explain xkcd - User contributions [en]

2592: False Dichotomy

2023-05-27T16:27:18Z

162.158.86.201: /* Explanation */

{{comic
| number = 2592
| date = March 11, 2022
| title = False Dichotomy
| image = false_dichotomy.png
| titletext = There are two types of dichotomy: False dichotomies, true dichotomies, and surprise trichotomies.
}}

==Explanation==
A dichotomy is two alternatives which are normally mutually exclusive (such as the dichotomy between a flat Earth and non-flat Earth). A {{w|false dichotomy}} is a {{w|logical fallacy}} based on an incorrect perception of limited options (for example: if the page background isn't white, it is black).

[[Cueball]] has apparently made one such error and is being called out by [[White Hat]] for it. Upon having this pointed out to him, Cueball says that we must '''embrace''' false dichotomies, because the '''only other option''' is {{w|cannibalism}}. This statement is another false dichotomy, as presenting false dichotomies is not the only alternative to cannibalism{{Citation needed}}. The reverse (that cannibalism is incompatible with expressing false dichotomies) is also not potentially true, as eating people may eventually result in having nobody you need to present false dichotomies to.

Cueball has thus created another false dichotomy to excuse his first.

The false dichotomy Cueball appears to be referring to is the notion that those identified as human must not be eaten, but even closely related animals are not human and can be eaten, i.e. species can be divided clearly between "human" and "food". If this dichotomy is not accepted, then consuming any species that shares, for instance, any significant percentage of DNA with humans could be considered a measure of cannibalism.

The title text states that there are two kinds of dichotomies, making a dichotomy in itself. Due to three types of dichotomy being mentioned, and only two being foreshadowed, this statement is itself a surprise trichotomy, or three-parted choice. The title text is a variation of the [https://tropedia.fandom.com/wiki/There_Are_Two_Kinds_of_People_in_the_World "Two kinds of People"] joke. The classic math nerd variant is "There are three kinds of people in the world, those who can count, and those who can't." Alternatively, it may refer to a variation about {{w|base 2|binary}}. The original joke usually goes something like this: "There are 10 types of people: those who know binary, and those who don't." The variation is usually something like the following: "There are 10 types of people: those who know binary, and those who don't, and those who weren't expecting a {{w|base 3|ternary}} joke." Another version of this kind of joke is "there are two kinds of people: those who can extrapolate from an incomplete data set,"

The word {{wiktionary|trichotomy}} is a relative neologism, to be understood as to mean "divided into (or amongst) three parts", having replaced the original prefix "di-" (a factor of two, either doubled or, by context, halved) with that of "tri-" (similarly tripled/thirded). Strictly, though, {{wiktionary|dichotomy}} more directly stems from Greek elements that say "apart, I cut", with "apart" being represented by the "dicho-" (itself being roughly "into two", or to separate) which does not have a direct "tricho-" equivalent, although it does ultimately derive from "duo", Greek for "two". This is the kind of linguistic nuance that [[Randall]] clearly enjoys, yet may also happily or carelessly (mis)use without compunction.

It can also be translated through the other Greek word, θρίξ (thríx), turning "trichotomy" into "cutting hair off". The fact that both characters in this strip don't have visible hair is probably just a coincidence.

==Transcript==
:[White Hat and Cueball are talking to each other. White Hat has his arms spread outwards in exasperation, while Cueball gestures assertively with his pointer finger.]
:White Hat: That's a false dichotomy!
:Cueball: Yes, but we have to embrace false dichotomies, because the only alternative is cannibalism.

{{comic discussion}}
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Language]]
[[Category:Self-reference]]

2759: Easily Confused Acronyms

2023-04-06T07:14:11Z

162.158.86.201: /* Explanation */ direct LEVER link to w:lever

{{comic
| number = 2759
| date = April 5, 2023
| title = Easily Confused Acronyms
| image = easily_confused_acronyms_2x.png
| imagesize = 557x444px
| noexpand = true
| titletext = 'Lever' was originally an acronym for Load Emplification by the Vimulated Emission of Radiation.
}}

==Explanation==
{{incomplete|Created by a RIGHT OMPLIFICATION BY THE BIMULATED OMISSION OF TADIATION - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
In this comic, [[Randall]] compared the Acronym "Laser" with various other five-letter acronyms. He first explained the "Laser" and "Maser" correctly, but the following three are simply the full name of "Laser" with the first word and initials changed. The replacement first word is correct for these acronyms, but the other words formed from changing the first letter are nonsense.

{| class="wikitable" style="margin:auto"
!Acronym !! Comic !! Actual
|-
| {{w|LASER}} || Light Amplification by the Stimulated Emission of Radiation || Light Amplification by the Stimulated Emission of Radiation
|-
| {{w|MASER}} || Microwave Amplification by the Stimulated Emission of Radiation || Microwave Amplification by the Stimulated Emission of Radiation
|-
| {{w|SONAR}} || Sound Omplification by the Nimulated Amission of Radiation || SOnic Navigation And Ranging
|-
| {{w|RADAR}} || Radio Amplification by the Dimulated Amission of Radiation || RAdio Detection And Ranging
|-
| {{w|LIDAR}} || Light Implification by the Dimulated Amission of Radiation || LIght Detection And Ranging
|-
| {{w|lever|LEVER}} (title text) || |Load Emplification by the Vimulated Emission of Radiation. || ''(not an acronym)''
|}

Laser and maser are true-to-life acronyms. The remaining 3 words' true meanings are as follows: sonar is short for "sound/sonic navigation and ranging", radar for "radio detection and ranging", lidar for "light detection and ranging". (Note that these 3 each include the second letter from their first word in the acronym.)

The three false definitions simply suppose that all 5 of the acronyms follow the same model and swap out the necessary letters to fit, in a square-peg-round-hole manner.

The title text extends this to the 5-letter word "lever". This is an ordinary word (derived from an Old French word ''levier'', which means "to lift"), not an acronym at all. {{w|Lever}}s have been used since time immemorial (even [https://quatr.us/physics/levers-simple-machines-physics.htm animals have been known to use them)], and predates high-tech uses of radiation by millennia (it's one of the {{w|simple machines}} that {{w|Archimedes}} studied in Ancient Greece).

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:Easily-confused acronyms cheat sheet

:Laser

:Light Amplification by the Stimulated Emission of Radiation

:Maser

:Microwave Amplification by the Stimulated Emission of Radiation

:Sonar

:Sound Omplification by the Nimulated Emission of Radiation

:Radar

:Radio Amplification by the Dimulated Amission of Radiation

:Lidar

:Light Implification by the Dimulated Amission of Radiation

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

Talk:2719: Hydrogen Isotopes

2023-01-04T13:08:10Z

162.158.86.201: atom size does not depend on temperature

This shows as a 404 on xkcd.com but in my RSS feed i can see the comic
: Works for me. [[Special:Contributions/172.69.34.9|172.69.34.9]] 02:25, 3 January 2023 (UTC)
::works for me now too but it didnt before
::: It works on m.xkcd.com and on the homepage of xckd, but the direct link gives me a 404. Various services such as the Wayback Machine show it as loading though. Could be a bad cache on some service. [[Special:Contributions/162.158.63.86|162.158.63.86]] 02:37, 3 January 2023 (UTC)

Could someone add an explanation of Nydnonen? I don't get it and it's google proof [[Special:Contributions/172.71.210.209|172.71.210.209]] 05:04, 3 January 2023 (UTC)Benzodiakanine
: Nothing. Was hopeful about {{w|List of Greek and Latin roots in English/N}} but nope. Tried stemming on all the Wiktionaries too. [[Special:Contributions/172.71.158.91|172.71.158.91]] 05:28, 3 January 2023 (UTC)
::Kudos to whomever figured it out, lol! [[Special:Contributions/172.71.158.231|172.71.158.231]] 08:02, 3 January 2023 (UTC)
:::Seems someone already did. There are four N's in that word replacing three of the consonant in Hydrogen so there are now four Ns one for each of the four neutrons in Nydnonen. ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:10, 3 January 2023 (UTC)

Are these to scale? I recently read that the Helium is smaller in terms of measured atomic radius than the Hydrogen. Possibly this is true of Deuterium as well? [[Special:Contributions/172.70.85.45|172.70.85.45]] 06:50, 3 January 2023 (UTC)
:They are almost the same size but it depends on temperature: https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.200800063 [[Special:Contributions/162.158.90.153|162.158.90.153]] 08:00, 3 January 2023 (UTC)
::Is the reason Helium is smaller not that there are double the positive charge which the electrons thus orbit in a lower orbit (I know this is not the correct in reality with the orbit). But if true then Deuterium would not have this effect as it is not the weight but the charge that changes the orbit. And Deuterium has the same charge as Hydrogen as does Tritium. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:10, 3 January 2023 (UTC)

::[[User:Kynde|Kynde]] is right, it is essentially the charge of the nucleus that determines orbital size, not its mass (which is always thousands of times larger than the mass of the electron). Nuclear mass has only very small effects on the electron orbitals. The most prominent effect probably would be that with a heavier nucleus, the center of mass of the atom would shift a little bit closer to the center of the nucleus (or, in other words, the reduced mass of the electron would increase a little bit), where the "little bit" is on the order of less than 10^-3. Other effects like nuclear size (distribution of the positive charge) or gravitation would be even much smaller. Note that the paper [https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.200800063 cited above] does not deal with the size of atoms. Instead, it describes the effect of temperature on the molecular volume of benzene (C6H6) versus deuterated benzene (C6D6). This makes sense, since the apparent volume of a molecule depends on, among others, the amplitudes of intramolecular vibrations, which in turn depend on bond strength, mean energy (temperature), and atomic mass (hence the isotope effect). However, temperature does not affect the size of an atom. In fact, for a single atom, "temperature" has no meaning at all. --[[Special:Contributions/162.158.86.201|162.158.86.201]] 13:08, 4 January 2023 (UTC)

Is "oops all neutrons" distinct from Neutronium, which is also all neutrons? [[Special:Contributions/172.70.100.131|172.70.100.131]] 07:38, 3 January 2023 (UTC)
:Neutronium is ultra-dense and bound by gravity, with a minimum of about 1.2x1058 neutrons in a 40 kilometer diameter sphere. [[Special:Contributions/162.158.90.153|162.158.90.153]] 08:00, 3 January 2023 (UTC)
::Well actually a {{w|neutron star}} is only 10 km in radius (20 km in diameter) according to Wikipedia. And it is 1057 neutrons acording to this [https://www.astronomy.ohio-state.edu/ryden.1/ast162_5/notes21.html lecture on Neutron Stars]. {{w|Neutronium}} was actually used as a name for neutrons without protons and suggested to be placed as number 0 on the periodical table. But is has also been used as a name for the matter in the center of neutron stars, but usually not in scientific papers! There it is called degenerate matter. The wiki article mentions how a single neutron decays to proton/electron/neutrino in 15 minutes. It also mentions that two neutrons could form for very short periods in nuclear decay. An then mentions that more than two neutrons together is not likely to exist. Specifically mentioning the three from Randall's Oops particle as not being stable for even the shortest of times. Of course a neutron would also not be able to orbit a group of neutrons. But even the three at the center is impossible. More neutrons together would be isotopes of number 0 element... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:22, 3 January 2023 (UTC)
::: My bad memory; thanks. [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)

I think "Maximum Strength" is a reference to medicines marketed as such - in particular brands of Ibuprofen "Maximum Strength Tablets". --[[Special:Contributions/172.69.79.132|172.69.79.132]] 14:59, 3 January 2023 (UTC)
: Yes - typically meaning that it contains far more of whatever its active ingredient is than is necessary to be efficacious.[[Special:Contributions/172.70.91.128|172.70.91.128]] 15:54, 3 January 2023 (UTC)

Considering that Deuterium is derived from Greek and Tritium works in both Greek and Latin, wouldn't the correct name for ⁴H be Tetartium?
:Tetrium maybe? Tetraium? [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)

Is it just me or have the recaptchas gotten much more difficult over the past week, to the point of ambiguous or indiscernibly blurred images and frequently rejecting correct responses (i.e. "please try again" in red)? Granted, I'm not saying this behavior makes it any less valid as a captcha, but it's a little surprising to always get several-step challenges lately. [[Special:Contributions/172.71.154.38|172.71.154.38]] 05:08, 4 January 2023 (UTC)
: Captchas are in a continual arms race with bot writers, and wax and wane in difficulty as new attacks and counter-measures are deployed. ReCAPTCHA occasionally becomes more lengthy when they refresh their image library; we may be experiencing that. It sure doesn't seem to be slowing down the creation of new phantom usernames -- does registration even have the captcha? [[Special:Contributions/172.71.154.159|172.71.154.159]] 07:43, 4 January 2023 (UTC)
:: Firstly yes, and that might be the problem, because ReCAPCHA is still quite mild on other sites. Whomever is automating username registration here (which has been going on at least five years) may have fallen prey to a new countermeasure increasing their failure rate and making our site's angry. [[Special:Contributions/172.70.206.150|172.70.206.150]] 12:21, 4 January 2023 (UTC)

Re "ium": Shouldn't we try to keep the explanation short and to the point? This comic is about "isotopes", i.e. about different options of how to construct a single atom (or atom-like entity). IMO, there is no need to include many-body effects in a set of multiple electrons ([https://www.explainxkcd.com/wiki/index.php?title=2719%3A_Hydrogen_Isotopes&type=revision&diff=303973&oldid=303971 "Fermi velocity"] or [https://www.explainxkcd.com/wiki/index.php?title=2719:_Hydrogen_Isotopes&oldid=304060 "electron degeneracy pressure"]); just as there is no need to discuss, say, the kinetic theory of gases made up of these isotopes, or how they would be able to form fluids or solids. It is good to see that people who contribute here know about these effects, but I think that the explanation does not benefit from extending the discussion too far beyond the subject of a given comic. If anything, it might be worthwhile to include a reference to {{w|ion trap|ion traps}} - especially since in a Penning trap electrons actually go in circulating orbits (although not exactly circular). --[[Special:Contributions/172.70.246.210|172.70.246.210]] 11:56, 4 January 2023 (UTC)
: Go for it. We all agree to have our "writing to be edited mercilessly" in the fine print just below the Summary. Editing on whims is good because if someone else liked something earlier they will just merge it back in somehow. [[Special:Contributions/172.70.206.150|172.70.206.150]] 12:21, 4 January 2023 (UTC)

221: Random Number

2022-12-07T10:00:43Z

162.158.86.201: /* Trivia */

{{comic
| number = 221
| date = February 9, 2007
| title = Random Number
| image = random_number.png
| titletext = <nowiki>RFC 1149.5</nowiki> specifies 4 as the standard IEEE-vetted random number.
}}
==Explanation==
The comic specifies a function (in a {{w|C (programming language)|C}} similar syntax), which judging by its name should be designed to return a random number. Most functions of this form are random number ''generators'', meaning that on subsequent calls they return ''different'' random numbers. But the programmer has instead implemented a function that just returns the ''same'' random number each time, which, while it could indeed have been truly randomly chosen by rolling a die as the [[156: Commented|comment]] documented, is essentially worthless were it ever to be called more than once (with the expectation of different, i.e., random, results). In other words, the results over time would not be random at all, but completely predictable and deterministic.

The {{w|IEEE}} is the organization responsible for maintaining a number of computer standards. An RFC, or {{w|Request for Comments}}, is a formal document put out to computing experts by {{w|IETF}} in the hopes of becoming a future standard. However, RFC 1149 was an {{w|April Fools' Day Request for Comments|April Fools' joke}}, defining how carrier pigeons can be used to transmit Internet packets. "<nowiki>RFC 1149.5</nowiki>," meanwhile, simply does not exist.

==Trivia==

* The well-known "helper website" ([http://gChq.github.io/CyberChef/#recipe=XKCD_Random_Number() CyberChef]) has a function that simulates XKCD's program.
* Esolangs.org features a [http://esolangs.org/wiki/user:XKCD_Random_Number challenge] that requires you to rewrite the program in XKCD's comic in another programming language, as either a function or a full program that prints the "4".
* The most commonly used ORM framework for SQL databases, '''Hibernate''', uses the xkcd method to generate a random UUID generation strategy.
From the hibernate-core-5.6.7.Final.jar:

<nowiki> public class StandardRandomStrategy implements UUIDGenerationStrategy {
/**
* A variant 4 (random) strategy
*/
@Override
public int getGeneratedVersion() {
// a "random" strategy
return 4;
}
}
</nowiki>

==Transcript==
[A computer program.]
int getRandomNumber()
{
return 4; // chosen by fair dice roll.
// guaranteed to be random.
}

{{comic discussion}}
[[Category:Programming]]
[[Category:Computers]]
[[Category:Comics with lowercase text]]

2706: Bendy

2022-12-03T21:13:42Z

162.158.86.201: Undo revision 300256 by 172.71.142.170 (talk)

{{comic
| number = 2706
| date = December 2, 2022
| title = Bendy
| image = bendy_2x.png
| imagesize = 291x209px
| noexpand = true
| titletext = Squaring the circle is really easy with some good clamps.
}}

==Explanation==
{{incomplete|Created while BENDING OVER PULLBACKWARDS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Geometry usually represents 2D polygons with simple straight lines. In the comic, the lines are compared to a physical object, and are shown to have the property of bendiness. Randall claims this simplifies geometry as now triangles can have arbitrarily defined side lengths by merely stretching the lines, but it is unclear what benefits this may have over current Euclidean geometry. These lines cannot have Euclidean properties, but other non-Euclidean systems have been invented in the past with non-standard properties.<ref>{{w|Non-Euclidean_geometry}}</ref>

This comic may be a reference to axis breaks in graphs, which shrink large segments and enhance readability and are denoted by a wiggly line on the axis in question.

The title-text talks about "{{w|Squaring the circle}}", a famous geometry problem based around constructing a square with the same area as a given circle with a compass and straightedge, which was proven to be impossible (even with more powerful forms of construction, such as marked straightedges or origami) in 1882 as pi is a transcendental number (Not to be confused with {{w|Tarski's circle-squaring problem|circle-squaring}}.) However, it then goes on to describe a way to literally turn one of these bendy shapes from a circle into a square, namely using clamps.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[There are two right triangles. One triangle has side lengths of 3, 4, and 5, and is scribbled out in red. The other triangle has the same general shape but with the catheti appearing like longer but bent lines, so that all the side lengths equal 5 if straightened.]

:[Caption below the panel:]
:Huge geometry breakthrough: Turns out those lines we make triangles out of are bendy!

{{comic discussion}}

[[Category:Math]]
[[Category:Comics with color]]