explain xkcd - User contributions [en]

Talk:3111: Artificial Gravity

2026-06-10T16:44:23Z

82.132.237.84:

Note the motion lines around the main body of the spacecraft, showing that it is also shaking to a much lesser extent. [[Special:Contributions/181.214.218.76|181.214.218.76]] 15:26, 4 July 2025 (UTC)
:That is just Newton's Third Law, which is very often taken into account in space obviously. [[User:Thehydraclone|Thehydraclone]] ([[User talk:Thehydraclone|talk]]) 16:04, 4 July 2025 (UTC)
:: I prefer to think it's using thrusters either side of the main body to slightly oscillate that back and forth, which then translates into the larger movement of the capsule through the joint. [[Special:Contributions/82.13.184.33|82.13.184.33]] 08:17, 7 July 2025 (UTC)

Report: Total crew bone mass remains constant. {{unsigned ip|2804:7f0:bf02:c680:390e:8bb5:b4a9:db40|16:05, 4 July 2025}}
: Now you made it sound like some bones have changed owner. Whether intentional or not, very xkcd. --[[User:Coconut Galaxy|Coconut Galaxy]] ([[User talk:Coconut Galaxy|talk]]) 13:28, 5 July 2025 (UTC)
:: "We may have made the change of direction a ''little'' too abrupt..." [[Special:Contributions/82.13.184.33|82.13.184.33]] 15:58, 7 July 2025 (UTC)

The spinning idea reminds me of the spin drive from Andy Weir's "Project Hail Mary."[[Special:Contributions/136.47.216.1|136.47.216.1]] 17:34, 4 July 2025 (UTC)

Wait, nothing about the 4th of July today? That's odd. [[Special:Contributions/2601:647:8500:1E09:55BB:EEBB:23EA:178A|2601:647:8500:1E09:55BB:EEBB:23EA:178A]] 23:04, 4 July 2025 (UTC)
: this rocket was clearly sent up mistaken for a firework {{unsigned ip|2600:4040:52f1:300:8c1d:959a:d4c2:80be|14:07, 5 July 2025}}
: Not at all surprising - clicking through [[:Category:Comics from July]] to find the relevant week each year, the only one I can see in twenty years ''directly'' referencing it is [[1858: 4th of July]]; at a stretch, you could suggest that [[285: Wikipedian Protester]] was also specifically timed. More notably, it's the 19th anniversary of [[123: Centrifugal Force]], which feels relevant. - [[User:IMSoP|IMSoP]] ([[User talk:IMSoP|talk]]) 10:00, 7 July 2025 (UTC)

aw, great, "steadily"--[[User:Bb777|me, hi]] ([[User talk:Bb777|talk]]) 03:37, 7 July 2025 (UTC)

This rocket design and the intent to provide artificial gravity to the crew module is similar (but not identical) to the design of the ship in Andy Weir's novel Project Hail Mary, for which the film adaptation's trailer was released on June 30. [[Special:Contributions/24.85.198.95|24.85.198.95]] 16:36, 9 July 2025 (UTC)

Could this possibly be a reference to james bond preferring his drinks "shaken not stirred?" Especially given how the engineers never even considered spinning the capsule, despite the obvious impracticality of having it "shaken not spun," like they had some kind of personal preference. [[User:Ip36|Ip36]] ([[User talk:Ip36|talk]]) 00:02, 10 July 2025 (UTC)
:No obvious Bondian reference (saving for prior centrifugal/centripetal death-traps). And incidentally also interesting to note that stirring is also the ''prefered'' method of mixing, by anyone not solely influenced by Fleming's œuvre. [[Special:Contributions/82.132.236.42|82.132.236.42]] 12:33, 10 July 2025 (UTC)

Woah i got this comic twice in a row from the "random explination" button. What is the chances that, if you click on it, you will get the comic you were already on? Seems maybe not one hundred percent random. --[[User:Kirinhatchi|Kirinhatchi]] ([[User talk:Kirinhatchi|talk]]) 14:00, 10 June 2026 (UTC)
:Assuming random selection, as of this moment, 1 in 3111. Which isn't likely, but unlikely things ''do'' happen occasionally. How many times have you clicked that button in total? One tends to pay no attention to all the times that coincidences ''don't'' happen, and focus on the times that they do come up; there's a bias to our attention. [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 14:10, 10 June 2026 (UTC)
::Because of a known flaw in the randomising mechanism (as currently implemented), it's also probably less than 1 in 3111 (erm, I mean 1 in less-than-3111, as in ''more'' likely than 1 in 3111... IYSWIM). And it would be a 1-in-3256 as 'baseline', right now as we write, anyway.
::But exactly how much more than whatever-it-should-be, I don't know. But I recall testing out the 'randomness' back when the biased randomness was first noted, and getting several 'revisits' (but not immediate revisits) within short blocks of just ten sequentially "random comic" clicks. With a bit of testing, you could try to pin down the 'long tail' 8n the frequency stats and pin down a normal distribution for getting a random-revist straight off any particular prior random landing spot. [[Special:Contributions/82.132.237.84|82.132.237.84]] 16:44, 10 June 2026 (UTC)

3256: Nostalgia Content

2026-06-10T16:30:21Z

82.132.237.84: /* Trivia */ Better current Trivia. The correctly (re)uploaded file would need linking (perhaps the word "originally" could lead there.

{{comic
| number = 3256
| date = June 8, 2026
| title = Nostalgia Content
| image = nostalgia_content_2x.png
| imagesize = 276x404px
| noexpand = true
| titletext = Gen-Z got a chunk of the Carboniferous, and now all their memes are about how pathetic and small today's dragonflies are.
}}

==Explanation==
{{incomplete|This page was created by a Parataxtite. Don't remove this notice too soon.}}
This comic is a joke about nostalgia content. In it, a database for creating nostalgia content has accidentally included some {{w|Early Devonian}} features in it. These features, while certainly being old, are far too long ago for anyone to be alive at the time,{{Citation needed}} let alone remember it, hence defying the purpose.

In the example in this comic, [[Cueball]] puts the more new creations of {{w|Pogs}} & {{w|Tamagotchi}}s (previously the subject of [[1546|another comic]]) with the Devonian Prototaxites and armoured fish - with the ridiculous age comparison between them part of the joke. (Pogs became a fad in the early 1990s, and Tamagotchis came into production in 1996, while the Devonian period ended 359 million years ago.) {{w|Prototaxites}} (here formerly referred to as Parataxites) were huge fungi that lived during the Devonian. The armoured fish [[Cueball]] speaks of are from an ancient class known as {{w|Placodermi}}, which appeared during the {{w|Silurian}} and Devonian. Placoderms were among the first jawed fish, and the first fish clade to have pectoral fins. Devonian placoderms include Dunkleosteus, Titanichthys, Bothriolepis and Rhamphodopsis. Silurian placoderms include Xiushanosteus, Anglaspis, and Poraspis. There was also Sacabambaspis from the {{w|Ordovician}}.

The title text shows another example of nostalgia content warped by the accident, where Gen Z memes got a chunk of the {{w|Carboniferous}} in their nostalgia database. During the Late Carboniferous, species such as {{w|Meganeura}} were prolific, which resemble today's dragonflies, with the notable difference of having wingspans of up to 65 cm long, which would obviously dwarf modern dragonflies. However, this change happened over millions of years, and in Gen Z's time the dragonflies are as small as ever, hence the ridicule.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Cueball is standing, with his arms out, in front of a Prototaxite towering over a mossy landscape. To his right, a Tamagotchi (bottom-left) and milk-caps (referred to in this comic as "pogs", top-left) appear. The 3 milk-caps that can be seen show a skull with a snake through its eyeball, a figure 8 & a star (3 more milk-caps are also shown, but have obscured pictures).]
:Cueball: Who else remembers pogs? Tamagotchis? Vast forests of Prototaxites towering over the mossy landscape as armored fish stir in the deep?
:[Caption below the panel:]
:Due to a database error, millennial nostalgia now includes a portion of the early Devonian.

==Trivia==
Cueball had originally incorrectly refered to the huge fungi as "parataxites", but the text in the comic was later corrected to read "prototaxites".
{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Geology]]
[[Category:Biology]]
[[Category:Time]]
[[Category:Comics to make one feel old]]
[[Category:Comics edited after their publication]]

Talk:3256: Nostalgia Content

2026-06-10T16:22:30Z

82.132.237.84:

I'm not a paleobotanist by any stretch of the imagination, but the comic contains an error. It should be `prototaxites` instead of `parataxites`. [[User:Blagae|Blagae]] ([[User talk:Blagae|talk]]) 12:57, 9 June 2026 (UTC)
:This has now been fixed on the main website, not sure how it propagates to explainxkcd. [[Special:Contributions/2601:241:8002:3E0:E405:A8CA:8B60:4A9C|2601:241:8002:3E0:E405:A8CA:8B60:4A9C]] 04:35, 10 June 2026 (UTC)
::Manually. Theoretically the upload-BOT could pick up on such things and automatically note it (like it does with abnormally-sized uploads), but it doesn't and I'm not sure it needs to waste its time back-checking comics, especially at the risk of a random glitch making it look like a comic changed then changed back (with a human being more capable of ignoring that.)
::The process generally is:
::*Someone reuploads the latest source comic (replacing the current one, or as a "v2"-like newly named one, but in the latter case also change then {{template|comic}} parameter to use the new one, too). Noting that it takes an autoconfirmed user to do the (re)upload bit.
::*Then it's good form (and anyone can do this, after the fact) to link to the original version, in the Trivia (in this case, modify the existing Trivia about it being 'currently' wrong). Simplest to do if it was a "v2"-like seperate upload, but you can link to the file-history version otherwise, if you're comfortable with wikimarkup for that.
::*After all that, add [[:Category:Comics edited after their publication]] to the page.
::Fairly simple (even if it's not something I could do all of, nor you). Just have a look at other members of the CEATP-category for past instances of what it might look like (slightly different circumstances, across each, possibly). [[Special:Contributions/82.132.237.84|82.132.237.84]] 16:22, 10 June 2026 (UTC)

Explainxkcd was down when this comic came out, which I would assume is why the explanation is blank, but I'm just glad the page is back up. [[User:RadiantRainwing|K9Dragon23, or RainWingSquares (talk)]] ([[User talk:RadiantRainwing|talk]]) 13:56, 9 June 2026 (UTC)
:So it wasn't just me! When I saw it was down I just thought it was just a problem with my computer![[User:GSLikesCats307|GSLikesCats307]] ([[User talk:GSLikesCats307|talk]]) 14:35, 9 June 2026 (UTC)
::It was a "global problem", effectively, from the message I was getting. I'd decided it was one of three things:
::*Some (new?) editor had tried something fancy that accidentally broke the whole site (hoped not, and it's fairly rugged against the obvious accidental errors)
::*Someone had ''deliberately'' broken it, as above (again, hoped not...)
::*Some extrernal system had started trying to scrape the site for data, with absolutely no thought for throttling this down to non-disruptive levels.
::Given no signs of error-prone edits, now it's back, the last of these is now the most obvious. The cloudflare gateway obviously didn't prevent it, originally, but may yet have added this particular inconsiderate attempt by now (maybe why it's working right now... leaving it up to the instigator to decide whether or not to reconfigure to hammer here again... unless they already realised they were hammering it, and had turned off/tuned down to correct that error).
::Though there's at least two further possible reasons, that I'll not bother mentioning. [[Special:Contributions/82.132.239.2|82.132.239.2]] 15:42, 9 June 2026 (UTC)
:::If someone deliberately broke it, then it could’ve been to create a real database error, in accordance with the comic. [[User:Logalex8369|Logalex8369]] ([[User talk:Logalex8369|talk]]) 16:06, 9 June 2026 (UTC)
::::That explains why the "Random comic" link showed me cave drawings earlier today.{{citation needed}} [[Special:Contributions/64.201.132.210|64.201.132.210]] 18:40, 9 June 2026 (UTC)
:I saw this page without any transcript and I thought "Hey, I could do that." So I did. I hope someone else edits the explanation for me, for I have very little knowledge on paleobotany. [[User:Clarkexckd8|Clarkexckd8]] ([[User talk:Clarkexckd8|talk]]) 14:39, 9 June 2026 (UTC)

I remember back in the good old days when people used to link to real Wikipedia pages. --[[Special:Contributions/2A10:D586:3E93:0:6485:4264:AFE9:80FF|2A10:D586:3E93:0:6485:4264:AFE9:80FF]] 14:41, 9 June 2026 (UTC)

That's about as far back as nostalgia googles can go, given the difficulty of glassmaking before the evolution of woody fibers in plants. [[User:RegularSizedGuy|RegularSizedGuy]] ([[User talk:RegularSizedGuy|talk]]) 20:33, 9 June 2026 (UTC)

3137: Cursed Number

2026-06-10T15:57:36Z

82.132.237.84: /* Explanation */ Inserted a more direct 'riff' on the Lovecraftian 'original'. Whch sort of requires it to go 'first' in the followup, sorry.

{{comic
| number = 3137
| date = September 3, 2025
| title = Cursed Number
| image = cursed_number_2x.png
| imagesize = 388x449px
| noexpand = true
| titletext = Another group of mathematicians is working to put an upper bound on the number, although everyone keeps begging them to stop.
}}

==Explanation==

It is quite common on mathematics to not know the value (or existence) of a number but be able to put bounds on it. For example, we know the first counterexample to the {{w|Collatz conjecture}} is at least 10^21, if it exists. There are also constants where we have an upper bound.

In this case, there is apparently postulated to exist a number that extremely harmful to the human mind to read it without eye protection - an {{w|information hazard}}. Dangerous pieces of writing like this are a fairly common trope in speculative fiction, such as the {{w|Necronomicon}} in the {{w|Cthulhu Mythos}}, the [https://wiki.lspace.org/Necrotelicomnicon Necrotelicomnicon] of Discworld (a possible "Telephone Book of the Dead", inspired by the former), [https://wiki.teamfortress.com/wiki/Bombinomicon The Bombinomicon] in Team Fortress 2 (a similar riff on the Necronomicon), [https://scp-wiki.wikidot.com/scp-033 cognitohazards] in the {{w|SCP Foundation}}, the Basilisk in {{w|BLIT_(short_story)|BLIT}} by David Langford, and {{w|Monty Python}}'s {{w|The Funniest Joke in the World|Funniest Joke in the World}}. It is also very similar to the concept of an {{w|illegal number}}, or the {{w|Number of the beast}}.

Saying that it is once ''again'' safe to view large random numbers without eye protection may imply that the cursed number used to not be cursed (as opposed to no one realizing that the cursed number existed). This might indicate an evolutionary change in human brain structure, or, [[2332: Cursed Chair|considering previous comics]], someone with magical powers literally placing a curse on it (but not telling humans which). In the latter case, the fact that mathematicians have been able to place a lower bound might suggest that the magic-wielder gave some sort of hint, such as a hashed or encrypted version or a mathematical puzzle/riddle. Alternatively it could be that after the existence of the cursed number was discovered, but before there was a lower bound on it, people were advised to wear eye protection when viewing any large number, because no one could be sure which large number was cursed. The mechanism by which the eye protection works is not explained; theoretically any eye protection which allowed someone to view the cursed number at all shouldn't work, as being able to see or read the number means you can perceive it.

Naturally, the mathematicians of this world are doing their best, in the interest of public safety, to keep this number away from as many human eyeballs as possible. Through some process they have figured out the number is at least 22 digits long. Numbers this large (greater than 10<sup>21</sup>, i.e. at least a {{w|Orders_of_magnitude_(numbers)#1021|'sextillion'}}) are extremely unlikely to be found in the day-to-day lives of non-mathematicians (and almost all mathematicians); even if a person spent their entire lives looking at random strings of 22 digit numbers flashing by every millisecond, for a 100 year lifetime, they would still only have about 3 in a (short) billion chance of seeing the number. Because of the low risk, public officials have deemed it safe for people to go about their daily lives reading numbers again without eye protection, which apparently protects you from the number.

Despite this, there are some instances of large numbers (more than 21 decimal digits) that may be encountered relatively frequently. IT professionals may encounter "{{w|Universally unique identifier}}s". These are 128 {{w|bit}} binary numbers requiring up to 39 decimal digits to display. However, with 2^128 possible possible numbers of that length, even if you look at UUIDs all day long you are extremely unlikely to see this "cursed number" if it exists.

In the title text another group of mathematicians are trying to narrow down the number's identity even further. The more attributes of the cursed number the mathematicians identify, the easier it is for someone with morbid curiosity or someone researching more attributes of the number to discover the number themselves and get their mind damaged. This includes the researchers themselves, as they are now willingly going above the lower safe limit, increasing their chances of encountering it accidentally. Furthermore, the cursed number may appear as part of another number; for example, 223 appears as part of 2237. Worse, if the number could be determined in some controllable way that didn't necessarily expose its discoverers, it {{w|BLIT (short story)|might be used as a weapon}}, and this might be easier with the upper bound discovered, if the method used to find the number is brute force. This echoes concerns about knowledge gained from research on nuclear forces having been used to create atomic weapons. This was also how the Funniest Joke in the World was used in Monty Python.

==Transcript==
:[A large screen with one equation in the middle is shown to the left of three people. The left part of the equation shows a black bar with a skull in the middle:]
: 💀 > 2.6 x 10<sup>21</sup>

:[Cueball is standing to the right of the screen and further right is Miss Lenhart. Miss Lenhart is standing behind a lectern with a label in front. Hairbun stands further and holds a paper up in front of her using both hands. The paper shows illegible text surrounding what is visibly the same equation as appears on the screen, with a skull, but not the black bar. None of the text can be read and the skull can only be made out as such, knowing what it is from the screen.]
:[The lectern reads:]
:Math Dept

:[Caption below the comic:]
:Good news: Mathematicians have put a new lower bound on the '''Cursed Number that destroys the minds of all who perceive it'''!
:It's at least 22 digits, which means it's unlikely to be seen by any human no matter how many random numbers they look at.
:They say it's once again safe to view large random numbers without eye protection.

{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Miss Lenhart]]
[[Category:Comics featuring Hairbun]]
[[Category:Math]]
[[Category:Comics with cursed items]]