explain xkcd - User contributions [en]

Talk:3089: Modern

2025-05-15T05:50:02Z

172.69.43.221:

Hate to be that guy, but wow, it’s empty [[User:Broseph|Broseph]] ([[User talk:Broseph|talk]]) 19:04, 14 May 2025 (UTC)

This strip reminded me of the comments in [[3063]]. Historians / historiographers typically define (early) "modernity" to begin around 1500. {{w|early modernity}} [[Special:Contributions/172.71.182.126|172.71.182.126]] 19:12, 14 May 2025 (UTC)

A similar problem exists, where a recent version of the Bible is known as the New Revised Standard Version. It will be a bit awkward when it is not new, revised, or standard. [[User:BobcatInABox|BobcatInABox]] ([[User talk:BobcatInABox|talk]]) 19:38, 14 May 2025 (UTC)
:The US Military has a similar problem: naming a system "Next-Gen [X]" but then the "Next Gen" item eventually becomes the current generation, and is eventually moving towards being obsolete and you need a successor (next-next gen?).[[Special:Contributions/172.69.6.111|172.69.6.111]] 20:05, 14 May 2025 (UTC)
::I guess the phone companies got it right with the 3G, 4G, 5G naming. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:23, 14 May 2025 (UTC)
::: Except for that {{w|10G}} glitch. And Dilbert predicted people copyrighting "8G" years before that. [[Special:Contributions/104.23.172.75|104.23.172.75]] 20:34, 14 May 2025 (UTC)
::There is a (not ''always'' consistent) "nth generation" classification system that is quite developed. The F-22 Raptor is a 5th Generation fighter, for example, with the (next-)next-gen ones being designed for the next decade being 6th. Though, yes, "Next Gen" still pops up (currently the programs I know of are ''mostly'' aimed at the solutions for #6, of course). [[Special:Contributions/141.101.99.129|141.101.99.129]] 22:23, 14 May 2025 (UTC)

Wasn't there an earlier strip describing a similar problem on Wikipedia edits, maybe tied to the {{w|recency bias}}? There's the idea that every more recent slice needs a new, relevant name. It also seems to work going backwards, where humanity's genus, tribe, subfamily, and family are "homo", "hominini", "homininae", and "hominidae" respectively. We seem to crave a name for every arbitrary slice that is relevant for a particular researcher. And now I'm thinking of Futurama's "New New York". I'm surprised there's not already a New New York somewhere. [[Special:Contributions/162.158.233.117|162.158.233.117]] 20:31, 14 May 2025 (UTC)
:Eventually, there'll be a [https://tardis.fandom.com/wiki/New_New_York New New New New New New New New New New New New New New New York]...
:Anyway, I actually live not far from a(nother) {{w|New York#United Kingdom|New York}}, and am also a regular visitor to (old) York. So I may not have been to New York, New York, on my travels, but I've got it covered on both sides. (I ''have'' been to both new Boston ''and'' the old one, but only been to the old Washington, both the original Richmond and its first copycat (but none of the US copycopyⁿcats), etc.) [[Special:Contributions/162.158.216.175|162.158.216.175]] 22:01, 14 May 2025 (UTC)

::Hmmm. I've a suspicion I know who you are.
::I'm gonna say...you ain't heavy? [[User:Yorkshire Pudding|Yorkshire Pudding]] ([[User talk:Yorkshire Pudding|talk]]) 22:16, 14 May 2025 (UTC)
:::Ah, no. Sorry, I'm not aware of any fraternal relationship. Not just not with you, but not with anyone. ;) Nice to know there are potentially more of you out there, though.
:::I also forget where I think you're ''exactly'' from, from past information, but I do know that it's a different corner from me. Though I think you wisely left it vague, and I'm happy to be even vaguer (hence why I supplied multiple possibilities)... I think it's only rather specific (sort-of-)local knowledge that even let guess what more exacting info I ''think'' I know about you. West Riding, for starters, but I'm not going to narrow you down further. :p [[Special:Contributions/172.70.86.134|172.70.86.134]] 22:38, 14 May 2025 (UTC)
::I know where you live now /j [[User:Commercialegg|Commercialegg]] ([[User talk:Commercialegg|talk]]) 00:13, 15 May 2025 (UTC)
:::...to within 3 million acres or so, sure... ...maybe! /jj [[Special:Contributions/172.69.43.221|172.69.43.221]] 05:50, 15 May 2025 (UTC)

Where do I post site suggestions?¿?¿?¿?¿ [[User:Aprilfoolsupdate!|Aprilfoolsupdate!]] ([[User talk:Aprilfoolsupdate!|talk]]) 04:20, 15 May 2025 (UTC)
:What kind of suggestion? (And, for that matter, what kind of site?!?) Though I would probably start by clicking on the Community Portal link in the side navbar over <- there (and up a bit?). Might also be worth seeing if your potential suggestion already has something like it, rather than add a new section the repeats one (or more) past subheader(s). Also might help you find which sub-page suits your particular input. [[Special:Contributions/172.69.43.221|172.69.43.221]] 05:50, 15 May 2025 (UTC)

3080: Tennis Balls

2025-04-25T11:40:05Z

172.69.43.221: /* Explanation */ Still worth a link, methinks

{{comic/sandbox 
| number = 3080
| date = April 23, 2025
| title = Tennis Balls
| image = tennis_balls_2x.png
| imagesize = 411x574px
| noexpand = true
| titletext = After initial tests created a series of large holes in the wall of the lab, the higher-power Scanning Tunneling Tennis Ball Microscope project was quickly shut down.
}}

==Explanation==
{{incomplete|The first sentence might be a little too short, maybe we should give examples where scanning electron microscope are used? Could use clarification on what is needed for quantum tunneling to happen.}}

A {{w|scanning electron microscope}} produces images of a sample by scanning the surface with a focused beam of electrons, and interpreting the different signals that are generated in response. Since [[Megan]] and [[Cueball]] find electrons too small to work with, they have created a macroscopic version using tennis balls instead. The tennis ball launcher uses a similar mechanism to a scanning electron microscope: it fires tennis balls, instead of electrons, over a wide range of heights, and detects objects obstructing the stream (in this case a person) by the noises generated on impact. However, this would mostly be 'useful' in scanning things at a macroscopic level, so is not really a microscope. {{w|Computational microscopy}} can be used to increase the resolution of an image beyond the size of the sampling medium by extensively analyzing details of interactions, and a tennis ball microscope could potentially be used to tune such algorithms at an observable scale — the joke of striking a human, as well as the manual single-ball operation, imply that Randal did not intend this use.

Megan and Cueball have detected a person using their device, by the fact that it generated two yells during the scan, possibly from impacting the person's face or another part of their body. They intend to repeat the experiment to determine the person's height, by working out the angle of the tennis balls that generate the yells. Combined with the velocity and time to impact, this should give them enough information to work out the height above ground at impact and the distance from the launcher. The joke is that this height measurement could probably have been completed with a visual assessment, and with far more accuracy than using tennis balls to approximate their height. Most humans work with large-scale objects in their day-to-day lives and hence do not see using a microscope, although the lens in the eye operates on the same principal as the objective lens in an optical one. This method is also likely to be problematic, as the person would likely duck or run away in response to being bombarded with tennis balls, affecting future measurements. This is known as the {{w|Observer effect (physics)|Observer Effect}} as well as a normal {{w|Sampling (signal processing)#Practical considerations|consideration of sampling}}. (It may also be why the 'scanning' is done from the top down, as early {{tvtropes|GroinAttack|low-hitting projectiles}} might reduce the height that later projectiles can detect.)

The title text is a reference to {{w|scanning tunneling microscope}}s, which take advantage of the {{w|quantum tunnelling}} effect. In this case, the tennis balls were actually tunneling through the wall, creating holes in the process, which is not what tunneling electrons would do. Tunneling is a non-intuitive quantum phenomenon whereby particles may "teleport" across a barrier they would otherwise bounce off of, but it requires a number of particles of extremely low mass to exploit quantum effects, with a comparatively thin barrier, to be observable. It would not be reasonable to produce this effect at tennis ball scale with any typical building wall, but naively attempting to do so by launching tennis balls at a sufficiently high velocity (the required speed dependant upon whether they are aimed at the likes of plasterboard, brick or concrete) could lead to damaging the wall instead.

==Transcript==
:[Cueball fires eight tennis ball at decreasing heights using a tennis ball machine, which makes four "thunk" noises. Megan is standing behind him. The tennis ball machine has a container for tennis balls at the top, which is connected to a tube where the balls are launched. Behind the machine is a handle that Cueball holds with both hands to control the machine, and at the bottom is a stand with two legs.]

:[Cueball has stopped firing tennis balls and is resting his hand on the handle of the machine. Ten noises come from the right side of the panel:]
:Bonk
:Bonk
:Bonk
:Bonk
:Bonk
:OW!
:Bonk
:OW!
:Bonk
:Bonk
:[Megan has her hand to her chin.]
:Megan: Ok, there's definitely a person over there. Let's do one more pass to try to measure their height.

:[Caption below the panel:]
:Electrons are small and hard to work with, so some scientists have developed a scanning tennis ball microscope instead.

==Trivia==

{{w|Electron tomography#Atomic Electron Tomography (AET)|Atomic electron tomography}} uses electrons to precisely identify and map the individual atoms of a sample and is leading to extensive novel materials research.

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Physics]]

2558: Rapid Test Results

2025-03-25T08:47:33Z

172.69.43.221: Nope.

{{comic
| number = 2558
| date = December 22, 2021
| title = Rapid Test Results
| image = rapid_test_results.png
| titletext = A solid red area with two white lines means that you have been infected with the anti-coronavirus, COVID+19, which will cure anyone you have close contact with.
}}

==Explanation==
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|COVID-19 pandemic}}.

This comic is a joke about COVID-19 rapid {{w|lateral flow test}} results. These devices are used in many countries for individuals to test their own nasal and oropharynx fluid for evidence of COVID-19 virus to detect asymptomatic infection. These tests have two indicator strips - a test line for covid-19 and a control line to check the device is working correctly. Where a control line is not present, the test should be ignored and repeated. Until comparatively recently {{w|Pregnancy test|pregnancy}} was the occasion [[583|most familiar]] for requiring this form of test.

The first 2 answers are the standard indicators for a negative and positive result, but Randall takes this to absurdity, see below in the [[#Table of results|table]].

The title text interprets the hyphen in "Covid-19" as a negative sign to make a mathematical joke. Here Randall postulates a counterpart virus to Covid-19, resulting in a test with inverted colors, which he names Covid+19. When combined this anti-coronavirus exactly matches the original one and results in zero Covid, curing those who had previously been infected.

This was the last comic before this year's [[:Category:Christmas|Christmas comic]]. It was about Covid-19 testing. The last comic before the 2020 Christmas comic, [[2402: Into My Veins]], was about the Covid-19 vaccine.

===Table of results===
{| class="wikitable"
!Result
!Interpretation
!Explanation
|-
|Control line only
|Negative
|As for all such actual tests, the Control line indicates that the test has run without error. Without this Control line (which ''always'' shows on a correctly functioning test after proper use), a lack of result on the test strip is meaningless.
A control line with no Test line indicates that the molecule being tested for is not present.

|-
|Control and test line
|Positive
|This clearly shows the (un)desired test result, with both the Control line and the indicator of the tested-for condition.
|-
|2 wavy lines resembling the {{w|Approximation#Typography|approximately equal}} sign
|Approximately positive
|While it would be possible to make the test produce wavy line(s) by default, and some versions 'activate' more complex patterns such as tick-marks or wording, these are still binary yes/no results. The waviness or other patternation would not normally be contingent upon the testing state it must reveal, and the complicated pattern could result in a fainter Test line (However, {{w|National Health Service|NHS}} advice states that any positive line, no matter the strength, should be considered a positive).

A real test intended to produce straight lines might become wavy if manufactured poorly. Two lines would still indicate a positive test, but the poor quality of the device calls into question that result - making "approximately positive" an appropriate description.

Whilst this may have been unintended, it is worthwhile noting that lateral flow tests sacrifice some accuracy in order to be quick and cheap. They therefore have some risk of {{w|false-positive}} test results, hence the need for a follow-up gold-standard laboratory controlled confirmation test. In this sense, a positive rapid test result would give an approximately positive result.
|-
|2 lines closer together than usual
|Positive (college ruled)
|This is the same as the Positive result, just with less distance between the two lines. {{w|Ruled paper#United States|College ruled}} refers to how college ruled notebooks in the United States have narrower spacing between the lines.
Again, there is no simple way to make the test reveal different patterns as a result-indicator of any qualitative or quantitative result; this is not a different result from the original Positive. It also remains more desirable to maintain an easily-identifiable separation between lines and not risk the Test and Control lines bleeding together into one.
|-
|Five lines of decreasing lengths
|Good cell signal
|Mimics the standard image for a strong mobile (or cellular in the United States) phone signal.
This implies that the Rapid Test being used in the comic can also detect cellphone signals, which is both strange and useless for someone trying to test themselves for COVID-19 (but useful to know if you're planning to call a hospital). Furthermore, it is unknown how a chemical test can pick up on electromagnetic phenomena involving radio waves.
|-
|2 lines on a background of radiating lines
|Did you know these lines are actually parallel?
|This is a reference to an {{w|optical illusion}} called the {{w|Hering illusion}}, where two parallel lines appear to bend outward.
Whether the radial lines can (or should) be designed into the test has no bearing upon the core test, and probably won't cause misidentification of whether the test reveals one or two clear "straight" lines.
|-
|Multiple lines in the shape of a scary stick figure
|The Blair Witch is near
|In the found-footage movie ''{{w|The Blair Witch Project}}'', stick figures shaped like this indicated that the Blair Witch was near.
The type of rapid test used for COVID-19 probably does not have any useful method for revealing the proximity of witchcraft,{{fact}} unless a witchcraft-related molecule could be identified that can be indicated within the sample material itself.
|-
|Three lines
|Click to expand COVID menu
|A reference to {{w|Hamburger button|hamburger buttons}}, an icon that is widely used on websites to reveal a menu. It is especially used on mobile versions of sites designed to be read on a small screen, where compressing a menu until needed saves space.
This seems to show that the test can provide more data via a hidden menu, which shouldn't be able to fit on a small screen such as the one shown in the comic. Many COVID-19 tests have associated apps alongside the rapid test device for better analysis and dissemination of the results, but such an app isn't normally integrated into the rapid test device itself.
|}

==Transcript==
:[Header above the comic:]
:Interpreting Rapid Test Results

:[What follows is a set of 8 possible rapid test results for COVID-19.]

:[One line on the "C".]
:Negative

:[Two lines, one on the "C" and one on the "T".]
:Positive

:[Two curvy lines on the "C" and the "T", resembling the "approximately equal" sign.]
:Approximately positive

:[Two lines, not on the "C" or the "T", but they are instead closer together.]
:Positive (college ruled)

:[Five lines resembling a cell signal symbol.]
:Good cell signal

:[Two straight lines, on the "C" and "T", with lines going outward from the centre, giving an illusion of the lines being curved.]
:Did you know these lines are actually parallel?

:[One line on the "C", and two lines in a cross with one line sticking upward of the center of the cross.]
:The Blair Witch is near

:[Three lines, with one on the "C", one on the "T", and one in the middle of the "C" and "T".]
:Click to expand Covid menu

{{comic discussion}}
[[Category: COVID-19]]
[[Category: Comics with color]]
[[Category: Charts]]
[[Category: Fiction]]

817: Mutual

2025-03-25T08:46:22Z

172.69.43.221: Undo revision 370196 by 172.68.211.159 (talk) Not (currently) a category.

{{comic
| number = 817
| date = November 10, 2010
| title = Mutual
| image = mutual.png
| titletext = A universe that needed someone to observe it in order to collapse it into existence would be a pretty sorry universe indeed.
}}

==Explanation==
The comic depicts [[Cueball]] and [[Megan]] simultaneously thinking about each other thinking about each other thinking about each other etc etc. this is one of the many comics that feature meta things. It may be a deliberate prelude to [[818|the next comic]].

The title text refers to the aspect of {{w|Quantum Mechanics}} where a system can exist in more than one state until it is observed. An observation is required in order to "collapse" the system into a particular state; the {{w|thought experiment}} of {{w|Schrödinger's cat}} is a popular way of explaining this concept. The title text proposes that, if a universe needed to be observed to exist, as with a quantum state, it would be a pretty sorry universe indeed, as who would exist to observe it if it needed to be observed in the first place?

==Transcript==
:[Cueball and Megan are inside each others' thought bubbles.]

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

Talk:3063: Planet Definitions

2025-03-18T13:54:00Z

172.69.43.221:

The one currently posted has Pluto highlighted in the second box and not highlighted in the first box. Too hard to tell if it's trolling or a genuine mistake. :-D

:Apparently a mistake since it's fixed now. [[User:HughNo|HughNo]] ([[User talk:HughNo|talk]]) 19:59, 14 March 2025 (UTC)

And the first one also has a moon hilighted instead I think?? [[Special:Contributions/162.158.126.5|162.158.126.5]] 15:59, 14 March 2025 (UTC)

:Was about to write the same. The coloring in the first two lines arund Pluto seem wrong (or mistankingly switched). --[[Special:Contributions/172.71.222.246|172.71.222.246]] 16:17, 14 March 2025 (UTC)

This, this is the hill I will die on. I was radicalised by this paper: [https://arxiv.org/abs/2110.15285 Moons Are Planets: "Scientific Usefulness Versus Cultural Teleology in the Taxonomy of Planetary Science"]
In short; planets are what planetary scientists study. Round things with the *good stuff*: atmospheres, oceans, volcanoes (of lava or water ice) (see diagram page 53).
Pluto, Titan, Ceres, Io and Europa are all in the sweet spot where you're not so small you're just a lump of rocks who happen to be stuck together into a lump, and not so large you're just a mostly undifferentiated mass of fusing hydrogen/helium plasma.
And it's consistent with our pre-20th Century understanding of what a planet is, whereas the IAU definition is trying to preserve 19th Century astrology. An amazing read and a strong recommend for anyone who cares about this subject. [[Special:Contributions/172.69.79.138|172.69.79.138]] 16:45, 14 March 2025 (UTC)
:Ooh, thank you! That was fascinating and I'm head-canonizing that definition now. –[[User:P1h3r1e3d13|P1h3r1e3d13]] ([[User talk:P1h3r1e3d13|talk]]) 23:57, 17 March 2025 (UTC)

Does this sort of count as pi-related for pi day? [[User:TomtheBuilder|TomtheBuilder]] ([[User talk:TomtheBuilder|talk]]) 17:04, 14 March 2025 (UTC)
:he doesn't do themed comics anymore 😔 [[User:CalibansCreations|'''Caliban''']] ([[User talk:CalibansCreations|talk]]) 17:12, 14 March 2025 (UTC)
:: Sure he does. [[2962]] and [[2969]] weren't too long ago. Seems like it, though. [[Special:Contributions/172.71.182.222|172.71.182.222]] 03:31, 15 March 2025 (UTC)
:::I don't understand either the "he doesn't do themes" bit, or the full nature of the reply, frankly. [[Special:Contributions/172.68.205.122|172.68.205.122]] 22:52, 15 March 2025 (UTC)

I was somewhat disappointed to get to the end of the table without seeing either an astrology or Sailor Moon joke. -- [[User:Angel|Angel]] ([[User talk:Angel|talk]]) 18:12, 14 March 2025 (UTC)

Is it possible that Uranus is marked under "Empiricist" because of the "Randall has seen Uranus" joke? [[Special:Contributions/172.70.42.178|172.70.42.178]] 18:38, 14 March 2025 (UTC)

The "{{w|Classical planet|Classical Planets}}" should be 7, including the Sun and the Moon.
:The average distance of the orbit of the Moon around the Earth must be slightly farther away than the orbit of the Sun around the Earth, since the Moon lags behind the Sun a little more each day, but the orbits must cross or we would never have a solar eclipse :P [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:41, 14 March 2025 (UTC)

Wouldn't the Regolithic one depend on the exact definitions of "dirt", "ice", and "covered"? It seems that an argument could be made that the giant planets also count there but have a much thicker atmosphere on the outside, and disqualifying because of the atmosphere could exclude others like Earth depending on the exact threshold used. [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:08, 14 March 2025 (UTC)

Has Randall not seen the sun before?
:I'm impressed that he has seen Uranus (unless that actually is a joke), especially if he saw it unaided (apparently it actually can be barely seen with the naked eye if the conditions are incredibly good). [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:36, 14 March 2025 (UTC)
:Could the sun be classified as a "world"? --[[User:MothWaves|MothWaves]] ([[User talk:MothWaves|talk]]) 19:43, 14 March 2025 (UTC)
:I assumed he meant "seen directly with my eyes", so that a photograph would not count, but looking through a telescope during an astronomy night at the local University would count. And he hasn't looked *closely* at the Sun, because of the need for eye protection. [[User:JimJJewett|JimJJewett]] ([[User talk:JimJJewett|talk]]) 23:49, 14 March 2025 (UTC)

Technically, spacecraft have landed on Mercury, Jupiter, and Saturn. Just not in a survivable manner. [[User:Redacted II|Redacted II]] ([[User talk:Redacted II|talk]]) 19:37, 14 March 2025 (UTC)
:Have we really not sent anything directly into the Sun yet? [[User:JimJJewett|JimJJewett]] ([[User talk:JimJJewett|talk]]) 23:51, 14 March 2025 (UTC)
::The most "into the Sun" we've done is [https://science.nasa.gov/mission/parker-solar-probe/ the Parker Solar Probe], and it hasn't attempted to 'land' there (apart from that being effectively impossible, even beyond the likes of Cassini's final fall "onto" Saturn). It's also ''very hard'' to even send things into the Sun, because the direct method would need you to send a craft from Earth backwards at the same speed as the Earth orbits forwards (or very close to that), otherwise all you can do is fall ''past'' it and loop back up again. [[Special:Contributions/162.158.74.94|162.158.74.94]] 01:00, 15 March 2025 (UTC)
:No one even knows if Jupiter and Saturn have a *land* to land on. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 14:54, 15 March 2025 (UTC)
::Sstill subject to further study, but the crushed and burnt (and probably unrecognisable) remains of the probes will be 'landed' (or floating on top of any layer that they're ultimately more buoyant than) down there, somewhere (unless they're totally ablated away, but there'll probably be ''some'' fragments of hi-tech metal frame, even if no circuit boards or metal foils survive) Should there be a form of life in existence down in the depths of the gas-giant's mass, with any curiosity to them, I imagine they'll be wondering what this new variety of 'space rain' is, that's totally unlike the usual ex-asteroidal/cometish stuff that they must occasionally get punching down through from the inaccessible upper reaches above their native environment. [[Special:Contributions/162.158.74.68|162.158.74.68]] 19:59, 15 March 2025 (UTC)

It looks like the Pluto error in Traditionalist and Modernist images were fixed. I now see Pluto highlighted in traditionalist and Pluto unhighlighted in Modern. [[Special:Contributions/172.68.7.91|172.68.7.91]] 19:44, 14 March 2025 (UTC)

indeed, it seems fine now, i removed my earlier comment--[[Special:Contributions/162.158.233.116|162.158.233.116]] 23:06, 14 March 2025 (UTC)

//Jean-Luc Margot wrote a serious planet definition proposal// in 2024 as a starting point for community conversations and welcomes feedback. In 2019 I wrote a small article myself on planet and moon classes simply by size. //Mondklassen "wwwahnsinn"// (in German).
[[Special:Contributions/162.158.159.108|162.158.159.108]] 19:49, 14 March 2025 (UTC)

I'm disputing that there has never been a formal definition of "planet" prior to 2006 - the ancient Greek definition of "wandering [relative to seemingly-fixed stars] points of light in the night sky" seems formal enough to me. I marked it {{tl|actual citation needed}}. [[Special:Contributions/198.41.227.73|198.41.227.73]] 19:52, 14 March 2025‎
: I've reworded the sentence to say "in modern times" so we aren't making unfounded and likely-incorrect claims about antiquity. [[Special:Contributions/198.41.227.73|198.41.227.73]] 21:19, 14 March 2025 (UTC)

Does anyone else strongly dislike the term '''natural satellite''' replacing ''moon''? Under the new nomenclature, only Earth's moon is 'the Moon'. All other moons are now merely natural satellites. Phobos, Deimos, Ganymede, are no longer considered moons. My biggest problem with the new definition is that planets themselves are natural satellites of stars. [[Special:Contributions/172.71.182.225|172.71.182.225]] 20:13, 14 March 2025 (UTC)

It seems likely that the Saturnian moon highlighted in the Maritime definition is Titan, since it has liquid seas and lakes on its surface. [[Special:Contributions/172.69.6.5|172.69.6.5]] 21:54, 14 March 2025 (UTC)
:I've noted in the Transcript that (despite apparently being ''identical'' pre-highlight drawings in all other ways, or at least very consistently reproduced), Saturn is given one moon ''most'' of the time, but two moons on occasion. Similarly, Uranus's moons (spread from upper-right to lower-left) do-or-do-not include the dot (in one case suffering a highlighting) moving across the face of the planet. From an analytical perspective, I'm wondering if Randall did indeed copypaste the 'normal' iillustration, but then have to manually add in "whoops, I forgot I need to highlight a further item thaat I haven't already drawn" into some of the established copies, touching up where necessary (and maybe where still not necessary too). ...But I'm not sure it matters what he did or did not do. It's just an observation about the result. [[Special:Contributions/172.69.79.190|172.69.79.190]] 23:03, 14 March 2025 (UTC)
:Yeah, Titan's present in all the diagrams, and a second moon of Saturn shows up when highlighting is necessary. The bonus "Marine Biologist" planet is clearly Enceladus, but the bonus "Judgemental" planet doesn't line up with it: presumably it's one of Saturn's other moons. Which one? My wild guess is Iapetus. [[Special:Contributions/172.68.150.27|172.68.150.27]] 01:48, 15 March 2025 (UTC)

Great explanation, thank you, but was it really necessary to include a snide dig at Baby Boomers? Not a BB myself - I'm gen X, if we're using those facile labels - but surely we don't need to encourage intergenerational resentment and conflict. [[Special:Contributions/172.68.174.116|172.68.174.116]] 03:22, 15 March 2025 (UTC) 
As a historian, I strongly disagree with the snide definition of tradition. (No, not a BB.) [[Special:Contributions/162.158.212.132|162.158.212.132]] 07:40, 15 March 2025 (UTC)
:That's a direct quote from a prior comic, that whoever wrote it in the first placce ysed, so I've rewritten it to perhaps ''not'' look quite so much like some editor's own grudge/snidiness (which it may or may not be, but not without Randall giving justifiable precedent to say it). Maybe can be tweaked further, but it might be a shame to lose the inter-comic referential humour that (regardless of tone) is staple for this site. [[Special:Contributions/162.158.74.109|162.158.74.109]] 12:25, 15 March 2025 (UTC)
::I wrote it. No snideness intended. I thought the connection was topical. Unfortunately, thanks to the "Okay boomer" phenomenon, any reference to the generation comes across as condescending. The "Tradition" strip was published in 2011, and the phrase rose to popularity in 2019. It, like [[36]], is just one of those things that is not standing the test of time. [[Special:Contributions/172.70.47.89|172.70.47.89]] 20:22, 15 March 2025 (UTC)

I believe we're currently missing part of the joke in the mouseover text. Not only is Earth now a star because of human fusion, it's also no longer a planet, because, due to human satellites and spacecraft, it no longer clears its orbit.
[[Special:Contributions/198.41.227.42|198.41.227.42]] 06:20, 15 March 2025 (UTC)

Isn't the usual singular of criteria criterion? According to my dictionary, a criterium is a type of cycling race.--[[Special:Contributions/172.71.26.100|172.71.26.100]] 09:46, 15 March 2025 (UTC)
:Indeed. Maybe a thinko, though, rather. [[Special:Contributions/172.69.79.139|172.69.79.139]] 11:06, 15 March 2025 (UTC)

I am curious why only one of the Galilean moons counts as pretty, and I wonder which one (either Ganymede or Callisto, given where its drawn). They are all pretty to me, I like how surprisingly distinct they look from one another.
[[User:Terdragontra|Terdragontra]] ([[User talk:Terdragontra|talk]]) 13:18, 15 March 2025 (UTC)

Re title text: With the launch of the JWST, Earth has no longer cleared its orbital neighborhood, right? [[Special:Contributions/172.70.176.57|172.70.176.57]] 14:27, 15 March 2025 (UTC)

I tend to go by an expansive definition myself, considering all dwarf planets "planets" in my eyes. But I'm not like, arguing with the IAU's definition, this is just how I prefer to think of them, because dwarf planets are really cool. [[Special:Contributions/172.70.126.140|172.70.126.140]] 19:35, 15 March 2025 (UTC)

In the title text explanation, there's no mention of the inclusion of the phrase about Earth clearing its orbital neighborhood. I think this has something to do with all of our man-made satellites that have not been cleared from Earth's orbital neighborhood. Does anyone else think that's an important part of the title text and needs to be explained? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 13:33, 16 March 2025 (UTC)

I think I like the "Recognizable" criteria. Something is a planet if it orbits the Sun and there exists at least one photograph of the object that a reasonably knowledgeable layperson can correctly identify. That would mean that all of the IAU defined planets are planets (except maybe Mercury), and that Pluto became a planet in 2015. [[Special:Contributions/172.68.245.141|172.68.245.141]] 14:34, 16 March 2025 (UTC)
:...there's a risk that Uranus and/or Neptune ("or both... hang on... which one's supposed to be bluer..? and is this one of those miscalibrated images or not..?") might drop out of the Recognisable grouping. And the Moon would be added, unless you arbitrarily banned near-side images, in which case it'd be demoted to "dunno" except by particularly adept selenophiles who probably even know the far-side, and limbs, like the back of their own hands. [[Special:Contributions/162.158.74.94|162.158.74.94]] 16:55, 16 March 2025 (UTC)

A definition I thought up a while ago that I'm pretty proud of is that a planet is an object that is not a star or moon, has a stable orbit around a star, and that has a larger mass than the largest moon in its solar system. (a moon is defined as having a barycenter inside an object that directly orbits the Sun). That way, there is a clear, natural, distinction of larger bodies and smaller ones that conforms to the public thinking of a planet as large and not a moon. By my definition, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. (Though Mercury is famously smaller in radius than the moons Ganymede and Titan, it has more mass -- and given that mass grants greater gravity, I consider mass to be more important). My wider category of a world is for all star-orbiters that have differentiated layers, so the worlds in the Solar System would be (I think) Mercury, Venus, Earth, the Moon, Ceres, Vesta, Jupiter, Ganymede, Callisto, Europa, Io, Saturn, Titan, Uranus, Neptune, Triton, Pluto, Charon, Quaoar, Haumea, Makemake, Gonggong, Eris, and Sedna. This would be a harder category to assign than planet and a bit more fuzzy -- which plays in to the fuzzy use of world already existing -- but is still more clear cut than "gravitationally rounded" as no object is a perfect sphere and the strict definition of hydrostatic equilibrium means Mercury is not a planet. Of course, since no exomoons have been discovered as they are very hard to find, all exoplanets discovered would be planets -- which is nice and uncomplicated and natural for the human to assume that the bodies are planets. [[Special:Contributions/108.162.245.145|108.162.245.145]] 18:11, 16 March 2025 (UTC)
: Having the status of bodies be contingent on what is going on elsewhere seems even more problematic than current arguments over where artificial lines between categories should be drawn. In theory, Jupiter could capture a passing wandering planet and, under your system, instantly demote a bunch of the current planets to non-planets, even though nothing about them has actually changed.[[Special:Contributions/172.70.160.219|172.70.160.219]] 09:51, 18 March 2025 (UTC)
:: And, in a way, that's what happened to Pluto. Nobody was really bothered about it not having 'cleared' Neptune from its orbit (or, it appears, consider it a problem that Neptune hasn't cleared Pluto from its own, so already a partial fudge of meaning there) when it was an acceptible planet. Maybe the runt of the litter (comparing disfavourably against even some moons, including our own), but most people were happy to slide with it as one (with perhaps a bit more attention on Ceres, too, once more), even as it became clear that its own largest moon was more co-binary, and that there were a number of other (lesser) plutoids doing the same sort of thing. The 'sudden appearance' (i.e. realisation of) a larger (now dwarf-)planet changed that.
:: I mean, I'm not advocating for either turn of terminology (though I definitely grew up, and lived most my adult life, ''knowing'' that Pluto was a planet), but taxonomy of all kinds is tricky. Just ask Linnaeus. As more information overturns how we group things, even when the realities of the things we group don't themselves change. [[Special:Contributions/172.70.162.57|172.70.162.57]] 11:23, 18 March 2025 (UTC)

'''"Modern" vs "Current"'''. Does anyone feel frustrated when people confuse "modern", "contemporary", and "current"? "Modern" is post-1500, "contemporary" is the age someone lives in, and "current" is 'today'. Throughout 75 years of the modern era, Pluto 'was' considered a planet. Is anyone willing to shift non-canonical usage of "modern" to "current" in the article? [[Special:Contributions/172.71.95.28|172.71.95.28]] 15:59, 15 March 2025 (UTC)
: "''Modern" is post-1500''" -- '''Museum of '''Modern''' Art''', 1929/1930 until today (essentially Pluto's reign); works to 1885 --[[User:PRR|PRR]] ([[User talk:PRR|talk]]) 00:54, 17 March 2025 (UTC)

I added a bunch of Wikipedia citations. I went by the WP rule (citation needed) of linking the first non-parenthesized instance of a word/phrase. That does make for some awkward things, like lists with only some of the items linked, and the {{w|natural satellite|moon}} link in a mention under '''Simplistic''' rather than on the more relevant '''Lunar'''.
–[[User:P1h3r1e3d13|P1h3r1e3d13]] ([[User talk:P1h3r1e3d13|talk]]) 22:34, 14 March 2025 (UTC)

According to the "simplistic" definition, the rings themselves (also round) are separate planets. If the simplistic definition had merely been "spheroidal" rather than "round", they would not be. I'd love to see a version of the chart where Saturn is green, but the rings are white. [[Special:Contributions/172.71.99.166|172.71.99.166]] 23:36, 14 March 2025 (UTC)

Shouldn't the Utratraditionalist version of the solar system have 7 planets (including the Sun and the Moon)? [[Special:Contributions/172.68.245.136|172.68.245.136]] 15:15, 17 March 2025 (UTC)

Given that it is now considered a dwarf planet, and a lot of people, and perhaps the world itself, are unhappy, would it not be appropriate to rename it Grumpy?{{unsigned|Jmbryant|12:22, 18 March 2025}}

I wonder if this comic was tangentially inspired by the fairly recent discovery of a further 128 (suspiciously round number, that..!) moons of Saturn, making it now having well into the 200 'moons', on top of its ring-debris. And the possibility of the IAU having to weigh in and now officially decide what a ''moon'' is, especially in contrast to all the material in Saturn's rings (maybe broken up ex-moons, possibly raw material for future moon-clumps). One would suspect a version of "clear the area around the planet it orbits", and a (looser?) threshold of hydrostatic equilibreum/sphericity might be the starting point. [[Special:Contributions/172.69.43.221|172.69.43.221]] 13:54, 18 March 2025 (UTC)

3060: Omniroll

2025-03-10T14:31:49Z

172.69.43.221: /* Explanation */

{{comic
| number = 3060
| date = March 7, 2025
| title = Omniroll
| image = omniroll_2x.png
| imagesize = 528x443px
| noexpand = true
| titletext = It seems wrong that Fruit by the Foot is only sold by weight or by number of rolls.
}}

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

[[Cueball]], [[Megan]], and [[White Hat]] are making a "Wikipedia Omniroll," a roll made by combining all rolls in the {{w|list of rolled foods}} into one large roll. The Latin prefix "omni-" is a combining form meaning "all" or "universal." Thus, an "Omniroll" would mean an "everything roll." The three are in the process of assembling this roll. The penultimate stage in the preparation till this moment was a "{{w|spring roll}} {{w|burrito}}" which ''probably'' means a burrito whose identifying ingredient is a spring roll (as a bean burrito is filled with refried beans), but could also mean a burrito in spring-roll form. The following step was to roll it in breadcrumbs and fry it, possibly as a part of a {{w|croquette}}. Right now, they are wrapping the concoction in a {{w|cabbage roll}}. White Hat asks about the {{w|Fruit Roll-Ups}} layer, which Megan responds that it goes around the {{w|cinnamon roll}} layer.

On the wall behind them is a picture of a cross-sectional cut through the Omniroll showing each layer. There seems to be 12 labeled layers that are broad enough to be seen in this large picture. But there is also a cutout that zooms into six thin layers, that also has labels. If the drawing is to be taken at face value there are 18 different layers, and there should thus have been 18 rolled foods on the Wikipedia list when [[Randall]] made the comic; in fact there were 51. However, it is possible that the highlighted area is only for the layers they are currently preparing, and other layers are not currently shown.

All labels are unreadable, which seems like a good idea, as no-one can complain that Randall left out their favorite rolled food. Having people getting agitated over comics relating to food has happened a few times. For instance [[388: Fuck Grapefruit]] got so much reaction that Randall commented on it, as noted in the [[388:_Fuck_Grapefruit#Controversy|trivia]]. On explain xkcd the [[Talk:1534: Beer|talk page]] for [[1534: Beer]] also shows how people react when someone openly dislikes one of your favorite drinks.

Although there will be many people who love each of the mentioned rolls, not many would enjoy eating them all at once, as it would mix very different kinds of food which would be prepared very differently. Different layers would also require different treatments to prevent them spoiling, which would be difficult to achieve once they are rolled together.

The title text refers to {{w|Fruit by the Foot}}, a similar snack to Fruit Roll-Up made by the same producers. Although the name implies a per-distance measurement, Fruit by the Foot is in fact sold in boxes based upon number of rolls, with measurements on the packaging given by weight. [[Randall]] expresses his dismay at this discrepancy.

The 'omni-' prefix was earlier used in [[2653: Omnitaur]] and [[2738: Omniknot]].

In [[2123: Meta Collecting]], Cueball used Wikipedia's article "list of collectables" for his hobby.

==Transcript==
:[Cueball, Megan and White Hat are standing up near a table handling ingredients. Megan is working on a large roll while the other two are holding on to some strings like food going towards the roll. To the left of them is a poster on the wall showing multiple layers of a roll. There are 12 labels going around the roll starting around 10 going to just shy of 6 o'clock. They have lines going in to different layers with the first label's line going to the outer layer, the second label's line going to the third layer, the third labels line going to the second layer, but then the rest of the labels going to layers deeper and deeper ind from 4 to 12. But there is also a zoom in in the bottom left, where a square on the roll has been zoomed out and displayed just outside the roll. Six layers can been seen in this zoom in, and each of these have also been labeled with three labels on either side of the frame of the zoom in. All 18 labels are unreadable.]
:Megan: Okay, we've rolled the spring roll burrito in breadcrumbs and fried it. Now we'll wrap it in cabbage roll leaves.
:White Hat: What about the Fruit Roll-Up?
:Megan: That goes around the cinnamon roll layer.

:[Caption below the panel:]
:A Wikipedia omniroll is a cylindrical food containing one layer of every item from the Wikipedia article "List of rolled foods."

==Trivia==
*At the time the comic was published, the Wikipedia article contained 51 entries - [https://en.wikipedia.org/w/index.php?title=List_of_rolled_foods&oldid=1253171858 List of Rolled Foods as it was on March 7, 2025].
**The article had last been edited on October 24, 2024, but several edits were made in the hours after the comic was published, which is presumably not a coincidence.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Food]]
[[Category:Wikipedia]]

Talk:Little Bobby Tables

2025-02-11T19:38:21Z

172.69.43.221: /* What's his full name? */

One of the things I like to do in my free time is to make up names poor Little Bobby Tables could go by, presumably he does not use the full SQL Injection as his Starbucks name, but we don't ever know what he calls himself. These are some of my favorites:
* Robert Roberts (The obvious, but hilariously redundant sounding)
* Bobby Roberts
* Robert "Bobby Tables" Roberts
* Bobby "Tables" Roberts
* "Little" Bobby Tables (not a particularly good porn-actor name)
* Bobby (Possibly a good 20's mob gangster name)
* Tables (A less good mob gangster name)
* DROP the TABLE (Perhaps a rapper/nerdcore/dubstep name)

Anyone else? [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 21:59, 24 September 2012 (UTC)

:I think his full name would officially be <code>Robert'); DROP TABLE students;--</code> Roberts, which should probably be added to the article, but that's besides the point. [[User:Schiffy|Schiffy]] ([[User talk:Schiffy|talk]]) 17:03, 12 March 2013 (UTC)
::Actually, his full name is Robert'); DROP TABLE '''''S'''''tudents;--, not Robert'); DROP TABLE '''''s'''''tudents;--, according to [[327: Exploits of a Mom]]. I added the correct version to the article and renamed the category and the article itself. --[[User:FaviFake|FaviFake]] ([[User talk:FaviFake|talk]]) 08:37, 7 July 2023 (UTC)

Under real life occurrences are examples of Cross-Site Scripting attacks. Old Bobby Tables uses a SQL injection, which is more rare these days, but a lot more damaging. {{unsigned ip|162.158.154.63|12:21, 14 July 2023}}
:Thanks! Feel free to edit the section, I don't know much about hacking methods. --[[User:FaviFake|FaviFake]] ([[User talk:FaviFake|talk]]) 14:52, 19 July 2023 (UTC)

Robert’); DROP TABLE Students;-- Roberts [[User:TenGolf MathHacker|TenGolf MathHacker]] ([[User talk:TenGolf MathHacker|talk]]) 20:06, 25 January 2024 (UTC)

== What's his full name? ==

Hey, I was wondering which one of these is his full name:
*Robert'); DROP TABLE Students;--
*Robert'); DROP TABLE Students;-- Roberts
Afaik, there are no comics mentioning his surname, but hat might be the case for other members of the Roberts family. Can someone research this? --[[User:FaviFake|FaviFake]] ([[User talk:FaviFake|talk]]) 18:31, 11 February 2025 (UTC)
:One would assume that, as brother to Elaine (insert middle names here) Roberts and son of Mrs. (whatever her other names are) Roberts, he'd still be a Roberts.
:I know there are some family peculiarities (e.g. for unmarried parents, or retention of maiden names, with whatever decision made/enforced for subsequent birth certificates, etc), so ''maybe'' if we knew that the (ex-?/late-?)husband of Mrs Roberts (neé Roberts) might have been Mr Jones (né Jones) and they decided to surname according to gender of parent (rather than anti-gender, or variations upon double-barelling, though we know none of that happened for Elaine), then he's "Robert (inject SQL) Jones". But we have no such indication of anything so exotic.
:And there's no reason for him ''not'' to be surnamed as you'd normally expect. It doesn't even change the efficacy of the troublesome full name. William of Ockham would barbrously cut off any suggestions that might extend the list of assumptions, even by abnormally truncating the familial suffix.
:All this supposition being open to any found facts that I'm not currently recalling, naturally. [[Special:Contributions/172.69.43.221|172.69.43.221]] 19:38, 11 February 2025 (UTC)

2520: Symbols

2024-03-14T02:51:08Z

172.69.43.221: /* Symbols */ Ok, so meant to give this one the 'Merkin spelling 'on page', too (but maintain the official wiki title/no redirect)

{{comic
| number = 2520
| date = September 24, 2021
| title = Symbols
| image = symbols.png
| titletext = "röntgen" and "rem" are 20th-century physics terms that mean "no trespassing."
}}

==Explanation==
This comic refers to elements of (mostly mathematical or engineering) notation commonly used in various fields of math and science. Each piece of notation is presented as "symbolizing" not what it specifically means, but a typical ''context'' in which it might be encountered, see [[#Symbols|below]].

Many of the individual descriptions look like verbiage that might be found on informational or warnings signs or placards, although typically with a silly edge.

The title text refers to two non-SI units of radiation measurement, {{w|Roentgen (unit)|röntgen}} and {{w|Roentgen equivalent man|rem}}. In the mid-20th century when they were in use, the dangers of radiation weren't as well understood as today, so an area with radiation that was noteworthy back then is [https://archive.md/v3dME probably dangerous], hence the no trespassing part.

Later [[Randall]] made a similar comic, [[2586: Greek Letters]], regarding the use of Greek letters in math.

===Symbols===
'''d⁄dx: An undergrad is working very hard''' d/dx is the symbol for a single-variable {{w|Derivative|derivative}}. This is one of the basic operations in {{w|calculus}} and consequently is ubiquitous in the work of undergraduates in the sciences. A hard-working undergraduate in the relevant fields would churn through exercises using this symbol.

'''∂⁄∂x: A grad student is working very hard''' The replacement of the standard "d" letters with the curly letters "∂" denotes the partial derivative, which generalizes the ordinary derivative to multi-variable calculus. Problems with partial derivatives, especially partial differential equations, can be extremely challenging. Although PDEs would typically be first taught at an undergraduate level, difficult partial derivatives would be encountered in graduate-level work.

'''ħ: Oh wow, this is apparently a quantum thing''' ħ (pronounced "h-bar") is a symbol used for (the reduced) {{w|Planck's constant}}, a universal, fundamental constant in quantum physics. h, the normal version of Planck's constant, is equal to the energy of a photon divided by its frequency. ħ is equal to h/2π, and angular momentum in quantum mechanical systems is measured in quantized integer or half-integer units of ħ.
Classical physics appears as a limit of quantum physics if all "actions" (quantities of dimension energy * time, momentum * length, or angular momentum) are much larger than ħ. Conversely, you can also formally set ħ=0 to get classical results from quantum formulae. This means that effects that are proportional to some power of ħ cannot be explained classically, and instead are "a quantum thing".

'''Rₑ: Someone needs to do a lot of tedious numerical work; hopefully it's not you''' The {{w|Reynolds number}} (which is usually denoted by "Re," not "Re" as it appears in the comic) is the most important dimensionless group in fluid mechanics. Named for Osborne Reynolds, Re characterizes the relative sizes of inertial and viscous effects in a moving fluid. Large values of Re are indicative of turbulent flow, which cannot usually be retrieved analytically, and so numerical modeling is necessary. Accurate numerical studies of high-Reynolds-number flows are notoriously difficult to create and program.

Alternatively, Rₑ could stand for electronic {{w|transition dipole moment}} in a molecule. This appears in quantum-mechanical calculations of transition probabilities and also includes a lot of unpleasant numerical work. Rₑ is also a term used for the radius of the Earth at mean sea level, though this is not necessarily a complex term in and of itself.

Another alternative is that Rₑ could refer to Relative Error, a measurement of precision or accuracy. Used often in the analysis of scientific data and numerical analysis.

'''(Ta⁴ - Tb⁴): You are at risk of skin burns''' The {{w|Stefan-Boltzmann law}} says that a perfectly absorbing ("black body") source emits electromagnetic radiation with a power per unit area of σT4, where σ is a known constant and T is the absolute temperature. The quantity (Ta4 – Tb4) thus appears in any calculation of purely radiative energy transfer between two bodies, one at temperature Ta and the other at Tb. When the radiative transfer is large enough to be the most important form of heat interchange, it is normally also large enough to sear the skin with thermal or ultraviolet burns.

'''NA: You are probably about to make an incredibly dangerous arithmetic error''' NA, or {{w|Avogadro's number}}, is the number of molecules in a mole of a substance, approximately the number of carbon atoms in exactly 12 grams of carbon-12. This is an enormous number, exactly 6.022 140 76 × 10²³, or 602 214 076 000 000 000 000 000. Working with NA, it is easy to accidentally divide by it instead of multiplying or vice versa, leading to erroneous and nonsensical answers such as ~10-23 molecules (even though you can't have less than 1 whole molecule) or ~1046 moles (>1043 to 1045 kilograms, depending on the chemical) of a substance.

'''µm: Careful, that equipment is expensive''' {{w|Micrometre|Micrometer}}s are a very small unit of distance. Micrometers are commonly used to measure wavelengths in the infrared, and infrared detectors are very expensive, compared with visible wavelength counterparts. Of course, micrometers are used as a measurement of distance in other contexts, but any distance-measuring device capable of accurately measuring micrometer distances would also be expensive. Similarly, tools used to create or calibrate items within micrometer tolerances can also be expensive.

'''mK: Careful, that equipment is very expensive''' {{w|Kelvin}} is a temperature scale roughly speaking similar to Celsius, but taking absolute zero as its zero point instead of the freezing point of water (rigorously speaking, its definition is now {{w|2019_redefinition_of_the_SI_base_units#Kelvin|based on the Boltzmann constant}}). {{w|Millikelvin}}s (1/1000 of a Kelvin) are used for high precision temperature work. Frequently this is used in processes of cooling temperatures to nearly absolute zero - such as superconductors or other quantum effects that occur when atoms are almost still. This is suggesting that the symbol appears on a sensitive experimental system probing quantum mechanical behavior that would likely only exist in an advanced laboratory. Any equipment that works down at mK temperatures, or at least to mK precision and accuracy, is likely to be very expensive.

'''nm: Don't shine that in your eye''' {{w|Nanometre|Nanometer}}s are frequently seen in the listed wavelengths for lasers. Pointing a visible or infrared laser at someone's eye is notoriously dangerous; the tightly-focused coherent light can cause permanent damage very quickly.

'''eV: Definitely don't shine that in your eye''' {{w|Electronvolt}} energies are typical of moderate-energy particle beams, produced by accelerating electrons (or protons) over macroscopic voltages. These particle beams can be {{w|Anatoli Bugorski|even more damaging (and are probably a direct reference to Anatoli Bugorski)}} to soft tissues than optical-wavelength lasers.

'''mSv: You're about to get into an Internet argument''' The {{w|millisievert}} is a unit of radiation dose absorbed. It is a very small dosage, but the joke refers to Internet trolls debating the effects of low-dose radiation sources, such as 5G wireless networks. [[Randall|Randall's]] comment may also be referring to [[Radiation]].

'''mg/kg: Go wash your hands''' This unit measures the dose of a drug or other chemical in milligrams per kilogram of body mass. If the appropriate dose - or worse, the lethal dose - is measured in mg/kg (parts per million), then the substance may be quite toxic.

'''µg/kg: Go get in the chemical shower''' A unit 1/1000 times the size of mg/kg. If a dosage is measured in micrograms per kilogram (parts per billion), any accident probably requires whole-body decontamination procedures.

'''π or τ: Whatever answer you get will be wrong by a factor of exactly two''' π is defined as the ratio of a circle's circumference to its diameter, while τ is defined as the ratio of a circle's circumference to its radius (and is therefore equal to 2π). {{w|pi|π}} has been used as the primary constant for describing the circumference and area of circles millennia ago, but proponents of {{w|Turn (angle)|τ}} claim that τ is more natural in most contexts since it makes working in radians more straightforward. Actually, the "Pi" symbol used to be occasionally used for the constant now called Tau. The joke here is that whichever constant you use, it will probably be the wrong one (off by a factor of two, one way or the other) for the formula you are trying to use. The debate over Pi vs. Tau was solved by Randall in this compromise: [[1292: Pi vs. Tau]].

==Transcript==
:[A list with 14 different scientific constants/symbols are shown. Next to each symbol is a description. Above the list is a heading and beneath that a subheading.]
:::::<big>Symbols</big>
::::And what they mean

:::d⁄dx    An undergrad is working very hard
:::∂⁄∂x    A grad student is working very hard
:::ħ       Oh wow, this is apparently a quantum thing
:::Rₑ     Someone needs to do a lot of tedious numerical work; hopefully it's not you
:(Ta⁴ - Tb⁴)    You are at risk of skin burns
:::NA    You are probably about to make an incredibly dangerous arithmetic error
:::µm    Careful, that equipment is expensive
:::mK    Careful, that equipment is very expensive
:::nm    Don't shine that in your eye
:::eV     '''''Definitely''''' don't shine that in your eye
:::mSv  You're about to get into an internet argument
::mg/kg      Go wash your hands
::µg/kg      Go get in the chemical shower
::π or τ      Whatever answer you get will be wrong by a factor of exactly two

{{comic discussion}}

[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Biology]]
[[Category:5G]]

2899: Goodhart's Law

2024-02-28T09:06:24Z

172.69.43.221: /* Explanation */

{{comic
| number = 2899
| date = February 26, 2024
| title = Goodhart's Law
| image = goodharts_law_2x.png
| imagesize = 295x321px
| noexpand = true
| titletext = [later] I'm pleased to report we're now identifying and replacing hundreds of outdated metrics per hour.
}}

==Explanation==

In this comic, [[White Hat]] suggests creating a meta-metric, "number-of-metrics-that-have-become-targets," and making it a target.

First, the comic introduces and defines {{w|Goodhart's Law}}, which is the observation that when a metric — a {{w|performance indicator|measure of performance}} — becomes a goal, efforts will be unhelpfully directed to improving that ''metric'' at the expense of systemic objectives.

For example, imagine a scenario in which a car dealership is looking to grow profits, and its managers decide to focus on increasing a component metric of profit: how many cars it sells. So they offer a bonus to their salespeople to sell more cars. But then the salespeople offer deep discounts to rack up sales, rendering the car sales unprofitable. This example shows how a ''metric'' (cars sold) can become the ''target'', replacing the real target, profit growth, if individual incentives are not properly managed.

White Hat's suggestion could be a good or a bad idea. It all depends on how the bonus incentive is awarded:

* A '''good implementation''' would award bonuses only for finding metrics which truly aren't serving their purpose, so the organization's managers could fix the measurement issues, and then only if the effort in finding and removing them did not outweigh the benefit of removing them. If bonuses are awarded only for approved submissions and the identifications result in real improvements, the organization will benefit in each individual case. However, even a prima facie 'good' implementation could drive significant activity seeking out metrics that are eventually rejected as deserving a bonus, undermining the overall benefit.

* A '''bad implementation''' would offer a bonus to every identification, regardless of quality. This would incentivize the identification of even quite useful metrics — and perhaps even the ''creation'' of new metrics-as-targets for the sole purpose of then removing them and collecting the bounty.

The title text imagines this '''bad implementation''', leading to the creation of a new metric (metric changes per hour) and the organization identifying — and ''replacing'' — hundreds of metrics per hour, crowding out actual focus on the organization's true goals. It's the ultimate example of "change for change's sake."

Part of the joke is that White Hat's original suggestion — the new metric causing the issue and one that ''should'' be replaced — seems to be ironically surviving the replacement of hundreds of other metrics.

This comic illustrates that the thoughtless combination of Goodhart's Law and poorly designed incentives can have ruinous results for an organization.

While there is a temptation to game any metric, measurement is the main objective way of describing the success of an activity and assessing the effect of changes. "Data-driven" or "evidence-based" approaches are used to drive measurable improvements in various areas of society. The proper usage of organizational metrics and incentives is the focus of {{w|managerial accounting}}, a field within organizational management. Discussions of Goodhart's Law have noted [https://commoncog.com/goodharts-law-not-useful/] that people may respond to a metric by either (1) improving the system, (2) distorting that system (examples below), or (3) distorting the data (e.g., governments publishing false or cherry-picked economic data). Channeling energy toward improvement requires an organization to make (1) more appealing (flexibility and culture) and the others less (transparency, culture, reduced pressure to meet unrealistic goals). Figuring out how to do that involves a slow and thoughtful process unlike White Hat's unilateral jump to a new metric.

===Additional examples of Goodhart's Law===
* A school's exam results may ''suggest'' how well the school works with its pupils, but may lead to rigidly "teaching to the exams" and lead to less enjoyment and ability of life-long learning, or even flexibility in non-academic activities.
* A hospital measures inpatient ''Length of Stay'' because shorter stays save money and also free up beds for any admitted patients waiting in the ER. But if improperly incentivized, doctors may discharge inpatients too early, causing some to "bounce back" to the hospital as a costly readmission.
* A call center measures the number of calls handled per hour, but poorly decides to overly incentivize this metric to make the workers more productive; that leads workers to cut calls short, frustrating customers.
* The hypothetical {{w|Instrumental convergence#Paperclip maximizer|Paperclip Maximizer}} concept demonstrates how having a seemingly benign metric as a goal might still result in almost unlimited adverse effects, if unchecked.

==Transcript==
:[Cueball and White Hat are standing and talking, White Hat with hand on his chin.]
:Cueball: When a metric becomes a target, it ceases to be a good metric.
:White Hat: Sounds bad. Let's offer a bonus to anyone who identifies a metric that has become a target.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Statistics]]

2897: Light Leap Years

2024-02-23T15:54:57Z

172.69.43.221: /* Explanation */

{{comic
| number = 2897
| date = February 21, 2024
| title = Light Leap Years
| image = light_leap_years_2x.png
| imagesize = 288x389px
| noexpand = true
| titletext = When Pope Gregory XIII briefly shortened the light-year in 1582, it led to navigational chaos and the loss of several Papal starships.
}}

==Explanation==
{{incomplete|Created by A FLEET OF PAPAL STARSHIPS FROM ANNO DOMINI MDLXXXII - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

The comic portrays [[Cueball]] and [[Ponytail]] updating astronomical distances in some sort of database, noting how long and unpleasant the process is; the caption reveals that the reason is that {{w|leap year}}s "make light-years 0.27% longer" (366/365 = 1.0027397...). This makes the distance to Alpha Centauri "0.27% shorter". 2024 is a leap year in the Gregorian calendar, and leap day (February 29) was just over one week away when this comic was released.

The joke of this strip is based on the fact that "one year" isn't a precise unit of measurement: there have been different definitions, evolving over time, of what constitutes a year. The {{w|Gregorian calendar}} (the one most commonly used in modern times) includes a system of leap years in which an additional day is added every fourth year (with some exceptions) to make up for incompatibilities between day and year cycles. This temporarily changes the length of a year from 365 to 366 days.

A {{w|light year}} is a unit of distance, commonly used in astronomy, equal to the distance light travels in a vacuum in one year; the year used is the {{w|Julian year (astronomy)|Julian year}}, or 365.25 days. This results in a light year which is standardized at 9,460,730,472,580.8 km, no matter how long the calendar year may be. However, in this comic, a light year has been defined based on the length of the ''current'' year, and consequently becomes longer during leap years, meaning databases with astronomical distances have to be adjusted. Thankfully, most systems of measurement do not change continually, and even those that do (eg. DST) usually are setup to automatically update when necessary.

The title text jokes that {{w|Pope Gregory XIII}}, the originator of the Gregorian calendar, "briefly shortened the light-year in 1582." What really occurred in 1582 was that the Pope decided to advance the previously Julian calendar by 10 days to make up for an accumulated excess of past leap days and bring the subsequent Gregorian one more into line with astronomical measurements. Not all places went with the change, at that time. Some of the later adopters had to {{w|List of adoption dates of the Gregorian calendar by country|skip yet other days once they did}}, while others continue to use a calendar with an offset factor. In the world of the comic, this change led to "navigational chaos and the loss of several Papal starships". This is of course ludicrous since there have not (yet) been any (known earthly) starships, nor any church-funded space programs that might create a "Papal starship",{{Citation Needed}} still less in the 16th century. (There have been vehicles named {{w|SpaceX_Starship|'Starship'}}, but these do not meet the common definition of craft that can travel between star systems.) Furthermore, the light-year wasn't developed as a unit of measurement until 1838. Indeed, it wasn't known that the speed of light is finite until {{w|Rømer's determination of the speed of light}} in 1676. Navigational chaos ''has'' been a cause of shipwrecks, notably the {{w|Scilly naval disaster of 1707}} in which 4 ships were lost and over 1,400 sailors died.

The joke is that the evolving and somewhat loose and changing definitions of early calendars had significant impacts on the units of measurement we still use today. Such changes did serve to catalyze political and religious conflicts in some instances, and raised temporary issues around matters such as taxes, rents, etc., but as technology has advanced and become increasingly reliant on precise and consistent measurements, they could be significantly more disastrous.

The values given for Proxima Centauri's distance from the Sun, 4.2377 light-leap-years and 4.2493 light-nonleap-years, are consistent with a distance of 4.2464 actual light-years as described by the {{w|International Astronomical Union}}, which is only minutely different from 4.2465 light-years, the value given by {{w|Gaia catalogues|Gaia Data Release 3}} in 2020. Though tiny on an interstellar scale, the difference between 4.2377 and 4.2493 light-years, 0.0116 light years, equals 109.7 billion km (68.2 billion miles), about 730 times the average distance between the Earth and the sun (150 million km or 93 million miles).

Ironically, this kind of change would not actually bother astronomers in the slightest. Astronomical distances on scales larger than the solar system are universally (or rather, globally: we do not know how things are done in other parts of the universe) measured in {{w|parsec}} (with 1 pc equal to approximately 3.24 light years) or multiples thereof (kpc, Mpc, or Gpc). While light years are common in science popularizations, they are essentially not used at all in astronomy and astrophysics research.

==Transcript==
:[Cueball is sitting at a desk with a laptop on it and leaning to the back of his office chair, while having his other hand on the laptop. He is looking at Ponytail standing behind him. The text from the laptop screen is shown above it, indicated with a zigzag line.]
:Cueball: It took until February, but I finally got all the distances updated!
:Ponytail: I really wish we didn't have to do this.
:[Laptop screen:]
:Proxima Centauri
:Distance: <s>4.2493 ly</s> 4.2377 ly

:[Caption below the panel:]
:Astronomers hate leap years because they make light-years 0.27% longer.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics with color]]
[[Category:Astronomy]]
[[Category:Time]]
[[Category:Calendar]]
[[Category:Comics featuring real people]]

Category:Furries

2024-02-01T20:13:10Z

172.69.43.221: Awful wikilink changed, transplanted ("Furry" was a disambiguation) and clarified to include the source fiction. Specified Randall's presumed attitude. This category may *partly* overlap Animals, but mostly seems to lie outside it, so not a member of it.

{{w|Furry Fandom|Furries}} are fans of fictional anthropomorphic animals, or a direct description of those characters that they particularly admire. The fans may express their interests by wearing ears and tails, sometimes even constructing elaborate full-body fursuits that embody their {{w|fursona}}. They often are accused of sexual perversion, despite all evidence to the contrary. Randall's full opinion on furries is currently unknown, but he has never mentioned/depicted such things in an unsympathetic manner.

[[Category:Comics by topic]]

1463: Altitude

2024-01-23T12:43:39Z

172.69.43.221: /* Explanation */ The attempt to say that "low oxygen" is not specific "low altitude oxygen" didn't seem to accomplish the purpose. Expanded and added in the (irrelevent) "high oxygen (layer)" as contrast, to aid the prior edit's purpose.

{{comic
| number = 1463
| date = December 22, 2014
| title = Altitude
| image = altitude.png
| titletext = "TURN OFF THE LASER GUIDE STAR" "WHY" "STAR CATS"
}}

==Explanation==
In this comic, Randall is making fun of how {{w|Altitude sickness|oxygen deprivation}} can lead to reduced mental acuity. Dizziness, lightheadedness, impaired judgment, and euphoria are symptoms of oxygen deprivation, or hypoxia. Those researchers would benefit from having a written list or plan developed while they were still functioning at peak mental acuity.
Note that high altitude does not lead to severe effects as described in the comic.

Here, two astronomers are heading up a mountain, towards the observatory they work at. Initially, they discuss what they are planning on doing once they reach the summit, mentioning [http://exoplanets.astro.yale.edu/instrumentation/iodine_cells.php Iodine cells], used for wavelength calibrations of high-resolution RV spectra between 501 and 610 nm. As they continue, the mental clarity of the researchers devolves as they approach the high altitude telescope, leading to increasingly juvenile and almost intoxicated behavior. One researcher mentioned her head feels funny, while the other makes a remark about taping down the observatories to prevent them from rolling away, an absurd remark considering observatories are firmly rooted and even if they weren't, it would take an excessive amount of tape to stop them from rolling away.

Once inside the observatory, they have completely forgotten about their original plans. Instead of doing a general calibration, they are playing with the telescopes, looking at each other's faces through them and deciding to make out with each other. This is why [[Randall]] mentions that astronomers working at high altitude observatories must write down their plans ahead of time at sea level, as the low oxygen leads to reduced mental acuity.

It should be noted that the phrase "low oxygen" would usually refer to the lower partial pressure of oxygen at altitude. The proportion of oxygen at high elevations is still approximately a fifth of the atmosphere, the same as at sea level, and there is not a significant stratification of gases that means oxygen (moreso than the other major constituents of air) can only be found at lower altitudes, nor that they encounter a distinctively different "high (altitude) oxygen" (though something different {{w|Ozone layer|of that kind}} exists even higher up, not relevent to this scenario). The altitude sickness is caused by lowered atmospheric pressure which leads to smaller amount of oxygen actually delivered ("pushed") into bloodstream.

The title text refers to a {{w|laser guide star}} a device for focusing telescopes by making artificial reference points in the sky. The reference points are created by shooting a powerful laser into the sky. The concern of the astronomer in the comic is that an imagined "star cat" may be attracted to the laser in the same way that cats playfully chase laser beams projected on surfaces. Cats' reactions to laser pointers were previously explored in [[729: Laser Pointer]].

==Transcript==
:Because of low oxygen, astronomers working at high altitude telescopes may need to write down their plans ahead of time while at sea level.

:[Some astronomers are inside a sea-level research facility.]
:Astronomer #1: Ok, let's head up to the observatory.

:[The astronomers drive uphill.]
:Astronomer #1: When we reach the summit, we'll check the iodine cell and do a general calibration.
:Astronomer #2: Sounds good.

:[The astronomers have reached the high-altitude observatory.]
:Astronomer #1: My head feels funny.
:Astronomer #2: Look at those telescope domes. I hope they don't roll away.
:Astronomer #1: Maybe we should tape them down.

:[The astronomers are inside one of the domes.]
:Astronomer #1: Haha, look at this mirror! My face is huge!
:Astronomer #2: I see your face in the telescope! I discovered you!
:Astronomer #1: Let's make out!

{{comic discussion}}

2883: Astronaut Guests

2024-01-21T10:29:41Z

172.69.43.221:

{{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 RUSSIAN 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]]

Talk:2880: Sheet Bend

2024-01-15T09:52:08Z

172.69.43.221:

Why is this called a "sheet" bend? [[User:SystemParadox|SystemParadox]] ([[User talk:SystemParadox|talk]]) 21:17, 12 January 2024 (UTC)
:I don't know the full answer but it's a sailing thing: the 'sheet' is the rope you pull in or let out to control the position of the sail. I guess bend describes the category of knot. [[Special:Contributions/172.70.90.48|172.70.90.48]] 21:23, 12 January 2024 (UTC)
::NO NO NO. The sheet is the sail. [[User:JohnB|JohnB]] ([[User talk:JohnB|talk]]) 21:36, 12 January 2024 (UTC)
:::It is the rope - {{w|Sheet (sailing)}}. "In sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) (clews) of a sail." [[Special:Contributions/172.71.242.5|172.71.242.5]] 21:56, 12 January 2024 (UTC)
::::Huh. Dueling Wikipedia articles. The Sheet_bend article has a definition section that says the term "sheet bend" derives from its use bending ropes to sails (sheets). But the Sheet_(sailing) article says a sheet is a line used to control the movable corner(s) of a sail. [[User:JohnB|JohnB]] ([[User talk:JohnB|talk]]) 23:08, 12 January 2024 (UTC)
:::::A sail is never, and was never, properly called a "sheet", since at least the 13th century. The Wikipedia explanation of the name is misleading. According to https://www.etymonline.com/word/sheet, it's "shortened from Old English sceatline "sheet-line," from sceata "lower part of sail," originally "piece of cloth," from same Proto-Germanic source as sheet (n.1)." [[User:Jlearman|Jlearman]] ([[User talk:Jlearman|talk]]) 17:44, 13 January 2024 (UTC)
:::::: When I took a sailing class as a kid they used the word “sheet”, I think it was the lines connected to the sails used for adjusting them? [[Special:Contributions/108.162.245.82|108.162.245.82]] 19:46, 13 January 2024 (UTC)
::The sheet bend is named for its ability to to secure a sail, or sheet. You fold over the corner of the sail and that's one of your "ropes". The sheet bend is generally used as a knot for tying a large, inflexible rope (or rope-like object) to a smaller, more flexible rope.[[Special:Contributions/172.69.70.22|172.69.70.22]] 22:30, 12 January 2024 (UTC)
::I would take the Ashley Book of Knots as authoritative. Sheet Bend is the first knot in the book, and is always (in modern terms) rope-to-rope, not to sail. It is one of the basic knots. https://en.wikipedia.org/wiki/The_Ashley_Book_of_Knots https://en.wikipedia.org/wiki/Sheet_bend
::{{unsigned|PRR|04:04, 13 January 2024}} 
:::But what dispute are you taking TABoK's authority on? Two things can have the same name in different contexts (or namespaces). And does Ashley use anything other than ropes exclusively in the whole book? [[Special:Contributions/108.162.241.170|108.162.241.170]] 14:42, 14 January 2024 (UTC)
:I added a link to the wikipedia entry, it explains the name. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:25, 12 January 2024 (UTC)

Presumably the "different loads" title text is a pun between electrical load and mechanical stress on the knot? [[User:Jim-at-home|Jim-at-home]] ([[User talk:Jim-at-home|talk]]) 21:56, 12 January 2024 (UTC)

“silver being joined to silver and gold being joined to gold within the insulating white cable” is not the conventional way to join cables.
Unless you are joining one cable to itself (like a Möbius strip), you have ''two'' cables with insulation.
And usually you use non-cursed connectors, where you first remove the insulation at the end of the cable and then crimp or solder the conductors to metal parts of the connector; or solder the conductors and then add a different type of insulation for protection; or use screw terminals;...
Only with insulation displacement connectors you keep using all the insulation of the two cables.
And finally, conductors are usually copper ''or'' aluminum, and very rarely silver ''and'' gold. --[[Special:Contributions/162.158.94.141|162.158.94.141]] 08:45, 13 January 2024 (UTC)
:I think the gold and silver is just color coded for the reader. Not that they are meant to indicate that the conductors are made from this material. Apart from that you comment sounds like you know what you are talking about. So please improve the explanation if you can. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:58, 13 January 2024 (UTC)

::: I changed it to gold- and silver-colored. It was obvious to me that it was the colours used in the comic that were being referenced, but fixed for the avoidance of doubt. The join being made within the one cable was clearly an error though. [[Special:Contributions/172.70.85.161|172.70.85.161]] 22:13, 13 January 2024 (UTC)

:: cables often have the signal parts copper-colored (described gold atm) and they are obviously copper, and the outer ground more the color of steel or something, not sure what metal it is, but it’s easy to solder like copper or silver is, not aluminum which is very hard to solder. usually gold and silver are used at the contacts of a connector, not inside a wire, i don’t know who would ever make that mistake. [[Special:Contributions/108.162.245.83|108.162.245.83]] 19:49, 13 January 2024 (UTC)
:::"''more the color of steel or something, not sure what metal it is, but it’s easy to solder like copper or silver''" Traditionally tinned copper. Tinned not just for identification, or easier soldering, but because early rubber insulation actively rotted copper and tinning slowed the damage. Many sorts of damage, why much copper today is silvery. [[User:PRR|PRR]] ([[User talk:PRR|talk]]) 04:16, 14 January 2024 (UTC)
::: Not wishing to spoil it, but the series finale of {{w|Cabin Pressure (radio series)|a certain radio comedy}} reveals... ah well, that's the spoiler (in the article, if you read that far down... rather than just listen to it if you haven't heard about it already but now think you like the premise). [[Special:Contributions/172.69.79.188|172.69.79.188]] 21:01, 13 January 2024 (UTC)

Okay I looked at the wikipedia article and the knot depicted in the comic looks like a right handed one. I still don't know why it's called right handed, or why the left handed one is insecure.[[Special:Contributions/198.41.236.207|198.41.236.207]] 11:46, 13 January 2024 (UTC)
:It's not. Ropes and heavier ropes (called cables) are commonly made by twisting smaller ropes together, the twist direction (terminologically the 'lay' of the rope, (s-laid or z-laid)) is the main thing (that I know about) that can make chirality (handedness) of knots important to their strength. Electrical cables and wires aren't usually expected to have any tensile strength, and their tensile components aren't usually twisted in a way that would affect their strength. (Sorry for all the parentheticals.) [[Special:Contributions/108.162.241.130|108.162.241.130]] 14:56, 14 January 2024 (UTC)
::As I understand it (at least in knots that I'm familiar with), it's not chirality (like stereo isomers) but cis-/trans-ness (e.g. isomers which have active groups pointing in different directions across a double-bond).
::If the left cable came into the right's loops on on the bottom, dove under the two loops of the RH cable, over the conductor then under then over to have the loose end emerge where the offscreen-length currently comes in, then it'd be electrically the same but any tension would pull more off-axis and the knot could 'capsize' into an unwanted form (topologically similar, but with different relative loops.
::If you did that but ''also'' rethreaded the RH length to come up through the LH's loop (as now), but then passed over the top, down behind the two LH bits (free and loose end) to go back over the (lower) LH, under itself then over the (upper) LH, to dangle free, it would be a chiral inversion and (as you say) probably not greatly affected by the cable's own rotational symmetry.
::Re-rethread the LH loop as it was, and you'd get a chiral alternative to the first 'capsizable' change.
::Proper mathematically-inclined knot-theorists probably have better terms to use for both chiral and cis-trans transforms (as well as functional sub-mirroring such as the difference between reef and granny). There will already be terms known amongst practical knot-practioners such as sailors and other riggers, but (at least until "knot bibles" were written) they'll have been given homegrown/traditional terms that might not be particularly consistent with other knot-cultures. [[Special:Contributions/172.69.43.163|172.69.43.163]] 17:26, 14 January 2024 (UTC)
::^^^^ Addendum... Maybe [https://forum.igkt.net/index.php?topic=1551.0 this link I just found] is relevent, from a quick scan of it... Or maybe not. ~same IP/time as above .sig~

A note I nearly added in the bit about short-circuits (or, as I added, 'un'circuiting) is that the electrical behaviour of the knot is different according to which 'end' slips. If the left-side cable 'slips through' enough, then its gold and silver bits of sheath could contact (would short-circuit any current driven at that side). If the right-side cable slips out, it is in no danger of doing so for a right-driven current (it would just disconnect). That ignores the cross-talking that could occur (on one conducting line at a time, so may not matter if there's no external ground-return element, except as far as not being a proper connection any more), or ''both'' ends slipping (where one of the LHS sheaths ''might'' shuffle into a position to bridge the two RHS sheaths). But, as tied, the LHS silver (being bent in and out of the page around its crossing counterpart wire) seems unlikely to be pressed against both gold and silver, should it trivially untwine/slip through. Actual studies with actual knots might be useful. I thought I had a spare length of unterminated Cat5, nearby, but apparently (k)not... that, with some coloured permanent marker-pen marks made upon it, would probably have made a decent analogue for visual analysis of failure conditions. Maybe I'll de-plug an old cable (I've got a number of damaged USB cables I could chop, but their being thinner would change the scale and dynamics of the knot, meaning I might as well just use a scrap of twisted-pair internally-sheathed strands). – But I thought you'd like my mind's-eye analysis of the knot behaviour, before I get around to trying anything practical to this end. [[Special:Contributions/141.101.99.7|141.101.99.7]] 17:08, 13 January 2024 (UTC) (<- ex Cub-/Boy-/Venture-Scout, but never got any Knot ''Un''tying badge... that brief stint with escapology aside... ;) )

This comic contained material familiar to a hobby engineer that was cast critically and derogatorily (e.g. “sheety” bend) throughout the explanation. I edited a lot of it. I’ve seen this happen repeatedly in other explanations. I don’t edit most of them. [[Special:Contributions/172.71.150.155|172.71.150.155]] 18:41, 13 January 2024 (UTC) 

"this is a scenario commonly encountered by hobby engineers from the last millenium"
"commonly"? Can any hobbyist engineers from the last millennium attest? Also, this sounds ageist - is it ageist? [[Special:Contributions/172.70.86.166|172.70.86.166]] 21:56, 13 January 2024 (UTC)
:Well, I definitely did electrics/electronics pre-millenium. I'm not at all unhappy with the idea with the possibility of an occasional 'bodge job' connection having happened (e.g. tying a cable in a simple knot, in suitable cases, to add mechanical resistance to any further tendency for a cable to be tugged out of a grommit-hole and the core conducting wires being tugged out of whatever terminal/patch-block they need to be connected to - or, more likely, pulling the core copper strands beyond their tensile limits).
:Although (while I respected the ''idea'' of this being based upon a repair-bodge), I don't see this as a "this wire was damaged, this is how the two ends are reconnected", but rather as a deliberate cable termination method (like adding moulded plugs/etc) which could then be mated end-to-end with another similarly terminated cable. (Like using a gender-changer 'double-socket' between two phono-ended lengths of cable, or using a {{w|File:BNC Tee connector, with Ethernet cable connected-92166.jpg|BNC T-connector just to join two lengths of networking cable}} but without the need for the extra connector ''and'' adding intrinsic tensile resistance - though actually not as much as the BNC 'bayonet' version already does...)
:If I was writing this from scratch, I'd actually remove all the 'repair' aspect of it, TBH. It looks more like a deliberate patch-type cable (1x2core) manufactured to be directly and hermaphroditically compatible with any other such cable, tied together without the need for tools (screwdrivers, crimpers, punch-downs, etc) ''and'' untied as and when required (at least as easily as any similar rope-knot can be undone, which isn't always a given if mishandled and overtightened).
:I'd also be looking at various knots and working out which (if any) could support ''more'' than two contact-patches/sleavings per cable, for three-core or more-core connections between any two such cables. The geometry of the knots would define roughly where (and how long) the external contact-sleaves would need to be (presumably identical for both cables) such that they made appropriate connections between the two halves (cross-overs could be allowed, but that'd have to be down to the IEEE specifications of how to detect/interpret RX/TX assymetry at the end devices, etc). But then I'd also be writing a vastly more complicated alternate explanation. Perhaps just remove the bodge-job implications, someone? Clearly it's not an end-user bodge. Though it could be a manufacturer/industry bodge (such as using an 8P8C connector for essentially 6P4C purposes). [[Special:Contributions/172.69.79.138|172.69.79.138]] 00:53, 14 January 2024 (UTC)
I use the reader app in inverted color mode, so I could not for the life of me figure out what all the discussion about silver and gold was about. Also, can I just comment on how the conductive sleeves are magically flexible? I wonder if they are braided. Even then, this would severely limit how tight the knot could be pulled. [[Special:Contributions/162.158.154.238|162.158.154.238]] 13:26, 14 January 2024 (UTC)
:I initially imagined either a particularly ductile 'foil' or, as you say, braided (like an STP cable's 'S' layer), though the failure modes of both (tearing or fraying) are potentially problematic. Perhaps a conductive polymer of similar mechanical flexibility to the non-conductive regular sheath. The attachment of respetive core to the outer seems to me the most intensive process.
:I once jury-rigged two cameras on a length of CAT5, using two pairs each for power/signal. One camera was around half way along the cable from where it was commonly terminated, but rather than than cutting the cable entirely and reconnecting the 'onwards' TPs (or threading a half-used full cable and a half-used part-length through the false ceilings/etc) I made a careful slit in the outer insulation (and shielding foil/braid, whatever it had), pulled the two chosen pairs out enough to get the necessary length of mid-cable free ends for my purposes and then snipped just those.
:It wouldn't need as much work to connect outer-conducting sheathing to an inner core. Possibly an into-insulation 'displacement' blade, but not sure how you'd guarantee the (single, and only) inner core contact, so slitting outer insulation, fishing for the chosen inner-core, piercing, twining and/or wrapping that conductive strand then reinsulating as necessary or shrink-wrapping with the 'conductive rubber' outer (preventing the slit from tearing too far open on bending). Twice, though you don't need to preserve the 'gold inner' up to or beyond the 'silver inner' tapping point.
:I would imagine (if this were a serious cable-end spec) there'd be careful balancing of robustness and flexibility of the [[2856: Materials Scientists|materials]] and construction methods in use. But handwaved away, in our 'reality'.... [[Special:Contributions/172.69.43.163|172.69.43.163]] 17:26, 14 January 2024 (UTC)
:...see {{w|Conductive elastomer}} (and some of that article's onward links) for a possible type of material to use. [[Special:Contributions/141.101.98.156|141.101.98.156]] 18:32, 14 January 2024 (UTC)

;Knot category?
We've seen some recurring knot-themes, I was thinking. A quick check shows that it's not as overwhelming as I thought it was, but here's what I easily found anyway (possibly missed some, as I skimmed things).
*[[595: Android Girlfriend]] - averted, but knots are mentioned/could have been expected in the parodied scenario (probably not really so cattable).
*[[730: Circuit Diagram]] - drawn knot
*[[1572: xkcd Survey]] - mentioned as an option
*[[1762: Moving Boxes]] - written down (ambiguously)
*[[2738: Omniknot]] - full-fledged 'knotty comic'
*...this one, as above.
So it might just be the two 'proper knot-focused' comics, but (like 'birds' or 'real people' as categories) two or three others that should be considered relevant. Maybe wait until there's a third (it might take a year?), but placing the groundwork for it. Or maybe even being sufficient to prompt someone to act sooner, now that we can be sure that Knots is one of the many subjects Randall may dive into. [[Special:Contributions/141.101.99.131|141.101.99.131]] 18:52, 14 January 2024 (UTC)
:The android comic doesn't mention knots. It is only the explanation here that does. The circuit diagram may have a knot, but it is not labeled, and could be something else. Not like saying this is a comic about knots. Of course it has a relation to this comic, but the relation is more in the connector than in knots. The survey doesn't have knot mentioned in the actual comic. Knots are for sure mentioned in a word in Moving boxes, but the comic is not about knots. Which leaves only Omniknot and this one, and I think even three about knots would be too little for a category. So unless there are at least a couple more, it is way too soon to make a knot comic category. But would be fine to include a link between the two knot comics. I will do that! --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:43, 15 January 2024 (UTC)

2880: Sheet Bend

2024-01-13T17:17:51Z

172.69.43.221: /* Explanation */ The weight of things attached is just one manifestation (knots should still work when floating in space, etc...)

{{comic
| number = 2880
| date = January 12, 2024
| title = Sheet Bend
| image = sheet_bend_2x.png
| imagesize = 317x244px
| noexpand = true
| titletext = A left-handed sheet bend creates a much weaker connection, especially under moderate loads.
}}

==Explanation==
{{incomplete|Created by a SHEETTY BEND - Please change this comment when editing this page. Can anyone elaborate on of this knot is right handed and what the differnces to a left handed would be and why this would decrease the strength of the knot as mentioned in the title text. Do NOT delete this tag too soon.}}
This is the seventh installment in the series of [[:Category:Cursed Connectors|Cursed Connectors]] and presents Cursed Connectors #46: The Sheet Bend. At the time of release this was the lowest number used for a cursed connector, with #286: [[2507: USV-C]] being the one with the highest number after those seven comics.

This comic shows two double-core wires being joined to make an electrical connection. Instead of the join being made the conventional way, that is, silver being joined to silver and gold being joined to gold within the insulating white cable, the diagram shows each core being connected to a ductile outer sheath, then the wires being tied together such that the outer sheaths touch and the connection is completed that way.

This is not the way electrical connections are usually made, as you might get an electric shock from touching the outer side of the wires, if the current being passed was significant enough, and the possibility of contact between any of the wire's conductors and any other item (bridging gaps, leaking signal or possibly even ''introducing'' external interference) could be problematic for both high and low ampage cables (e.g. used to transmit power or just signals). Most connectors, even those like the relatively exposed {{w|punch-down block}} or {{w|screw terminal block}} types, would use some structural housing (and even {{w|AC power plugs and sockets#Protection from accidental contact|other methods}}) to ensure that the 'live' ends of a socket/plug/hybrid terminator are not trivially contactable to other exposed wires or objects/people, generally according to the relative dangers from, or to, the equipment to which the cable is connected.

If this knot were tightened, the gold and silver connectors would probably touch, shorting out the circuit, but there is also the possibility of the cable slipping loose (perhaps by improper tensioning or handling of the knot, from the start) and the exposed conducting sheaths making other improper/dangerous connections across or beyond the knot itself. In both cases, the connection of the 'connector' would be at least become unreliable, even if it only disconnected the intended contact-points due to slippage – whether or not it became mechanically untied.

The knot used to tie the two halves of the cable is a {{w|sheet bend}}, which is often used to join two ropes of different thicknesses, and explains the name for this type of cursed connector.

The title text says that a left handed sheet bend would provide a weaker connection. An actual left handed sheet bend provides less strength to the knot. This makes the title text a pun on the double meaning of "moderate load" (as in a moderate amount of physical tension applied through the cables ''or'' a moderate amount of electrical current passing through them). The difference between a left handed and right handed sheet knot is the free ends of the knots are on the same side in a right handed sheet knot (here both on the bottom side), but on opposite sides in a left handed sheet knot.

==Transcript==
:[Above the drawing there is a header. Below the header there is a double-core wire going in from the left and stopping just past the middle of the picture. It shows how the inside of the wire looks and how the silver and golden wires inside are connected to two rectangular pieces of silver and golden material respectively. The golden piece is to the left and the silver piece to the right, closest to the end of the wire. Beneath this wire is shown two double-core wires forming a knot of the sheet bend type. Here it becomes clear that the silver and golden pieces are on the outside of the wires (but connected to the wires running inside the wires). In the knotted part of the wires gold touches gold and silver touches silver, without them touching the other color. Beneath this knot there is a label for the connector.]
:Cursed Connectors #46:
:The Sheet Bend

{{comic discussion}}

[[Category:Cursed Connectors]]
[[Category:Comics with color]]

Talk:144: Parody Week: A Softer World

2024-01-12T01:54:13Z

172.69.43.221: Original IP/time, allowing for the update apparently by same individual

XKCD Volume 0 also has

UATAQANUUNG QSICHINGNKUCHAANG CHSICHINGSICHINGNG

SICHINGULUUNGUUNG CHASNGATAQANCHATAQANNG

above the strip. {{unsigned ip|172.69.214.108|23:04, 11 January 2024}}

2878: Supernova

2024-01-09T18:52:59Z

172.69.43.221: /* Explanation */ It definitely isn't magnitude in an astronomical manner.

{{comic
| number = 2878
| date = January 8, 2024
| title = Supernova
| image = supernova_2x.png
| imagesize = 348x227px
| noexpand = true
| titletext = They're a little cagey about exactly where the crossover point lies relative to the likelihood of devastating effects on the planet.
}}

==Explanation==
{{incomplete|Created by A CAGEY ASTRONOMER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
A {{w|supernova} occurs when a heavy star collapses when its original fuel runs out and it can no longer produce enough energy to fight its own gravity. The collapsing mass leads to a violent explosion, one of the most interesting events for astronomers to observe and one that can be used to glean information about the universe.

At first glance, this graph shape appears to show a '''light curve''', a common supernova graph constructed by plotting the '''brightness''' of a supernova as a function of '''time'''. Such a light curve graph looks somwhat like this, with negative values perhaps indicating a logarithmic scale (below zero indicates a linear brightness of less than the unit amount), to explain how that segment of the line reaches into the negative range, but not the astronomical "magnitude" (for which lower, and thus negative, values actually indicate ''increasingly'' brightness). But it has been most often the case that an unremarkable star, possibly not even visible to the naked eye, has become notably bright over a short period of time before trailing off again to leave a stellar remnant and expanding cloud of ejecta.

However, this comic reimagines the light curve graph shape to show a graph that displays how '''happy''' astronomers would be when they discover a new supernova based on how '''far away''' it is from Earth. The further away one is, the less detail can be learned from it, and thus the less happy astronomers are. But a supernova closer than, say, 100 light years might be ''too'' close. Its radiation could destroy life on Earth, or at least significantly harm the biosphere. Astronomers (and many others) would be really unhappy if that happened,{{cn}} shown as sharply negative happiness (below the X axis) for a supernova that is too close.

Many astronomers watch and study the stars in the night sky, even the ones that don't change appreciably over human timescales, but observing and recording such a huge event would be interesting for many reasons. Even if not directly involved in the science, humans can observe some supernovae with the naked eye, especially if they occur within {{w|Milky Way|our own galaxy}} and are clearly visible from Earth. A potential supernova in the news lately is {{w|Betelgeuse}}, a {{w|red giant}} star that is the left shoulder in the constellation Orion. About 430 light years from the Sun, it has been pulsating, dimming and brightening over exceedingly short time scales compared to the tens of millions of years such a big star is expected to burn. Though it could yet easily go several thousand years before it goes supernova, it could also already have exploded and we are only waiting for the light from the event to reach Earth. Betelgeuse should be far enough away from Earth that the inevitable explosion would be safe enough for life on Earth (although [https://www.skyatnightmagazine.com/space-science/earth-danger-betelgeuse-supernova some assessments] are not so sure), but it ''will'' outshine all other stars in the night sky, possibly competing with the Moon, and could even be visible during daytime. This would be a dream come true for many astronomers and something obvious to others interested in the night sky. In the first [[:Category:Stargazing | Stargazing]] comic, [[1644: Stargazing | 1644]], the wish that it goes supernova (in [[Randall|Randall's]] lifetime) is clearly expressed.

Since this ''should'' be safe for us, and since it would be a spectacle not seen for hundreds of years here on Earth, this would make the astronomers very happy, not just from all they could learn, but also from just from all the increased interest in gazing at the sky with the 'new' star (and then seeing what happens to it next).

A distance exists where the astronomers would be the most happy, with anything nearer than that being less good (or very bad). As more distant phenomena only decrease the positive effects (and certainly do not increase the bad ones), the graph beyond the maximum happiness appears to show an asymptotic approach to less and less positive influence on the mood of the astronomers. There are thought to be about three supernovae occuring per century within our own galaxy (most stars of which are far further away from Betelgeuse), and many other nearby and far more distant galaxies within which a supernova explosion can be detected. These remain useful to see, and are often studied as intensively as possible, but have decreasing amounts of thrill to them and are harder to notice/record in the early stages of the explosion (or immediately before, to add even more understanding).

The title text expands upon the latter point of nearness, in that the astronomers themselves are not quite clear/unwilling to admit how close they would like a supernova to be. If it were {{what if|73|close enough}} to severely impact the quality of human life, they would presumably not be happy, but they might actually be willing to accept some trouble for Earth life if they get to the see a supernova comparatively close by.{{cn}}

If the supernova were to instantly destroy Earth, or kill off all life on it, the astronomers may no longer be able to be happy or unhappy; this could be very much dependent upon what, if any, are the subsequent feelings of theologists/spiritualists/etc.

This is the second comic in a row that mentions exploding stars, after [[2877: Fever]], which like this comic is also a [[:Category:Charts|Charts comic]].

==Transcript==
:[A graph is shown where the axes are labeled and arrows are pointing upward above the Y axis label and to the right above the X axis label. There is a single line on the graph that peaks close to the Y axis, where it reaches close to the top of the drawn part of the Y axis. Then the line approaches the X axis asymptotically towards the far right. But closer to the Y axis, the peak line goes almost vertically down, and continues far below the "bottom of the chart", outside of the boundary of the graph that was only supposed to be above the X axis.]
:Y axis: How happy astronomers are
:X axis: How far away the new supernova is

{{comic discussion}}

[[Category:Line graphs]]
[[Category:Astronomy]]

521: 2008 Christmas Special

2024-01-09T12:15:51Z

172.69.43.221: /* Explanation */ That's not a comma-break. Lists like "Megan and Cueball and (the others)", streamlined, only require non-final conjunctions replaced with commas. No good reason to add a comma before the retained "and". And you can tell Oxford that...

{{comic
| number = 521
| date = December 24, 2008
| title = 2008 Christmas Special
| image = 2008_christmas_special.png
| titletext = 'How could you possibly think typing 'import skynet' was a good idea?'
}}

==Explanation==
This comic is the xkcd Christmas Special from the year 2008. The prologue states that due to the {{w|2008 financial crisis}}, only very few images of the strip could be produced, leaving the others to be blacked out. It is therefore left to the reader to reconstruct the whole story based on the given images. While it is claimed that the reconstruction should be rather easy, the complicated and abstruse plot-line makes it nearly impossible to fill the gaps. Any attempt at inferring the missing images would therefore be largely guesswork. The comic features the well-known xkcd characters getting involved in a strange fight with cyborgs and raptors on Christmas Eve.

The line "We apologize for the inconvenience." is possibly a reference to the famous book series ''{{w|The Hitchhikers Guide To The Galaxy}}'' by {{w|Douglas Adams}}. It appears there as God's Final Message to His Creation, written in letters of fire on the side of the Quentulus Quazgar Mountains.

'''Panel 2:''' [[Megan]] strives to outdo some Christmas lights she has seen on YouTube.

'''Panel 3:''' Dissatisfied with her work, Megan is thinking about alternative ways to improve her light arrangement. The idea of firing {{w|Sodium}} pellets into snow is probably a bad one, as Sodium reacts exothermically with water and may, in large amounts, induce explosions.

'''Panel 5:''' Probably still obsessed with creating a large and impressive light display, Megan has constructed an electronic device with an {{w|Arduino}} processor, perhaps to make the light chain show patterns. However, the energy she used was too high, causing one of the control boards to sublimate – go directly from a solid to a gaseous state without an intermediate liquid phase. She then wishes she could make the system self-repairing.

'''Panel 7:''' Megan's device has developed {{w|artificial intelligence}}, allowing it to feel. This is presumably a result of Megan attempting to make the device self-repairing. This common trope in science-fiction works usually leads to the system's attempt to eradicate its creator. [[Cueball]] attributes the emergence of a personality to the awesome ease and power of programming in {{w|Python (programming language)|Python}}.

'''Panel 11:''' Out of context, this panel introduces the idea of {{w|Santa Claus}} being a {{w|Muslim}}. This may be a reference to the persistent Internet rumours that Barack Obama is a Muslim, though he declares himself to be a Christian. However, the statement could also relate to the fact that Santa Claus is usually displayed with a large beard, which is sometimes also sported by conservative Muslims. Or it could just be nonsensical.

'''Panel 13:''' At this point, the self-aware Christmas light control systems have released {{w|cyborgs}} that tried to kill Megan and Cueball. To repel the cyborgs, they have cloned {{w|Velociraptors}}. Cueball expresses doubt about whether that was a good idea. Velociraptors appear frequently in xkcd, as seen in [https://www.explainxkcd.com/wiki/index.php/Category:Velociraptors these comics]

'''Panel 17:''' As predicted, the raptors have gone wild, but Megan, Cueball and the two smaller characters (perhaps their children) managed to cage the dinosaurs. They believe themselves safe unless the raptors learn how to build {{w|lightsabers}}. This is a reference to a line in {{w|'' Jurassic Park''}} where the main characters believe themselves safe unless the raptors can learn how to open doors.

'''Panel 19:''' The raptors have indeed succeeded with constructing lightsabers and must now be fought. The "Clever girl" refers to a line from ''Jurassic Park'' where the raptors outflank (and kill) one of the human characters wearing a similar hat. “Snap-hiss” is a common phrase originated by Timothy Zahn to describe the sound of a lightsaber igniting in Star Wars literature.<ref>Zahn, Timothy, "Author Annotations: Chapter 7, 1", Star Wars: Heir to the Empire: The 20th Anniversary Edition, ISBN 0345530004, "I thought long and hard about how to write the sound of an igniting lightsaber. I finally went with snap-hiss.", corroborated by [https://boards.theforce.net/threads/snap-hiss.25830511/ forums]</ref>

'''Panel 23:''' IT billionaire {{w|Bill Gates}} has mistakenly killed Santa Claus, possibly in a sword fight. He claims to have mistaken him for [[Richard Stallman]], a prominent {{w|free software}} activist. (Gates strongly opposes the idea of free software and is therefore considered an antagonist by many of its supporters.) The most striking resemblance between Stallman and Santa Claus is probably the long and untamed beard. [[225: Open Source]] features Stallman involved in a sword fight. Only much later did [[Randall]] again kill off Santa in his Christmas comics, but then twice in only three years. First in [[2559: December 25th Launch]] from 2021 and then in [[2872: Hydrothermal Vents]] from 2023.

'''Panel 29:''' Megan, possibly [[Danish]], asks [[Black Hat]] where he obtained the enormously large {{w|Christmas tree}} that can be seen on the right side of the picture. It is implied that he logged {{w|Yggdrasil}}, a giant ash tree in Norse mythology. According to tradition, Yggdrasil is the world tree representing the whole of creation and holding together the cosmological structure.

'''Panel 31:''' [[Randall]] wishes Merry Christmas to all xkcd readers.

The title text refers to panel 7. In Python, modules are imported using the "import ''module''" syntax. {{w|Skynet (Terminator)|Skynet}} is a self-aware artificial intelligence system featured in the ''{{w|Terminator}}'' film series as the main antagonist. Importing the Skynet module might therefore account for Megan's system's developing an evil personality.

Note that this comic was first published in another version that had panel 29 as panel 27 and the "Merry Christmas from xkcd" message at the bottom. As 27 is not a {{w|prime number}}, the current version was published in place of the erroneous one.

It has been observed that the top left nine panels form a {{w|Glider (Conway's Life)|Glider}} in ''{{w|Conway's Game of Life}}''. The glider is sometimes used as an emblem representing {{w|hacker subculture}}, although rotated by 90 degrees. It remains however unclear whether the occurrence in the comic is intentional or owed to the prime number pattern. Also, if you put the shown comic panels in The Game of Life, it turns into a Beehive (for some reason).

==Transcript==
:The 2008 XKCD Christmas Special
:Due to the slowing economy, we could only afford to produce the prime-numbered panels.
:You should be able to infer the missing parts of the story easily enough.
:We apologize for the inconvenience.
:[The first panel is blank.]
:[Megan carrying Christmas lights and Cueball watching.]
:Megan: I'm going to one-up those Christmas light displays on YouTube.
:[Megan thinking.]
:Megan: Hmm. Needs more flair. Do you know what happens when you fire sodium pellets into a snowbank?
:Cueball: No.
:Megan: Me neither.
:[The next panel is blank.]
:[Megan sitting in front of a console.]
:Megan: Whoops, one of the Arduino control boards sublimated.
:Megan: If only I could make it self-repairing...
:[The next panel is blank.]
:Megan: Shit. The system has become sentient.
:Cueball: Friggin' Python.
:System: GRAAARR!
:[The next three panels are blank.]
:[Megan showing laptop to Cueball.]
:Megan: But according to this email forward, Santa is secretly a Muslim!
:Cueball: It explains everything!
:[The next panel is blank.]
:Megan: Okay, the cloned raptors are hunting the last of the cyborgs. We're safe.
:Cueball: Are you sure you thought this through?
:[The next three panels are blank.]
:[Two couples appear in this next panel.]
:Cueball: Are the raptors contained?
:Ponytail: Sure. Unless they figure out how to build lightsabers.
:[The next panel is blank.]
:[Guy with hat fighting with a raptor using lightsabers.]
:Cueball: It's all right. I've got her.
:[Lightsaber appears from behind.]
:Snap-hiss!
:Cueball: ...Clever girl.
:[The next three panels are blank.]
:[Bill Gates is holding a weapon over Santa's body. The two girls are watching.]
:Megan: Great. Bill Gates kills Santa.
:Bill Gates: I thought it was Stallman with a dyed beard.
:[The next five panels are blank.]
:[Danish and Black Hat are looking at a tree.]
:Danish: Where did you get this Christmas tree?
:Black Hat: Nowhere.
:Danish: Did you cut down the Yggdrasil?
:Black Hat: ...Maybe.
:[The next panel is blank.]
:[Megan and Cueball holding hands and looking at reader.]
:Merry Christmas from XKCD <3
:[The last panel is blank.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Richard Stallman]]
[[Category:Comics featuring real people]]
[[Category:Christmas]]
[[Category:Programming]]
[[Category:Star Wars]]
[[Category:Velociraptors]]
[[Category:Terminator]]
[[Category:Comics featuring Danish]]

2877: Fever

2024-01-05T20:56:23Z

172.69.43.221:

{{comic
| number = 2877
| date = January 5, 2024
| title = Fever
| image = fever_2x.png
| imagesize = 514x587px
| noexpand = true
| titletext = Hypothermia of below 98.6 K should be treated by leaving the giant molecular cloud and moving to the vicinity of a star.
}}

==Explanation==
{{incomplete|Created by the BIG BANG - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

{| class="wikitable" style="margin:auto"
|+ Table describing
|-
! Fever Temperature (Celsius) !! Equivalent Fahrenheit temperature !! Treatment !! Additional notes
|-
| 38-40 || 100-104 || Fluids, rest, normal doctor stuff || Normal fever temperatures.
|-
| 40-45 || 104-113 || Hospital, advanced doctor stuff || Point at which humans might start experiencing brain damage from fever.
|-
| 45-100 || 113-212 || Exit that steam cloud immediately ||
|-
| 100-400 || 212-752 || Stop, drop, and roll ||
|-
| 400-500 || 752-932 || Leave Venus ||
|-
| 500-1,500 || 932-2,732 || Leave the volcano ||
|-
| 1,500-5,000 || 2,732-9,032 || Leave the tunneling machine under Earth's surface ||
|-
| 5,000-6,000 || 9,032-10,832 || Leave the Sun's surface ||
|-
| 6,000-50,000 || 10,832-90,032 || Leave another star's surface ||
|-
| 50,000-20,000,000 || 90,032-90,032 || Leave another star's core ||
|-
| 20,000,000-10,000,000,000 || 90,032-18,000,000,032 || Leave the exploding star ||
|-
| 10,000,000,000 or higher || 18,000,000,032 or higher || Leave the Big Bang ||
|}

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

:Treating a Fever

:Fever   Treatment
:38°C-40°C (100°F-104°F): Fluids, rest, normal doctor stuff
:40°C-45°C: Hospital, advanced doctor stuff
:45°C-100°C: Exit that steam cloud immediately
:100°C-400°C: Stop, drop, and roll
:400°C-500°C: Return to Earth from Venus ASAP
:500°C-1,500°C: Please climb out of that volcano
:1,500°C-5,000°C: Turn your tunneling machine around and come back up to the surface
:5,000°C-6,000°C: No, the surface of the '''Earth''', not the Sun
:6,000°C-50,000°C: Wait, that's not the Sun. What star are you visiting? Come back right now.
:50,000°C-20,000,000°C: At least stay on the '''surface''' of the star instead of diving down to the core
:20,000,000°C-10,000,000,000°C: You know, you could've picked a normal star instead of one that's exploding
:10,000,000,000°C or higher: I hope you're enjoying your visit to the Big Bang but you should really come back home immediately

{{comic discussion}}