been a spectacular sight had anyone been around to see it.[[Special:Contributions/2A02:8388:1701:E100:60D1:5BC3:D420:5528|2A02:8388:1701:E100:60D1:5BC3:D420:5528]] 16:44, 27 July 2025 (UTC)

Should the explanation of the Zanclean flood have some sort of reference to [[1190: Time]]? [[User:Morgan Wick|Morgan Wick]] ([[User talk:Morgan Wick|talk]]) 00:38, 28 July 2025 (UTC)
:That would be obvious and could explain his dislike mentioned above. Lots of animals would have died during this event. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:07, 28 July 2025 (UTC)

I have deleted my previous comment, as it was in response to text in the Explanation that no longer exists. [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 03:00, 30 July 2025 (UTC)

Randall is wrong - parisitoid wasps are ''very'' cool. [[Special:Contributions/82.13.184.33|82.13.184.33]] 08:14, 28 July 2025 (UTC)

The Quaternary is obviously so called because it's the period of Quatermass. [[Special:Contributions/82.13.184.33|82.13.184.33]] 09:46, 28 July 2025 (UTC)

If y'all disagree with my docutainment interpretation, feel free to erase it again of course, but the common denominator in Randall's table here really ''is'' each period's entertainment value as a focal point. Also, I'd like to add that it's not a bad thing at all for a documentary to be entertaining; quite the opposite. For example, I might never have studied geography if it wasn't for films about interesting foreign places and cool-looking books about volcanoes and dinosaurs and weather, all of which I devoured in my childhood. [[User:PaulEberhardt|PaulEberhardt]] ([[User talk:PaulEberhardt|talk]]) 20:54, 28 July 2025 (UTC)

: Whatever the inspiration, Randall has been using the table as a comic device for a powerful long time, see the category Charts on this wiki, and i.a. the comics 181: Interblag (20061108) and 394: Kilobyte (20080310). [[Special:Contributions/2605:59C8:160:DB08:8552:7338:3C0A:5AFC|2605:59C8:160:DB08:8552:7338:3C0A:5AFC]] 06:34, 29 July 2025 (UTC)

And thus Velociraptors return after (according to the velociraptor category) 12 years of silence, all hail the great Deinonychus! [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 12:13, 20 August 2025 (UTC)

Talk:2936: Exponential Growth

2024-05-25T04:17:22Z

Xkcdjerry:

If that's done by each of your moves being to add one (more) grain to the board, the game would last quite a while. Even with reduced time-limits on the game-clock. [[Special:Contributions/172.70.91.154|172.70.91.154]] 21:27, 22 May 2024 (UTC)

Hmmm. Interesting. [[Special:Contributions/172.69.58.203|172.69.58.203]] 21:31, 22 May 2024 (UTC)

First transcript! Hope it's good.[[User:Danger Kitty|Danger Kitty]] ([[User talk:Danger Kitty|talk]]) 21:36, 22 May 2024‎ (you only <nowiki>~~~</nowiki>ed, it looks like...)

Total of 2^64 - 1 ≈ 1.8 x 10^19 grains of rice. If a grain of rice averages 30 mg, then that's 5.5 x 10^14 kg of rice. That's around the mass of Lake Erie. [[Special:Contributions/172.71.223.56|172.71.223.56]] 21:38, 22 May 2024 (UTC)

The legend about the chess board and doubling the grain placed on each square is researched here:
https://history.stackexchange.com/questions/5992/what-is-the-origin-of-the-wheat-and-chessboard-legend [[Special:Contributions/172.71.150.113|172.71.150.113]] 21:50, 22 May 2024 (UTC)~

The rice is on the side or the board is turned wrong. {{unsigned ip|172.70.115.17|23:13, 22 May 2024}}
:...not sure what you mean here. (Also, do sign your contributions.) [[Special:Contributions/172.70.162.186|172.70.162.186]]
::The white square always goes on your right corner so this border is sideways (assuming we're looking at it head on, which seems likely) [[User:Apollo11|Apollo11]] ([[User talk:Apollo11|talk]]) 23:35, 22 May 2024 (UTC)
::a1 is a dark square, so wherever the one grain of rice is, it can't be a1. [[Special:Contributions/172.71.102.35|172.71.102.35]] 08:41, 23 May 2024 (UTC)
:::Either a8 or h1, which is SO annoying (most likley a mistake on Randall's part tho)[[User:Apollo11|Apollo11]] ([[User talk:Apollo11|talk]]) 15:35, 23 May 2024 (UTC)
With all those zeros in the values given for row eight i assume we are looking at the limitations of someones calculation skills/calculator... last I checked 5 was not a factor of any 2^n value? [[Special:Contributions/172.70.80.246|172.70.80.246]] 00:13, 23 May 2024 (UTC)
:I think we don't need this part at all. If we really want to illustrate the numbers we could simply use the illustration from here: https://en.wikipedia.org/wiki/Wheat_and_chessboard_problem#Second_half_of_the_chessboard [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 07:15, 23 May 2024 (UTC)

That doesn't look like Hairy in the final panel. Is it a Kasparov caricature? [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 02:12, 23 May 2024 (UTC)
:I agree it is not the standard Hairy. Since this is Kasparovs gambit and Karpov tried to counter it, then it should be Karpov that walks out! Even though it is not Kasparaov but Black Hat that used the gambit. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:59, 24 May 2024 (UTC)
:Maybe it's the same Cueball from the first panel, but he's had to wait so long while Black Hat fetched all the rice that his hair grew out.[[Special:Contributions/172.70.160.249|172.70.160.249]] 13:32, 24 May 2024 (UTC)

I have to wonder if this comic is related to the Casablanca Chess Tournament that took place this past week, where 4 top-ranked players competed by playing a series of real historical games starting from the middle of each game. Magnus Carlsen won the tournament, which also included Hikaru Nakamura, Viswanathan Anand, and Bassem Amin. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 04:38, 23 May 2024 (UTC)

Russia pulling out of Black Sea agreement has been labelled "grain gambit" --[[Special:Contributions/172.71.131.158|172.71.131.158]] 06:36, 23 May 2024 (UTC)

Trivia: 1. e2–e4 c7–c5 2. Sg1–f3 e7–e6 3. d2–d4 c5xd4 4. Sf3xd4 Sb8–c6 5. Sd4–b5 d7–d6 6. c2–c4 Sg8–f6 7. Sb1–c3 a7–a6 8. Sb5–a3 d6-d5!? is the Kasparov Gambit, see Wiki. [[Special:Contributions/172.71.160.30|172.71.160.30]] 08:56, 23 May 2024 (UTC)

This is a completely normal amount of rice. I eat this much grain daily. [[User:Psychoticpotato|Psychoticpotato]] ([[User talk:Psychoticpotato|talk]]) 13:21, 23 May 2024 (UTC)

Counter with Tree countergambit. plant tree(1) seeds in the first square and tree(2) on the next square then tree(3) in the next square. Nobody has found out what happens afterwards. {{unsigned ip|172.70.131.212|14:25, 23 May 2024}}

So, out of curiosity, how many grains of rice can you actually fit on an average chess board square? Or maybe, how big would a chessboard have to be in order for the rice to fit on top of every square without overflowing? [[Special:Contributions/172.69.91.144|172.69.91.144]] 22:13, 23 May 2024 (UTC)
:Assuming that its a standard size and it can stack up around 10 cubic inches upwards about 4117267200 grains [[User:Apollo11|Apollo11]] ([[User talk:Apollo11|talk]]) 03:08, 24 May 2024 (UTC)

:Judging by [https://www.instructables.com/Chess-Board-Full-of-Rice-Exponential-Growth/ this], I reckon if you were really, really patient you might just about corral the 2048 on square 12 to stay within the bounds without additional housing, but you'd have no hope with the 13th.[[Special:Contributions/172.70.90.98|172.70.90.98]] 14:25, 24 May 2024 (UTC)

Also, I noticed everyone here seems to have an ip in the 172.69.0.0 to 172.71.255.255 range, but I just checked and that's not even my ip address at the moment. What's that about? Does the wiki mask our actual ip addresses? [[Special:Contributions/172.69.90.110|172.69.90.110]] 22:29, 23 May 2024 (UTC)
:Not the wiki, but the gateways to the wiki that help with load-balancing and related connection issues. And you'll also see some IPs in the 141.x.y.z range, and others. I ''usually'' am in 171.[69-71].y.z range, but between one contribution another I might be anywhere.
:It's a known thing, for better or worse. Ultimately, there are behind-the-scenes details that would know the 'true' origin of everyone (give or take what load-balancing your own ISP also does at ''your'' side of the connection), but it's left obscured from our more plebian eyes.
:Getting a username will also remove the wider and more general geographic potshots someone can make a out your origin (the gateways seen to be used are likely to reveal ''at least'' your continent, if anyone's bothered), but I never saw the need.
:...now. I wonder under what range will the following put me..? => [[Special:Contributions/172.69.194.96|172.69.194.96]] 23:34, 23 May 2024 (UTC) 8) Postscript: I first quickly used Preview, and I actually got the 141.range, then posted for real and got the 172s. About ten seconds between the two 'postings'. Hah! [[Special:Contributions/141.101.98.129|141.101.98.129]] 23:36, 23 May 2024 (UTC)

"If exponential growth is unrestricted, it will eventually grow beyond the constraints of anything that could plausibly be built to contain it." - Given that the increase in rice grains is, itself, not plausible, I see no reason why the growth in size of rice cookers needs to be plausible either.[[Special:Contributions/141.101.98.119|141.101.98.119]] 09:59, 24 May 2024 (UTC)
:I was tempted to add something about square/cube-law (not quite applicable, as there'll be a smidgen of cubing as you raise the square-area of container material, etc, but along tbose lines), but that of course makes the implausibility threshold of the cookers higher than the same threshold of rice (everything else being equal). So then you're on to the heat-penetration abilities (after a while, the outer rice is overcooked, when the innermost rice has barely felt the heat). And that leads me to believe that something like a {{w|rotary kiln}} design might be best adopted (external heat, internalised water delivery, properly tuned, and could even be effectively pressurised with the right cycling addons to either end) to just accept rice in at a constant rate and produce perfectly cooked rice at the commensurate output rate. Of course, exponential increase in feed would then require exponential increase in parallel rotary-cookers to handle it, but starting at an already more efficient/controllable mass-cooking process than merely upscaling a traditional pot-style cooker. [[Special:Contributions/172.71.242.220|172.71.242.220]] 11:09, 24 May 2024 (UTC)

This is easily defeated. Simply counter by placing one {{w|Fox_games#Fox_and_Geese|goose}} on the 64th square, two geese on the 63rd, and so on. They'll quickly deal with the rice situation.[[Special:Contributions/172.70.163.120|172.70.163.120]] 13:39, 24 May 2024 (UTC)
:But then you need to add an increasing number of foxes starting at the first square to deal with the geese.[[User:Mathmannix|Mathmannix]] ([[User talk:Mathmannix|talk]]) 19:27, 24 May 2024 (UTC)
::And good luck taking the whole setup across a river with just a small boat! [[Special:Contributions/172.69.79.165|172.69.79.165]] 22:43, 24 May 2024 (UTC)

Correct me if I'm wrong, but assuming that the chess board is 20 inches square, the rice being stacked into a pyrimid 15 inches high, then it only works out to [https://www.wolframalpha.com/input?i=5.5+x+10%5E14+kg%2F%2820inches*20inches*15+inches*1%2F3%29 1.7x10^16 kg/m^3], which, according to Wolfram, is dwarfed by the density of a Neutron Star, much less a black hole. So is there some other reason the explanation claims it will become a black hole? Or was it just wrong [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 04:17, 25 May 2024 (UTC)

2915: Eclipse Clouds

2024-04-06T06:34:07Z

Xkcdjerry: changed funni text

{{comic
| number = 2915
| date = April 3, 2024
| title = Eclipse Clouds
| image = eclipse_clouds_2x.png
| imagesize = 526x251px
| noexpand = true
| titletext = The rare compound solar-lunar-nephelogical eclipse
}}

==Explanation==
{{incomplete|Created by CLOUDS OBSCURED BY AN ECLIPSE. Do NOT delete this tag too soon.}}

Following on from [[2914: Eclipse Coolness]], Randall makes another comic about the {{w|Solar eclipse of April 8, 2024|solar eclipse occurring on April 8, 2024}}.

[[Cueball]] is checking the weather forecast. At the time that this comic was posted, much of the eclipse path was projected to be overcast, and Cueball expresses disappointment as someone wishing to watch the Moon slowly block out the Sun (and not the clouds obscuring both). The off-panel voice points out the mild irony that he wanted to see something block out the Sun, so the clouds technically fit his wish, leading Cueball to exclaim that he has a specific taste for things blocking the Sun.

The title-text references the 'alignment' of Sun, Moon ''and'' cloud (Nephele [νεφέλη] is Greek for cloud), describing it as rare, although this is not really as desirable as it might make it sound. Sun/Moon conjunctions are already quite rare, so that the balance against Sun/Moon/no-cloud probabilities isn't really so notable. In theory, it should equal being the difference between cloud and no-cloud on any average day for your chosen location. In practice, scholars such as {{w|Murphy's law|Edward A. Murphy}} and {{w|Finagle's law|Finagle}} would argue that conjunctions of the Sun, Moon, and clouds are considerably more likely than a Sun/Moon conjunction occurring on a sunny day.

Note, as of the posting of this comic the weather reports had consistently shown the Eclipse path in Northern Vermont, New Hampshire and Maine, the points nearest to Randall's actual home in Cambridge, MA, to have the best potential viewing in the country with near 0% projected cloud cover. While this should in theory negate Randall's anxiety, the historical forecast called for a 75% chance of cloud cover and may have prompted Randall to make other plans like visiting friends or family in sunnier portions of the eclipse path like Texas. Randall may therefore be still faced with the choice of altering his eclipse viewing plans, even if the situation technically favors New England.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball sits on an office chair at a desk, typing at his laptop.]
:Cueball: These eclipse weather forecasts are killing me.
:Laptop: ''refresh''

:[Cueball remains at his desk. An off-panel voice from the left speaks.]
:Off-panel voice: So you really want to see something block out the sun...

:[Cueball is still at his desk.]
:Off-panel voice: ...But not a cloud. It has to be the Moon specifically.
:Cueball: '''''My tastes are very singular!'''''

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Weather]]
[[Category:Astronomy]]
[[Category:Solar eclipses]]

2883: Astronaut Guests

2024-01-21T02:49:45Z

Xkcdjerry: Better comparison

{{comic
| number = 2883
| date = January 19, 2024
| title = Astronaut Guests
| image = astronaut guests 2x.png
| imagesize = 331x391px
| noexpand = true
| titletext = They didn't bring us a gift, but considering the kinetic energy of a bottle of wine at orbital speed, that's probably for the best.
}}

==Explanation==
{{incomplete|Created by SIX ASTRONAUTS OVER YOUR HEAD RIGHT NOW - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Cueball]], [[Megan]], [[Ponytail]], and [[Hairbun]] can all be seen eating dinner together. Presumably, Ponytail and Hairbun were invited over for dinner, as, to impress them, [[Cueball]] misleadingly claims that they previously "had six {{w|astronauts}} over for dinner." Normally, this would be interpreted as the astronauts being friends with the hosts (which confers social prestige), going inside their house, and eating. As it turns out, the astronauts actually only briefly passed overhead while in {{w|orbit}}, and, by chance, this happened during dinnertime. This is a pun on the word "over", as the personnel of the {{w|International Space Station}} are overhead when it passes above you— yet they did not go "over ''to'' someone's house" in the sense that English speakers would usually assume.

Cueball may also be considering the property lines to extend up indefinitely (just like in "What If?" article "{{what if|161|Star Ownership}}"), causing the astronauts to technically be at their house despite being hundreds of miles away, vertically. The astronauts in question were presumably occupying the International Space Station, which has an orbital period of between 90 and 93 minutes (depending on its altitude) or 5400 to 5580 seconds.[https://eol.jsc.nasa.gov/Tools/orbitTutorial.htm] If the astronauts were "over" for 7½ milliseconds, that would be somewhere between 1.34x10⁻⁶ and 1.39x10⁻⁶ of an orbit. Earth's circumference (at the equator) being approximately 40,000 kilometers (24,850 miles), the station was apparently "over" for a ground distance of between 53.9 m and 55.7 m (177 to 183 feet). That would imply quite a large property, but may also take into account the locations of the astronauts within the ISS, which is 109 m (356 feet) long (before considering the much smaller [[1276: Angular Size|angular size]] with respect to the ground).

The caption makes Cueball's statement even less impressive, alleging that statements like it are correct in a lot of places. This would make it not even interesting as a {{w|coincidence}}. Though it can only happen for latitudes of less than 51.64° north or south, which is as far as the orbital inclination of the ISS takes it, leaving almost 21.6% of the Earth's surface never directly 'over'ed.

The title text suggests that Cueball didn't want a gift (a bottle of wine) from the astronauts. The kinetic energy of a 1.2 kg (full) bottle of wine traveling at the linear velocity of the International Space Station (8000 m/s) is on the order of [https://www.wolframalpha.com/input?i=1%2F2*%288km%2Fs%29%5E2*1.2kg 40,000 kilojoules] (40 megajoules). For comparison, the kinetic energy of a fully loaded semi-truck (max legal weight 80,000 pounds) at 70mph (a typical highway speed limit for passenger cars) is around [https://www.wolframalpha.com/input?i=1%2F2*%28110km%2Fh%29%5E2*80000+pounds 17 megajoules]. A bottle with more than double the kinetic energy of that would be hard to keep on the table, and would likely do damage to people or things that tried to keep it there. {{Citation needed}}

This comic was posted the same day as the American release of a film set on the ISS (conveniently named ''{{w|I.S.S. (film)|I.S.S.}}'').

==Transcript==
{{incomplete transcript}}
:[Cueball, Megan, Ponytail, and Hairbun are eating around a table. Cueball is leaning on the back of his chair and has his palm out.]
:Cueball: We don't have houseguests often, but we once had six astronauts over for dinner.
:Hairbun: Oh, wow!
:Cueball (muttering): ''…for 7½ milliseconds in mid-August 2012.''

:[Caption below the panel:]
:If you spend enough time looking at orbital records and property lines, you can make this claim in a lot of places.

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Ponytail]]
[[Category: Comics featuring Megan]]
[[Category: Comics featuring Hairbun]]
[[Category: Space]]

2883: Astronaut Guests

2024-01-21T02:39:16Z

Xkcdjerry: Added wolfram link for kinetic energy calcuations

{{comic
| number = 2883
| date = January 19, 2024
| title = Astronaut Guests
| image = astronaut guests 2x.png
| imagesize = 331x391px
| noexpand = true
| titletext = They didn't bring us a gift, but considering the kinetic energy of a bottle of wine at orbital speed, that's probably for the best.
}}

==Explanation==
{{incomplete|Created by SIX ASTRONAUTS OVER YOUR HEAD RIGHT NOW - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Cueball]], [[Megan]], [[Ponytail]], and [[Hairbun]] can all be seen eating dinner together. Presumably, Ponytail and Hairbun were invited over for dinner, as, to impress them, [[Cueball]] misleadingly claims that they previously "had six {{w|astronauts}} over for dinner." Normally, this would be interpreted as the astronauts being friends with the hosts (which confers social prestige), going inside their house, and eating. As it turns out, the astronauts actually only briefly passed overhead while in {{w|orbit}}, and, by chance, this happened during dinnertime. This is a pun on the word "over", as the personnel of the {{w|International Space Station}} are overhead when it passes above you— yet they did not go "over ''to'' someone's house" in the sense that English speakers would usually assume.

Cueball may also be considering the property lines to extend up indefinitely (just like in "What If?" article "{{what if|161|Star Ownership}}"), causing the astronauts to technically be at their house despite being hundreds of miles away, vertically. The astronauts in question were presumably occupying the International Space Station, which has an orbital period of between 90 and 93 minutes (depending on its altitude) or 5400 to 5580 seconds.[https://eol.jsc.nasa.gov/Tools/orbitTutorial.htm] If the astronauts were "over" for 7½ milliseconds, that would be somewhere between 1.34x10⁻⁶ and 1.39x10⁻⁶ of an orbit. Earth's circumference (at the equator) being approximately 40,000 kilometers (24,850 miles), the station was apparently "over" for a ground distance of between 53.9 m and 55.7 m (177 to 183 feet). That would imply quite a large property, but may also take into account the locations of the astronauts within the ISS, which is 109 m (356 feet) long (before considering the much smaller [[1276: Angular Size|angular size]] with respect to the ground).

The caption makes Cueball's statement even less impressive, alleging that statements like it are correct in a lot of places. This would make it not even interesting as a {{w|coincidence}}. Though it can only happen for latitudes of less than 51.64° north or south, which is as far as the orbital inclination of the ISS takes it, leaving almost 21.6% of the Earth's surface never directly 'over'ed.

The title text suggests that Cueball didn't want a gift (a bottle of wine) from the astronauts. The kinetic energy of a 1.2 kg (full) bottle of wine traveling at the linear velocity of the International Space Station (8000 m/s) is on the order of [https://www.wolframalpha.com/input?i=1%2F2*%288km%2Fs%29%5E2*1.2kg 40,000 kilojoules] (40 megajoules). For comparison, the kinetic energy of a typical car at highway speeds is 200~900 kilojoules. A bottle with roughly 120 times the kinetic energy of a speeding car would be hard to keep on the table, and would likely do damage to people or things that tried to keep it there. {{Citation needed}}

This comic was posted the same day as the American release of a film set on the ISS (conveniently named ''{{w|I.S.S. (film)|I.S.S.}}'').

==Transcript==
{{incomplete transcript}}
:[Cueball, Megan, Ponytail, and Hairbun are eating around a table. Cueball is leaning on the back of his chair and has his palm out.]
:Cueball: We don't have houseguests often, but we once had six astronauts over for dinner.
:Hairbun: Oh, wow!
:Cueball (muttering): ''…for 7½ milliseconds in mid-August 2012.''

:[Caption below the panel:]
:If you spend enough time looking at orbital records and property lines, you can make this claim in a lot of places.

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Ponytail]]
[[Category: Comics featuring Megan]]
[[Category: Comics featuring Hairbun]]
[[Category: Space]]

2883: Astronaut Guests

2024-01-21T02:27:43Z

Xkcdjerry: Updated kinetic energy comparison to something roughly the same order of magnitude, also added a citation needed

{{comic
| number = 2883
| date = January 19, 2024
| title = Astronaut Guests
| image = astronaut guests 2x.png
| imagesize = 331x391px
| noexpand = true
| titletext = They didn't bring us a gift, but considering the kinetic energy of a bottle of wine at orbital speed, that's probably for the best.
}}

==Explanation==
{{incomplete|Created by SIX ASTRONAUTS OVER YOUR HEAD RIGHT NOW - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Cueball]], [[Megan]], [[Ponytail]], and [[Hairbun]] can all be seen eating dinner together. Presumably, Ponytail and Hairbun were invited over for dinner, as, to impress them, [[Cueball]] misleadingly claims that they previously "had six {{w|astronauts}} over for dinner." Normally, this would be interpreted as the astronauts being friends with the hosts (which confers social prestige), going inside their house, and eating. As it turns out, the astronauts actually only briefly passed overhead while in {{w|orbit}}, and, by chance, this happened during dinnertime. This is a pun on the word "over", as the personnel of the {{w|International Space Station}} are overhead when it passes above you— yet they did not go "over ''to'' someone's house" in the sense that English speakers would usually assume.

Cueball may also be considering the property lines to extend up indefinitely (just like in "What If?" article "{{what if|161|Star Ownership}}"), causing the astronauts to technically be at their house despite being hundreds of miles away, vertically. The astronauts in question were presumably occupying the International Space Station, which has an orbital period of between 90 and 93 minutes (depending on its altitude) or 5400 to 5580 seconds.[https://eol.jsc.nasa.gov/Tools/orbitTutorial.htm] If the astronauts were "over" for 7½ milliseconds, that would be somewhere between 1.34x10⁻⁶ and 1.39x10⁻⁶ of an orbit. Earth's circumference (at the equator) being approximately 40,000 kilometers (24,850 miles), the station was apparently "over" for a ground distance of between 53.9 m and 55.7 m (177 to 183 feet). That would imply quite a large property, but may also take into account the locations of the astronauts within the ISS, which is 109 m (356 feet) long (before considering the much smaller [[1276: Angular Size|angular size]] with respect to the ground).

The caption makes Cueball's statement even less impressive, alleging that statements like it are correct in a lot of places. This would make it not even interesting as a {{w|coincidence}}. Though it can only happen for latitudes of less than 51.64° north or south, which is as far as the orbital inclination of the ISS takes it, leaving almost 21.6% of the Earth's surface never directly 'over'ed.

The title text suggests that Cueball didn't want a gift (a bottle of wine) from the astronauts. The kinetic energy of a 1.2 kg (full) bottle of wine traveling at the linear velocity of the International Space Station (8000 m/s) is on the order of 40,000 kilojoules (kJ). For comparison, the kinetic energy of a typical car at highway speeds is 200~900 kJ. A bottle with roughly 120 times the kinetic energy of a speeding car would be hard to keep on the table, and would likely do damage to people or things that tried to keep it there. {{Citation needed}}

This comic was posted the same day as the American release of a film set on the ISS (conveniently named ''{{w|I.S.S. (film)|I.S.S.}}'').

==Transcript==
{{incomplete transcript}}
:[Cueball, Megan, Ponytail, and Hairbun are eating around a table. Cueball is leaning on the back of his chair and has his palm out.]
:Cueball: We don't have houseguests often, but we once had six astronauts over for dinner.
:Hairbun: Oh, wow!
:Cueball (muttering): ''…for 7½ milliseconds in mid-August 2012.''

:[Caption below the panel:]
:If you spend enough time looking at orbital records and property lines, you can make this claim in a lot of places.

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Ponytail]]
[[Category: Comics featuring Megan]]
[[Category: Comics featuring Hairbun]]
[[Category: Space]]

2829: Iceberg Efficiency

2023-09-16T13:31:47Z

Xkcdjerry: Fixed funni text

{{comic
| number = 2829
| date = September 15, 2023
| title = Iceberg Efficiency
| image = iceberg_efficiency_2x.png
| imagesize = 649x251px
| noexpand = true
| titletext = Our experimental aerogel iceberg with helium pockets manages true 100% efficiency, barely touching the water, and it can even lift off of the surface and fly to more efficiently pursue fleeing hubristic liners.
}}

==Explanation==
{{incomplete|Created by A 90% EFFICIENT ICEBERG. Do NOT delete this tag too soon.}}

This comic humorously plays with the idea of efficiency in a typically absurd and satirical "Black Hat" fashion. Black Hat starts by critiquing traditional {{w|iceberg}}s, which are mostly hidden underwater, as inefficient. Efficiency is typically measured in relation to a desired outcome or purpose; Black Hat seems to imply that the obvious purpose for icebergs is to be seen above the water. He then presents his solution - a foam-filled iceberg that floats almost entirely above the water, claiming it to be highly efficient.

Black Hat's idea is absurd. Icebergs are naturally formed structures, and his proposal to create a "foam-filled iceberg" is not only impractical but also comically exaggerated.

Black Hat then absurdly suggests that his lightweight iceberg can still pose a threat to ocean liners (as if that's the "purpose" of icebergs – in the 20th century, at least six ships sank directly as a result of iceberg collisions, famously the ''Titanic'') through the use of torpedoes. In addition, given that Black Hat is promoting the idea that icebergs ''should'' be able to damage ships, it's not really so inefficient to have much of the iceberg underwater, since ocean liners also have a significant portion of their hulls underwater, which can be damaged by an iceberg. The second panel shows that the foam-filled iceberg has a small attachment underneath it, which is apparently a turret for launching torpedoes.

The unnamed individuals in the last panel are clearly baffled and concerned.

The title text introduces the concept of an "experimental aerogel iceberg with helium pockets." {{w|Aerogel|Aerogels}} are a class of solid, porous materials known for their extremely low density (making them among the lightest solid materials yet synthesized). Their low density should make them float well in liquids, though their low mass and their porous and brittle material properties make them unsuitable as a ramming implement. The structure of an aerogel surrounds pockets of air, leaving spaces that could be infused with a specific gas such as Helium. {{w|Helium|Helium}} is lighter than air, and is often used to make gas-filled objects such as balloons float. An aerogel iceberg infused with helium gas could theoretically hover or fly like a balloon as suggested in the comic. This idea of producing a man-made flying iceberg for the sole purpose of endangering cruise liners, would likely be seen as preposterous, as more practical or direct methods of attacking such vessels exist{{citation needed}}, thereby adding an extra layer of exaggerative humor to the comic.

The mention of this high-tech iceberg being able to "more efficiently pursue fleeing hubristic liners" is a playful nod to the comic's theme of optimizing icebergs for efficiency. It implies that not only can this special iceberg float efficiently, but it's also equipped to chase after and "efficiently pursue" arrogant or prideful ocean liners, turning the concept of iceberg efficiency into a surreal scenario. The "hubris" alludes to the (possibly apocryphal) quote "God himself couldn't sink this ship," and similar sentiments expressed in reference to the ocean liner {{w|Titanic}}, which struck an iceberg and sank with many casualties.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Black Hat is holding a stick and standing next to an image of an iceberg halfway submerged in water, presenting to an unseen audience.]
:Black Hat: A standard iceberg is only 10% efficient.
:Black Hat: 90% of the ice is hidden underwater, totally wasted.

:[Black Hat is now standing next to an image of the same iceberg, with another "iceberg" almost entirely above the surface of the water to the right of it.]
:Black Hat: Our next-generation foam-filled iceberg achieves near-100% efficiency, floating almost entirely above the ocean surface.

:[Black Hat is still holding a stick, but is standing next to nothing. There are no other people directly shown, but three distinct 'off-frame' voices are indicated.]
:Black Hat: "But wait," you might be thinking. "How will such a lightweight iceberg pose a threat to hubristic ocean liners?"
:Black Hat: That's where the torpedoes come in.
:Off-panel voice 1: I'm sorry, what project are you part of, again?
:Off-panel voice 2: I assumed he was with you.
:Off-panel voice 3: Security?

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Physics]]

Talk:2812: Solar Panel Placement

2023-08-08T15:38:18Z

Xkcdjerry: New idea to balance out gravity and increase efficiency.

Can someone smarter than me do the math on running power lines to a panel on the sun? How long until it would pay for itself?[[Special:Contributions/172.70.214.125|172.70.214.125]] 05:08, 8 August 2023 (UTC)
:$22 million / $0.20 per kWH = 110 million kWH, divide by hours in a year and you get about 12549 kW. Google says the sun is 150 million KM away. IDK the exact details, but a calculator I found online suggests a copper cable with a cross-sectional area of 10m^2 can handle that amount of power transported 150 million KM. The density of copper's about 9 cm/g^3. 150 million km * 10 m^2 * 9 g/cm^3 = 1.35 * 10^16 kg. The cost to get one kilogram to Low-Earth Orbit according to google is >$10,000, let's just use that. Total cost to get to LEO: $1.35 * 10^20. Divide by profit per year => 6.1 trillion years. [[User:Tiln|Tiln]] ([[User talk:Tiln|talk]]) 07:10, 8 August 2023 (UTC)
::"The cost to get one kilogram to Low-Earth Orbit [...], let's just use that." Ummm... It's actually easier to ''leave'' the solar system than to rendezvous with Mercury (never mind attain even closer stability to the Sun's surface).
::I supose you could always go to an orbit a very long way away (near solar-escape) and add a little extra reverse delta-V to zero your orbital movement and then fall down. But you must not miss the pinprick Sun, or you're in a highly elliptic comet-like trajectory (with even higher demands needed to circularise at perihelion), so you need to be very precise about stopping and dodging through the gravity wells of any planets you plunge past. Not that ''not'' missing is going to do you much good, either.
::...hmmm, hang on, maybe that's what the cables back to Earth are for. Spooled in/out just at the right rate (perhaps some bungee-chord included), it's how you stop ''just above'' the Sun's surface (at the limit of the conductive cable, then cut the retarding bungee just as you're stable enough at the bottom of the bounce!) and stay there. Ok, not a problem. It'll work after all{{Actual citation needed}} and I withdraw all my petty objections! [[Special:Contributions/172.71.242.82|172.71.242.82]] 10:43, 8 August 2023 (UTC)
::: And then you'll have to deal with the end of the bungee cord retracting under it's own tension... and since it's no longer tethered to the craft it would probably whip back towards Earth. As an afterthought, have you ever been whipped by a released rubber band? Imagine that... but at a cosmic scale. I'd probably take my chances with the cables. [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 14:39, 8 August 2023 (UTC)

Congrats, you've just made the universe's smallest Dyson sphere component! [[Special:Contributions/162.158.2.38|162.158.2.38]] 07:33, 8 August 2023 (UTC)

I'd just like to point out an error in Randall's math:
The light incident on the panel would only be from the portion of the surface with line-of-sight to the panel. This fraction is called the "view factor", and has its own Wikipedia page, which I'm too lazy to link since I'm editing this on my phone. Carry on! [[Special:Contributions/172.70.126.217|172.70.126.217]] 13:26, 8 August 2023 (UTC)
:I thought Sun luminosity (total outgoing light, in all directions from all points of itsvsurface) divided by Sun area (total luminescing surface area) multiplied by the 1m² (the actual 'capturable' parts normalised to the effectively-in-contact portion of the Sun exactly in the way you're defining the view factor.
:Further out, distance from the Sun factors in as an inverse square relationship, but it'll be negligable when you're practically at the Surface and close to the full 2pi steradian of incident light from a significantly greater area of emitting surface than the unit-area of receiving surface. Once you're at Earth-orbit distance, it's a tad below 70 nanosteradian of "panel view" and almost none of the light even from the directly facing square metre of Sun even comes close to the even smaller solid angle subtending the outwards spread of light.
:Set your panel at the height of various solar-surface features, you might not intercept much of the light (hence division by Sun's area) yet what you'll capture will be significant. Probably well beyond any long-(/medium-, perhaps even short-)term survivability of a lump of plastic, silicon and metals normally stuck on a house roof. [[Special:Contributions/172.70.91.161|172.70.91.161]] 15:36, 8 August 2023 (UTC)

I was briefly confused because HVAC usually stands for heating, ventilation, and air conditioning, but is here used to mean high-voltage alternating current. [[Special:Contributions/172.69.247.50|172.69.247.50]] 13:31, 8 August 2023 (UTC)
:I often have the ''opposite'' confusion... ;) [[Special:Contributions/172.70.91.161|172.70.91.161]] 15:36, 8 August 2023 (UTC)

I ran some calculations on using rechargeable batteries to get power from the Sun to Earth, full markdown file is [https://github.com/xkcdjerry/markdown-pages/blob/main/explainxkcd-2812-talk-calcuations.md here] is anyone to check it out.

TL;DR: it's ''way'' better than running powerlines to Earth but falls slightly shy of putting a panel on Earth, though that may be remedied by more precise data. [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 15:09, 8 August 2023 (UTC)

: New idea: maybe we can make some sort of belt in which one side has fully discharged batteries and the other has fully charged ones, so that gravity balanced out and we only need to do work against friction, that should raise the efficiency greatly, with some engineering we might get it above 0.1% or even 1%, however I don't have exact data on this so this remains the work of someone with more knowledge than me XD [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 15:38, 8 August 2023 (UTC)

Talk:2812: Solar Panel Placement

2023-08-08T15:29:17Z

Xkcdjerry: Fix calcuations and update TL;DR to fit

2812: Solar Panel Placement

2023-08-08T15:14:20Z

Xkcdjerry: Rechargable batteries

{{comic
| number = 2812
| date = August 7, 2023
| title = Solar Panel Placement
| image = solar_panel_placement_2x.png
| imagesize = 506x364px
| noexpand = true
| titletext = Getting the utility people to run transmission lines to Earth is expensive, but it will pay for itself in no time.
}}

==Explanation==
{{incomplete|Created by an underpaid solar panel installer - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

{{w|Solar panels|Solar panels}} are a relatively common method of supplying/augmenting power for uses from calculators to factories. They work by gathering solar energy reaching the Earth from the Sun and converting it to electricity. More specifically, they absorb vast amounts of photons from the solar rays and use them to knock electrons free. Those electrons produce the flow of electric current around the circuit and convey power onwards to where it is needed.

This comic proposes a solution to the issue of solar panels not generating enough power due to basic physical limitations. Solar panels on Earth have multiple things reducing their efficacy, such as their distance from the Sun as well as atmospheric effects reducing the intensity of light hitting them and the fact that for half of the time they can't generate any power because their position on the Earth is facing away from the Sun. Putting your solar panels in a close orbit above the Sun would eliminate most, if not all, of these issues (and is a partial implementation of the concept of a {{w|Dyson sphere}}, theorised by scientists and used in science fiction). However putting solar panels on the surface of the Sun, as suggested here, introduces many new problems that can negatively impact their energy generating capacity, such as transmission losses and more undesirable effects from their proximity to the Sun, including total destruction of the panels.

The cost-effectiveness of solar panels is a complex topic, involving [https://www.energy.gov/eere/solar/solar-performance-and-efficiency efficiency], installation, and even costs of [https://cen.acs.org/environment/recycling/Solar-panels-face-recycling-challenge-photovoltaic-waste/100/i18 recycling at end-of-life]. The comic demonstrates a simplified calculation, where a solar panel of 1m2 is estimated to return electricity equivalent to around $58/year, using 20% as the efficiency of conversion of sunlight to electricity for an otherwise optimally roof-installed solar panel unit.

To solve this, Randall here proposes a rather more direct solution: place the identical solar panel ''downwards'', on and towards the Sun, rather than ''upwards'' (upon a suitable equitorially-facing sloping roof), from the surface of the Earth. This gives access to substantially more light energy and would (through naïve upscaling of the power flux available, ignoring a number of technical issues) produce greatly increased amounts of energy for the owner.

The title text acknowledges ''some'' difficulties, but hand-waves them away as being surmountable and entirely worthwhile given the theoretical income generated. This may or may not be true, but is actually extremely unlikely at the end of the economies of scale whereby an individual is expected to make their own best use of a single solar panel. Perhaps in this case a better interpretation of "in no time" is "never".

Given that standard transmission losses (for long distance HVAC power lines) are [https://iea-etsap.org/E-TechDS/PDF/E12_el-t&d_KV_Apr2014_GSOK.pdf around 3% per 1000 km] and the Sun is 150 million km away, the energy reaching the Earth would be 0.97^(150000), a truly negligible amount (10^-1985 of the input energy). In this case, you'd be better off literally sending huge packs of rechargeable batteries to Earth.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Heading:] Option A:

:[A stereotypical house with a single solar panel upon its roof and an arrow from a label:] 1 m2 (south-facing)

:[Formula:] ($0.20/kWh)×(4 kWh/m2/day)×(1 m2)×20% = <big>$58/year</big>

:[Heading:] Option B:

:[A short width of the Sun's undulating 'surface', with two solar prominances/flares and at their height (but above a different part of the surface) a solar panel with some attachment upon its upper surface, depicted horizontally aligned to the Sun and with an arrow from a label:] 1 m2 (downward)

:[Formula:] ($0.20/kWh)×(sun luminosity/sun area)×(1 m2)×20% = <big>$22 million/year</big>

:[Caption below the panel:]
:Solar energy tip: To maximize sun exposure, always orient your panels downward and install them on the surface of the sun.

{{comic discussion}}

[[Category:Tips]]

Talk:2812: Solar Panel Placement

2023-08-08T15:09:02Z

Xkcdjerry: Some calcuations and a link

Talk:2812: Solar Panel Placement

2023-08-08T14:39:11Z

Xkcdjerry: No bungee cord please

User:Xkcdjerry

2023-03-24T02:02:20Z

Xkcdjerry: blank page

Talk:2750: Flatten the Planets

2023-03-18T12:48:25Z

Xkcdjerry: Added calcuation of bearing size, Randall seems to be serious about astroid belt bearings

I have to wonder, would you slide down to the sun, or be flung outwards? [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 19:39, 15 March 2023 (UTC)
: The discs are centered on the orbit of the parent planet, and presumably rotating at the same frequency as the parent planet's orbit. That means the inner edge of each disc is going slower than you'd need to orbit the Sun at that distance, and the outer edge faster. If you moved inward from the original planet's orbit, the Sun's gravity would pull you in, but when you crossed the boundary to the next disc, you'd get flung back outward.[[Special:Contributions/162.158.62.61|162.158.62.61]] 19:58, 15 March 2023 (UTC)
::No Each planet fills out the space within their orbit into the next planet. Easy to see as the outer edge of Neptune's orbit is the same as with the planet flattened. There is a distance from Mercury to the Sun indicated. Maybe because it would melt if it got any closer? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:03, 15 March 2023 (UTC)
:::Take another look at the top and bottom images, you'll notice that the Neptune disc is significantly larger than Neptune's orbit (especially on the left hand side of the image). I suspect that, as the other response suggested Mercury and Neptune takes the inner edge of the disc as the average between Neptune and Uranus's orbital radii, and then the outer radius the same distance on the other side of Neptune's orbit. Similar for Mercury.
:::First, they're rings not discs, but I'm skeptical of the math. And it looks to me like the ring's edges are halfway between the orbits, with Neptune extended outwards the same distance as halfway to Uranus's orbit. [[Special:Contributions/172.69.22.4|172.69.22.4]] 20:08, 15 March 2023 (UTC)

{{cot|My mistake, Randall's math is correct, sorry.}}

{| class="wikitable" style="text-align: right;"
|-
! Planet !! Volume (109 km3) !! Orbital radius (106 km) || halfway to prior || halfway to next || Annulus area (10<s>9</s> ''12'' OOPS! km2) || Thickness (<s>cm</s> ''10s of microns'')
|-
| Mercury || 61 || 58 || 29 (to 0) || 83 || 19,000 || 321
|-
| Venus || 928 || 108 || 83 || 129 || 30,637 || 3,029
|-
| Earth || 1,083 || 150 || 129 || 189 || 59,942 || 1,802
|-
| Mars || 163 || 228 || 189 || 504 || 685,794 || 24
|-
| Jupiter || 1,4310,00 || 779 || 504 || 1,107 || 3,051,847 || 46,890
|-
| Saturn || 827,130 || 1,434 || 1,107 || 2,154 || 10,726,236 || 7,711
|-
| Uranus || 68,340 || 2,873 || 2,154 || 3,684 || 28,061,145 || 244
|-
| Neptune || 62,540 || 4,495 || 3,684 || 5,304 (symmetry) || 45,743,348 || 137
|}

:::: The volumes in this table are at 2 different scales. Only the Mercury to Mars volumes are at 1010 km3. Jupiter to Neptune are at 1012 km3 [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 21:01, 15 March 2023 (UTC)
::::: Thanks, fixed; I had the scale wrong for the radii too. [[Special:Contributions/172.71.158.231|172.71.158.231]] 21:16, 15 March 2023 (UTC)
:::Someone please double-check this, I think Randall is off by a factor of 1000. [[Special:Contributions/172.71.154.229|172.71.154.229]] 21:37, 15 March 2023 (UTC)
:::: I did my own spreadsheet, and my figures agree with Randall's (roughly). I think your thinkness figures are mostly out by 1000, and a few of your volume figures also have the wrong scale (Mercury is smaller than Mars, and the giants are too big by a factor of 10). [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 22:07, 15 March 2023 (UTC)
::::: 61 * 10^9 km^3 is [https://www.google.com/search?q=61+*+10%5E9+km%5E3+in+cm%5E3 6.1 × 10^25 cm^3], 19000 * 10^9 km^2 is [https://www.google.com/search?q=19000+*+10%5E9+km%5E2+in+cm%5E2 1.9 × 10^23 cm^2], and (6.1 × 10^25 cm^3) / (1.9 × 10^23 cm^2) is [https://www.google.com/search?q=%286.1+%C3%97+10%5E25+cm%5E3%29+%2F+%281.9+%C3%97+10%5E23+cm%5E2%29 3.2 meters]. I'm afraid I'm correct. [[Special:Contributions/172.69.22.145|172.69.22.145]] 22:31, 15 March 2023 (UTC)
::::: According to {{w|List_of_Solar_System_objects_by_size#Objects_with_radius_over_400_km}} yes I had Mars wrong (corrected) but the others are roughly correct. I stand by my claim that Randall is in error. [[Special:Contributions/172.71.154.86|172.71.154.86]] 22:39, 15 March 2023 (UTC)
:::::: Mercury's orbital radius is about 58 * 106 km, not 58 * 109 km, which makes the annulus' area 19000 1012 km2. [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 23:20, 15 March 2023 (UTC)
::::::: I fixed that label, hold on... [[Special:Contributions/172.71.154.86|172.71.154.86]] 23:30, 15 March 2023 (UTC)
::::::: You're right. Thanks. Sorry. Reverted on main. [[Special:Contributions/172.71.154.215|172.71.154.215]] 23:39, 15 March 2023 (UTC)

|} 

This makes about as much sense as other Flat Earth theories. [[Special:Contributions/172.70.200.137|172.70.200.137]] 20:00, 15 March 2023 (UTC)
:But this would actually be a flat Earth. Albeit with a rather larger surface area ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:03, 15 March 2023 (UTC)
:And..the Earth-ring is not a disc and it's also in the same plane as the sun. Meaning If you were to stand on the surface of this ring earth , there would be a perpetual sunrise / sunset... And similar for everything else in the plane of the ecliptic. [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:36, 16 March 2023 (UTC)

But what does the plot of surface gravity vs distance from the Sun look like? Gravity of an infinite plane and all that?--[[User:Brossa|Brossa]] ([[User talk:Brossa|talk]]) 00:01, 16 March 2023 (UTC)

The explanation currently says that it would require "several solar system's worth" of matter, but isn't there enough matter in the actual solar system? --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 00:49, 16 March 2023 (UTC)
:That was said in reference to the Alderson Disk, which requires 1000km or so of thickness. Clearly more than the proposal here that gives a minute thickness (relatively) from the ''actual'' planetary mass in the solar system. Even if you reduced its extent (smaller outer, bigger hole for the Sun) it wouldn't thicken up enough. The prior (non-xkcd) version would require a mass of material rivaling, if not exceeding, that of the Sun itself. [[Special:Contributions/172.70.162.222|172.70.162.222]] 02:07, 16 March 2023 (UTC)

One of the reasons NASA rejected this could've been the use of inches. [[Special:Contributions/172.71.102.13|172.71.102.13]] 02:26, 16 March 2023 (UTC)
: Except for Mars. I can only imagine that use of the metric system for the Mars ring is a reference to the [https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure Mars Climate Orbiter] fiasco, which certainly would not endear Randall, or his proposal, to a NASA granting agency program officer. [[Special:Contributions/172.70.214.150|172.70.214.150]] 02:45, 16 March 2023 (UTC)
:: I assume the use of microns there is simply because 5/512 is a really awkward fraction. [[Special:Contributions/172.71.223.25|172.71.223.25]] 05:48, 16 March 2023 (UTC)
::: Awkward? Its vulgar! [[Special:Contributions/172.70.162.56|172.70.162.56]] 08:05, 16 March 2023 (UTC)
:: Oh right, the Mars Climate Orbiter reference makes sense! I was wondering why Randall would mix imperial and metric units like that. No sane physicist would do that, especially not Randall. [[Special:Contributions/172.71.250.88|172.71.250.88]] 12:52, 16 March 2023 (UTC)
::: And Randall rubs more salt into the wound by using "micron", when the formal/correct SI unit name is "micrometer".[[Special:Contributions/172.70.206.187|172.70.206.187]] 17:13, 16 March 2023 (UTC)

If the planets of the solar system were to become disks centered on the respective planet's current orbit, how do we deal with the different orbital eccentricities? For example, per That Other Wiki, Venus has an orbital eccentricity of 0.006772, Earth has 0.0167086, and Mars has 0.0934. Not to mention Neptune's 0.008678 and Pluto's 0.2488; Pluto's orbit actually crosses Neptune's. Surely that would cause issues with the disks? [[Special:Contributions/172.71.98.5|172.71.98.5]] 08:33, 16 March 2023 (UTC)
:Pluto isn't involved, so at least that difficulty doesn't have to be dealt with. Maybe Pluto and other dwarf planets could be used to supplement the asteroid ball bearings.[[Special:Contributions/172.71.242.63|172.71.242.63]] 10:55, 16 March 2023 (UTC)

It appears that there is enough material in the asteroid belt to do this, since a ring of asteroid ball bearings with a 1 trillion kilometer diameter where each ball bearing was a cube 1 meter by 1 meter (clearly more than enough!) would be less than 10 trillion cubic meters. Since the total mass of the asteroid belt is 10^21 kg, and the average density is around 2 g/cm^3, = 2000 kg/m^3, then the amount of matter required is 2,000*10 trillion = 2 quadrillion which is much less than 10^21. (Not sure if this is actually correct) --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 12:17, 16 March 2023 (UTC)
:Ahh yes, the classic cubic-bearing. Just what we need in this planetary ring system we've created. Since Randall elects to eschew spheres for the planets, let's go all in and refuse them for the bearings as well. Bravo. ;-) [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:40-12:47, 16 March 2023 (UTC) 
::''I just want to say that this line of logic ''really'' tickled my funnybone. Well done! ...I've got no other valid contribution at this time, just that.'' [[Special:Contributions/172.70.90.101|172.70.90.101]] 13:11, 16 March 2023 (UTC)
::That was to further overestimate the material needed, since a cube is more mass than a sphere. --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 15:09, 16 March 2023 (UTC)
Did anyone notice that this came out just after pi-day? [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:40, 16 March 2023 (UTC)
: That's really crusty of Randall. It does explain the rolling pin. He probably also knows, and chooses (for cause) not to disclose, that pronunciation of the Greek letter as "pie" [https://www.dude-n-dude.com/2023/03/14/amoebas-lorica-14-march-icymi/ doesn't conform to modern language usage]. [[Special:Contributions/162.158.90.232|162.158.90.232]] 17:01, 16 March 2023 (UTC)
:: for the same reasons outlined in the link, beta and phi are also pronounced differently, and I'm pretty sure zeta, eta, theta, xi and chi are too [[Special:Contributions/172.71.26.105|172.71.26.105]] 22:03, 16 March 2023 (UTC)Bumpf
:::Although all these terms were deliberately taken from ancient Greek, because that's when they were first proposed! I believe Pi was devised around 250 BC by the Greek mathematician Archimedes, and is sometimes called Archimedes' Constant. There is no reason to use more modern pronunciation, except to make jokes about "Pee Day", I suppose. Why are we talking of hypotheticals of Randall's knowledge and secret humor, anyways? Do we need such an elaborate justification to quote and link to this dude, "Amoebe"? Please wait til next time, next year![[User:Cuvtixo|Cuvtixo]] ([[User talk:Cuvtixo|talk]]) 22:40, 16 March 2023 (UTC)

I don't know if there's a non spoilery-way to mention that there are similar ideas explored in the novel ''Death's End'' by Liu Cixin. [[User:Nedlum|Nedlum]] ([[User talk:Nedlum|talk]]) 13:22, 16 March 2023 (UTC)

What would even happen here? Would the rings collapse into planets again? Where will the atmospheres go? Are the rings a uniform material like rock or many small pebbles? What happens at the borders? Would i be squished or will all life still be intact? If i a squished, do i have to put up with my worst enemy next to me? Will it be like the flat skins from //All Tomorrows//? Will i die? I expect to see this in «What If 2» coming out 13th october. [[Special:Contributions/172.68.134.38|172.68.134.38]] 14:31, 16 March 2023 (UTC)
:Presumably for the gas giants to hold a disc shape, the gas would have to be encased in hollow discs made out of the solid cores. How thick would the walls be? What if we used thinner cavities to store the inner planets' atmospheres as well? And how much would the core material decompress as a result of not being a core? [[User:Promethean|Promethean]] ([[User talk:Promethean|talk]]) 18:18, 16 March 2023 (UTC)
::isn't it hypothesized that they're "solid cores" are only solid because of the immense pressures? Like isn't much of Jupiter's inner core (or outer-inner core) metallic helium or something? My reading about this is outdated, but it's mentioned in the explanation that it requires "tensile strength beyond what is likely physically possible for any known form of matter." Actually I'm a little annoyed that this statement doesn't get "citation needed", rather than "planets of our solar system would not be suitable for this endeavor", because obviously if the first statement is true, the second needs no citation if the first is true, because no planet is made of unknown forms of matter. Correct?" [[User:Cuvtixo|Cuvtixo]] ([[User talk:Cuvtixo|talk]]) 22:19, 16 March 2023 (UTC)

Is there an element of Pluto discourse here? IIRC, one of the complaints about the "clearing your orbit" was that different metrics would 'punish' (for those who view the reclassification as a punishment) objects orbiting at a greater distance. I find the distribution of thicknesses really intriguing, and I wonder how the various dwarf planets at different parts of the system would stack up, thickness-wise. [newbyBoredAtWork]

I've replaced 'roller pin' with 'rolling pin' because a quick online search indicates that a roller pin facilitates relative motion, linear or rotary, between objects whereas a rolling pin is used to make a mass of material thinner, especially in culinary contexts.

I did an estmate of max 210m for the bearing sizes which is clearly enough even if I was off by a factor of a thousand, the proceedings are [https://0paste.com/448864 here] if someone wants to put it into the main article or check for errors. [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 12:48, 18 March 2023 (UTC)

Talk:2743: Hand Dryers

2023-02-28T08:05:00Z

Xkcdjerry: added comment

The mouseover text is trolling, since that would be impossible. [[Special:Contributions/172.70.200.140|172.70.200.140]] 16:23, 27 February 2023 (UTC)
:Indeed, Randall wrote about that in ''How To 2''. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 03:49, 28 February 2023 (UTC)

The Pratt & Whitney J58 is capable of producing exhaust velocities exceeding that of Mach 2 at ground level. It would be possible (though extremely inadvisable) to dry one's hands in the exhaust, at least for the brief period where one still has hands. [[Special:Contributions/172.70.115.72|172.70.115.72]] 16:44, 27 February 2023 (UTC) J. Kupec

:There are hand-sized supersonic blowers used to clean and dry train tracks. https://www.ge.com/news/reports/this-software-guided-supersonic-air-blower-sweeps They are very dangerous to exposed skin even several feet away. [[Special:Contributions/172.71.142.21|172.71.142.21]] 06:52, 28 February 2023 (UTC)

With a low enough vacuum in the surrounding area, a supersonic hand dryer should be able to apply drying without enough energy dissipation to damage the skin. [[Special:Contributions/172.69.65.184|172.69.65.184]] 17:27, 27 February 2023 (UTC)

As far as I understand it, the low velocity dryers heat the air, the high velocity ones don't, but rely on the air being compressed and air speed is of the essence. The other problem with the idea of very high speed is that 'stuff' could penetrate the skin (there is a type of needle-less vaccination gun on that principle).[[User:RIIW - Ponder it|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it|talk]]) 19:31, 27 February 2023 (UTC)

That matches my memory, the first ones I remember were fairly low airspeed and had a data tag "1500 watts" for the heating element. Has anyone tried one of these with *dry* hands, to see how long the element takes to get hot? I don't think they heat up instantly. They certainly get hot--motorcycling on cold days I've pointed the nozzle inside my clothing to warm up at a rest stop.[[Special:Contributions/172.70.111.76|172.70.111.76]] 19:40, 27 February 2023 (UTC)

I don't think this effect fully explains observations. For example, the airflow feels warmer sooner when someone has used the dryer just before you. [[User:P1h3r1e3d13|P1h3r1e3d13]] ([[User talk:P1h3r1e3d13|talk]]) 21:10, 27 February 2023 (UTC)

"though this was first achieved many decades ago, in the 1950s" Yeager broke the sound barrier in level flight on Oct. 14, 1947, and planes had been doing it in dives for years. [[User:Cser|Cser]] ([[User talk:Cser|talk]]) 21:29, 27 February 2023 (UTC)
:Without reading your comment, I further changed the (as it was for me) "1940s" version of the statement to include the original "inadvertent" barrier-breaking (of prop-planes in almost always irrecoverable dives, without control surfaces that would work well in supersonic/transonic airflows) and included the developments made, which these days are somewhat more trivial than having to sit on a rocket that is released from a high-altitude bomber's wing, and fight to keep it flying straight and level. (We even had a supersonic airliner, for several decades!) There's a lot of interesting history to this, but not really the place to say it all. [[Special:Contributions/172.70.85.57|172.70.85.57]] 01:45, 28 February 2023 (UTC)

Should we make an "airplane banner" category? [[Special:Contributions/172.70.111.76|172.70.111.76]] 02:31, 28 February 2023 (UTC) I was thinking the same thing, but I'm here about Covid (below).

Hand dryers were disabled in the early days of Covid in 2020 before hand transmission was ruled out as significant. I still feel awkward using one in a bathroom with others. I'm old and still mask when indoors publicly more than briefly. In 2023, I submit that you risk appearing hypocritical with a mask and a hand air dryer. Thus, I saw this XKCD as a reminder that hand air dryers had nothing to do with Covid. Still, there seems to be a bunch of fuss about the dryers. Apparently, some use mechanical air force (jet air) more than warm air for drying, from respectable gavi.org and wired.org in 2021 (https://www.gavi.org/vaccineswork/we-know-hand-dryers-can-circulate-germs-through-air-why-are-they-still-used and https://www.wired.com/story/wash-your-hands-but-beware-the-electric-hand-dryer/). I'm just rambling here; I'm not ready to do any editing. [[User:Bismuthfoot|Bismuthfoot]] ([[User talk:Bismuthfoot|talk]]) 04:16, 28 February 2023 (UTC)
: The alternative to dryers was often a stack of paper towels. Always a 'contact threat', in my eyes (I never really like using a shop's communal hand-sanitiser bottles, on entry, for that very reason; I just didn't touch anything, that I wasn't already taking off the shelves to take with me, if I could help it), although thankfully that wasn't a great a problem as it was initially feared.
: Ditto, the precaution of taping off every other seat (or two out of every three, etc), in order to prevent congregation of people in public seating areas. This forced every new arrival to always choose from the more limited number of pre-touched seats, rather than just advising people to randomly choose to sit only in any non-neighboured seats and so diluting the hypothetical risk.
: (I still mask up for entry to supermarkets/shops/indoor places of similar kinds. I would for buses/trains, if I used them. I'm otherwise still mostly "bubbling" with close family, or only going to places where we're mostly/all going, together or separate, but that probably equally applied before 'things changed' as well.) [[Special:Contributions/172.70.162.57|172.70.162.57]] 05:20, 28 February 2023 (UTC)

Previous usages of planes with banners: [https://www.explainxkcd.com/wiki/index.php/1965:_Background_Apps Background apps] and [https://www.explainxkcd.com/wiki/index.php/1355:_Airplane_Message Airplane Message], both of which's banners bore information and the first one commented on the cheapness of the banners. Maybe mention them in the explanation and/or add a category about them? [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 08:05, 28 February 2023 (UTC)

Talk:2737: Weather Station

2023-02-15T13:13:29Z

Xkcdjerry: added comment

I'm not sure if the comment about the spinning speed in the explanation section is needed, still, added it for clarity. Feel free to remove it if it seems out of place. [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 07:13, 14 February 2023 (UTC)

:Totally needed. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:14, 14 February 2023 (UTC)
:: It's what Randall would have done [[User:Boatster|Boatster]] ([[User talk:Boatster|talk]]) 22:28, 14 February 2023 (UTC)

''Wheeeeeeeeeeeee!'' [[User:Mushrooms|Mushrooms]] ([[User talk:Mushrooms|talk]]) 10:57, 14 February 2023 (UTC)

It would be great if the explanation also offered a comparison between Cueball's arm speed and the wind speed of most tornadoes, as knowing the speed that Cueball's spinning it at in a bid to make it think there's a tornado doesn't mean much if one doesn't know how fast tornadoes also go. --[[Special:Contributions/172.71.242.191|172.71.242.191]] 13:46, 14 February 2023 (UTC)

FYI the rain gauge in Borrowdale, Cumbria, England - reputedly the wettest place in England - is set into a wall at thigh-height, with a collecting spout. A local farmer told me that as a boy, the gauge was between the school bus drop-off and the farm, so he and his brothers used to regularly top it up by taking a p1ss....distorting weather records has a long history!
15:34, 14 February 2023 (UTC)[[Special:Contributions/172.71.178.187|172.71.178.187]] 15:34, 14 February 2023 (UTC)

:And wait until chinese weather balloons come into play ;-) --[[Special:Contributions/162.158.129.139|162.158.129.139]] 17:59, 14 February 2023 (UTC)

::They don't. That's the point of shooting them down. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:14, 14 February 2023 (UTC)
::I haven't been watching Chinese weather reports, but have they been reporting that the weather over North America is explosive? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:17, 14 February 2023 (UTC)

;Another note to user "No idea if there's a character limit..."
[https://www.explainxkcd.com/wiki/index.php?title=2693:_Wirecutter_Recommendation&diff=306271&oldid=306270 We don't put that there.] It is already below the comic. The Transcript is for things not otherwise in (non-graphical) text form, i.e. to describe only what is drawn/scrawled in the image itself. Discussions about this can be found in the Community Portal and maybe elsewhere, and you'll see that very few (if any, and ought to be none) articles have this repeated in the Transcript, reflecting the current community consensus/practice/habit. HTH, HAND. (See prior comic's Discussion, as well. I wrote something about this, and other things, also in that spot. Won't repeat it, as it got longer than intended and confused other people.) [[Special:Contributions/141.101.98.189|141.101.98.189]] 01:02, 15 February 2023 (UTC)

No WAY "ten turns per second" is in a reasonable limit for a person. That's insanely fast! --[[User:Mushrooms|Mushrooms]] ([[User talk:Mushrooms|talk]]) 07:56, 15 February 2023 (UTC)

: Sorry, my bad :( should have made it clear that it meant something along hitting it with a hand to get it turning and not the hand rotating with it (which I agree would be ridiculous), any idea how to clarify that without making the paragraph too long? [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 08:33, 15 February 2023 (UTC)

: Afterthought: I tested the 10 r/s with a ruler, a aero-whatsit would probably have less friction from the bearings but much more air resistance so it might not be easy to get it up to speed. However I do not have the means to test *that* scenario. And I'll be ever so grateful if someone with the means would check if it can be done. If it can't the last sentence would be better off as something like "This speed is not acheveable by hand but can be reached by whatever" [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 08:51, 15 February 2023 (UTC)

: For the record, the top speed reached by a ping-pong ball (which should be a bit above the top speed of a human arm dut to the bit of length added by the racket) is 112.6km/h. So a bit less than what's needed for the minimum speed quoted. [[Special:Contributions/172.71.122.227|172.71.122.227]] 11:46, 15 February 2023 (UTC)

; Turning manually runs quickly into drag — cube of speed — so it is unlikely that high rotational speeds can be achieved.
[[Special:Contributions/172.71.222.76|172.71.222.76]] 12:27, 15 February 2023 (UTC)

: Using the drag equasion from google, a speed of 16m/s per the article, a drag coefficant of 0.38 when the air is blowing at the rounded side and human power 600W (10W/kg times an average-if-a-bit-low 60 kg) gives an estmate of [https://www.wolframalpha.com/input?i=sqrt%28600W%2F%281%2F2*density+of+air*0.38*%2816m%2Fs%29%5E3*pi%29%29 max r] of ~43cm (which means it measures ~3 foot across), it's a rough calcuation but it should suggest that power itself shouldn't be an issue. The problem is how fast we can get the power flowing from the arm into the object (which is going to be the real pain). [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 13:13, 15 February 2023 (UTC)

: OK this is in no way revalent but when I calcuated the above figures I decided to plug in a cup that's 20cm across to see how fast we can make it go if we managed to dump all 600W into it and found we can make it spin at [https://www.wolframalpha.com/input?i=%28600W%2F%281%2F2*density+of+air*0.38*%2810cm%29%5E2*pi%29%29%5E%281%2F3%29 43m/s] (96mph) and make the computer think wind speeds are at a ridiculous [https://www.wolframalpha.com/input?i=%28600W%2F%281%2F2*density+of+air*0.38*%2810cm%29%5E2*pi%29%29%5E%281%2F3%29*3 ''128m/s''] (289mph) which according to [https://www.weather.gov/ffc/fujita this chart] is a F5 "incredible tornado" capable of, cite: "Strong frame houses lifted off foundations and carried considerable distances to disintegrate; automobile sized missiles fly through the air in excess of 100 meters; trees debarked; steel re-inforced concrete structures badly damaged." (Which somehow this feels oddly satisfiying) [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 13:13, 15 February 2023 (UTC)

Talk:2737: Weather Station

2023-02-15T13:02:41Z

Xkcdjerry: added comment

Talk:2737: Weather Station

2023-02-15T08:53:58Z

Xkcdjerry: extended comment

Talk:2737: Weather Station

2023-02-15T08:51:47Z

Xkcdjerry: added afterthought, the claim might not be well thought-out welp

Talk:2737: Weather Station

2023-02-15T08:34:53Z

Xkcdjerry: changed wording

Talk:2737: Weather Station

2023-02-15T08:33:37Z

Xkcdjerry: added comment

2737: Weather Station

2023-02-14T09:29:43Z

Xkcdjerry: added the explaination of the phrase "Pouring one out", also restructured the last paragraph.

{{comic
| number = 2737
| date = February 13, 2023
| title = Weather Station
| image = weather_station_2x.png
| imagesize = 359x401px
| noexpand = true
| titletext = 'Pour one out for precipitation data integrity,' I say, solemnly upending the glass into the rain gauge.
}}

==Explanation==
{{incomplete|Created by a WEATHER DATA INTERPRETING BOT EXCITED BY A TORNADO. Do NOT delete this tag too soon.}}

Weather stations are usually equipped to measure atmospheric conditions for weather forecasts and studies on the weather and climate. An anemometer is a device often found in such stations that measures wind speed and direction. The anemometer shown in the comic is a typical three-cup anemometer, whose spin rate is proportional to the wind speed. Thus spinning the cups quickly by hand can create an impression of fast winds.

Combing the speed of winds in a F1 tornado (73~112 mph; 117~180 km/h) and the speed ratio of typical three-cup anemometers (1/2~1/3) gives a cup speed of ~16m/s, comparing the diameter of the anemometer to that of Cueball's arm gives an upper estimate of 0.5 meters (~two feet), [https://www.wolframalpha.com/input?i=16m%2Fs%2F%280.5m*pi%29 topping out at roughly 10 turns per second], which is within a reasonable range for a human.

The title text continues the trend of messing with weather equipment, this time by messing with {{w|rain gauges}}. "[https://en.wikipedia.org/wiki/Libation Pouring one out]" usually refers to the act of pouring a liquid, usually alcohol, on the ground as a symbol of reverence for a deceased friend or relative. Thus Cueball is mourning the now destroyed (aka "deceased") integrity of the precipitation data by pouring a glass of liquid into the gauge.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is standing halfway up a stepladder on the top of a building, spinning a anemometer quickly.]
:''SPIN SPIN SPIN''

:[In the lower-left corner of the panel, a array of computers are shown on server racks, connected to each other by cables. A sound is coming from one of the computers:]
:''WHEEE!''

:[Caption below the panel:]
:Whenever I see one of those little weather stations, I have to fight the urge to climb up and spin the anemometer real fast to make a computer somewhere think it's in a tornado.

{{comic discussion}}

[[Category: Comics featuring Cueball]]
[[Category: Weather]]
[[Category: Tornadoes]]

2737: Weather Station

2023-02-14T09:17:25Z

Xkcdjerry: fixed duped line

{{comic
| number = 2737
| date = February 13, 2023
| title = Weather Station
| image = weather_station_2x.png
| imagesize = 359x401px
| noexpand = true
| titletext = 'Pour one out for precipitation data integrity,' I say, solemnly upending the glass into the rain gauge.
}}

==Explanation==
{{incomplete|Created by a WEATHER DATA INTERPRETING BOT PREDICTING A TORNADO - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Weather stations are usually equipped to measure atmospheric conditions for weather forecasts and studies on the weather and climate. An anemometer is a device often found in such stations that measures wind speed and direction. The anemometer shown in the comic is a typical three-cup anemometer, whose spin rate is proportional to the wind speed. Thus spinning the cups quickly by hand can create an impression of fast winds.

Combing the speed of winds in a F1 tornado (73~112 mph; 117~180 km/h) and the speed ratio of typical three-cup anemometers (1/2~1/3) gives a cup speed of ~16m/s, comparing the diameter of the anemometer to that of Cueball's arm gives an upper estimate of 0.5 meters (~two feet), [https://www.wolframalpha.com/input?i=16m%2Fs%2F%280.5m*pi%29 topping out at roughly 10 turns per second], which is within a reasonable range for a human.

In the title text weather falsification continues, this time by confusing a {{w|rain gauge}}, ironically in the form of a {{w|libation}} for the now "deceased" correct rainfall data.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is standing halfway up a stepladder on the top of a building, spinning a anemometer quickly.]

:[In the lower-left corner of the panel, a array of computers are shown on server racks, connected to each other by cables. The word "WHEEE!" is coming from one of them.]

:[Caption below the panel:]
:Whenever I see one of those little weather stations, I have to fight the urge to climb up and spin the anemometer real fast to make a computer somewhere think it's in a tornado.

{{comic discussion}}

[[Category: Comics featuring Cueball]]
[[Category: Weather]]
[[Category: Tornadoes]]

2737: Weather Station

2023-02-14T07:15:11Z

Xkcdjerry: fixed the link

{{comic
| number = 2737
| date = February 13, 2023
| title = Weather Station
| image = weather_station_2x.png
| imagesize = 359x401px
| noexpand = true
| titletext = 'Pour one out for precipitation data integrity,' I say, solemnly upending the glass into the rain gauge.
}}

==Explanation==
{{incomplete|Created by a WEATHER DATA INTERPRETING BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Weather stations are usually equipped to measure atmospheric conditions for weather forecasts and studies on the weather and climate. An anemometer is a device often found in such stations that measures wind speed and direction. The anemometer shown in the comic is a typical three-cup anemometer, whose spin rate is proportional to the wind speed. Thus spinning the cups quickly by hand can create an impression of fast winds.

Combing the speed of winds in a F1 tornado (73~112 mph) and the speed ratio of typical three-cup anemometers (1/2~1/3) gives a cup speed of ~16m/s, comparing the diameter of the anemometer to that of Cueball's arm gives an upper estimate of 0.5 meters (~two feet), [https://www.wolframalpha.com/input?i=16m%2Fs%2F%280.5m*pi%29 topping out at roughly 10 turns per second], which is within a reasonable range for a human.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

Cueball is standing halfway up a stepladder on the top of a building, spinning a anemometer quickly.

In the lower-left corner of the panel, a array of computers are shown on server racks, connected to each other by cables. The word "WHEEE!" is coming from one of them.

Caption below the panel: Whenever I see one of those little weather stations, I have to fight the urge to climb up and spin the anemometer real fast to make a computer somewhere think it's in a tornado.
{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Weather]]
[[Category: Tornadoes]]

Talk:2737: Weather Station

2023-02-14T07:13:40Z

Xkcdjerry: Add comment

2737: Weather Station

2023-02-14T07:11:33Z

Xkcdjerry: Explanation stub

{{comic
| number = 2737
| date = February 13, 2023
| title = Weather Station
| image = weather_station_2x.png
| imagesize = 359x401px
| noexpand = true
| titletext = 'Pour one out for precipitation data integrity,' I say, solemnly upending the glass into the rain gauge.
}}

==Explanation==
{{incomplete|Created by a WEATHER DATA INTERPRETING BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Weather stations are usually equipped to measure atmospheric conditions for weather forecasts and studies on the weather and climate. An anemometer is a device often found in such stations that measures wind speed and direction. The anemometer shown in the comic is a typical three-cup anemometer, whose spin rate is proportional to the wind speed. Thus spinning the cups quickly by hand can create an impression of fast winds.

Combing the speed of winds in a F1 tornado (73~112 mph) and the speed ratio of typical three-cup anemometers (1/2~1/3) gives a cup speed of ~16m/s, comparing the diameter of the anemometer to that of Cueball's arm gives an upper estimate of 0.5 meters (~two feet), [topping out at roughly 10 turns per second](https://www.wolframalpha.com/input?i=16m%2Fs%2F%280.5m*pi%29), which is within a reasonable range for a human.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

Cueball is standing halfway up a stepladder on the top of a building, spinning a anemometer quickly.

In the lower-left corner of the panel, a array of computers are shown on server racks, connected to each other by cables. The word "WHEEE!" is coming from one of them.

Caption below the panel: Whenever I see one of those little weather stations, I have to fight the urge to climb up and spin the anemometer real fast to make a computer somewhere think it's in a tornado.
{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Weather]]
[[Category: Tornadoes]]

2737: Weather Station

2023-02-14T06:54:08Z

Xkcdjerry: A barebones stub for the transcript

2680: Battery Life

2022-10-04T04:02:43Z

Xkcdjerry:

{{comic
| number = 2680
| date = October 3, 2022
| title = Battery Life
| image = battery_life_2x.png
| imagesize = 264x251px
| noexpand = true
| titletext = It's okay, I'm at 10%, so I'm good for another month or two.
}}

==Explanation==
{{incomplete|Created by a BOT WITH ONE MONTH OF BATTERY LIFE LEFT. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

A Cueball carrying a gigantic battery with a phone in it in three different positions in frame

Caption: Plugging in my phone is a pain, so I got one with a 100LB battery, and when it runs out of charge every few years I just upgrade.

{{comic discussion}}

Talk:2664: Cloud Swirls

2022-08-28T02:49:47Z

Xkcdjerry: Add comment

3-D video games? HUH??[[Special:Contributions/172.70.131.126|172.70.131.126]] 09:33, 27 August 2022 (UTC)
:It's not how I would have started the Explanation, but I think it'll quickly be rewritten enough that this element is downplayed/subsumed in some more generalised attempt to explain everything from QFD to the CBR. As I'm only just reading this now, just before I have to wander off to do something else, I shall have to defer my own dabbling edits until later, by which time it will have been matured (or at least remixed) into a more thorough text, so no point me worrying upon how to improve the necessary but rarely inviolable initial attempt to Explain. [[Special:Contributions/172.70.85.5|172.70.85.5]] 11:51, 27 August 2022 (UTC)
:: Maybe in some combination with the {{w|Observer effect (physics)}}, it's an attempt to get at the simulation hypothesis maybe?
::I absolutely do not get whatever it is that the title text is saying, so I'm sitting this one out. [[Special:Contributions/172.70.214.189|172.70.214.189]] 14:56, 27 August 2022 (UTC)
:::I'd interpret it as them studying fluid dynamics in hope of discovering a way to create the coolest possible cloud. --[[Special:Contributions/172.68.50.207|172.68.50.207]] 15:07, 27 August 2022 (UTC)
::::Aye. Given we can't see the 'best clouds' here (because the chances are low that we can) and we can't go and see the absolute best clouds (due to limitations on visiting every likely place out there), by intensely studying the phenomenon that in part dictates how all clouds look one might create (or visually predict the look of) the superior type through rigorous simulation/emulation/etc. [[Special:Contributions/172.70.162.155|172.70.162.155]] 15:53, 27 August 2022 (UTC)

''Much more computing power could be saved by skimping on the chemistry of the quattuordecillions of atoms in the oceans than the clouds in the sky ... but skimping on oceanic chemistry would make biogenesis much less feasible. However, Earth has life.''

Wait, what if this is the solution to the Fermi paradox? /jk [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 02:49, 28 August 2022 (UTC)

2664: Cloud Swirls

2022-08-28T02:44:21Z

Xkcdjerry: Explanation Expansion

{{comic
| number = 2664
| date = August 26, 2022
| title = Cloud Swirls
| image = cloud_swirls.png
| titletext = 'Why did you get into fluid dynamics?' 'Well, SOME planet has to have the coolest clouds, odds are it's not ours, and rockets are slow.'
}}

==Explanation==
{{incomplete|Created by a UNIVERSE WITH NOTHING BETTER TO DO EXCEPT MAKE CLOUDS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
There are planets.{{Citation needed}} A lot of them, even. Like our planet, many of them have clouds, and some that we know of even have {{w|Saturn's hexagon|gigantic clouds}} identifiable as a key landmark (or perhaps airmark).

In 3D video games, it is most common for models to be rendered at a lower quality when the camera is far away from them to save on extra rendering work being done for something the player can't actually get a close look at. Here, Cueball and Megan theorize that such a principle is being done for complicated cloud formations that occur naturally on other planets way far away with no observers on them. On planets with no observers to look at the clouds closely, the Universe can afford to not render/calculate the atmosphere with high quality, but it has to do more intensive calculations on Earth because otherwise, people on Earth (specifically meteorologists and physicists) would notice that the atmosphere is not obeying the Navier-Stokes equations but instead demonstrates behavior that reflects low-quality physics calculations by a computer that is skimping on fluid dynamics calculations. This would make sense if the Universe is actually simulated by a computer, and the beings that are running the physics simulator/have coded our universe wanted to speed things up. However, there would be several problems with this:
* Much more computing power could be saved by skimping on the chemistry of the quattuordecillions of atoms in the oceans than the clouds in the sky (especially considering that it would not be necessary to simulate every individual atom and molecule in the sky (for the purpose of making realistic clouds with fluid dynamics); the computer program could instead divide all of the gas particles (e.g., dinitrogen, dioxygen, water vapor, argon, and carbon dioxide) into small chunks, simulate how each chunk would move, and update the chunk boundaries every so often), but skimping on oceanic chemistry would make biogenesis much less feasible. However, Earth has life.{{Citation needed}}
* It would be difficult to judge when "no one is looking closely". There are many organisms that have some degree of at least rudimentary sight but would have no idea (and in fact no way to conceptualize) whether the computer simulating the Universe is skimping on the cloud-rendering calculations or not. It would be difficult to make some foolproof intelligent-sight-detecting code that would render the clouds with much greater precision once a planet had life that would notice if the clouds were following lazy fluid dynamics. For one thing, this would not only depend on a species's intelligence but also on its knowledge of physics; e.g., humans did not develop the Navier-Stokes equations right after evolving large enough brains to conceive and understand them. Even coding a computer program to detect sight-having life would be difficult, at least for a computer program only looking at the positions and velocities of atoms, electrons, and photons; for example, a blue photon hitting a retinal molecule in a cone cell, causing it to change shape, which triggers a signal transduction cascade that sends a nervous signal to the optical cortex somewhat resembles an ultraviolet photon hitting a DNA strand, leading to the creation of a thymine dimer whose detection by DNA-repairing enzymes triggers a signal transduction cascade that increases the production of melanin, but only one counts as sight. Furthermore, assuming that the computer simulates each part of the Universe in a manner that is is about synchronized according to most celestial bodies, when the computer simulating the Universe simulates a planet, it does not know whether a civilization on a planet a dozen or two light-years away that has advanced enough to have telescopes capable of detailed views of the clouds of planets light-years away will point any telescopes at that planet dozens of light-years later. Even if the advanced civilization on another planet does not have such powerful telescopes yet, even a low-resolution (in terms of that planet's entire solar system being one pixel) spectrometer would be enough to reveal that something is up with the fluid dynamics simulations on that planet. Observers light-years away could deduce how much condensed water vapor there is in the atmosphere by calculating the atmosphere's absorbance in a wavelength where condensed water has a low but detectable absorptivity and everything else in that planet's atmosphere either has a negligible absorptivity or can be compensated for, and then one can deduce how compact the clouds are from that and the absorbance of a wavelgnth where condensed water has a high absorptivity and everything else in that planet's atmosphere either has a negligible absorptivity or can be compensated for. (Actually, in order to calculate the amount and compactlygroupedness of condensed water in the atmosphere from the raw numbers/direct measurements, the scientists would have to know not only the absoprtivity of condensed water suspended in air as clouds but also characteristics of the planet such as its radius and the thickness of its atmosphere. There are also other complicated factors, such as that some of the aerosolized water in clouds is in the form of solid ice, not liquid water. However, the scientists would still notice if the raw numbers from the more rudimentary observational equipment suddenly changed the second they switched on a more powerful telescope, so the following point still stands.) If the computer simulating the Universe did not switch to the more precise simulation of the planet's atmosphere in time for the scientists to only see spectrographs of the planet's atmosphere rendered with precise calculations, then if the scientists later developed a more powerful telescope, like the one described earlier, and then pointed it at the planet, either they would see poorly-rendered clouds and know that the Universe is simulated by a computer that skimps on the fluid dyanmics calculations for the atmospheres of certain planets, or the measurements from transit spectrography would suddenly change, so the scientists would know that something weird was going on—although probably not exactly what. This is important because it is more feasible for a society to develop low-resolution transit spectrography quickly enough to catch the computer simulating the Universe off-guard than it would be for a society to develop the technology required for a telescope advanced enough to look at the clouds of a planet in another solar system with high enough resolution to determine whether the atmosphere is simulated by a computer that is skimping on the fluid dynamics calculations quickly enough to catch the computer simulating the Universe off-guard. However, either could conceivably catch the computer simulating the Universe off-guard because it would be difficult for a computer to deduce whether a planet has life and how technologically advanced the life of any planet that has life is when the only raw data for the computer to work with are the positions and velocities of atoms, electrons, and photons.
* If atmospheric physics suddenly changed upon the evolution of a species capable of distinguishing whether the atmosphere is simulated by a computer program that is skimping on the fluid dynamics calculations, that would likely cause sudden changes in the climate, and the resulting heat waves, droughts, freezes, famines, floods, storms, and/or other (formerly) extreme weather would likely drive that species extinct (considering that it had just evolved, so it would have a small population and therefore be especially susceptible to natural disasters) because it would not have evolved to survive in such conditions. Such disasters and climate changes) would not have to directly kill all members of the species in order to drive it extinct; they could instead diminish the size of the gene pool by killing most of the members or divide the once-larger population into smaller, genetically isolated populations (e.g., by causing the creation of uncrossably swollen rivers dividing what used to be a single genetically-interconnected range into several smaller populations), either of which would cause an unsustainable level of inbreeding that would eventually lead to extinction. However, our species was not driven extinct shortly after it first developed.{{Citation needed}}

(However, the last two can be averted by just running the improvised calculations over the last hour or so, which makes seem as if it was obeying the Navier-Stokes equations and at the same time not changing the overall climate too much)

Of course, most people do not think that the Universe is a simulation, but society does not know that it isn't a simulation with absolute certainty.

Megan proposes an additional theory that the universe is just about making cool swirly clouds, and that the presence of life to observe these clouds is a bothersome coincidence. This goes against the previous theory, which implies that the Universe must not care about making cool swirly clouds since it wants to skimp on the fluid dynamics calculations.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball and Megan looking out at a landscape of clouds]
:Cueball: It's weird to think there are countless planets with air and stuff but no life.
:Cueball: Billions of years of clouds making cool shapes with no one to look at them.

:[Just Cueball and Megan standing next to each other]
:Megan: Yeah, it seems like a waste. The universe getting the complex fluid dynamics right for every momentary swirl of cloud.
:Megan: Just a ''huge'' amount of work.

:[Cueball and Megan walk away to the right]
:Cueball: Maybe atmospheres have smooth laminar flow until someone looks closely.
:Megan: Or maybe the universe just ''likes'' making swirly clouds, and is annoyed that we're watching.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Weather]]
[[Category:Physics]]
[[Category:Astronomy]]

2657: Complex Vowels

2022-08-11T02:45:58Z

Xkcdjerry: format editing,added {{cn}}

{{comic
| number = 2657
| date = August 10, 2022
| title = Complex Vowels
| image = complex_vowels.png
| titletext = Pronouncing [ṡṡċċḣḣẇẇȧȧ] is easy; you just say it like the 'x' in 'fire'.
}}

==Explanation==
{{incomplete|Created by a ROUNDED TONGUE. Do NOT delete this tag too soon.}}

[[File:Ipa-chart-vowels.png|thumb|200px|The IPA vowel chart]]

In phonetics based on the {{w|International Phonetic Alphabet}} (IPA), the space of {{w|vocal tract}} articulators determining {{w|vowel}}s  is represented as two-dimensional, from the position of the tongue. The vertical axis represents vowel height or ''closedness'' (i.e. how close or far the tongue is from the top of the mouth), and the horizontal axis represents front-to-back ''place'' (i.e., how close or far the top of tongue is from the teeth.) The position of the tongue, along with the frequency of the {{w|vocal cords}} vibrating in the larynx from air being exhaled by the diaphragm, are the primary determinants of the fundamental and second {{w|formant}}s of vowel sounds.

A third dimension of vowel sounds is the "roundedness" of the lips, and to a much lesser extent the tongue and cheeks, which is not represented on the IPA vowel chart to the right. [[Randall]] thus suggests using complex notation to indicate such a third dimension. Other higher-dimensional vowel representations include {{w|diphthong}}s, which are simply two different sequential vowels slurred together; diphones, which represent the last half of one phoneme followed by the first half of the next; the {{w|vowel shift}} mappings delineating different accents[https://core.ac.uk/download/pdf/47086396.pdf][https://www.sciencedirect.com/science/article/abs/pii/S0095447010000562] and long-term evolution of voiced phone sounds; and {{w|cepstrum|ceptstral}} representations such as {{w|Mel-frequency cepstrum|mel-frequency ceptstral coefficients}}.

In mathematics, {{w|complex number}}s are numbers including both real numbers and {{w|imaginary number}}s. A complex number can be expressed as, "''a'' + ''b''i," where ''a'' and ''b'' are real numbers, but the latter imaginary part is combined with 'i,' the square root of negative one, as depicted in the central expression in the comic by √-1, indicating three dimensional coordinates. When expanding the one-dimensional number line with an imaginary axis, it becomes two-dimensional with any "''b''i" component being represented perpendicularly away from the original 'real' line. Linguists never use the {{w|complex plane}} to represent vowel roundedness, or any other higher-dimensional features of phonemes.{{cn}}

This comic conflates complex numbers in mathematics with "complex vowels" in linguistics. Such complex vowels are implied to create sounds which cannot be properly processed by the human brain, represented graphically as {{w|Zalgo text}} IPA, similarly to the cliché of "black speech" in {{w|Lovecraftian horror}}, a language created by alien beings with different vocal patterns than humans. In reality, people find Zalgo text amusing, thus the humor of the comic, but not particularly insanity-inducing or even more than mildly confusing.{{cn}} This is also funny because unadorned IPA shares some characteristics with Zalgo text, such as extremely uncommon {{w|glyph}}s and weird {{w|diaeresis}}.

In linguistics, 'ə' is the {{w|schwa}} symbol, referred to in the title text as well as the depiction of complex phonemes, the most common vowel sound in English polysyllabic words (the 'a' in "comma" or the second 'e' in "letter.") Production of the schwa sound takes place with the tongue, jaw, and lips all in a relaxed, central position; and certainly sounds nothing like the 'x' in "fire", because "fire" doesn't contain the letter 'x'.{{cn}}

Another example of weird diaeresis is in [[2619: Crêpe]]. The linguist in the comic appears to be {{w|Gretchen McCulloch}}, as previously depicted in [[2421: Tower of Babel]] and [[2381: The True Name of the Bear]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[A diagram shows the extrusion of the trapezoidal IPA vowel chart upwards into three dimensions. A point near the center is labeled with an equation that shows "ə + 1/2 * sqrt(-1)" as being equivalent to a made-up symbol that looks like two schwas mirroring each other with other markings above and below.]

:[Below the diagram, a character with shoulder-length dark wavy hair pronounces the new vowel in a speech bubble with unstable lines surrounding it. Two bystanders to her right are bent over slightly, clutching their heads in apparent anguish.]

:[Caption below the panel:]
:Linguistics tip: Extend the IPA vowel plane along the imaginary axis to produce ''complex vowels'', cursed sounds which the human mind cannot comprehend.

{{comic discussion}}
[[Category:Tips]]
[[Category:Language]]

235: Kite

2022-01-07T06:36:45Z

Xkcdjerry: changes "we'll ignore it for now" into citation needed

{{comic
| number = 235
| date = March 14, 2007
| title = Kite
| image = kite.jpg
| titletext = It's easy to regret your awkward conversations but hard to regret the ones you didn't have.
}}

==Explanation==
This comic presents, through a surreal scenario, one of Randall's recurring themes: that it is better to [[458:_Regrets|take a chance]] and make an [[308:_Interesting_Life|interesting]] [[267: Choices: Part 4|choice]].

[[Cueball]] flies a kite, then fixes it to a tree and climbs its string. In real life, of course, the string would not be able to support the weight of a human{{Citation needed}}. Up in the sky, [[Megan]] appears hanging on a blimp, looking at him throughout the encounter. Cueball wonders about her and considers talking to her, but he does not act. After she has gone, Cueball is alone again; nothing has changed.

The title text explains the meaning of this metaphor. It is easy to regret an awkward conversation you had. In contrast, you don't regret the conversations you didn't have the nerve to start, because their cost is invisible--yet, they may have been missed opportunities, possibly a much higher cost than a simple awkward conversation.

Later in the [[1614: Kites]] title text, it turns out that other people ([[Beret Guy]]) can also fly with a kite.

==Transcript==
:[Cueball readies a kite.]
:[Cueball starts to fly the kite.]
:[Cueball continues to fly the kite.]
:[Cueball ties the kite string to a tree.]
:[Cueball grabs the string.]
:[Cueball starts to climb the string.]
:[A scene showing Cueball holding onto the string at a high altitude, against a colour backdrop of the ground, clouds, water, and the sky.]
:[Black and white again. Megan comes into view holding onto a small blimp.]
:Cueball (thinking): Hey, there's someone else up here. I wonder what her story is.
:[Megan floats to the other side of the panel.]
:Cueball (thinking): Maybe I should say hi.
:[Cueball is alone holding onto the string.]

==Trivia==
There is a [https://youtu.be/3fCxyVSzd2k fan made animated version of this comic].

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with color]]
[[Category:Kites]]
[[Category:Airships]]
[[Category:Comics sharing name|Kite01]]
[[Category:Social interactions]]

861: Wisdom Teeth

2021-04-17T10:49:08Z

Xkcdjerry: Corrected typo

{{comic
| number = 861
| date = February 16, 2011
| title = Wisdom Teeth
| image = wisdom_teeth.png
| titletext = I heard the general anesthesia drugs can cause amnesia, so when I woke up mid-extraction I started taking notes on my hand so I'd remember things later. I managed 'AWAKE BUT EVERYTHING OK' before the dental assistant managed to find and confiscate all my pens.
}}

==Explanation==

{{w|Wisdom teeth}}, as many people are no doubt {{w|Wisdom teeth#Post-extraction problems|painfully aware}}, are the third set of molars found in humans. Because human jaws are smaller than other ape jaws, most of us don't have room for a third set of molars, and the teeth become impacted so they grow straight into the other teeth, requiring a painful, debilitating procedure to remove them.

Because recovering from dental surgery often entails a period of rest following the operation and the use of {{w|painkillers|prescription painkillers}} (which have a tendency to make a person go a little loopy), [[Cueball]] prepares to play ''Minecraft'' the entire time. ''{{w|Minecraft}}'' is a PC game known for its addictive qualities; the game itself primarily revolves around a three-dimensional world in which the goal of the player is centered on the aspects of structural creation using blocks found in the environment and the creation of different materials for use in building these structures. Despite its addictive nature, the game doesn't provide the player with a goal, so most people take to building lots of nifty stuff, such as large cities, computers made from the game's built-in automation mechanics, massive scale replicas of Earth, etc.

Cueball's conversation with [[Megan]] indicates that he has previously decided against playing ''Minecraft'' precisely due to its addictive gameplay and lack of internal goal, deeming it unproductive. However, 'productivity' is not something that Cueball believes he can achieve post-extraction, and so Cueball decides that addictive gameplay and lack of internal goal "sounds like the perfect distraction".

Unfortunately for Megan (and any other users of her server), Cueball, while intoxicated with painkillers, has instead opted to flatten an entire continent and sort it into layers (by type of block, presumably). While there's no real indication of how big the continent is, as ''Minecraft'' worlds are randomly generated, sea level in ''Minecraft'' is at Y level 64, which means he sorted at least 65 layers of a continent large enough to be sufficiently developed, so it is clear that this task would take a lot of time. Collecting a block in ''Minecraft'' takes a certain minimum amount of time, depending on the block type, so even if he did everything as fast as he possibly could, there's still a substantial lower bound.

Ironically, in the second panel Megan says she'll set Cueball up on her server, which indicates she probably uses a whitelist to secure the server from griefers who might destroy structures created by others, not expecting that Cueball would do exactly that. The last panel simply illustrates that painkillers tend to make one loopy.

The title text refers to people waking up during surgery. Because anesthesia requires a lot of careful calibration and dosage - there's a reason anesthesiologists are paid hundreds of dollars an hour to be there, after all - it's possible to sometimes get it wrong, resulting in the patient waking up in the middle of the surgery. The three most important parts of anesthetics used for surgery are an analgesic (blocks pain), a sedative (puts you to sleep), and a paralytic (keeps you from moving). The worst-case scenario that most people hear about is when the analgesic and sedative are under-dosed, but the paralytic is correct, leaving the person awake, able to feel pain, but unable to alert the surgeons that anything is wrong. As a result, some countries and medical institutions have passed laws requiring surgeons to monitor brain activity so that these problems can be quickly remedied. The situation the title text is describing, with both the sedative and paralytic wearing out (leaving the person able to write notes), would be quite unlikely. As for confiscating all the pens, it was probably just to keep the patient from disturbing the procedure while the anesthesiologist corrected the dosage.

In reality, sorting a ''Minecraft'' map into layers (assuming the grass in the comic is at sea level—y=64 blocks) would take an unbelievable amount of time, even in creative mode, as you would have to mine away everything below that, and then sort it into layers. ''Minecraft'' maps are extremely big, so it would actually be almost impossible to sort the entire map into layers. Randall, like Cueball, has also tried to do weird things with ''Minecraft'', see [https://what-if.xkcd.com/153/ this] for more details.

In the current version of Minecraft: there is a way to create a world flattened with the option superflat world. However, this option was not available at the time the comic was published, so Cueball really flattened an entire world himself. Also, in the current version, by standard, worlds are almost infinite, again, this was not avaliable at the time.

==Transcript==
:Cueball, on phone: Hey! Know how you've been bugging me to play Minecraft for the past year? I'm game.
:Megan, on phone: But you said you didn't want to "get hooked and spend days on end moving virtual cubes around while sitting motionless." What changed?

:Cueball, on phone: I'm having my wisdom teeth out, and I'll be useless and doped up on painkillers for the next few days, so that actually sounds like the perfect distraction.
:Megan, on phone: Oh. I'll set you up on our server!

:72 hours later...
:[Megan sitting at computer.]
:Megan, on phone: Hey — starting to feel better? Enjoying the game? Let's see what you've... What the hell? Where ''IS'' everything?

:[View of a Minecraft screen showing a vast empty expanse of land. In Cueball's hotbar is, from left to right, an stone pickaxe, sword, and shovel, seven feathers, 42 torches, a non-enchanted bow, a blank space, 64 blocks of stone and a clock. He has full health and 15 armor points.]
:Megan, offscreen: ...You made the entire continent perfectly flat?
:Cueball, offscreen: And sorted it into layers.
:Megan, offscreen: ...
:Cueball, offscreen: I feel good about things. This is a good game.

:[Cueball sitting on the floor at his laptop, bleeding from the mouth, surrounded by bloody wadded-up tissues and holding a bottle of medication.]
:Megan, on phone: ...What exactly is in the painkillers they gave you?
:Cueball, woozy: I can't read the label because I'm a hologram.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with color]]
[[Category:Video games]]

User:Xkcdjerry

2021-02-27T10:16:13Z

Xkcdjerry: Created page with "Recusing is fun! https://www.explainxkcd.com/wiki/index.php/User:Xkcdjerry My ''real'' home page"

Recusing is fun!

[[https://www.explainxkcd.com/wiki/index.php/User:Xkcdjerry My ''real'' home page]]

1821: Incinerator

2021-02-27T10:11:05Z

Xkcdjerry:

{{comic
| number = 1821
| date = April 7, 2017
| title = Incinerator
| image = incinerator.png
| titletext = My trash can broke recently and I had to get rid of it. When I picked it up, I suffered a brief but harrowing existential crisis.
}}

==Explanation==
[[Cueball]] and [[Ponytail]] have just finished installing an {{w|Incineration|incinerator}} for some unspecified purpose at some establishment. Ponytail brings up the problem of having to get rid of the old incinerator, and Cueball begins to suggest using the new incinerator to incinerate the old one, but he is shut down by Ponytail off-panel. This makes him noticeably disappointed, probably because the idea of using an incinerator to destroy an incinerator is novel to him.

Throwing an incinerator inside another incinerator would probably break some kind of regulations or safety concerns, and since incinerators are meant to withstand their own high heat capacities it would be ineffective anyway.

The title text implies that this comic was inspired by recent events at [[Randall]]'s house: his trash can broke and he struggled with how to dispose of it. At least for Randall, there is something wrong with forcing anything to destroy something of its own kind -- in this case, throwing the old trash can in the new trash can. Since machines have no human emotion this would not cause any [https://www.youtube.com/watch?v=I07xDdFMdgw trauma for the machine], but the humans in charge might feel as if something is wrong, and Randall mentions having an {{w|existential crisis}}. This is because humans tend to project human qualities onto the machines they are working with ({{w|anthropomorphism|anthropomorphization}}), thus possibly framing the situation in the context of something like cannibalism or homicide.

Another way of taking it would be in the sense of "being replaceable". Many people live without wanting to think of what might happen to everything around them after they die, but in this title text one can start comparing the trash can to themselves — the same way the trash can turns into something to be disposed and replaced with a new one after it becomes useless, what about people then? What will happen to you when you grow older? Should you suddenly go sick and become useless? How about in your job, what would happen if someone more superior than you comes around and starts threatening your hard-earned position?

Yet another interpretation is that while disposing of the trash can, Randall realized that he was now in the same situation as the trash can itself. The trash can was a tool used by others, in order to dispose of trash. And yet, in time, the trash can itself became trash and had to be disposed of by Randall. Which makes one wonder if Randall is himself a tool created/used by others, who will one day dispose of Randall when he has outlived his usefulness, the same way that he disposed of the trash can when it outlived its usefulness. From this perspective, Randall is simply a more intelligent and autonomous trash-junking-tool, different in degrees but similar in nature to his own trash can.

Many people define themselves by the things they do and are capable of. The idea of losing those, and then being replaced for it, is a bitter pill that we will all have to swallow at some point. All things must come to end after all, including ourselves.

A more simple reason for this may be that for almost anything else you might pick up, having done so you now have the option to put it in the trash can. Picking up the trash can itself (perhaps just to work out ''if'' it is beyond use) simultaneously removes "the trash can you may opt to put something you hold in" from its usual point in your normally 8nstintively simple mental mapping of the domestic universe.

Plus, [https://slatestarcodex.com/2014/06/08/map-territory-distinctions/ actually throwing out a garbage can can be surprisingly difficult].

Another device to perform a meta-action was previously explored in [[952: Stud Finder]].

==Transcript==
:[Cueball and Ponytail stand next to an incinerator, with a combustion chamber and flue that rises up to the top of the frame.]
:Ponytail: Great, the new incinerator is installed. Now we just need to dispose of the old one.

:[Ponytail walks out of the frame.]

:[Cueball lowers his head, beat panel]

:[Cueball raises his hand and begins to ask a question.]
:Cueball: Hey, could—
:Ponytail (off-panel): ''No.''
:Cueball: Aww, maaan.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Recursion]]
[[Category:Comics featuring Ponytail]]

2376: Curbside

2021-02-27T10:03:08Z

Xkcdjerry: Added catgory "Recursion" because of "tracer tracing"

{{comic
| number = 2376
| date = October 23, 2020
| title = Curbside
| image = curbside.png
| titletext = The state has had so many contact tracers disappear into that shop that they've had to start a contact tracer tracing program.
}}

==Explanation==
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.

[[Beret Guy]] is making contact with {{tvtropes|TheLittleShopThatWasntThereYesterday|a shop that sells cursed items, only to vanish when the customer tries to return the product}}. He has previously mentioned doing most of his shopping (including groceries) at such locations in [[1772: Startup Opportunity]], and visited one (possibly the same one) several months earlier in [[2332: Cursed Chair]]. That visit ended with him trying to stop the COVID-19 pandemic by destroying the cursed chair, but evidently he either failed to destroy the chair (which claimed to be immortal) or found that doing so didn't halt the pandemic. (Apparently Beret Guy has visited this same store before, since he says that "it's so stuffy in there", but has not attempted to return any of his purchases, since the store has not disappeared yet.)

After confirming that he has the right number, Beret Guy asks if the cursed store does curbside pickup, as he intends to place an order for bread and a cursed amulet, but does not wish to go inside during the pandemic. Many grocery stores have started offering such services, allowing a customer to place an order over the phone or online, then receive it outside the store, thus minimizing the interaction with store staff or other customers. Closed spaces are understood to pose a greater risk of contagion than the outdoors, where wind and sun can mitigate airborne viral particles.

The store's contact replies that no, they do not offer curbside pickup, but tries to assure Beret Guy that all employees at the location wear masks. (They might be wearing [[2367: Masks|haunted Halloween masks]].) When Beret Guy expresses disappointment at the revelation, complaining about the stuffy air of the shop, the contact advises him to consider the virus as part of the curses that come with their products. Beret Guy gets angry at this -- apparently, he's okay with buying cursed items, but not exposing himself to [[2330: Acceptable Risk|unacceptable risks]] of catching COVID-19. Beret Guy promptly proclaims that he will ''not'' be doing business with the location if they are going to showcase such an attitude towards the pandemic. It's unclear how he will find another store with similar unusual characteristics, although it [[1772: Startup Opportunity|has been mentioned]] that there is an entire industry of these stores.

Beret Guy mentions that he wants to buy an amulet in order to 'do battle with ghosts', which is not an ordinary thing to do given that most people cannot interact directly with ghosts{{Citation needed}}. Perhaps he has a ghost-fighting weapon that he has also bought from the shop, although a more likely explanation (given Beret Guy's peculiarity) seems that he is somehow able to engage in martial combat with them. A common argument for how ghosts can exist is that they are in another dimension; given that Beret Guy has extra dimensions in his bones ([[2310: Great Attractor]]), he might appear as a skeleton warrior in the ghosts' dimension. Thus, being able to battle ghosts would be one of the many [[:Category:Strange powers of Beret Guy|strange powers of Beret Guy]]. It is also unclear why Beret Guy specifically wants to anger the ghosts.

He also mentions that he is there to buy groceries, which is rather ordinary in contrast to the previous request. This is another example of Beret Guy's seemingly oblivious view of the world, putting the purchase of a ghostly amulet on par with buying bread.

The title text explains that {{w|Contact tracing|contact tracer}}s have been attempting to visit the store to figure out who else has been working or shopping there, which suggests that people may have been exposed to COVID there. However, presumably because of the peculiar nature of the store, a notable number of the contact tracers have not returned from visiting it, leading the state to create a tracing program to find the missing contact tracers. The joke here is that the contact tracers must now be traced by another tracing program. This same kind of recursivity of tracking tracers has been previously explored for [[952: Stud Finder|finding finders]] and [[1821: Incinerator|incinerating incinerators]].

==Transcript==

:[Beret Guy talking on a cell phone. The response from the person on the phone is in a jagged bubble.]
:Beret Guy: Hi, is this the shop that sells cursed items but when you try to return them the shop is gone?
:Phone: Yes, how can I help you?

:[A frameless panel. Beret Guy still talking on the phone]
:Beret Guy: Do you do curbside pickup? I wanted to buy a cursed amulet that angers ghosts, and some groceries.
:Phone: No, but it's okay, we wear masks.

:[Zoomed in on other side of Beret Guy's face]
:Beret Guy: So you can't bring stuff out?
:Phone: I'm afraid not.
:Beret Guy: But it's so stuffy in there!

:[The callee's response is on the top of the panel. Beret Guy is now holding his phone in front of him, ready to end the call.]
:Phone: Why not think of the virus as part of the amulet's curse?
:Beret Guy: '''''Excuse me!?''''' I'm trying to buy some bread and do battle with ghosts, not endanger my family and friends in a pandemic!
:Beret Guy: I will take my business '''''elsewhere.'''''

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:COVID-19]]
[[Category:Recursion]]
[[Category:Strange powers of Beret Guy]]

Category:Recursion

2021-02-27T10:01:30Z

Xkcdjerry: Reverted my own edit XD

These are all the comics that feature the concept of recursion in a strong way, presenting a situation inside the same type of situation. A dream within a dream. Or an apple within an apple.

[[Category:Comics by topic]]
[[Category:Recursion]]

952: Stud Finder

2021-02-27T09:59:12Z

Xkcdjerry: Added catgory "Recursion"

{{comic
| number = 952
| date = September 16, 2011
| title = Stud Finder
| image = stud_finder.png
| titletext = According to every stud finder I've tried to use, my walls contain a rapidly shifting network of hundreds and hundreds of studs.
}}

==Explanation==
''It sounds like you may be interested in my new product, a—'' '''stud finder finder.'''

[[Cueball]] cannot locate his {{w|Stud_finder|stud finder}}, so [[Black Hat]] begins a sales pitch, presumably for a "stud finder" finder. The joke is in the irony of having to find something that is used to find other things. Cueball interrupts Black Hat before he can make the obvious joke. The same comic technique is used later in [[1059: Bel-Air]]. Currently no product exists that will locate a stud finder, although online review compilations are useful for finding the right stud finder to buy.

Studs are vertical wood members in {{w|Framing_(construction)|wood-framed construction}} common in North America, although steel framing has become a popular alternative. These supports reinforce a wall at regular intervals, typically 16 inches (about 40 cm), and at corners, windows, and doors.

Most stud finders use an electrostatic field that is affected by the densities and types of materials in the vicinity, identifying where studs and other significant framing elements are located. One might want to know the locations of studs within a wall for installing wiring, mounting shelves and heavy objects to walls, or in this comic, hanging a picture. Wiring can be inserted between studs behind the {{w|drywall}}, while shelves, pictures, etc. are better affixed to studs.

Many stud finders have a light that turns on in conjunction with a beep when a higher density is detected, indicating the edge of a stud. But there are circumstances that can fool stud finders. Most are designed for the drywall-over-wood-framing construction, and can be fooled by older {{w|Lath_and_plaster|plaster and lath}} construction where the density is much more uniform throughout the length of the wall. Lower quality stud finders can also be fooled by things like moisture in the drywall or wiring within the wall cavity, and may thus beep when there is not a stud behind the scanned location. As a result, many people will try alternatives such as using a magnet to find the drywall screws or nails, or tapping a finishing nail through the wall to see if there is a stud underneath.

At the title text, [[Randall]] just gives up. Assuming there was no electrostatic interference, a stud finder going off randomly would indicate lots and lots of studs at random places that change position.

The idea of a "something doer doer" was explored again in [[1821: Incinerator]] and the title text of [[2376: Curbside]].

==Transcript==
:[Black Hat sits on a couch, reading a book. Cueball is approaching him from behind the couch holding a picture in a frame, a screwdriver, and some screws.]
:Cueball: Have you seen my stud finder? I've looked everywhere.
:Black Hat: It sounds like you may be interested in my new product, a—
:Cueball: Shut up.

{{comic discussion}}
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Recursion]]

2429: Exposure Models

2021-02-26T12:17:47Z

Xkcdjerry: Added citation needed

{{comic
| number = 2429
| date = February 24, 2021
| title = Exposure Models
| image = exposure_models.png
| titletext = "Cumulative number of coronavirus spreadsheets created over time" is a spreadsheet I am coming dangerously close to creating.
}}

==Explanation==
{{incomplete|Created by a CUMULATIVE NUMBER OF COVID SPREADSHEETS CREATED OVER TIME. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This is another comic in a [[:Category:COVID-19|series]] related to the {{w|2019-20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.

[[Cueball]] created another COVID exposure model to help lower his risk of catching COVID-19 in the pandemic. [[Megan]] inquires about the model's result, to which Cueball admits that he's been sitting at his computer continuously debugging models, and draws the conclusion that debugging COVID-19 models lessens close contact with other people. This is similar to the premise of [[1445: Efficiency]] and [[1708: Dehydration]], except with the situation reversed — where before, researching a situation made the situation worse, here Cueball's time "wasted" has actually benefited him.

By "model," Randall likely means a manually crafted model, since he describes debugging it, but he may also mean the form of automatically generated software that is used in modern machine learning. This comic is the first in which Randall may be directly discussing this popular new form of technology. Machine learning has been in use among engineers for a number of years now, and is spreading more and more rapidly. There are nowadays toolkits and courses for almost anybody to make use of machine learning to accomplish their tasks, especially if they are willing to train their models remotely in a corporate datacenter.

Cueball is too busy making models to figure out how to actually lower his risk other than sitting around repeating the work of others and improving his model-building skill. He has also created a meta-model, reporting the number of models Cueball has to create to wait the pandemic out. The title text further expands on recursive graphs by charting charts about COVID-19.

A meta model is a model about models, like most meta things. Software engineers have a practices such as DRY (don't repeat yourself) and reusability, that can result in continued code generalisation. Often generalisation to the point of producing software that generalises its own behavior results in reduced return, but with advanced systems such as machine learning it could produce a very rapid, effective solution to a wide variety of problems. Hence, meta-models relate to the concern of making machines too smart without first addressing dangers of poor alignment. Alignment relates to designing systems that respect human values when allowed to run autonomously, and is an unsolved problem.

==Transcript==
:[Cueball is sitting at a desk with a laptop. Megan walks in.]
:Cueball: I built another COVID exposure model to help me limit my risk.

:[Megan is now standing behind Cueball, who has turned in his chair to face her.]
:Megan: Any new insights?
:Cueball: Yeah: "If you spend all day debugging models, you don't have close contact with a lot of people."

:[Cueball turns back to his laptop. The back of his chair has disappeared.]
:Megan: Well, I guess it worked.
:Cueball: According to my meta-model, the end of the pandemic is only four more models away.
:Megan: ''So close!''

==Trivia==
Cueball's chair is missing its back in the last panel. Given the fact that most chair backs do not disappear when someone stops leaning on them{{Citation needed}}, [[Randall]] probably just forgot to draw it.
{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Recursion]]
[[Category:COVID-19]]

Category:Recursion

2021-02-26T12:17:17Z

Xkcdjerry: I have no premission to edit the list,can someone add this for me :(

These are all the comics that feature the concept of recursion in a strong way, presenting a situation inside the same type of situation. A dream within a dream. Or an apple within an apple.

(Comic 952 is also recursive but is not included below)

[[Category:Comics by topic]]
[[Category:Recursion]]

Talk:2382: Ballot Tracker Tracker

2020-11-18T12:44:51Z

Xkcdjerry:

In the title text, Randall explicitly endorses candidates for one party. He's said things before to suggest which side he's pulling for, but has he ever done so explicitly like this? If not, it should be mentioned. [[User:DKMell|DKMell]] ([[User talk:DKMell|talk]]) 17:54, 9 November 2020 (UTC)

:He endorsed Clinton in 2016 through a comic. https://xkcd.com/1756/ [[Special:Contributions/108.162.216.22|108.162.216.22]] 14:41, 11 November 2020 (UTC)

Could this also refer to sites that track whether one’s ballot has been counted? --[[Special:Contributions/172.68.132.239|172.68.132.239]] 03:31, 7 November 2020 (UTC)

This sense of "calling it" is relatively uncommon, especially for non-native English speakers to encounter. Although having it in quotes is good, some explanation should be added in parentheses. [[Special:Contributions/188.114.110.4|188.114.110.4]] 04:13, 7 November 2020 (UTC)
:See [https://english.stackexchange.com/questions/550851/call-the-race-in-the-election English.stackexchange.com] [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 07:50, 7 November 2020 (UTC)

I remember an earlier comic,Cueball trying to incinerate an incinerator.(xkcd1821),and people tracking trackers(xkcd2376),Maybe there should be a "meta-usage" category?(e.g using an incinerator to incinerate another incinerator,using a tracker to track a tracker etc.) [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 13:34, 7 November 2020 (UTC)

The current explanation refers to a ballot tracker as a government site, but I believe they're typically independently provided by either news organizations or political information websites. However, I decided not to edit the explanation yet until someone else confirms they have the same interpretation of the term "ballot tracker" here. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:27, 7 November 2020 (UTC)

:Well, I see that the next paragraph talks about "ballot tracker" in the context of my interpretation, so I'm not sure whether to modify the first paragraph that mentions government sites or not, but I would support removing that first part and just simplifying it to talk about the news organization interpretation of the term. Other input from anyone? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:31, 7 November 2020 (UTC)

:I strongly agree that the correct interpretation for "ballot tracker" is the various sites that provided updates on the ongoing ballot counts at the various states. I think the first interpretation of sites where individual voters can check their ballots is wrong. It especially does not make sense to track how quickly those sites update, since one voter can only view the one site for their ballot, and can't see it updating at some frequency. On the other hand I was an example of the topic of this comic. I obsessively refreshed the New York Times tracking pages to add numbers to spreadsheets graphing trends while also refreshing the live blog at fivethirtyeight.com. As a result I noticed that the live blog quoted results from tracker site Decision Desk HQ several minutes before the same results from the states appeared on the NYT tracker page. I consider myself an example of the target of this comic using that interpretation. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 21:39, 7 November 2020 (UTC)

The article that is linked to is not about tracking tracker sites. The article title is "Tracking Which News Outlets Have Called the Presidential Race in Each State". The article tracks which news sites have called which states. Each such news site presumably has a tracker page for each state in which they display the current reported vote counts. Cueball's tracker tracker is tracking how often each news site's tracker pages are updated with new counts. Each news agency has a "decision desk" which uses the data from their tracking page plus other related information to decide when they will declare a projected win for a candidate in a state. That is referred to as "calling" the race in a state. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 06:45, 8 November 2020 (UTC)

Well now AP's called it. Biden won. [[User:Bubblegum|bubblegum]]-[[User_talk:Bubblegum|talk]]|[[Special:Contributions/Bubblegum|contribs]] 06:57, 8 November 2020 (UTC) (hm, my name looks to be in a different font than the timestamp, odd)
:Also, is anyone up for creating a recursive names category?
:News organizations may have called it, but states still have to certify the results, and certification in some states can't happen until pending litigation has finished making its way through the court system, which will take a few weeks. [[User:Dogman15|Dogman15]] ([[User talk:Dogman15|talk]]) 11:04, 9 November 2020 (UTC)

this makes me think of stud finder finder(Please Sign)

Which will be better, "recursive names" "recursive use“ or "meta-use"? (I think there's enough to make a category about -- 956,1821,2376 and maybe this one deciding on how it's interpreted). [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 15:32, 9 November 2020 (UTC)
: How about just "Recursion"? --[[User:NotaBene|NotaBene]] ([[User talk:NotaBene|talk]]) 16:57, 9 November 2020 (UTC)
: The Explanation gives me a good idea, "Rurcive Naming" ''will'' be nice.
There must be a a tracker that tracks when Randall updates the comic ... Where is that? How does it run? Is it open source? I want to make a tracker that tracks it ... [[Special:Contributions/173.245.52.215|173.245.52.215]] 20:13, 9 November 2020 (UTC)

Are we sure this is cueball in the panel? I mean it looks like there is some hair on his / her scalp. --[[Special:Contributions/188.114.110.132|188.114.110.132]] 18:52, 10 November 2020 (UTC)

Talk:2382: Ballot Tracker Tracker

2020-11-09T15:39:19Z

Xkcdjerry: Changed my comment :)

Could this also refer to sites that track whether one’s ballot has been counted? --[[Special:Contributions/172.68.132.239|172.68.132.239]] 03:31, 7 November 2020 (UTC)

This sense of "calling it" is relatively uncommon, especially for non-native English speakers to encounter. Although having it in quotes is good, some explanation should be added in parentheses. [[Special:Contributions/188.114.110.4|188.114.110.4]] 04:13, 7 November 2020 (UTC)
:See [https://english.stackexchange.com/questions/550851/call-the-race-in-the-election English.stackexchange.com] [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 07:50, 7 November 2020 (UTC)

I remember an earlier comic,Cueball trying to incinerate an incinerator.(xkcd1821),and people tracking trackers(xkcd2376),Maybe there should be a "meta-usage" catogry?(e.g using an incinerator to incinerate another incinerator,using a tracker to track a tracker etc.) [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 13:34, 7 November 2020 (UTC)

The current explanation refers to a ballot tracker as a government site, but I believe they're typically independently provided by either news organizations or political information websites. However, I decided not to edit the explanation yet until someone else confirms they have the same interpretation of the term "ballot tracker" here. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:27, 7 November 2020 (UTC)

:Well, I see that the next paragraph talks about "ballot tracker" in the context of my interpretation, so I'm not sure whether to modify the first paragraph that mentions government sites or not, but I would support removing that first part and just simplifying it to talk about the news organization interpretation of the term. Other input from anyone? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:31, 7 November 2020 (UTC)

:I strongly agree that the correct interpretation for "ballot tracker" is the various sites that provided updates on the ongoing ballot counts at the various states. I think the first interpretation of sites where individual voters can check their ballots is wrong. It especially does not make sense to track how quickly those sites update, since one voter can only view the one site for their ballot, and can't see it updating at some frequency. On the other hand I was an example of the topic of this comic. I obsessively refreshed the New York Times tracking pages to add numbers to spreadsheets graphing trends while also refreshing the live blog at fivethirtyeight.com. As a result I noticed that the live blog quoted results from tracker site Decision Desk HQ several minutes before the same results from the states appeared on the NYT tracker page. I consider myself an example of the target of this comic using that interpretation. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 21:39, 7 November 2020 (UTC)

The article that is linked to is not about tracking tracker sites. The article title is "Tracking Which News Outlets Have Called the Presidential Race in Each State". The article tracks which news sites have called which states. Each such news site presumably has a tracker page for each state in which they display the current reported vote counts. Cueball's tracker tracker is tracking how often each news site's tracker pages are updated with new counts. Each news agency has a "decision desk" which uses the data from their tracking page plus other related information to decide when they will declare a projected win for a candidate in a state. That is referred to as "calling" the race in a state. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 06:45, 8 November 2020 (UTC)

Well now AP's called it. Biden won. [[User:Bubblegum|bubblegum]]-[[User_talk:Bubblegum|talk]]|[[Special:Contributions/Bubblegum|contribs]] 06:57, 8 November 2020 (UTC) (hm, my name looks to be in a different font than the timestamp, odd)
:Also, is anyone up for creating a recursive names category?
:News organizations may have called it, but states still have to certify the results, and certification in some states can't happen until pending litigation has finished making its way through the court system, which will take a few weeks. [[User:Dogman15|Dogman15]] ([[User talk:Dogman15|talk]]) 11:04, 9 November 2020 (UTC)

this makes me think of stud finder finder(Please Sign)

Which will be better, "recurcive names" "recurcive use“ or "meta-use"? (I think there's enough to make a catogory about -- 956,1821,2376 and maybe this one deciding on how it's interpeted). [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 15:32, 9 November 2020 (UTC)

Talk:2382: Ballot Tracker Tracker

2020-11-09T15:32:56Z

Xkcdjerry:

Could this also refer to sites that track whether one’s ballot has been counted? --[[Special:Contributions/172.68.132.239|172.68.132.239]] 03:31, 7 November 2020 (UTC)

This sense of "calling it" is relatively uncommon, especially for non-native English speakers to encounter. Although having it in quotes is good, some explanation should be added in parentheses. [[Special:Contributions/188.114.110.4|188.114.110.4]] 04:13, 7 November 2020 (UTC)
:See [https://english.stackexchange.com/questions/550851/call-the-race-in-the-election English.stackexchange.com] [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 07:50, 7 November 2020 (UTC)

I remember an earlier comic,Cueball trying to incinerate an incinerator.(xkcd1821),and people tracking trackers(xkcd2376),Maybe there should be a "meta-usage" catogry?(e.g using an incinerator to incinerate another incinerator,using a tracker to track a tracker etc.) [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 13:34, 7 November 2020 (UTC)

The current explanation refers to a ballot tracker as a government site, but I believe they're typically independently provided by either news organizations or political information websites. However, I decided not to edit the explanation yet until someone else confirms they have the same interpretation of the term "ballot tracker" here. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:27, 7 November 2020 (UTC)

:Well, I see that the next paragraph talks about "ballot tracker" in the context of my interpretation, so I'm not sure whether to modify the first paragraph that mentions government sites or not, but I would support removing that first part and just simplifying it to talk about the news organization interpretation of the term. Other input from anyone? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:31, 7 November 2020 (UTC)

:I strongly agree that the correct interpretation for "ballot tracker" is the various sites that provided updates on the ongoing ballot counts at the various states. I think the first interpretation of sites where individual voters can check their ballots is wrong. It especially does not make sense to track how quickly those sites update, since one voter can only view the one site for their ballot, and can't see it updating at some frequency. On the other hand I was an example of the topic of this comic. I obsessively refreshed the New York Times tracking pages to add numbers to spreadsheets graphing trends while also refreshing the live blog at fivethirtyeight.com. As a result I noticed that the live blog quoted results from tracker site Decision Desk HQ several minutes before the same results from the states appeared on the NYT tracker page. I consider myself an example of the target of this comic using that interpretation. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 21:39, 7 November 2020 (UTC)

The article that is linked to is not about tracking tracker sites. The article title is "Tracking Which News Outlets Have Called the Presidential Race in Each State". The article tracks which news sites have called which states. Each such news site presumably has a tracker page for each state in which they display the current reported vote counts. Cueball's tracker tracker is tracking how often each news site's tracker pages are updated with new counts. Each news agency has a "decision desk" which uses the data from their tracking page plus other related information to decide when they will declare a projected win for a candidate in a state. That is referred to as "calling" the race in a state. [[User:Bugstomper|Bugstomper]] ([[User talk:Bugstomper|talk]]) 06:45, 8 November 2020 (UTC)

Well now AP's called it. Biden won. [[User:Bubblegum|bubblegum]]-[[User_talk:Bubblegum|talk]]|[[Special:Contributions/Bubblegum|contribs]] 06:57, 8 November 2020 (UTC) (hm, my name looks to be in a different font than the timestamp, odd)
:Also, is anyone up for creating a recursive names category?
:News organizations may have called it, but states still have to certify the results, and certification in some states can't happen until pending litigation has finished making its way through the court system, which will take a few weeks. [[User:Dogman15|Dogman15]] ([[User talk:Dogman15|talk]]) 11:04, 9 November 2020 (UTC)

this makes me think of stud finder finder(Please Sign)

Which will be better, "recurcive names" "recurcive use“ or "meta-use"? (I think there's enough to make a catogory about -- 956,1821,2376 and this one). [[User:Xkcdjerry|Xkcdjerry]] ([[User talk:Xkcdjerry|talk]]) 15:32, 9 November 2020 (UTC)

Talk:2382: Ballot Tracker Tracker

2020-11-07T13:34:48Z

Xkcdjerry: Suggested a new catogry

2332: Cursed Chair

2020-10-25T13:16:22Z

Xkcdjerry: Remove some "Citation needed",since they should only be used sparcingly

{{comic
| number = 2332
| date = July 13, 2020
| title = Cursed Chair
| image = cursed_chair.png
| titletext = The Wirecutter staff called the Herman Miller Siege Perilous "the most cursed product we've ever had to fight" and "nearly as immortal as it boasts."
}}

==Explanation==
[[Beret Guy]] informs [[Cueball]] that he purchased a cursed office chair from a mysterious shop. Cueball isn't sure if he remembers this happening, which is possibly because Beret Guy has [[1772: Startup Opportunity|previously stated]] that he makes a habit of purchasing daily necessities from such stores. Beret Guy then exclaims that the store he bought the chair from was gone when he went to return it, though given his buying preferences, he should perhaps not be so surprised. Cueball suggests that maybe the shop was simply closed due to the {{w|COVID-19 pandemic}}, as is the case for wide variety of non-cursed businesses. Beret Guy takes this as proof that the chair somehow caused the pandemic, a claim Cueball meets incredulously. In the final panel, Beret Guy is doing battle with the chair, which taunts him and claims to be immortal (“''I cannot die''”). In fact, most chairs cannot die, because they are not alive{{Citation needed}}. Cueball remarks that it would be simpler to shop at {{w|IKEA}}, a store famous for its minimalist flat-pack furniture, and which does not sell cursed items{{Citation needed}} (although they ''do'' sell “[[2024: Light Hacks|miniature Dyson spheres]]”).

The cursed chair and the boarded-up store are references to the stores that sell cursed items mentioned in [[1772: Startup Opportunity]]. In that comic, the stores vanished without a trace. But the fact the door was boarded is much more likely due to the pandemic or other causes than the store mysteriously disappearing.

Buying an item from a shop you never noticed before, bringing it home, discovering it is cursed, and trying to return it only to discover the shop isn’t there anymore is a popular trope. See {{tvtropes|TheLittleShopThatWasntThereYesterday}}.

In the title text, the {{w|Siege Perilous}} is the empty seat at the Round Table in Arthurian legend, reserved by Merlin for the knight who would find the {{w|Holy Grail}} (who turns out to be Sir {{w|Galahad}}) and fatal to anyone else who sits in it. {{w|Herman Miller (manufacturer)|Herman Miller}} is an American office furniture company that produced the {{w|Aeron chair}}, which is the basis for [https://www.instagram.com/blantonmuseum/p/BCYaKA4GLrg/ an artwork] by {{w|Glenn Kaino}} called ''The Siege Perilous''. {{w|Wirecutter (website)|''Wirecutter''}} is a website that evaluates and recommends consumer products. From the title text, it sounds like (in the xkcd universe) Wirecutter is used to encountering cursed products, so they didn’t even bother trying to sit in it to test the Siege Perilous’s perilousness (er, ''peril'') before they started fighting it—and emerged victorious, if it’s only ''nearly'' as immortal as it boasts.

==Transcript==
:[Beret Guy and Cueball are talking.]
:Beret Guy: Remember how I bought my desk chair from that mysterious shop?
:Cueball: I think so?
:Beret Guy: Turns out the chair was cursed.

:Beret Guy: So I went back to return it, but the shop was gone! The door was boarded up!
:Cueball: I think most of the shops are closed because of coronavirus.

:[Panel of just Beret Guy.]
:Beret Guy: Oh no!
:Beret Guy: ''The curse must have caused the pandemic!
:Cueball (off-panel): What.

:[Beret Guy starts running with a raised sword in a frameless panel.]
:Beret Guy: If I destroy the chair, we can stop the virus!
:Cueball: What.

:[Beret Guy is chasing a floating desk chair.]
:Beret Guy: ''Die, plague-bringer!''
:Desk chair: Hee Hee I can not die
:Cueball: Maybe you should just shop at IKEA.

==Trivia==

* The hotlink image for the comic was initially [https://web.archive.org/web/20200713231037/https://imgs.xkcd.com/comics/cursed_chair.png extremely pixelated], but the image displayed on the page was a different URL and looked fine. This was soon fixed.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Beret Guy]]
[[Category:COVID-19]]

2242: Ground vs Air

2020-09-30T13:26:41Z

Xkcdjerry: Corrected spelling

{{comic
| number = 2242
| date = December 16, 2019
| title = Ground vs Air
| image = ground vs air.png
| titletext = Water is thinner than both, and fire is *definitely* thicker.
}}

==Explanation==
{{incomplete|Created by a THICK FIRE. More on the general thickness of the "ground", especially on the oceans and at the thickest parts. Needs more about the actual data portrayed.}}
This comic depicts a map of the world using the {{w|Winkel tripel projection}}, comparing the thickness of the ground, which is defined as the {{w|lithosphere}}, to the "thickness" (or height) of the air above it, which refers to the {{w|atmosphere}}.

In an inserted figure, [[Randall]] defines the thickness using three boundaries. At the top is {{w|space}}, defined by the {{w|Kármán line}} at an altitude of 100 km (≈ 62 mi). (See the [[#Trivia|Trivia]] section below for a discussion of this definition of the beginning of space). Below that is the atmosphere which goes down to the ground, where [[Cueball]] is standing, or the water. Beneath the surface is the lithosphere, comprised of the Earth's crust along with the rigid upper part of the mantle, and beneath this is the {{w|asthenosphere}}, the partially melted, highly viscous region of the {{w|upper mantle}} just below the lithosphere. The lithosphere is variable in thickness, averaging about 100 km, but the oceanic lithosphere is much thinner than the continental lithosphere (oceanic crust is thinner and denser than continental crust). The diagram also shows oceanic cross-section to the left-hand side and, though the diagram does not make it explicit, presumably the two measurements used are of the atmosphere down from 'space' to the surface of the ground, if dry, or to the surface of the water covering the ground (which is essentially sea level in the oceans, flucuating slightly with the tides, but covers a broader range for inland water, from the Dead Sea, at 0.4 km below sea level, to Lake Titicaca, almost 4 km above sea level) and of rock descending from the solid interface down to the asthenosphere, as the sliver of liquid that can intervene between the two spans is referred to as a separate measurement elsewhere.

The map shades in the parts where the thickness of the ground is thicker than the thickness of the air. This almost only occurs directly over continents, and certainly only where the continental crust is located (which can stretch into the near-coast parts of oceans). Oceanic crust is much thinner than continental crust. It is also made of a different material; it is denser. Because it is denser, it floats lower in the liquid asthenosphere, causing it to be below sea level. Some parts of continental crust are also under sea level (the continental shelf). These are the areas on the map that are marked as having thicker ground that appear to be over the ocean (such as Northern Canada, or the Caribbean) - they are actually still continental crust. (There are still some exceptions, such as the Sea of Japan and the Philippines).

Randall has mainly used a work by Conrad and Lithgow-Bertelloni from 2006 to estimate the thickness of the "ground", and he gives the reference to the paper [https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005GL025621 DOI.1029/2005GL025621]. Basically, Randall has taken their map and shaded the green and blue areas. It is the second comic in a row with a citation, after the footnote in [[2241: Brussels Sprouts Mandela Effect]].

The title text refers to the ancient four {{w|classical element}}s: earth, water, air, fire. The lithosphere, or ground, is earth, the oceans is water, the atmosphere is air, and fire would thus be the hot, plastic rock of the Earth's mantle, see [[913: Core]]. The mantle is not "on fire", but it is hot enough that it would ignite almost anything on the surface. The water layer on Earth is never more than 11 km deep, even at the deepest part of the ocean, the {{w|Mariana Trench}}, and thus cannot compare to the thickness of the atmosphere or the lithosphere. An expansive definition of "fire" to include the rest of the Earth below the lithosphere puts the fire layer at 6,000 km thick, the radius of the Earth, much thicker than the other layers, hence the ''and fire is *definitely* thicker'' comment at the end of the title text. Space or vacuum would in the classical element terminology have been called the {{w|Aether (classical element)|Aether}}.

In [[977: Map Projections]] the [[977:_Map_Projections#Winkel-Tripel|Winkel-Tripel projection]] is the fifth projection which is linked to the {{w|Hipster (contemporary subculture)|hipster}} subculture.

==Transcript==
:[Caption above the drawing]:
:Which is thicker—the ground or the air?

:[The drawing shows a Winkel tripel projection of the Earth. The features of the main map is unlabeled, with only the outlines of the landmasses present. Various parts of the map are labeled with "Air" (four times) or "Ground" (5 times). Areas marked as "Ground" are differentiated with gray shading. These are always over large landmasses or close to them. They cover most of North America (labeled), the northern part of South America (labeled), Northern Europe and most of Asia (labeled), Japan, most of Australia and part of the Indonesia, Western Africa, sub-equatorial Africa (labeled), and finally the central parts of Antarctica (labeled). Air is written on the West Coast of the United States, in the Atlantic Ocean, over the central part of Africa and in the Pacific Ocean, near the Philippines.]
:[Over West Coast of the United States]: Air
:[Over North America]: Ground
:[Over Atlantic Ocean]: Air
:[Over South America]: Ground
:[Over the central part of Africa]: Air
:[Over the southern part of Africa]: Ground
:[Over Asia]: Ground
:[Over Pacific Ocean]: Air
:[Over Antarctica ]: Ground

:[A small diagram is present in the Pacific Ocean left of South America. The diagram depicts several labeled layers of Earth and its atmosphere, listed below. Cueball, a body of water, and several mountains are shown on the flat surface part of the diagram, with the ocean floor lower than where Cueball stands. Above is a line representing the border to space. The line beneath the surface is much more curved going both up and down. Two double arrows representing the thickness of the atmosphere and the lithosphere are drawn between the surface and the layers above and below. Another curved double arrow is pointing to each of these distances and it is marked with a question mark in the middle of the line.]
:Space
:Atmosphere
:Lithosphere
:Asthenosphere
:?

:[In the bottom right corner of the comic with gray text is a reference:]
:Based mostly on Conrad and Lithgow-Bertelloni (2006) DOI.1029/2005GL025621

==Trivia==
*[[Randall]] always uses the {{w|Kármán line}} as the boundary between Earth's atmosphere and space.
**He has previously mocked the alternative definition of the atmosphere boundary (at 80 km ≈ 50 mi) used by {{w|US Air Force}} and {{w|NASA}} in the title text of [[1375: Astronaut Vandalism]].
***That definition would, of course, have resulted in a significantly different picture where the ''air'' is thicker than the ''ground'' only inside small areas around mid-ocean ridges. Mid-ocean ridges are where new crust is created and the plates are spreading apart; because the crust is new, it is hot and relatively less dense, causing it to float higher up than the surrounding crust. However, the lithosphere thickens over time as the crust cools, these areas have the thinnest "ground."
***Because the lithosphere is comprised only in part of the crust, and in part of a cool, solid layer of mantle, an alternate definition of "ground" including only the crust (and not the mantle lithosphere) could have led to an alternate version of this map where air was thicker in all locations. The crust is rarely more than 70 km thick, still less than even the 80 km Air Force definition of the atmosphere.
**Although most authorities use the FAI definition of the Kármán line since it is the international organization of record for aeronautics, there are good scientific reasons for the U.S. Air Force definition {{Citation needed}}.
**The Kármán line is named for {{W|Theodore von Kármán}}, who originally calculated the height at which a vehicle would have to travel faster than orbital velocity to generate lift from wings (therefore making the vehicle a spacecraft in orbit rather an "air"craft using aerodynamics for flight).
**Von Kármán originally calculated this height as 51.9 miles (83.6 km) - closer to the Air Force definition.
**Additionally, the boundary between the {{W|Mesosphere}} and the {{W|Thermosphere}} is traditionally taken to be 52.7 miles (85 km), also close to the Air Force definition.
**On the other hand, some newer research suggests the mesopause (the line between the mesosphere and thermosphere) may have peaks between 53 and 62 miles (85-100 km).
**Also the {{w|turbopause}} - the line where gas molecules cease mixing atmospherically and begin stratifying by molecular weight as if they are in orbit - is generally taken to be about 100 kilometers (62 miles), and as such, closer to the FAI definition.
**Regardless of which definition is used, the reality is that the transition from atmosphere to space takes place gradually over tens of kilometers.
***But the idea behind this comic is only funny if an atmosphere of 100 km thickness is used.

{{comic discussion}}


[[Category: Comics featuring Cueball]]
[[Category:Maps]]
[[Category:Geology]]
[[Category:Space]]

2259: Networking Problems

2020-01-26T10:01:45Z

Xkcdjerry: Typo fix

{{comic
| number = 2259
| date = January 24, 2020
| title = Networking Problems
| image = networking_problems.png
| titletext = LOOK, THE LATENCY FALLS EVERY TIME YOU CLAP YOUR HANDS AND SAY YOU BELIEVE
}}

==Explanation==
{{incomplete|Created by an ODD-NUMBERED PACKET CLAPPING ITS HANDS. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

Computer problems are frequent and can be difficult to solve. Networking problems in particular can puzzle even seasoned people and sometimes seem to have arbitrary issues causing them. {{w|Network packet|Packets}} are units of data transfer used in computer networking, and one measure of network performance is ''lag'', the amount of time it takes for data to travel from one point to another (and perhaps back); saying a packet's transmission is 'laggy' means it is unacceptably slow.

Lag in packet transmission and other network performance measures can appear quite random. Just to start with, your ISP may be engaged in traffic shaping, which can do very weird things indeed to your packets (making the first megabyte of a transfer faster than any other, for example); now imagine that your ISP's ISP (usually known as an "Upstream Provider") is engaged in something similar, and you begin to see the scale of the problem. Wireless latency can relate to things as unexpected as where people are standing, what they are touching, and what the weather is.
Viruses and other system compromises, as well as legitimate features provided by hardware{{fact}}, may hide their network activity, radically confusing things. Becausee humans are wired to perceive patterns, they will {{w|Apophenia|find them even in random data}}, a fallacy that Cueball is (probably) suffering from here. He variously attributes the network behavior he sees to the packet number being even vs. odd, packet arrival time being before vs. after noon, and packet arrival day being today vs. yesterday (such a pattern would make sense if it were merely "every other packet" regardless of odd or evenness, but that still leaves the other "patterns" Cueball is seeing).

These non-existent patterns that Cueball is 'finding' are driving him mad, so much so that he says he believes in ghosts now. The statement of belief in ghosts may be a reference to the intermittent or fluctuating nature of the network issues being caused by mischievous spirits or malevolent poltergeists. Ghosts generally are not concerned with expressions of belief, but there are some religious traditions that include group clapping and chanting. Many works of fiction depict a future or alternate history where {{tvtropes|MachineWorship|machines are worshiped as gods or spirits}}, such as the Adeptus Mechanicus of ''{{w|Warhammer 40,000}}''. Some of this terminology can be found in present-day IT and other support personnel, including references to "{{w|Daemon (computing)|daemons}}" and "[http://catb.org/jargon/html/B/black-magic.html black magic]". Another possible reference Randall may be making is to the {{w|Ghost_in_the_machine|Ghost in the machine}}, a term describing AI. A third possibility is that Cueball's brain had stopped working (As Randall had suggested in his chart).

The title text continues Cueball's maniacal attempts at self-assurance, which may be him alluding to J.M. Barrie's play ''{{w|Peter Pan}}'' by saying that latency falls every time you "CLAP YOUR HANDS AND SAY YOU BELIEVE" or possibly 1800s mystic spiritualism that continues some today. In the play, Peter Pan says "If you believe in fairies, wave your handkerchiefs and clap your hands." A more mundane explanation of the network behavior Cueball is experiencing might be that it is random but he's seeing a pattern anyway, or that there is a loose connection or trace and the vibration of clapping and speaking in the vicinity of the equipment in question closes the connection.

==Transcript==
:[A chart is shown with one horizontal line with 13 ticks (the first larger) and ending in an arrow. There are three labels along the line, at the start in the middle an towards the end before the arrow. Below are two clouds in gray with labels. The first cloud is long and it is getting thinner towards the right. It goes between the first and second label above the chart. The second blob is smaller and of equal thickness and it goes from the last label towards right. Above the chart is a heading and a subheading:]
:<big>Types of Computer Problems</big>
:By how much debugging them makes your brain stop working

:[The three labels above and the two in the clouds:]
:None
:Some
:A lot
:Normal problems
:Networking problems

:[Below the chart, only in the right part of the comic is a comic drawing. Cueball is kneeling before a rack of servers. One of the server blades is extended and connected by a cable to a laptop sitting on a box, which Cueball is using. Behind Cueball, there is a wireless router sitting on a stool, which is connected by a cable to another wireless router sitting on the floor, which is connected to another laptop. From behind him to the right an off-panel voice emanates from a starburst at the edge of the panel.]
:Cueball: '''''Before''''' noon, '''''odd'''''-numbered packets were laggy, but ''after'' noon, '''''even'''''-numbered ones are! It's the '''''opposite''''' of yesterday!
:Off-panel voice: Are you sure you're okay?
:Cueball: '''''I'm fine and I believe in ghosts now!'''''

{{comic discussion}}

[[Category:Charts]]
[[Category:Comics featuring Cueball]]
[[Category:Cueball Computer Problems]]