explain xkcd - User contributions [en]

2809: Moon

2023-08-01T12:06:13Z

172.70.85.96: /* Explanation */

{{comic
| number = 2809
| date = July 31, 2023
| title = Moon
| image = moon_2x.png
| imagesize = 313x402px
| noexpand = true
| titletext = I mean, it's pretty, but it doesn't really affect us beyond that. Except that half the nights aren't really dark, and once or twice a day it makes the oceans flood the coasts.
}}

==Explanation==
{{incomplete|Created by a STRANGE ORB FLOATING IN THE SKY. Do NOT delete this tag too soon.}}

The {{w|Moon}} is a celestial body orbiting Earth, first formed approximately 4.5 billion years ago - about 50 million years after the initial formation of the solar system. As of today (August 1st, 2023), the Moon is still orbiting the Earth{{Citation needed}} at a distance of approximately 384,400 kilometers, or about 238,900 miles.

This comic points out how weird it is to have such an enormous celestial body near to us. The second nearest, Venus, is approximately 46.576 million kilometers away at its closest. The Moon is close enough that we can see the craters and other stuff on the surface with our naked eye, though a telescope would help.

There are other planets with moons, but Earth's moon is very big compared to Earth - Mars's moons are way smaller and the biggest moon in our solar system, Ganymede, is just twice as massive with 1.5 the radius despite orbiting Jupiter, which is 317x more massive than Earth with 11x bigger radius.

In human history, we have landed twelve people on the moon in the Apollo missions from 1969 to 1972. Despite advancements in technology since then, we have yet to land another person on the Moon, though plans are being made.

The title text refers to two facts how the moon majorly impacts life on Earth, which also would seem strange if it wasn't real: Firstly the lunar cycle, in which the Moon's orbit is roughly half the time on the opposite side of the Earth from the Sun and (being visibly at least half illuminated, whilst there, except briefly during rare eclipses) provides a low but significant amount of reflected illumination that nature (as well as humanity) has found a nocturnal use for. Secondly, the title text also refers to the tides, a very nearly twice-daily cycle where the Moon's gravity (modified by the Sun's) subtly pulls upon the Earth and dragging the waters of the seas and oceans around, periodically increasing the sea levels in most places.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Ponytail points to something in the sky, presumably the moon. Cueball stands nearby.]
:Ponytail: That thing hanging in the sky is a second nearby world. It's close enough that you can see its surface as it passes overhead.
:Cueball: Wow. Isn't that... weird?
:Ponytail: I dunno, it's just always been there.

:[Caption below the panel:]
:If it didn't exist, the moon would sound like such an outlandish sci-fi concept.

==Trivia==
Earth's moon is weird for an additional two reasons. First, it is by far the largest and most massive moon relative to the planet it orbits. Secondly, our moon is the only moon in the solar system to not have a proper name, not even a jumble of letters and numbers. In English it is simply given the proper name of "the Moon" (capitalized), being the ancient archetype for all other moons discovered since the time of Galileo, although it can also be described by other titles such as "Luna" (directly taken from from Latin mythology/astronomy).

{{comic discussion}}

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

Talk:2734: Electron Color

2023-02-09T15:57:26Z

172.70.85.96:

Electrons have no color?! BUt lIgHTnIng strIKeS aRe YEllOw, aND LigHTNing IS MaDe uP of eLECTrOns.[[Special:Contributions/172.71.254.115|172.71.254.115]] 22:43, 6 February 2023 (UTC)
: Actually most colors are emitted by electrons orbiting atoms after absorbing light. The color electrons emit depend on their kinetic energy and available places they can travel, a tiny bit similar to how things change color as they get hotter, but more extreme and general. [[Special:Contributions/172.70.114.198|172.70.114.198]]
: I'm pretty sure lighting strikes are white. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:58, 7 February 2023 (UTC)

It may refer to the Greek etymology of the word "electron". Originally it meant amber, a yellow gem. [[Special:Contributions/172.68.118.146|172.68.118.146]] 23:20, 6 February 2023 (UTC)
:But amber isn't yellow - it's... amber. [[Special:Contributions/172.70.85.222|172.70.85.222]] 10:40, 8 February 2023 (UTC)

I can't do formatting, I'm new. Sorry! {{unsigned|No Idea If There's A Character Limit LMAO}}

To me, this is 1000% building on the idea of debating the colors of school subjects. I've added a bit of explanation to the text about it. I used my own color associations & reasons (science = green, history = red) as an example, and I'm sure people will disagree with me. Leave your color/subject associations in a reply to this comment, could be a fun little debate! (also, English = blue)
[[User:Zman350x|Zman350x]] ([[User talk:Zman350x|talk]]) 23:50, 6 February 2023 (UTC)
: SocStud is yellow, Math is red, Science is green?, ELA is gray, French is blue, and orange is my least favorite subject out of the rest. I have gotten into many arguments with my friends.
:[[Special:Contributions/172.70.230.157|172.70.230.157]] 00:10, 7 February 2023 (UTC)
:: Science = Green (green flask bubbling)
:: Social Studies = Blue (blue and green globe, green is taking)
:: Math = Red (math is reliable, red is a strong color so i associate it with reliability)

:: English = Yellow (all other colors are taken)
:: Also electrons are blue
::[[User:Iffy|Iffy]] ([[User talk:Iffy|talk]]) 23:53, 6 February 2023 (UTC)
::: Hm! I've never heard of school subjects having any assigned colors; much less any debate about it! If we're identifying them by the folders they're kept in, my favorite subject was Ferrari & my least favorite was Porsche.
::: [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 04:41, 7 February 2023 (UTC)
:::: I don't recall colour-coded (UK) schoolbooks, in particular (except the "red pirate, green pirate, blue pirate, etc" stories for young kids, the red pirate like only rubies, the green one emeralds, the blue probably sapphires, and had clothing/etc that matched, naturally), but I had (have still, somewhere!) a collection of Usborne Encyclopaedias at home with a veritable rainbow of colours. Mathematics was yellow, I think, Computers a shade of blue, one of the Red or off-Red (slightly pinker, but still deep red) might have been Physics (had geophysics in it, IIRC), I think History was a light-green. I'm sure I never had the whole set, but I had enough to arrange in as close to Richard Of York order as I felt most content to do, when on the bookshelf.
::::: Obviously there ''were'' colours involved with the school stuff. I'm sure different levels of SPMG (Scottish Primary Maths Group?) workbooks were colour-coded, perhaps more for the benefit of the teacher, though the later {{w|School Mathematics Project|SMP}} ones were probably more just identified as "13a", "5b", etc, to work through various sub-subjects and the increasingly advanced techniques thereof, perhaps coloured with highlights only to not be boring black-on-white monochrome covers.
::::: And there's so many other colour-classifications that I instituted for myself, over the years, showing just how useful a hue can be to represent and differentiate a class of something, such as various 3M-style "post-it"-like arrow stickers stuck into the pages of a book for quick reference to all instances of one particular thing or another. For which I suppose I'm grateful to not having any notable form of colour-blindness, to limit my options. [[Special:Contributions/172.70.91.114|172.70.91.114]] 08:20, 7 February 2023 (UTC)
:::: Personally, I've always thought that English is red, Math is blue, Sciences are green, History is yellow, and "personal events" are orange.
::::::This is completely BS. This is about the diagrams used for drawing atoms where colors are used for different elementary particles. And Randall clearly explains that they do not have real color. And the jokes that people still have feelings for what colors are chosen based on the conventions used where people first learned about atoms. Have removed the color on subjects completely as it has nothing to do with this comic. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
::::::PS you cannot be more than 100% on anything :-D --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:46, 7 February 2023 (UTC)

I believe this comic was made in response to a book talk Randall did in Seattle, where this question was actually asked to him in person! If you want to hear it yourself, someone recorded the talk here: https://www.reddit.com/r/xkcd/comments/xjuc4i/a_recording_and_autotranscript_of_randalls_latest/
[[Special:Contributions/172.71.142.6|172.71.142.6]] 00:45, 7 February 2023 (UTC) A random new user
: Was it the dorky randall with red hair or the photogenic one with brown hair and blue eyes or am I going wildly mad? [[Special:Contributions/172.70.114.198|172.70.114.198]] 00:51, 7 February 2023 (UTC)

Am I crazy, I always thought of electrons as blue to contrast with the protons which are red[[Special:Contributions/172.70.211.89|172.70.211.89]] 04:47, 7 February 2023 (UTC)
:You're all crazy! Elections are 2817.9am & protons are 1.5am. "Yellow" is over 557,000,000,000am! Maybe you've all got your displays' color gamut set too low? ;S
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
::I have also seen protons as red and neutons as white and electron as blue in the diagrams I remember. Never yellow electrons. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
:::I'm not entirely sure about proton and electrons, but neutrons were black. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:58, 7 February 2023 (UTC)

"This comic appears to "elevate" that discussion to the college level." - considering that the students are considerably smaller than the teacher (notice the heads), I seriously doubt this is meant to be set in a college classroom - high school at most, IMHO. Also, "One common debate among schoolchildren is over the "color" of various subjects. Because of the brightly colored folders commonly used to separate subjects in the binder of a young student, the students tend to associate those colors with the subject." - well, not in any school I ever attended, nor with any school class I've ever worked with. I'd be inclined to dispute that this is at all common. [[Special:Contributions/172.70.46.85|172.70.46.85]]
: I agree that this is probably not supposed to be college-level, but the color-subject coordination is definitely real (albeit not a very common topic of debate). [[Special:Contributions/162.158.90.38|162.158.90.38]] 08:01, 7 February 2023 (UTC)
::I find it hard to believe Randall is referencing colors of school subjects without alluding to them in any way; to the contrary, I feel fairly certain he's directly referencing the various colors assigned to electrons, protons, quarks, etc, in diagrammatic illustrations of atomic structure. I think the whole first paragraph is way off base (though interesting tangentially).
::[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
:::I agree with all above here and have corrected the explanation to school class and pupils and diagram colors removing school subject color completely! --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
::::Was it also worth removing the synesthesia bit? Entirely unrelated to school-subject organisation-by-colour that I also think was an {{w|Red herring|incarnadine ''clupea harengus''}}, but very possibly relevent to "but I happen think it's obvious that <concept> is a <hue> thing!"... For consideration, or as a side-note, whether or not you restore that possible reference. [[Special:Contributions/172.71.242.203|172.71.242.203]] 10:42, 7 February 2023 (UTC)

Electrons are blue, right? In all my textbooks (Germany) electrons are blue. Is this a generally accepted addition? [[Special:Contributions/198.41.242.166|198.41.242.166]] 07:13, 7 February 2023 (UTC)
: I stopped the explanation saying that electrons were (by implication, ''solely'') yellow. If green is used for a nucleon (neutron? red being proton?), they might choose blue for an electron, as contrast. Or black dot or white (black-outlined) small circle to contrast with whatever the nucleons are with their much bigger circles clumped in the middle.
: But, given other regular colour-conventions, I could imagine yellow as a popular 'electron' colour. Either in its own right (influencing the choices given to the other things depicted) or as the main obviously remaining option (the other things having been decided upon first). Horses for courses. And I can imagine cultural/national differences (e.g. what colours your household wiring was set up as, at least before EU standardisation but then red and black still exists in the mindset, despite blue and brown, or whatever it might have been) if not localised 'linguistic puns' to make some choices more 'obvious' than others. [[Special:Contributions/172.70.91.114|172.70.91.114]] 08:20, 7 February 2023 (UTC)
::Indeed, yellow is sometimes indicative of electrical hazard, as opposed to red for flame... So many ways to draw associations!
::[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
:::Yes blue electrons, red protons and white neutrons are probably common on Europe, it is in Denmark. I'm a physicist and word with radioactive isotopes and teach about them. My drawings are red protons and white neutrons and blue electrons. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)

I don’t know what Ms. Lenhart is talking about. Electrons are blue, protons are red, and neutrons are definitely grey. Not sure how to sign my comment tho. Oh well {{unsigned ip|172.70.174.115|13:00, 7 February 2023}}
:(You sign your comments with a string of <code><nowiki>~~~~</nowiki></code> (as suggested by the comment at the top of many a comic-discussion page, when you start to edit it)... or you wait for someone else to do what I just did for you, but that's more effort than the four tildes on your part.)
:For what it's worth, I'm mostly with you. Red and grey/dark-grey/black in the centre, as you say. Light blue (or yer actual electric blue?) or (bluish?) white electrons. Depends what colour-pallettes are available to the illustrator/modeller, I imagine, and what else needs a distinct colour alongside the basic trio (e.g. yellow fission/fusion "sparky-flame energy things" or general labelling stuff). [[Special:Contributions/162.158.158.246|162.158.158.246]] 13:15, 7 February 2023 (UTC)
::I did some data collection on image searches for atom diagrams, and yes, the defacto color standard is protons red, neutrons grey (less commonly yellow or green), and electrons blue.
::I like this because it gives opposing colors to the opposing positive and negative charges, (the same color choices as the traditional magnet north and south ends, likely not coincidentally,) and a neutral color to the uncharged neutron.
::Which makes me think that when Lenhart says "electrons are yellow" she does not mean in the diagram sense, but rather in the sense "if you make an electron big enough to see, it is yellow".
::[[User:SomeDee|SomeDee]] ([[User talk:SomeDee|talk]]) 16:58, 7 February 2023 (UTC)
:electrons are green. y'all are trippin [[Special:Contributions/172.71.154.159|172.71.154.159]] 17:27, 7 February 2023 (UTC)
::definitely green. Have none of you ever used a transmission electron microscope? Or an oscilloscope? Green shine everywhere! [[Special:Contributions/162.158.95.22|162.158.95.22]] 09:01, 8 February 2023 (UTC)

I made a survey for this: https://forms.gle/Pu5mkEtBZPUZ6dbb8
[[User:RamenChef|RamenChef]] ([[User talk:RamenChef|talk]]) 18:03, 7 February 2023 (UTC)

Electrons are yellow, protons are red, and neutrons are gray. End of discussion.
:What about roses and violets? [[Special:Contributions/172.71.242.172|172.71.242.172]] 10:49, 8 February 2023 (UTC)

{{w|Quark_(dairy_product)|Quark}} is white, or off-white.[[Special:Contributions/172.70.85.96|172.70.85.96]] 10:47, 8 February 2023 (UTC)
:I find this comic puzzling. Virtually all colors we see are due to electrons (transitions between different states in atoms, molecules, and solids), so saying they are "too small to interact with visible light" is quite incorrect. [[Special:Contributions/172.69.134.130|172.69.134.130]] 18:48, 8 February 2023 (UTC)
::Yeah. They totally interact with visible light. But only with light of specific frequency matching the energy difference between some electron and free higher orbit it can move to. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 19:00, 8 February 2023 (UTC)

((Snipped))
: What language is this? This is and English site, so please write in English. Google Translate detects it as Hungarian, but leaves almost all of the words untranslated. [[Special:Contributions/162.158.90.38|162.158.90.38]] 04:31, 9 February 2023 (UTC)
:: It's just a past troll. Who has several times said they've finished trolling, or promised to finish trolling in a given instance if only someone would include some word or other in their next edit. (Spoiler: they never stopped, so we just have to deal with it and carry on.)
:: The 'language' was worked out (it's a conlang that's a mix of actual non-English root words and 'cod Latin'-type transforms, essentially) but I'm not wasting braincells on its inanity or going to make it a 'mainstream thing'. They do worse things to vandalise the site, but that doesn't mean that the above can be left unchallenged as relatively benign.
:: My advice is to ignore it (or revert it away, if nobody else does that quickly enough). [[Special:Contributions/172.70.162.222|172.70.162.222]] 09:14, 9 February 2023 (UTC)
:::What is a conlang and what is cod Latin? [[Special:Contributions/172.68.34.45|172.68.34.45]] 15:12, 9 February 2023 (UTC)
:::: "Conlang" means a {{w|Constructed language}}. And I think they actually meant {{w|Dog Latin}} or (more likely, in context) {{w|Pig Latin}}, though "Cod" does {{wiktionary|cod#Etymology_3|sometimes mean}} a fake/imitation of something, so Pig Latin might perhaps be described as a cod-Latin. Or confusingly misrefered to as such, by accident... [[Special:Contributions/172.70.162.222|172.70.162.222]] - ooo... I'm routing through the ''exact'' same IP, which is rare enough when I edit my own submissions. Above editor is probably with the same ISP as me. ;)

2735: Coordinate Plane Closure

2023-02-09T09:45:47Z

172.70.85.96: /* Explanation */ Minor correction (zero z-axis only an issue 'in zone') and knock-on effects from unwarned drivers making the 'obvious' ad-hoc travel plan revisions and causing problems.

{{comic
| number = 2735
| date = February 8, 2023
| title = Coordinate Plane Closure
| image = coordinate_plane_closure_2x.png
| imagesize = 271x376px
| noexpand = true
| titletext = 3D graphs that don't contact the plane in the closure area may proceed as scheduled, but be alert for possible collisions with 2D graph lines that reach the hole and unexpectedly enter 3D space.
}}

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

This comic is a "Math Notice," which is presumably a warning or reminder for mathematicians or others who interact with the field of mathematics, in a similar way to how a "Travel Notice" may prewarn drivers of planned road closures for repairs (or [https://www.cameroncountytx.gov/spacex/ rocketry]). Specifically, this one advises those who are using the coordinate plane to avoid drawing any graphs in the area with a hole until the damage is patched or fixed. This comic invents this concept of Math Notices, and is also very similar to that of a {{w|Notice to mariners}} or {{w|NOTAM|airmen}}, where nautical or aeronautical navigation might be impinged by a clear area (or volume) that should be kept clear from in the near future. The comic also resembles notices from websites or software providers about planned maintenance, which alert users about upcoming outages.

{{w|Coordinate planes}} are used in math for drawing graphs. The joke here is that a small section has been "closed for maintenance," likening the concept of a coordinate plane to an actual physical platform used by math, which is therefore vulnerable to damage such as is shown in the comic. In reality, the coordinate plane cannot be damaged as it is not a tangible thing.{{citation needed}}

Closure in mathematics can be a term relating to sets, specifically operations on sets, and a coordinate plane is a particular set of numbers. A set is closed under an operation if all the "answers" to the operation are also in the set. The coordinate plane is said to be closed under vector addition for example - adding together any two coordinates produces another coordinate in the plane. Many functions and operators may be said to have closure on the real plane, and this comic may be a pun on that term. However, if there actually is a hole in the plane, then suddenly the plane will no longer exhibit closure.

Also related to closure is the {{w|closure problem}}. Put simply, the closure problem is to find the highest or lowest weight of a closure in certain types of graphs. This comic may also be talking about the closure problem, as it talks about a hole in the graph, and to minimise it would be referring to the closure problem.

Closure can also be used in another sense, relating to the topology of a set; roughly speaking, a description of what parts of the set are "close" to others. In this sense, if one takes the closure of a plane with a hole, the result is indeed an intact plane, provided the hole is sufficiently (infinitesimally) small.

The title text notes that 3D graphs that cross the relevant x and y coordinates, but with non-zero z coordinates whilst in that zone, should be fine, since the hole only exists in the plane where z = 0. However, if they pass close - i.e. the z coordinate is small in this region - they should be wary of two dimensional graph lines suddenly become three-dimensional and interfering with them. This could be because they have intentionally entered three-dimensional space to avoid the closure, or possibly they have inadvertently been 'launched' above/below the plane by the torn and watped edges of the surface. This is similar to warnings to road traffic in open lanes being warned of traffic merging from lanes that have been closed due to works or any other general warning of increased congestion upon a parallel route used as a diversion.

==Transcript==

:<big>⚠️ Math Notice ⚠️</big>[emojis written without color]

:The coordinate plane will be closed Thursday between (1.5, 1) and (2, 1.5) to repair a hole.

:[A coordinate graph is shown, with a gray hole between (1.5, 1) and (2, 1.5). There are small fractures around the hole. The hole is highlighted with two dots in the corners of a hollow rectangle with split border lines.]

:If your graph uses this area, please postpone drawing until Friday or transform it to different coordinates.

{{comic discussion}}

[[Category:Math]]
[[Category:Charts]]

Talk:2734: Electron Color

2023-02-08T10:47:33Z

172.70.85.96:

Electrons have no color?! BUt lIgHTnIng strIKeS aRe YEllOw, aND LigHTNing IS MaDe uP of eLECTrOns.[[Special:Contributions/172.71.254.115|172.71.254.115]] 22:43, 6 February 2023 (UTC)
: Actually most colors are emitted by electrons orbiting atoms after absorbing light. The color electrons emit depend on their kinetic energy and available places they can travel, a tiny bit similar to how things change color as they get hotter, but more extreme and general. [[Special:Contributions/172.70.114.198|172.70.114.198]]
: I'm pretty sure lighting strikes are white. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:58, 7 February 2023 (UTC)

It may refer to the Greek etymology of the word "electron". Originally it meant amber, a yellow gem. [[Special:Contributions/172.68.118.146|172.68.118.146]] 23:20, 6 February 2023 (UTC)
:But amber isn't yellow - it's... amber. [[Special:Contributions/172.70.85.222|172.70.85.222]] 10:40, 8 February 2023 (UTC)

I can't do formatting, I'm new. Sorry! {{unsigned|No Idea If There's A Character Limit LMAO}}

To me, this is 1000% building on the idea of debating the colors of school subjects. I've added a bit of explanation to the text about it. I used my own color associations & reasons (science = green, history = red) as an example, and I'm sure people will disagree with me. Leave your color/subject associations in a reply to this comment, could be a fun little debate! (also, English = blue)
[[User:Zman350x|Zman350x]] ([[User talk:Zman350x|talk]]) 23:50, 6 February 2023 (UTC)
: SocStud is yellow, Math is red, Science is green?, ELA is gray, French is blue, and orange is my least favorite subject out of the rest. I have gotten into many arguments with my friends.
:[[Special:Contributions/172.70.230.157|172.70.230.157]] 00:10, 7 February 2023 (UTC)
:: Science = Green (green flask bubbling)
:: Social Studies = Blue (blue and green globe, green is taking)
:: Math = Red (math is reliable, red is a strong color so i associate it with reliability)

:: English = Yellow (all other colors are taken)
:: Also electrons are blue
::[[User:Iffy|Iffy]] ([[User talk:Iffy|talk]]) 23:53, 6 February 2023 (UTC)
::: Hm! I've never heard of school subjects having any assigned colors; much less any debate about it! If we're identifying them by the folders they're kept in, my favorite subject was Ferrari & my least favorite was Porsche.
::: [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 04:41, 7 February 2023 (UTC)
:::: I don't recall colour-coded (UK) schoolbooks, in particular (except the "red pirate, green pirate, blue pirate, etc" stories for young kids, the red pirate like only rubies, the green one emeralds, the blue probably sapphires, and had clothing/etc that matched, naturally), but I had (have still, somewhere!) a collection of Usborne Encyclopaedias at home with a veritable rainbow of colours. Mathematics was yellow, I think, Computers a shade of blue, one of the Red or off-Red (slightly pinker, but still deep red) might have been Physics (had geophysics in it, IIRC), I think History was a light-green. I'm sure I never had the whole set, but I had enough to arrange in as close to Richard Of York order as I felt most content to do, when on the bookshelf.
::::: Obviously there ''were'' colours involved with the school stuff. I'm sure different levels of SPMG (Scottish Primary Maths Group?) workbooks were colour-coded, perhaps more for the benefit of the teacher, though the later {{w|School Mathematics Project|SMP}} ones were probably more just identified as "13a", "5b", etc, to work through various sub-subjects and the increasingly advanced techniques thereof, perhaps coloured with highlights only to not be boring black-on-white monochrome covers.
::::: And there's so many other colour-classifications that I instituted for myself, over the years, showing just how useful a hue can be to represent and differentiate a class of something, such as various 3M-style "post-it"-like arrow stickers stuck into the pages of a book for quick reference to all instances of one particular thing or another. For which I suppose I'm grateful to not having any notable form of colour-blindness, to limit my options. [[Special:Contributions/172.70.91.114|172.70.91.114]] 08:20, 7 February 2023 (UTC)
:::: Personally, I've always thought that English is red, Math is blue, Sciences are green, History is yellow, and "personal events" are orange.
::::::This is completely BS. This is about the diagrams used for drawing atoms where colors are used for different elementary particles. And Randall clearly explains that they do not have real color. And the jokes that people still have feelings for what colors are chosen based on the conventions used where people first learned about atoms. Have removed the color on subjects completely as it has nothing to do with this comic. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
::::::PS you cannot be more than 100% on anything :-D --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:46, 7 February 2023 (UTC)

I believe this comic was made in response to a book talk Randall did in Seattle, where this question was actually asked to him in person! If you want to hear it yourself, someone recorded the talk here: https://www.reddit.com/r/xkcd/comments/xjuc4i/a_recording_and_autotranscript_of_randalls_latest/
[[Special:Contributions/172.71.142.6|172.71.142.6]] 00:45, 7 February 2023 (UTC) A random new user
: Was it the dorky randall with red hair or the photogenic one with brown hair and blue eyes or am I going wildly mad? [[Special:Contributions/172.70.114.198|172.70.114.198]] 00:51, 7 February 2023 (UTC)

Am I crazy, I always thought of electrons as blue to contrast with the protons which are red[[Special:Contributions/172.70.211.89|172.70.211.89]] 04:47, 7 February 2023 (UTC)
:You're all crazy! Elections are 2817.9am & protons are 1.5am. "Yellow" is over 557,000,000,000am! Maybe you've all got your displays' color gamut set too low? ;S
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
::I have also seen protons as red and neutons as white and electron as blue in the diagrams I remember. Never yellow electrons. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
:::I'm not entirely sure about proton and electrons, but neutrons were black. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:58, 7 February 2023 (UTC)

"This comic appears to "elevate" that discussion to the college level." - considering that the students are considerably smaller than the teacher (notice the heads), I seriously doubt this is meant to be set in a college classroom - high school at most, IMHO. Also, "One common debate among schoolchildren is over the "color" of various subjects. Because of the brightly colored folders commonly used to separate subjects in the binder of a young student, the students tend to associate those colors with the subject." - well, not in any school I ever attended, nor with any school class I've ever worked with. I'd be inclined to dispute that this is at all common. [[Special:Contributions/172.70.46.85|172.70.46.85]]
: I agree that this is probably not supposed to be college-level, but the color-subject coordination is definitely real (albeit not a very common topic of debate). [[Special:Contributions/162.158.90.38|162.158.90.38]] 08:01, 7 February 2023 (UTC)
::I find it hard to believe Randall is referencing colors of school subjects without alluding to them in any way; to the contrary, I feel fairly certain he's directly referencing the various colors assigned to electrons, protons, quarks, etc, in diagrammatic illustrations of atomic structure. I think the whole first paragraph is way off base (though interesting tangentially).
::[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
:::I agree with all above here and have corrected the explanation to school class and pupils and diagram colors removing school subject color completely! --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)
::::Was it also worth removing the synesthesia bit? Entirely unrelated to school-subject organisation-by-colour that I also think was an {{w|Red herring|incarnadine ''clupea harengus''}}, but very possibly relevent to "but I happen think it's obvious that <concept> is a <hue> thing!"... For consideration, or as a side-note, whether or not you restore that possible reference. [[Special:Contributions/172.71.242.203|172.71.242.203]] 10:42, 7 February 2023 (UTC)

Electrons are blue, right? In all my textbooks (Germany) electrons are blue. Is this a generally accepted addition? [[Special:Contributions/198.41.242.166|198.41.242.166]] 07:13, 7 February 2023 (UTC)
: I stopped the explanation saying that electrons were (by implication, ''solely'') yellow. If green is used for a nucleon (neutron? red being proton?), they might choose blue for an electron, as contrast. Or black dot or white (black-outlined) small circle to contrast with whatever the nucleons are with their much bigger circles clumped in the middle.
: But, given other regular colour-conventions, I could imagine yellow as a popular 'electron' colour. Either in its own right (influencing the choices given to the other things depicted) or as the main obviously remaining option (the other things having been decided upon first). Horses for courses. And I can imagine cultural/national differences (e.g. what colours your household wiring was set up as, at least before EU standardisation but then red and black still exists in the mindset, despite blue and brown, or whatever it might have been) if not localised 'linguistic puns' to make some choices more 'obvious' than others. [[Special:Contributions/172.70.91.114|172.70.91.114]] 08:20, 7 February 2023 (UTC)
::Indeed, yellow is sometimes indicative of electrical hazard, as opposed to red for flame... So many ways to draw associations!
::[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 09:18, 7 February 2023 (UTC)
:::Yes blue electrons, red protons and white neutrons are probably common on Europe, it is in Denmark. I'm a physicist and word with radioactive isotopes and teach about them. My drawings are red protons and white neutrons and blue electrons. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:43, 7 February 2023 (UTC)

I don’t know what Ms. Lenhart is talking about. Electrons are blue, protons are red, and neutrons are definitely grey. Not sure how to sign my comment tho. Oh well {{unsigned ip|172.70.174.115|13:00, 7 February 2023}}
:(You sign your comments with a string of <code><nowiki>~~~~</nowiki></code> (as suggested by the comment at the top of many a comic-discussion page, when you start to edit it)... or you wait for someone else to do what I just did for you, but that's more effort than the four tildes on your part.)
:For what it's worth, I'm mostly with you. Red and grey/dark-grey/black in the centre, as you say. Light blue (or yer actual electric blue?) or (bluish?) white electrons. Depends what colour-pallettes are available to the illustrator/modeller, I imagine, and what else needs a distinct colour alongside the basic trio (e.g. yellow fission/fusion "sparky-flame energy things" or general labelling stuff). [[Special:Contributions/162.158.158.246|162.158.158.246]] 13:15, 7 February 2023 (UTC)
::I did some data collection on image searches for atom diagrams, and yes, the defacto color standard is protons red, neutrons grey (less commonly yellow or green), and electrons blue.
::I like this because it gives opposing colors to the opposing positive and negative charges, (the same color choices as the traditional magnet north and south ends, likely not coincidentally,) and a neutral color to the uncharged neutron.
::Which makes me think that when Lenhart says "electrons are yellow" she does not mean in the diagram sense, but rather in the sense "if you make an electron big enough to see, it is yellow".
::[[User:SomeDee|SomeDee]] ([[User talk:SomeDee|talk]]) 16:58, 7 February 2023 (UTC)
:electrons are green. y'all are trippin [[Special:Contributions/172.71.154.159|172.71.154.159]] 17:27, 7 February 2023 (UTC)
::definitely green. Have none of you ever used a transmission electron microscope? Or an oscilloscope? Green shine everywhere! [[Special:Contributions/162.158.95.22|162.158.95.22]] 09:01, 8 February 2023 (UTC)

I made a survey for this: https://forms.gle/Pu5mkEtBZPUZ6dbb8
[[User:RamenChef|RamenChef]] ([[User talk:RamenChef|talk]]) 18:03, 7 February 2023 (UTC)

Electrons are yellow, protons are red, and neutrons are gray. End of discussion.

{w|Quark_(dairy_product)|Quark} is white, or off-white.[[Special:Contributions/172.70.85.96|172.70.85.96]] 10:47, 8 February 2023 (UTC)

2732: Bursa of Fabricius

2023-02-04T02:55:23Z

172.70.85.96: /* Explanation */

{{comic
| number = 2732
| date = February 1, 2023
| title = Bursa of Fabricius
| image = bursa_of_fabricius_2x.png
| imagesize = 298x399px
| noexpand = true
| titletext = If an anatomical structure is named for a person, it means they were the only person to have it. Pierre Paul Broca had a special area of his brain that created powerful magnetic fields, enabling him to do 19th century fMRI research.
}}

==Explanation==
{{incomplete|Created by FLYING BIRD SCIENTISTS WITH TRANSPLANTED AVIAN LYMPHATIC ORGANS - Do NOT delete this tag too soon.}}
The {{w|Bursa of Fabricius}} is an organ found in birds that is necessary for the development of their immune systems.

This comic claims that the 16th century anatomist {{w|Hieronymus Fabricius}} (for whom the organ was named) had that organ and therefore was able to fly like a bird. However, despite being found only in birds, this organ does not in fact contribute directly to flight. Also given that it only exist in birds, then it is doubtful that Fabricius also independently had this same anatomical feature.

Many scientific and mathematical discoveries, including anatomical structures, are named after the people who discovered or described them. For example, the {{w|islets of Langerhans}} were discovered by Paul Langerhans. Likewise, rare diseases are often named for the doctor who first describes the disease to the medical community, or for a researcher who identifies the specifics involved. They may attempt to set their own name to it, for posterity, or they are later honoured in this manner by those who recognise their vital contribution to the field, such as with {{w|Parkinson's disease#History|Parkinson's disease}}.

In other cases, rare diseases are named for the first or most famous (possibly even the only) person known to have had the disease. For instance {{w|ALS}} is commonly known as Lou Gehrig's disease in the US because of baseball player {{w|Lou Gehrig}} having notably developed the condition. Outside of the US, it may be more known just as "amyotrophic lateral sclerosis" (alternatively "motor neurone disease") or, for simplicity, the initials ALS (or MND).

The title text continues with the idea from the comic claiming that anatomical structures are solely possessed by the human for which they are named, in another similar example. {{w|Pierre Paul Broca}}, a French physician, anatomist and anthropologist, was known for his research on what is now known as {{w|Broca's area}}, a region of the brain used for speech and language processing. The premise being that, having this feature, he was uniquely gifted with the special ability to created powerful magnetic fields, enabling him to do {{w|fMRI}} research in the 19th century.

Broca did not do fMRI research,{{Citation needed}} a powerful method of non-intrusively imaging and analysing the internal structures of the living human body (amongst other things), as it was not invented in his lifetime. Nor is it likely that this ability could be 'naturally' possessed by any individual, such as he. He did, however, physically study brains of known speech-impaired patients who had then subsequently died, determining what damage (in the area of the brain which was then to be named for him) was directly related to their specific group of ailments. Today, we can safely view this area in living people, using fMRI, and directly connect what we see with the current condition of patients. This increases our knowledge of the brain, as with the mythical abilities Randall gave Broca, but also possibly even allows us to help those currently under the effects of any observed damage (not necessarily possible by any 19th century physician, even with this superpowered form of vision to assist them).

In reality, if Broca was the only person to have ever possessed Broca's area then this might have meant that only he had ever had the power of speech (as we understand it), which would indeed give him a very special ability; but one begging a number of other vital questions, if only anybody else could have asked them...

This may also be a nod to the Discworld character [https://wiki.lspace.org/Bursar "Bursar"], a wizard at Unseen University who can fly because he once hallucinated that he could, and so now he can.

==Transcript==
:[An almost bald man with hair around the neck and a full beard, is shown flying in the top right part of the image, swooping down from the sky with arms outstretched in front of him while yelling. Three dotted lines behind him indicate his path. Two people look up at him from the bottom left corner, a man with a wide-brimmed hat and a black haired woman with a scarf over her hair, which is hanging down behind her. She is holding both her hands up to her mouth. At the top of the panel there is text:]
:The '''''bursa of Fabricius''''' is a lymphoid organ found only in birds and in 16th century anatomist Hieronymus Fabricius, to whom it conferred the power of flight.
:Hieronymus Fabricius: ''Wheee''

{{comic discussion}}

[[Category:Comics featuring real people]]
[[Category:Characters with hats]]
[[Category:Biology]]
[[Category:Animals]]

Talk:2732: Bursa of Fabricius

2023-02-01T22:10:46Z

172.70.85.96:

One of the reasons for the success of humans is that the tools of humans do not depend on the structure and strength of the human body. Using fire as an example, a single person with a fire stick can burn down an entire forest in a matter of hours. Fire is not limited by the person who started it. The same goes for any other tool we make. ~ [[user:megan|Megan]] she/her [[user talk:megan|talk]] [[special:contribs/megan|contribs]] 18:35, 1 February 2023 (UTC)

Here's the wiki for Bursa of Frabricius: https://en.wikipedia.org/wiki/Bursa_of_Fabricius

And the wiki for Hieronymus Fabricius: https://en.wikipedia.org/wiki/Hieronymus_Fabricius [[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 18:51, 1 February 2023 (UTC)

So ''that's'' why I can't find the Gräfenberg spot! [[User:LunarNapolean|LunarNapolean]] ([[User talk:LunarNapolean|talk]]) 20:34, 1 February 2023 (UTC)
:Perhaps you should have met {{w|R. G. Waldeck|Frau Gräfenberg}}? [[Special:Contributions/172.70.85.96|172.70.85.96]] 22:10, 1 February 2023 (UTC)