explain xkcd - User contributions [en]

2981: Slingshots

2024-09-05T23:52:55Z

172.69.134.16: /* Explanation */

{{comic
| number = 2981
| date = September 4, 2024
| title = Slingshots
| image = slingshots_2x.png
| imagesize = 397x420px
| noexpand = true
| titletext = In my reboot, Dennis the Menace was just trying to send Mr. Wilson a nice comet, but accidentally wiped out his dinosaur garden.
}}

==Explanation==
{{incomplete|Created by a WRIST ROCKET SMUGGLED INTO MASSACHUSETTS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

The {{w|Slingshot|slingshot}} (in this comic, styled "Regular Slingshot") is a hand-held device used for accelerating small projectiles, such as stones or steel balls. In an {{w|Sling (weapon)|earlier form}}, the concept had existed since ancient times, and has been used for personal defense and for hunting game such as squirrels, birds and {{w|Goliath|Philistines}} through skillful use of its mechanical advantage and rotation. The more modern "forked stick and elastic" version (known as a catapult, in the UK) acts by a pull-back-and-release action, and has become associated with youthful recklessness (or an outright tendency towards vandalism), but is also the basis of manufactured sport/hunting devices as well as the more organic child-made contraptions.

The '''gravitational''' slingshot, or {{w|Gravity_assist|gravity assist}}, is not a device but a term used to describe how gravity may alter the path of an object in space, such as a spacecraft or an asteroid. A gravitational slingshot generally involves a small object passing by a much more massive object, which turns the smaller object's trajectory, trading momentum and kinetic energy between the two bodies. The smaller object can undergo a large change in velocity, "paid for" (in the sense of conserving the momentum and energy of the system) with a negligible change in the velocity of the more massive body.

This comic humorously compares the two, in tabular format.

{| class="wikitable"
|-
!
! Regular slingshot
! Gravitational slingshot
|-
! Used for hunting
| ✓
| X
|-
! Used for sport shooting
| ✓
| X
|-
! Used for spacecraft propulsion
| X
| ✓
|-
! Large online enthusiast community
| ✓
| ✓
|-
! May have caused dinosaur extinction
| Probably not
| Maybe
|-
! Used by Dennis the Menace to terrorize Mr. Wilson
| ✓
| Not yet, but I'm pitching a reboot
|}

The first four categories accurately reflect reality. As a hunting tool (and as an offensive weapon), recent designs have been claimed to propel a projectile with [https://www.uslawshield.com/tactical-slingshots-mere-toy/ more force than .22 and .38 caliber pistols]. Consequently, several communities have prohibited the possession of such slingshots, which may be called "wrist rockets". The state of Massachusetts, where cartoonist Randall resides, is one of those communities. Gravitational slingshots would be inefficient and overkill for such purposes, as well as being difficult to achieve sufficient accuracy and specificity.

Conversely, gravitational slingshots are a useful way to change the velocity of a spacecraft without having to use large amounts of fuel, whereas building a regular slingshot capable of propelling a spacecraft is likely to be impractical - not to mention the destructive/fatal consequences, to vehicle and cargo, of near-instantaneous acceleration to useful speeds, such as the Mach33 required for an object at sea level to escape Earth's gravity, especially when there's an atmosphere present.

Both types of slingshot excite interest among many people who may form online communities to discuss them, but for quite different reasons, and the size of overlap between these communities is uncertain.

The fifth category ventures into the absurd, at least with respect to "regular" slingshots, which did not exist (so far as we know) at the time of the {{w|Cretaceous–Paleogene_extinction_event|Cretaceous-Tertiary extinction event}}. (Humans, which invented them, did not exist at that time. Use of slingshots would therefore require some other contemporaneous intelligent species to have invented them, or some kind of {{w|A_Sound_of_Thunder|time}} {{w|A_Gun_for_Dinosaur|travel}}.) However, it is likely that the event resulted from the impact of a space-rock that was perturbed into an Earth-crossing orbit by a planet such as Jupiter, given at least a minor gravitational slingshot on its way to eventually crashing into the Earth.

The sixth category references the long-running comic and cartoon character {{w|Dennis_the_Menace_(U.S._comics)|Dennis the Menace (USA)}}, in which the titular character unintentionally harasses neighbor Mr. Wilson with (regular) slingshots and other devices and behaviors. In Randall's projected reboot of the franchise, which is elaborated on in the title text, Dennis trades his regular slingshot for a gravitational slingshot. By miscalibrating his ammunition, or the force of his slingshot, he turns a demonstration ("a nice comet") into a destructive event (the loss of Wilson's dinosaur garden). The reference is to the relative size and velocity of the space objects responsible for, respectively, comets and "meteors" versus asteroid impacts.

This is very similar to [[2844: Black Holes vs Regular Holes]].

==Transcript==
{{incomplete transcript|May yet be better Transcript-Format changes. Do NOT delete this tag too soon.}}

:[A table grid with two columns and six rows.]
:[Two column labels placed above the respective columns, six row labels to the left of the respective rows.]

::[Column 1:] Regular slingshot
::[Column 2:] Gravitational slingshot

:[Row 1:] Used for hunting
::[Tick]
::[Cross]
:[Row 2:] Used for sport shooting
::[Tick]
::[Cross]
:[Row 3:] Used for spacecraft propulsion
::[Cross]
::[Tick]
:[Row 4:] Large online enthusiast community
::[Tick]
::[Tick]
:[Row 5:] May have caused dinosaur extinction
::Probably not
::Maybe
:[Row 6:] Used by Dennis the Menace to terrorize Mr. Wilson
::[Tick]
::Not yet, but I'm pitching a reboot

==Trivia==
The "Dennis the Menace" that the [[Randall]] refers to, familiar to those in the US, is not to be confused with the ''other'' long-running comic and cartoon character from the UK, also called {{w|Dennis the Menace and Gnasher|Dennis the Menace}}, who has a surprisingly similar premise and identical date of creation but is more wilfully disruptive and capable of far more 'cartoonish' behaviour (which might well include planetary-scale fork-stick slingshots/catapults). {{w|Mark Hamill}} is a fan of the British character (possibly from his time filming the original Star Wars films in the local studios), and also has some experience with (fictional) disruption of planets by constructed weapons.

{{comic discussion}}

[[Category: Charts]]
[[Category: Space]]
[[Category: Dinosaurs]]

Talk:2916: Machine

2024-05-08T12:53:40Z

172.69.134.16: /* XKCD Prize */

rather late for an april fools comic innit? also there doesn't seem to be anything exciting in this one lol, none of the usual cool exploration easter eggs, as far as i could tell at least [[Special:Contributions/172.71.178.76|172.71.178.76]] 16:41, 6 April 2024 (UTC)Erfaniom
:Randall posted an eclipse comic on Apr. 1. All April Fools comics are interactive. [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 15:27, 10 April 2024 (UTC)

: We're exploring crowdsourced human creativity here, in a way, so it can be a lot more interesting then Randall's exploration comics, at least for me, because i did take two years of GCSE psychology and enjoyed it. [[Special:Contributions/172.64.238.130|172.64.238.130]]

: looks like the egg's on my face lmao, i think i was among the first people to make anything, so everywhere was under construction for me, i didn't even understand that it was like a crowd thing [[Special:Contributions/172.70.210.52|172.70.210.52]] 14:19, 9 April 2024 (UTC)Erfaniom

Just popped over using Chrome on Android and all I see is four "missing picture" logos spinning around, plus another down the bottom right... [[Special:Contributions/141.101.68.193|141.101.68.193]] 18:13, 6 April 2024 (UTC)
:Okay, followup: it behaves quite differently on the non mobile site. You get two entry points with red balls and yellow balls and you need to place the various gizmos to direct the balls to the correct exit point. Once enough have correctly passed to turn the red X into a green tick, you have the option to submit. If you do, once you have named your design it will be added to the grid with other submissions all of which exist to push red and yellow balls around. (if you come across "Memories of Ragnarok", that's mine)
Mine are "Balancing Act" and "100% Success Rate" [[Special:Contributions/172.71.146.14|172.71.146.14]] 21:11, 15 April 2024 (UTC)
[[Special:Contributions/172.71.134.207|172.71.134.207]] 18:27, 6 April 2024 (UTC)
::The number of inputs appears to vary between 1 and 4, each of a different color, with one color-coded output for each. [[User:Claire Kholin|Claire Kholin]] ([[User talk:Claire Kholin|talk]]) 18:49, 6 April 2024 (UTC)

On the "machine" section, you see lots of "under construction cells". Perhaps this will develop as more are submitted. I notice the "under construction tape" has "DJIA" and "31415", perhaps a reference to "dow jones industrial average" and the first five digits of pi. [[User:Zeimusu|Zeimusu]] ([[User talk:Zeimusu|talk]]) 18:37, 6 April 2024 (UTC)
:Whenever someone submits a cell, it fills in one of the under construction cells. [[User:Claire Kholin|Claire Kholin]] ([[User talk:Claire Kholin|talk]]) 18:49, 6 April 2024 (UTC)
[Robert'); DROP TABLE Student!:;--] i just got a machine with 3 outputs one yellow another red and a third blue AND green and 3 inputs one green one blue and one red blue and yellow https://xkcd.com/2916/#xt=7&yt=50 hope its still there {{unsigned ip|172.70.115.173|18:01, 9 April 2024}}
:I think I just 'did' one with a Red+Yellow source (also separate singular Blue and Green) and a combined Blue+Green sink (and separate Yellow and Red). Got it working well, actually using fan-levitation to separate the R+Y enough to route them to their destinations, the Y then having to cross the occasional flying Green (which I was forced to "Bonk" and bounce up, entry being nearly at the bottom on right, exit being nearly at top on left) for its exit, everything else fairly simple. No idea if it got integrated, of course. Never seen any of my machines be accepted (when I later look around at what's there), so I'm still unsure if there's anything I can do to increase my chance of a successful square being made permanent on the grid.... [[Special:Contributions/172.70.163.49|172.70.163.49]] 20:58, 9 April 2024 (UTC)
:...still had it sitting there [https://imgur.com/kZdp3kH on my browser], though note that the Red+Yellow supply (mid-left) and the Green supply (right) aren't working here, through the "move the screen around, lose the feeds from 'Under Construction' squares" issue, or similar. But still I managed to submit it. The occasional Yellow and Red are falling from the Blue entrance in the top (I've not done anything special to filter those out/send them to a more proper exit, and it's too late to do so now anyway, it was just a Blue entry during the development process, of course).
:It's a pity you can't see it working, but I quite like my Yellow/Red separation. This might be the only time you see it in place, though, so a shame I didn't take a screenshot immedediately after submitting it. [[Special:Contributions/172.70.163.49|172.70.163.49]] 21:30, 9 April 2024 (UTC)
:I encountered a puzzle with five distinct pairs of in/out (none combined): Two blue, two red, one yellow. It was difficult! AFAIK five pairs is the highest reported so far. When I submitted the solution to the Machine, it had Under Construction above and to each side, and (IIRC) empty below, and no balls were provided, alas.[[Special:Contributions/172.69.134.216|172.69.134.216]] 03:46, 12 April 2024 (UTC)
I wanted to add an image for each object, but do not have the necessary access, can someone who has access add the images that I linked in the table so they can be included? [[User:Claire Kholin|Claire Kholin]] ([[User talk:Claire Kholin|talk]]) 18:49, 6 April 2024 (UTC)

I found a discussion with some guy talking about the API at https://euphoria.leet.nu/room/xkcd/ ; this could be useful for the wiki.

<code>
[c+1] now time to try fucking with the api
[c+1] https://incredible.xkcd.com/
[userwithnoaccount] 404
[c+1] it seems there are numbered machines under incredible.xkcd.com/machine/x
[c+1] returns a grid of individual machinlets
[c+1] which are uids like 3a7af27c-5389-5dcb-b660-3feab6be2ceb
[c+1] they're stored at urls like incredible.xkcd.com/folio/3a7af27c-5389-5dcb-b660-3feab6be2ceb
[c+1] there appear to be 33 machines total
[c+1] the json it returns seems to refer to these as "versions"
[c+1] $ curl -s https://incredible.xkcd.com/machine/21 | jq ".version"
21
[c+1] there is a machine/0, but it's all null
[c+1] going to https://incredible.xkcd.com/machine/current redirects to the current machine
[c+1] $ curl -sL https://incredible.xkcd.com/machine/current | jq ".version"
35
[c+1] wait, is that the *total* number of mahcines?
[c+1] i would've thought there'd be more
[c+1] this whole think is rather esoteric
[c+1] Written in rust, too: https://rapier.rs/
[c+1] Uh oh.
https://i.hypercone.us/?v=8e283d
[c+1] HMMM
https://i.hypercone.us/?v=079f8f
[c+1] it seems there is no limit
[c+1] i've uploaded a ~50M title
</code>

With this I was able to make a script that visualizes paths of the balls. I was hoping that there would be an interesting pattern somewhere but it appears to be mostly random (https://i.imgur.com/ZvLlucU.png) --[[Special:Contributions/172.71.131.24|172.71.131.24]] 17:12, 12 April 2024 (UTC)

[[Special:Contributions/172.70.57.146|172.70.57.146]]

Had quite a lot of fun, added a few 'successful' machines to the grid. Noted that whenever I try to use the Prism that (after a short delay) the comic-pane blanks and I need to refresh the page/get a completely new 'challenge' to start from scratch, so I'm just not using the prism at all (used most of the other items, in combination or 'just the one across the whole board', whichever seems most fun). But it doesn't seem to do what I'd like it to do, which is sort multiple colours from the same inflow into different outflow directions. Which would be ''very'' useful in a 'crossroads' situation, the general solution of directing them cross-path being too prone to random collisions. Also might be useful in the 'submitted machine grid', as I note that errors propagate, whereas adding a filter on all inputs would clean out (dispose of/send off to a valid gate?) the rogue balls. Anyway, gonna have to come back to this later when there's more time... Maybe then I'll even have something useful to add to the Explanation. [[Special:Contributions/172.70.163.31|172.70.163.31]] 19:03, 6 April 2024 (UTC)

The balls appear to be different weights. I just saw a machine that used fans to separate yellows from greens and blues in a sort of 'wheat from the chaff' manner to direct them to their correct outputs. I wonder what other hidden tricks are included. [[Special:Contributions/172.68.1.159|172.68.1.159]] 19:40, 6 April 2024 (UTC)

They're not all accepted, though it makes you think they are. Or something else more complex is going on we haven't realized yet. I made a machine that was working reliably, submitted it, and saw it on the overall grid. Reloading from a different browser I found the same location of the machine, with the same surroundings, but my machine had been replaced. It's nowhere else on the grid either. The first browser still shows it (but not after a reload with a cache clear). I'm not sure if there's some kind of "save" event that needs to happen beyond seeing your machine in the broader one, or if all user collaboration is an illusion, or if the system changes its mind about us somehow.

: Yeah, i've been seeing this too. Please tell me if you find any of my machines, images at https://i.hypercone.us/?v=22d562 , https://i.hypercone.us/?v=ad8e3a , and https://i.hypercone.us/?v=8d4d6a . I want to be one of the few to have added Catalan and Spanish to the grid. [[Special:Contributions/172.71.134.164|172.71.134.164]] 20:56, 6 April 2024 (UTC)

I've added some more observations to the page. Also, a guess which is too uncertain to put on the main page: The ball launcher for the yellows on the far left side misses a lot, and the yellow container isn't the one on the left. So I think the whole machine with crossing streams will result in the colors being sorted in their container order, and possibly have the streams combined and deposited at the bottom just above the containers. --[[Special:Contributions/172.71.147.100|172.71.147.100]] 21:07, 6 April 2024 (UTC)

has anyone seen the boat at the very bottom? [[User:Mushrooms|Mushrooms]] ([[User talk:Mushrooms|talk]]) 21:21, 6 April 2024 (UTC)

trying to see it on Firefox for Ubuntu and it just tells me to "visit xkcd.com to view" - THAT'S WHERE I AM?! Tried clearing website data (but not my entire cache) and that didn't help. Is there something I'm missing?

Oooh, just had one with four ball-entries (four colours) and ''three'' exits (one caters for two arrows). Pity it's rather complicated to get entries to exits (even if I can merge two of the streams). Might have to give up on it, but I'd like to have seen how it fits in with the 'submited grid'. i.e. someone else gets a two-colour introduction spot. [[Special:Contributions/162.158.74.119|162.158.74.119]] 22:37, 6 April 2024 (UTC)
:Me again. I'm just refreshing the page, looking at the pattern of entries/exits (just a dozen or so screens in, getting some repeats of pattern, indicating that it's going back to tiles it was suggesting before, probably depends on how many others are contributing and extending...)
:Found another 'double-colour' example. Two yellows ''from the same side'', which probably means that there's a two-yellows been asked to exit from the neighbour (will check shortly).
:Quickly adapting from my spreadsheet notation, "R, Y, G, B" in order, each "(Entry, Exit)", I've been using <dir> of L/R/T/B and a number (nominally percentage, though seems to include only values of 20, 30, 50, 70 and 80, so it ''might'' be more 1/6..5/6?) relating to the distance along from L to R (for T/B) or T to B (for L/R).
:This line is therefore (0,0)(L20+L70,R30+B70)(R80,L80)(T70,L50) ... no reds, two yellow pairings, a red pairing, a blue pairing. Would require at least two path-crossings (but I was going to calculate those things later, and double-colours might confuse my intended simple line-intersection calculation).
:...anyway, spent some time on this message, which might mean I'll get into a 'new batch' of available patterns as people have succeeded some of the challenges that I've been 'swiping left'. [[Special:Contributions/172.70.162.20|172.70.162.20]] 19:28, 7 April 2024 (UTC)
:...very next click: (0,0)(T30+L20,R20+R70)(R80,L80)(R50,B50), which is clearly the actual left-neighbour of the above. [[Special:Contributions/172.70.162.19|172.70.162.19]] 19:32, 7 April 2024 (UTC)
:Ok, stopped my refreshing to [https://imgur.com/a/OMFOmzy 'solve' a screen]. First of all I routed both yellows entries (right-upper and upper-right) to one yellow exit (middle-left) and gradually teased the greens across (lower-left to middle-right), as that way I was avoiding a criss-cross of balls, but the the other yellow exit (left-lower) was, of course, invalid.
:Changed it to drop one stream of yellows down towards the lower exit, across the rapidly firing greens (added a fan to filter away the occasional yellow that gets bounced over there, not much of an opportunity to filter falling-greens out of the yellow exit, so apologies to whoever gets the sceen below). Submited as "Two Yellows, One Green!", whether or not that'll save (apparently, I should continue to contribute and not refresh/close, or else the server will not keep the solution?).
:Interestingly, all four adjacent tiles are "Under construction", and if I scroll up... *DARN* the comic has blanked out (nothing there between the upper PREV/RANDOM/NEXT buttons and the lower ones, just whitespace). This may mean that it did not save. This is the kind of 'page crash' I get when I try using a Prism or get too many balls rattling around on top of a Black Hole. Perhaps it doesn't like that I'm scrolling into an Under Construction that shouldn't be there? (But then, why ''is'' it there?)
:Anyway, all extra information for everyone.
:I'll just refresh the page and go back and do some more entry/exit mapping, maybe? [[Special:Contributions/172.70.162.20|172.70.162.20]] 20:17, 7 April 2024 (UTC)

If you combine a bunch of these silly claw things in the middle by just spamming it, it begins to lag and do some chaotic collisions, even without balls colliding on it. It's curious how it does that seemingly randomly though. I wonder how calculations are added and if there's a tiny sprinkle of RNG. (Also, errors occur and say something about damaging recursion in the Rust programming language, so I guess we know how it was made. It's also pretty weird how there's not a lot of opening combinations? It's possible that the machine loops over in chunks of gears or something (that's what I'll call them). ([[User talk:Leo|talk]]) 13:15, 7 April 2024 (UTC)

If you place a black hole in the centre of a wheel, it makes the wheel behave unpredictably between resets. Sometimes it's almost normal, sometimes it's a lot faster than usual, and sometimes it's stopped but launches balls that touch it with extreme force. I was able to use this to submit a machine which didn't actually let a single ball through after being submitted. https://i.hypercone.us/?v=928bcd [[Special:Contributions/162.158.33.149|162.158.33.149]] 01:19, 7 April 2024 (UTC)

The page says that (and I have taken note of) the ball hue is ''coded'' to certain values, but is there a logic to those values that might be derived from the colour (either as RGB triplet or HSV/other colourspace definition). For example, the two ball-types with zero green component in their makeup are 'unit density' (green is far heavier "green+red" is far lighter, so it's not a simple relationship, unless it converts from °hue, in some way) and the only secondary colour exhibits non-zero drag. There's the possibility that it just derived from "we need different properties, we need different colours, we have no reason to connect either with other deliberately" or even some non-mathematical symbology (fire=red, water=blue(?), earth=green, air(/sunlight?)=yellow). But it makes me wonder what combination of properties cyan/magenta balls might have, if added. (Or is the choice of those four colours constrained, anyway? Though R/G colorblindness is already something of an accessibility failure, if anyone suffers that.) [[Special:Contributions/172.69.194.205|172.69.194.205]] 17:02, 7 April 2024 (UTC)
:For color vision issues, on Mac, open System Preferences, select Accessibility, select Display (in the Vision group), select the Color Filters tab, select Enable Color Filters, then finally try the different filters in the Filter Type menu. One of them should help make the colors distinct.[[Special:Contributions/172.69.134.216|172.69.134.216]] 03:40, 12 April 2024 (UTC)

[https://pastebin.com/7PAiLnyF Python script to get the URL and title of each Cell in the current machine]

[https://pastebin.com/xBhywGde Result of running that script at the moment] (encoded with ROT13 because pastebin wouldn't let me save it otherwise)
:has anybody at all whatsoever been able to find their creation using this API? [[User:Bellydrum|Bellydrum]] ([[User talk:Bellydrum|talk]]) 21:58, 7 April 2024 (UTC)

[https://pastebin.com/jN5MP2za Result of running that script on the first 42 machines], at least on these it looks like the only difference is that one cell is added each time? [[Special:Contributions/172.71.99.195|172.71.99.195]] 17:22, 7 April 2024 (UTC)

I've submitted four now, none of which was accepted. I tend to spend a lot of time getting them just right. Any hints as to what the acceptance criteria might be? Or do I just stink at this?
[[Special:Contributions/172.69.59.204|172.69.59.204]] 19:47, 7 April 2024 (UTC)

There appears to be a new object: a cat that bats things that touch it.
[[Special:Contributions/172.69.214.39|172.69.214.39]] 20:17, 7 April 2024 (UTC)

Is anyone else experiencing the bug where prisms cause the comic to disappear (leaving only the white background where it was) after a while? It makes viewing the whole machine basically impossible. (On further testing it appears to be firefox-exclusive.) [[Special:Contributions/172.70.162.38|172.70.162.38]] 20:31, 7 April 2024 (UTC)
:I've had the "Prisms break things" from the beginning (before any practical content). As in, trying to use them in a design breaks things. But I ''did'' glance upon their occasional use in the 'view submissions grid'. Right now I'm suffering from "white only" issue (see my "multi-yellow" accounts, above). I ''am'' using Firefox, if that's indeed relevant to this issue, but right now I'm not near any other up-to-date browser I care to use. [[Special:Contributions/172.70.163.31|172.70.163.31]] 21:37, 7 April 2024 (UTC)
:I'm getting the same issue with black holes (which probably makes more sense - put a black hole there and you'd expect everything else to disappear :o) - except that on one occasion I was able to put about 6 black holes in before the 7th one vanished everything.[[Special:Contributions/172.69.194.121|172.69.194.121]] 09:15, 8 April 2024 (UTC)

Has anyone seen their own cell in the machine at all yet? A manual approval system is probably necessary for obvious reasons, but if so it does seem to be moving quite slowly.
[[Special:Contributions/172.69.65.24|172.69.65.24]] 02:58, 8 April 2024 (UTC)

I've never seen one of my own cells after refreshing the page. :( [[Special:Contributions/172.70.110.122|172.70.110.122]] 20:27, 12 April 2024 (UTC)

How on earth is everyone seeing different parts of the grid? If I request "view machine" I can only see my own square, and the edges of everyone elses. Nothing else, definitely not all of the machine. [[Special:Contributions/172.68.64.149|172.68.64.149]] 21:11, 8 April 2024 (UTC)
::You should be able to click and drag the view around. [[Special:Contributions/172.71.242.54|172.71.242.54]] 21:41, 8 April 2024 (UTC)

Whoever designed the room entirely full of fans is evil - every time I scroll near it my entire browser freezes up and becomes unresponsive. And then the comic usually blanks.[[;8Special:Contributions/172.69.194.81|172.69.194.81]] 08:23, 9 April 2024 (UTC)

None of [https://www.explainxkcd.com/wiki/index.php?title=2916:_Machine&diff=339487&oldid=339486 these edits] were anything to do with "grammar", so why would anyone describe the change as such? The spelling of "colo(u)r" is an internationali[s|z]ation issue, of note, and why I usually prefer to defer to using words like "hue", instead, in such contexts on this site. The change of the link from "The Incredible Machine" (where the page exists) to "The Credible Machine" (where it doesn't, because that's really just this comic's own joke) I aready changed back... If you think it doesn't properly explain the pun/negation, then rewrite; but don't make it an invalid link to something that doesn't even exist, as you'd know if you had even followed the link(s). [[Special:Contributions/172.69.194.141|172.69.194.141]] 15:22, 12 April 2024 (UTC)

Folks might be interested in my list of all published blueprints with their titles and permalinks: https://github.com/scpso/incrediblexkcd. scpso [[Special:Contributions/172.68.144.147|172.68.144.147]] 13:18, 14 April 2024 (UTC)

== Level scrolling bug ==

When one views the whole machine, and scrolls down far enough, everything just disappears, and the comic is completely unresponsive. Has anyone else seen this? [[Special:Contributions/198.41.236.152|198.41.236.152]] 20:38, 7 April 2024 (UTC)

:I'm now seeing the same issue, I wasn't before. (I'm using Chrome) [[Special:Contributions/172.70.162.20|172.70.162.20]] 21:06, 7 April 2024 (UTC)

::A hard refresh appears to have fixed this for me (same person as above). [[Special:Contributions/141.101.99.101|141.101.99.101]] 10:28, 8 April 2024 (UTC)

:I've been having this issue as well (I'm using firefox). Opening the site in Edge instead seemed to work around it for me, so it might only affect Firefox (and derivatives). [[Special:Contributions/172.70.163.31|172.70.163.31]] 21:27, 7 April 2024 (UTC)
::See also the 'firefox bug' comments currently immediately above this section. (Please don't ask me to start Edge up, I hate it, won't use it any more than the system requires me to...) [[Special:Contributions/172.70.163.31|172.70.163.31]] 21:37, 7 April 2024 (UTC)

:Update - I did a hard refresh so I could play around with the new additions and I'm no longer encountering the bug, even on firefox. I think the "white screen" bug is fixed now and you just need to hard-refresh to download the fixed JS instead of using the cached one. (same person as 172.70.163.31 and 172.70.162.38) [[Special:Contributions/172.70.86.16|172.70.86.16]] 11:16, 8 April 2024 (UTC)

==New Category: Ball Pit?==

What do you think about a new category for comics with [[ball pits]]? [[150]], [[219]], [[485]], [[498]], [[2916]]? [[Special:Contributions/162.158.134.229|162.158.134.229]] 21:50, 7 April 2024 (UTC)

[[:Category:Playpen balls]] already exists.
[[Special:Contributions/172.70.174.133|172.70.174.133]] 17:35, 9 April 2024 (UTC)

== Prism Use? ==

Can the prism be used to sort balls by color? (or in any other way that is useful and different?) [[Special:Contributions/172.68.34.61|172.68.34.61]] 12:11, 8 April 2024 (UTC)
:From what I've seen, no. Though may be ''extremely'' susceptible to incident angle. As far as my own use has been, they seem to randomise the trajectory (possibly also do a total-internal-reflection, I've had balls bounce around and exit at ''really'' weird angles), but it's hard to collimate a feed of balls into a single exact track, even straight down from a ceiling-feed (if you have a ceiling feed directly over the floor exit, lucky you, it'll still occasionally perturb balls off to the sides just enough to be bounced out as a gate-miss, unless you add 'funnel' architecture of one kind or another). Oh, and when balls do a lot of 'internal bouncing' it often forced me to reload the comic (overloaded the physics engine?), so could not continue to tweak the same design.
:On the other hand, perhaps this was the ''intent'', and just code/browser failings made it work erratically. Maybe would be an idea to go back and retest for this (anybody who can), do a little !!science!! to be recorded and explained on the page. [[Special:Contributions/172.69.43.183|172.69.43.183]] 12:51, 8 April 2024 (UTC)
:So, ive did some testing and found..nothing. i ''did'' find some uses for the prism though. Like outting them diagonally makes the balls follow a "path", speeding up more and more (not really that great but it works with yellows), and that any ball hitting the left edge will try to go the the right edge. Not sure what else it can do, though. [[User:Begocc|Begocc]] ([[User talk:Begocc|talk]]) 09:35, 10 April 2024 (UTC)
::I did some thorough testing on a combined Red/Blue set of balls (carefully managed so that they were dropping into the target area as similarly as possible) and both rotated and moved the prism in various ways to check for any effects - like needing to enter parallel/perpendicular to the colour-bands, either to land on the 'target band' or start to pass across it, with the band then either facilitating or angling its 'fall through'. (Just visually checked, at first, then later adding 'buckets' below and to the sides, to try to catch balls departing on various trajectories in various 'clumps' making note of any that hit the 'bucket'-boundaries and bounced off elsewhere.)
::I found no significant sorting, and some balls would jitter around so much (within the prism) that they even launched almost straight back up where they came from (less poerfully than a Bonk-buffered ball, but not far off - also not reliable enough to use as a ball-elevator).
::In my experience, Yellow-sorting is easy (even against Blue and/or Red) by other means. Green is the easiest to have everything else sorted ''from'' (because it resists the fan method). The hardest to unmix are Reds from Blues, which one might think ''should'' be the most prism-differentiated but I'm afraid I just can't invoke that. Easier to have them fall a long way then bounce off a suitable bit of 'furniture', I can then get them to distribute ''fairly'' distinctly in two handy recepticles/onward-feed-hoppers, though it does need some careful placement of items to do it justice. It appears that none of my designs have made it to the 'public wall', but I have made a submitable machine or two that does such sorting sufficiently successfully to send it out (theoretically) to be seen. [[Special:Contributions/172.70.163.30|172.70.163.30]] 11:38, 10 April 2024 (UTC)

== Bugs and Exploits ==

You can use a sword to break the physics on the hinge thingy and create your very own "magnetic hill": https://imgur.com/a/IRZ0AlL [[Special:Contributions/162.158.134.108|162.158.134.108]] 13:02, 8 April 2024 (UTC)
:Hard to tell from that what other fans (perhaps) you've got completely off-clip.
:Those hinge-thingies can definitely be shifted by horizontal (outwith ball-weight pressures), but I've not found them to be reliable components as the "Stop" button (ball reset) seems to let those 'hinges' slring back to level, which might need a re-reset by moving them back past the thing that's holding them off-level.
:I have tried a few things with them:
:*'Ticker' mechanism, almost like a clock escapement, nudged by the rotating 'waterwheel', perhaps to try to release balls through a stream of other balls whilst keeping the path clear of collisions for each set, in turn.
:*'Batch dumper', accumulating a number of balls (above the 'hinge', behind a vertical bulkhead) until there's weight enough to 'open the hatch' and roll them out. (Again, an attempt to reduce collisions, by clumping batches together).
:*Finely configured inclines, by shoving something up into a free end of hinge with better angular resolution (but, as mentioned, this doesn't seem to want to 'hold', so probably would fail upon submission).
:...I had wondered if there was supposed to be a "falling anvil creates a catapult/ballista" idea behind the piece, but we don't ''have'' falling anvils (and definitely not in a repeating manner), and ball-powered catapult (esssentially "clown/acrobat jumps on one end of seesaw, clown/acrobat on other end flies up into the air") also doesn't seem practical.
:I'll try to recreate ''your'' design, work out if there's anything new about it, but right now looks like it's a fan-powered incline-raiser. [[Special:Contributions/172.70.162.38|172.70.162.38]] 14:23, 8 April 2024 (UTC)
:: No fans! Here's a wider view: https://imgur.com/a/xPJcsor
:: It survives the reset, because the balls falling on the lever push it down to the sword and it gets stuck there every time. But you need to place the sword just right to make the gravity bug happen. And even then it depends on the number of balls in some ways. [[Special:Contributions/172.68.243.27|172.68.243.27]] 14:46, 8 April 2024 (UTC)
::: I've replicated the "tip of sword grabs the 'hinge'" thing, which is very interesting, but not the anti-gravity effect. The movement still seems ''to me'' more like a fan's 'area of effect' thing, than a wonky sense of gravity, the way that the balls are rolling/resisting/interacting with each other. No, I can't see where you've 'hidden' the fan (and I'm sure that fans can't act across submission-grid-boundaries, which was my next guess), so it's a bit of a funny thing that you've got there. [[Special:Contributions/172.70.163.49|172.70.163.49]] 21:35, 9 April 2024 (UTC)

On occasion, two balls will fall from the containers as a pair, as if glued together. When this happens, they float down as if under much lower gravity, and then suddenly explode violently away from each other.[[Special:Contributions/172.69.43.182|172.69.43.182]] 10:56, 10 April 2024 (UTC)
:What contaniners?? [[Special:Contributions/172.70.110.252|172.70.110.252]] 14:58, 12 April 2024 (UTC)
::At the bottom of the grid are four containers that the balls are fired in to, from where they drop in to a pit with a boat.[[Special:Contributions/172.70.162.38|172.70.162.38]] 08:40, 15 April 2024 (UTC)

When the browser is running slowly, sometimes the chamber doors will open, but none of the balls in them will drop, which can lead to huge backlogs of balls building up. However, there appears to then be a limit to how many will dispense in one opening - only half a dozen or so layers are released before the door closes again.[[Special:Contributions/172.70.163.31|172.70.163.31]] 12:01, 24 April 2024 (UTC)

== The USS Buoyancy ==

Guys. The Buoyancy. She ''floats''. When all four sets of balls reach the ball pit there aren't further additions. The boat starts floating on them. I've been watching it for a while. It seems she moves left and will probably end up escaping the ball pit. [[User:DL Draco Rex|DL Draco Rex]] ([[User talk:DL Draco Rex|talk]]) 20:44, 8 April 2024 (UTC)
:Update: A new row spawned in and it reset just before the Buoyancy could escape. Here's a screenshot I grabbed a while before the reset, she'd moved further left by the time the reset occurred. https://imgur.com/gallery/8UCASCu [[User:DL Draco Rex|DL Draco Rex]] ([[User talk:DL Draco Rex|talk]]) 20:51, 8 April 2024 (UTC)

Alright, I'm almost 100% of the time seeing Buoyancy sink. Yes, she *floats* at first. But as she drifts to the sides, instead of yellows going underneath, reds and greens pile on top. Then, as the balls under expire (90 second timeout), she will start to sink. Very consistent behavior over time.
[[User:Keybounce|Keybounce]] ([[User talk:Keybounce|talk]]) 19:20, 11 April 2024 (UTC)

What is the Bouaancy i cant find it anywhere??? [[Special:Contributions/172.70.110.252|172.70.110.252]] 14:58, 12 April 2024 (UTC)
== Added key combinations, found in source ==

ctrl+alt+b
ctrl+shift+option+d
wheel: arrow keys

: Can you clarify what "option" is? I have tried alt, function, and "operating system", and none are doing it.
::It is alt [[Special:Contributions/172.70.110.252|172.70.110.252]] 14:58, 12 April 2024 (UTC)

== Fixed Number of Possible Machinelets? ==

I was resetting my browser to try and find new machinelet configurations, but there seem to be fewer and fewer as the game progresses. Hypothesis: the 'under construction' machinelets are set, and once one of them gets approved and added to the grid, that specific configuration of entrances/exits can't show up again.

== Advanced components? ==

How does one get access to the full set of components to build from? I'm only given planks, mallets, swords, scoops, anvils, bricks and fans. I never get any pillows, bumpers, cats, stick figures et cetera. Do they need to be "unlocked" through some achievement, or what? [[Special:Contributions/162.158.222.102|162.158.222.102]] 11:04, 9 April 2024 (UTC)

:This caught me for a while as well. I have since discovered that the tool box has a scroll bar and can be scrolled down; that's where the others are hiding.
::Invisible scrollbars – every GUI obfuscator's favorite tool for making users' lives harder. [[Special:Contributions/162.158.222.142|162.158.222.142]] 18:17, 9 April 2024 (UTC)

== Limit of 100 components? ==

Has anyone else seen this? At some point I started getting a count "95 / 100" towards the bottom of the toolbar. When it hits "100 / 100" the rest of the toolbar greys out, and I can't add anything more. (I suppose the physics engine has to keep a ceiling on the number of possible interactions between components.) —[[User:Scs|Scs]] ([[User talk:Scs|talk]]) 11:53, 10 April 2024 (UTC)
:Yes, quite early on I was dealing with a quite simple 'drop from ceiling straight down to floor' setup. After adding just enough 'funnel' to deal with 'splatter', I then built a castle wall in the open space just to make it fun (with some figures on/below it, that I've also tried to decorate in later submissions), of the 'grey blocks'.
:I actually hit the 100/100 ''exactly'' as I placed my final intended block. (No doubt that it's easy to hit the limit by just overlapping things so you can't see most of them, and other 'useless' placement, too...) [[Special:Contributions/172.70.85.48|172.70.85.48]] 19:57, 10 April 2024 (UTC)

== uss boyancy ==

Why have i not been seeing any uss boyancy [[Special:Contributions/172.70.110.122|172.70.110.122]] 14:04, 10 April 2024 (UTC)

Haha I dare you to go to https://xkcd.com/2916/#xt=7&yt=57 and stare at the two black holes next to eachother >:) [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 15:27, 10 April 2024 (UTC)

== Build a "working" machine from parts? ==

Has anyone started working on this idea:

Since any given machine segment seems to be saved, even if not in the final result, *and* since these segments are failing when combined in the whole, how about a "really working" machine that starts replacing failing segments when they jam or otherwise fail to work in the real machine?

The idea being something like, start the machine. Watch the top row, and see where the parts are failing to pass balls properly after two minutes. Replace the segments that are failing/jaming/etc, and let the new part process balls.

As you work your way down, over about 2 hours at the current size, you will eventually get a machine that properly sends balls down to the bottom, without jamming, without having to "pretend" that off-screen parts are working.

I mean, it's not like a gigantic, 600 segment machine will overflow memory on modern 32gb systems, nor consume so much power that these big huge CPU's will fail, right?
There is a 100 piece limit sadly
[[User:Keybounce|Keybounce]] ([[User talk:Keybounce|talk]]) 17:41, 10 April 2024 (UTC)
ps.: Why do white holes, black holes, prisms, etc, cause problems on some machines like mine and not others?

== Foreshadowing ==

I think that this Machine comic / game is foreshadowed by comic # 2785 titled Marble Run. {{unsigned ip|172.70.130.120|22:15, 11 April 2024}}

== Implementation? ==

Should we have a section on how this thing is implemented? How much is known? Obviously it's hugely dependent on [https://rapier.rs/ Rapier], as credited in the header text. I assume everything else is written in {{w|Rust (programming language)|Rust}}, too. But how is it deployed? Does Rust compile to {{w|Web Assembly}}, or what? Under Color Routing, our explanation mentions that the ball "values were extracted from the code" — how much of the code is actually visible? —[[User:Scs|Scs]] ([[User talk:Scs|talk]]) 16:39, 12 April 2024 (UTC)
:There are source maps available for the client side. So most of the client source is pretty much there an available. DevTools will load these maps automatically by default, and you can find the ball parameters under incredible/src/components/widgets/Balls.tsx. As for the server, it has a Server header of Warp/3.3.31, a web server used for WAI applications in Haskell. [[Special:Contributions/172.70.114.44|172.70.114.44]] 13:37, 14 April 2024 (UTC)

== XKCD Prize ==

I propose the award of "Good Job" trophies for answers to the following weighty questions:

Cells ...

:C1. There is always at least one entry-exit (same color) pair. I have seen up to five pairs. Is there a limit?

:C2. I have never seen a two-color entry or exit, in over 100 tries, but I have seen pictures posted of this case. How rare are they?

Entry points (where balls enter the cell) ...

:E1. The entry rate varies randomly. Is there a limit to the range of time between two balls?

:E2. Some entries produce balls much faster than others, forever. Does this depend on color? Location? Anything else?

Exit points (where balls leave the cell) ...

:X1. At exits there is a display indicating x or check, and a ring meter showing progress towards check. Eating the wrong color reduces the ring score. By how much? Is it the same amount as is gained by eating the correct color?

:X2. The ring countdown starts about 4 seconds after the last ball, and lasts about 10 seconds. Does this ever vary?

Object properties ...

:O1. The pillow clearly absorbs energy. What other objects have variation in bounce, and how much? By sending a stream of green balls at high speed into targets, it can be observed that the brick and the shot glass (outside edge) are more bouncy than the anvil, which in turn is more bouncy than the plank. Are other colors (such as red) affected the same way?

:O2. Does the bounciness of any objects vary over their shape? The head of the mallet seems a little bouncier, but it's hard to set its angle to precisely match other test objects. The shaft of the pivot thing seems to be sticky. The dead edges of the triangle bonkers seem to absorb all inward energy from green balls, but only some energy from red balls.

:O3. Do the bonkers give a constant exit speed, or does it depend on something like the arrival speed or ball color? Does the exit speed replace the entry speed, or are they combined somehow? Like the dead edges (see O2) I suspect the live edge also absorbs inbound energy before it fires, so the outbound energy may be constant, though maybe not for all colors.

Cats ...

:K1. Over what range and direction will the cat swat at a nearby ball?

:K2. Does the cat always add the same amount of energy when swatting a ball?

:K3. Does the cat always add energy in the same direction when swatting a ball? At first glance the direction seems to be random over a range of angles, but this may be due to random entry points, speeds, and directions for the balls, rather than due to randomness by the cat.

:K4. Is there a rate limit for how often the cat will act?

Black holes and Repulsers ...

:B1. At their default size, repulsers are much stronger than black holes. How much stronger?

:B2. How does effect scale with distance? Are black holes inverse-square? What about repulsers?

:B3. Is there frame dragging around black holes? (good luck :)

:B4. At an exit, does the rate of ring decay slow down if a black hole is nearby?

Bonus observation: Black holes have large solid centers. A red ball stuck to a black hole can be seen bouncing off the center.

Spoiler for B1 and part of B2: If five default size black holes and one default size repulser are all placed at the default center, they seem to cancel out exactly, at all distances, though the solid centers still repel direct collisions. So the ratio is 5:1 and the distance equation (whatever it is) seems to be the same for both objects.
[[Special:Contributions/162.158.167.94|162.158.167.94]] 15:53, 14 April 2024 (UTC)

: C1: Current (as of y=70 filled) maximum across the machine is 5 pairs, only occuring 5 times, so I suppose it doesn't go higher. C2: So far there are only three combined gates in the machine, all two-color: one between (3, 8) and (4, 8) and two between (6, 50) and (7, 50). So yes, they are very rare. [[Special:Contributions/172.70.250.206|172.70.250.206]] 21:38, 14 April 2024 (UTC)

:Re. X1, I'm pretty sure (but don't have evidence, that the answer is 'no - a bad ball reduces it by more than a good ball increases it'. I can also think of an X3 - Does a good ball always increase the counter by the same amount; does this vary by colour or anything else? [[Special:Contributions/172.69.195.229|172.69.195.229]] 08:47, 15 April 2024 (UTC)

: E1: In the machine there is a value called ms_per_ball. Its value is 1000. Ie, a ball should be spawned every 1 second into the overall machine per entry. [[Special:Contributions/162.158.111.212|162.158.111.212]] 18:56, 15 April 2024 (UTC)
:: Measuring five random new puzzles, I found most entries deliver 1 ball per second, or almost that much. But I found one green entry that only provided 1 ball every 2 seconds (15 in 30, forever). When I delivered those green balls to the green exit point, I found the ring meter there filled up twice as much per ball consumed. Later I found a red entry that produced only 8 balls in 30 seconds, forever. Those red balls also filled the red exit ring meter much faster than usual. [[Special:Contributions/172.69.134.17|172.69.134.17]] 12:51, 8 May 2024 (UTC)
: K1: There are 3 collision zones defined for the cat swat: The head, its butt & a zone in front of it ("swat sensor"). [[Special:Contributions/162.158.111.212|162.158.111.212]] 18:56, 15 April 2024 (UTC)
: K2: Yes. There is in fact a hidden property called catMass. Its value is 2. I am not aware of any machines which submitted a different value. I have submitted my own (sadly not accepted) with stronger cats (a higher catMass value). [https://incredible.xkcd.com/folio/02092fc5-9e23-5468-990e-fba7d67d82c6 Here's an example]. This value is multiplied by 8 and then divided by the minimum of inverse mass of the ball or JS' Number.MIN_VALUE. So to answer your question: yes, it is the same, unless this value got altered (through external methods) and depending on the ball type. [[Special:Contributions/162.158.111.212|162.158.111.212]] 18:56, 15 April 2024 (UTC)
::I observe the cat imparts the same velocity to yellow balls and to green balls. The green balls weigh about 30x more than the yellow balls, so I think for "same energy" the answer appears to be no.[[Special:Contributions/162.158.167.28|162.158.167.28]] 15:29, 24 April 2024 (UTC)
: K4: A cat will at the fastest swat every 200 ms. However up to another 400 ms are added by random. So the limit is a range from 200 to 600 ms. (Simplified, there is a period called "baby jail" where the cat has stopped the 'swat' animation but still cannot swat a new ball. This time is included in the previous calculation.) [[Special:Contributions/162.158.111.212|162.158.111.212]] 18:56, 15 April 2024 (UTC)
: C2: After trying well over 200 reloads, I obtained a cell with three entries (inputs) and four exits. One of the entries produces both blue and red balls, at different rates. [[Special:Contributions/172.69.134.17|172.69.134.17]] 12:47, 8 May 2024 (UTC)
: E1, E2, X1, X2 and X3: The example link posted above regarding K2 is very enlightening. It reveals (in JSON) that entries and exits have assigned speeds called "rate"s (partly addressing E1, E2, X1, X2 and X3). Rates range from at least 0.55 to 0.76 (maybe balls-per-second, and maybe up to 1.0). It also reveals the items we add are "widgets" and they each have names such as "board" and "catswat". Also the entries and exits are called "inputs" and "outputs", and the balls have types including 1 and 2 which probably correspond to colors. Further review of such examples could be used to update and harmonize the main explanation. [[Special:Contributions/172.69.134.16|172.69.134.16]] 12:53, 8 May 2024 (UTC)

== Submission Rules ==

Has anyone had any luck determining what the rules for submission are? Like many others, I've submitted a few that I've taken painstaking care to get right only to have them disappear after the refresh, never to be seen again. At first I assumed it was first come, first served, with the first submission getting included, but I'm not so sure.

I took a look at the "[https://pastebin.com/jN5MP2za first 42]" versions that someone provided above, and noticed:
* The very first submission, "Pretty Bad" at (0,0) is still there.
* The second submission is "Don't Forget to Switch Your Fans" which is actually (7,0). It's also still there.
* These are followed by "sword" at (2,0) and "Fred" at (1,0), also still there.
* Next is "Pinball Bouncer" which is actually (0,1).
* Next is "undercomplicated". However this is then replaced by "OnlyFans" which is then replaced by "popcorn". "popcorn" appears at (3,0) and is still there.

What caused these to be added, then removed/replaced if it's first come, first served?

I also noticed over the weekend that I was getting assigned blocks that weren't even in the machine yet. I had rows 67 and 68, and the machine was only on row 65.

Also, I did two on row 68, then one on row 67.

None of these got added, which I assume means that someone else completed them before me, BUT that I started before they finished, otherwise I would hope I wouldn't have been assigned one that was already done.

Just now, I created one for a simple red-in, red-out at (7,73). I completed and submitted it. Then I refreshed and hit the edit button a few times and after a few tries I got another red-in, red-out with the input and output at the exact same place. I threw a couple of boards into it and submitted it and it showed it at the exact same spot, (7,73). So I was able to create a new one for the same spot I had already submitted one. I feel like this implied it's not first come, first served, as if so, why would it allow more people to submit for the same spot that someone had already successfully submitted? FWIW, the lowest row on the actual machine at this point is 70. [[Special:Contributions/172.70.134.54|172.70.134.54]] 15:16, 15 April 2024 (UTC)
:: The criteria is not known yet. But it seems you are supposed to be able to make multiple submissions per specific cell / puzzle type (there is a list of puzzles sent to the client, when you submit one, the server picks a position which fits that puzzle.). Then one seems to be chosen manually for a specific cell. There are times of day when the machine is being updated very often, and other times when nothing happens for a while, indicating it is likely a manual process. When a puzzle is added to the grid, the value `snapshot` is populated under its corresponding /folio/ URL. Otherwise it is null. The submission time does not seem to have an effect on if your machine would be accepted. [[Special:Contributions/172.68.195.183|172.68.195.183]] 18:29, 15 April 2024 (UTC)
:It's not simply the first submission, because then we'd see many more simple solutions. Most of the trivial cells get artistic designs and overcomplicated contraptions, which take longer to build and would have lost to simpler and quicker solutions. It's not always the most elaborate contraption, because there are a few really minimal solutions where surely someone else submitted something more complex. It's often not the most correct solution, because many designs get clogged quickly or lose many balls, and I've seen some good solutions get replaced with ones that mis-sort many more balls. It's not always a bad solution either, because there are some that work really well.
:It's possible that the server collects submissions for a while and then chooses one at random. It's also possible that the selection is manual, or maybe the manual step is just a final approval to ensure that no hate speech or other garbage gets in.

man I love messing with the hinges lol [[Special:Contributions/172.70.54.165|172.70.54.165]] 18:49, 18 April 2024 (UTC)Maxalon

==Is the Machine now 'complete'?==

For the first time, I'm seeing a machine with no 'under construction' cells. Do we think it has now stopped processing new submissions (despite still having the option to build them)? [NB - even with all the bottom row cells providing balls to the chambers, the Bouyancy is still only reaching the side of the pit and then sinking.][[Special:Contributions/172.70.91.146|172.70.91.146]] 11:57, 24 April 2024 (UTC)
:On the contrary, here. I submitted some machines. (Even did a hard-reload of the page, between them, in case I had to 'update' the scripting behind it.) I get my solution placed at the bottom layer (in once case, it had a "chuck across to the ball-bins" pipe, though nothing got sent across to the ball-bin/no activity was happening in the ball-pit and there's no USS Bouyancy floating around, in another, it just went into nothing) but I'm ''surrounded'' (to the sides, and above) with Under Construction Tape machine-cells. In one example, I had to scroll up 19 layers before I hit any actual machines (in another, it was well into the 20s, but I lost count).
:Latest submission was [https://xkcd.com/2916/#xt=9&yt=65&v=896 this one], didn't keep a note of the immediately prior ones. Not sure what it looks like from anybody else's perspective. (Nor [https://xkcd.com/2916/#xt=9&yt=66&v=896 a] [https://xkcd.com/2916/#xt=8&yt=69&v=896 selection] [https://xkcd.com/2916/#xt=10&yt=67&v=896 of] [https://xkcd.com/2916/#xt=1&yt=72&v=896 those] [https://xkcd.com/2916/#xt=1&yt=71&v=896 that] [https://xkcd.com/2916/#xt=5&yt=69&v=896 I] [https://xkcd.com/2916/#xt=1&yt=72&v=896 noted] previously... And given that there are two "xt=1&yt=72"s in that list, it looks like I later 'redid' a cell anyway, presuming the "v=896" is my constant UID, as it has never changed since I started to note these things.) [[Special:Contributions/172.69.79.139|172.69.79.139]] 23:30, 25 April 2024 (UTC)
:Postscript: "[https://xkcd.com/2916/#xt=9&yt=65&v=896 this one]" doesn't even send ''me'' to my own just done machine, when I test it! In fact, I'm fairly sure that the one I was linking had green and red (maybe red) balls that needed 'servicing', not the Blue/Red of the "LBC" cell. If not that, it was green, red and blue, but I think that was the one before the hard-refresh. [[Special:Contributions/162.158.33.145|162.158.33.145]] 23:36, 25 April 2024 (UTC)

:Definitely still under construction - it's up to version 1233 as of now. I've been keeping an eye on it - you can see a list of all published machines with permalinks on my [https://github.com/scpso/incrediblexkcd github page] and search for the names of machines you've submitted to see if they ever got published, or download the csv if you want. None of mine have been published but I've still had a lot of fun. [[Special:Contributions/172.68.144.154|172.68.144.154]] 13:27, 27 April 2024 (UTC)

== Balls have spin ==

This is subtle, and hard to see because the balls no visible texture: The balls carry spin. It can be seen, with effort, using green balls (which are heaviest). Rolling down a slope (say, two boards), green balls accumulate spin in the direction they are rolling. Let them drop off the end and then bounce off a brick such that they travel upward, but with very little sideways motion. Then "catch" the balls with a brick just past their apex, when they are moving slowly. If the ball lands on a horizontal brick, it can be seen that the ball will suddenly accelerate left or right based on the spin. [[Special:Contributions/172.71.155.18|172.71.155.18]] 15:17, 1 May 2024 (UTC)

== Stacking Objects ==

Stacking certain objects seems to stack their effects. For instance, enough multiple Fans placed directly on top of each other are strong enough to redirect even green balls in mid-flight.

Multiple Bonks create a more powerful bounce, sometimes fast enough to make the ball seem to disappear briefly. These effects can be useful in overcoming certain restrictions and difficulties, or just for the joy of watching balls rocket around.

Stacking moving objects like Hinged Hooks and Wheels creates a completely different effect. Multiple hooks of either handedness - left or right - will lock together and then start to rotate slowly or swing wildly, together or separately, in both directions. Even when the hooks are moving slowly, balls that interact with them will sometime either rocket away or stick to them with a gravitation effect.

Combining left and right hooks has similar effects, but more than 4-6 of either hook will typically slow the animation, and eventually freeze it completely.

More Wheels can be stacked than hooks, with numbers in the dozens still allowing the animation to proceed. They will act in a similar fashion, sometimes locking and sometimes spinning wildly. Balls that strike them will be projected away at high speed, sometimes disappearing, or reappearing in a different section (a round Bonk will often flash briefly with no visible interaction).

Other interaction include sucking the ball into the interior of the wheel, where it sometimes disappears, or clinging to the surface like a gravitational attraction. The more Wheels, the more likely that the ball will simply disappear.

These techniques create interesting chaotic environments in the cell, but make it difficult to meet the ball feed requirements for submission. With multiple inputs it becomes effectively impossible. One work around is to separate streams for the balls at the source, protecting one stream to feed it into the output while allowing the rest to interact with the chaotic object. This is easiest with a single input at the top of the cell, but is still possible with one or more side inputs, depending on the location of the outputs.

The easiest way to stack hooks is to leave them at the spawn point and spawn more on top. Moving hooks and stacking them manually seems to destroy the chaotic interaction. Wheels however can be effectively moved and stacked manually.

Adding another object on top may freeze the movement if the object is large large enough. A brick or a round Bonk will not significantly affect the Wheel, nor will a Black Hole or Repulser, but a Board, which extends beyond the Wheel, will lock it in place. The chaotic effects remain even when the wheels aren't moving - the balls seem to react as if they were spinning at high RPMs. [[User:Yusagi Yojimbo|Yusagi Yojimbo]] ([[User talk:Yusagi Yojimbo|talk]]) 17:22, 6 May 2024 (UTC)

== Wheel/Fan page crash ==

If you place a fan close to a wheel, such that the middle of the fan is about in line with the bottom edge of the lower wheel blade, and the fan blades are just barely touching the wheel blade, then the wheel accelerates apparently without bound. Eventually any ball that touches the wheel simply disappears from the page. Around 20 seconds later (as the wheel continues to accelerate apparently) the page crashes upon the next ball impact, with a javascript error:

<pre>Uncaught RuntimeError: unreachable executed
stepWithEvents rapier_wasm2d_bg.js:2726
step physics_pipeline.js:16
step world.js:111</pre>

At that point you lose your creation, which sadly I learned the hard way. This is fairly easy to reproduce. --[[Special:Contributions/172.71.166.206|172.71.166.206]] 01:23, 7 May 2024 (UTC)

Talk:2918: Tick Marks

2024-04-12T04:09:53Z

172.69.134.16: sign comment

The ticks on the y axis conceal the area of the graph between them. Why didn't Randall just build his graph so that the x axis did similar? Then he could keep up a continuous level of activity equal to the size of the ticks, rather than just doing short bursts to coincide with them.[[Special:Contributions/172.70.91.146|172.70.91.146]] 09:28, 11 April 2024 (UTC)
:Don't really know. But look, I was waiting all day yesterday for the Wednesday comic, so I'll take any comic at this point T_T [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 14:54, 11 April 2024 (UTC)
::It was at least half an hour before end-of-day-Midnight, for Randall's expected TZ. I know you're a new username, so perhaps you weren't aware that he often publishes (as best as we can pick up) ''quite late'' in the respective day (currently UTC+6). And it's also really not so much unknown to be (fairly) early in the following day (yet still officially on the relevent M/W/F).
::That doesn't mean we aren't often frustratingly gripped by antici.................pation, but we are very rarely stymied for more than a whole day (developmental delays to rolling out 'special comics', aside), and I think we are lucky to have such a conscientious creator as we do. It must be a hard schedule to keep up with. (And also that even if "not every one is a winner", ''most'' still are, for ''most'' people. Could be worse!) [[Special:Contributions/172.71.178.110|172.71.178.110]] 15:12, 11 April 2024 (UTC)

Should [[688: Self-Description]] also be linked as an example of "actual data is part of the graphical framing device"? [[Special:Contributions/172.70.39.12|172.70.39.12]] 21:01, 11 April 2024 (UTC)
:It already is linked, in the prior paragraph, and ''isn't'' quite so relevent to the flag-based variation (which is a kind of cousin to this tricky graph thing). But do rewrite it if you think it can be expounded better. [[Special:Contributions/172.70.90.173|172.70.90.173]] 22:13, 11 April 2024 (UTC)
::Thanks, I must have missed it on my first read. [[Special:Contributions/172.70.114.146|172.70.114.146]] 23:20, 11 April 2024 (UTC)

This doesn't seem like a useful method of hiding activity, simply as the area hidden under the ticks is too little to be of significance.[[Special:Contributions/172.69.134.16|172.69.134.16]] 04:09, 12 April 2024 (UTC)

1464: Santa

2024-02-06T17:56:21Z

172.69.134.16: /* Explanation */

{{comic
| number = 1464
| date = December 24, 2014
| title = Santa
| image = santa.png
| titletext = He probably just poops over the side of the sleigh.
}}

==Explanation==
This was the [[:Category:Christmas|Christmas comic]] for 2014 and broadly speaking, this comic follows a long list of issues raised about physical limitations {{w|Santa Claus}} faces, similar to other popular theoretical discussions such as the [http://www.daclarke.org/Humour/santa.html speed he has to travel] and [http://www.articlesbase.com/holidays-articles/10-impossible-facts-about-santa-claus-1509493.html the omniscience he purportedly possesses and the mass of presents he has to carry] — the story of Santa Claus was simply never designed for a world with over 7 billion people (and certainly not 8) spread through untold millions of homes. This comic combines some basic {{w|physiology}} with the physical law of the {{w|conservation of mass}}.

More specifically, this comic refers to the common tradition of leaving milk and cookies out on Christmas Eve for Santa Claus. If one assumes that Santa eats even a small percentage of the sweets left out for him, the question comes up where all the cookies ''go''. Megan suggests that, since Santa isn't ''that'' large, he must poop them out somewhere, and wonders if he does so in our houses.

Cueball doubts that. Megan replies that mass cannot disappear completely; it has to go somewhere, to which Cueball comments that Santa has a magic bag in which he could poop. The magic bag referenced is the bag in which he carries all the Christmas presents he delivers on Christmas Eve. It is called 'magic' because a bag large enough to carry billions of presents would be much too heavy and unbalanced to carry on a sleigh pulled by only eight (or nine) reindeer. Thus, it must be magic somehow. Megan is disgusted at the thought of Santa pooping on people's presents. An even more disgusting explanation is that the 'magic' bag might transform the poop into presents, in which case it would not need to carry many presents at a time.

Cueball proposes a third theory: that Santa only poops in a few houses, leaving large quantities in those houses. Megan says that there may not be anyone that naughty in the world, referencing the myth that Santa will leave coal instead of presents for those who misbehave. Cueball replies that it is randomly determined whose house is pooped in, burdening a smaller number of people. Specifically, Cueball quotes the beginning of {{w|Spock}}'s aphorism from ''{{w|Star Trek II}},'' "The needs of the many outweigh the needs of the few, or the one." The quote is used to justify the sacrifice people make in "allowing" Santa to poop in their homes by citing the numerous other people who are spared his feces.

The title text puts forth yet another theory: that Santa doesn't poop in houses at all, but off the side of his sleigh. This may be equally disgusting to anyone or anything unlucky enough to abruptly receive a rain of poop from the sky.{{cn}} This problem could be minimized by taking advantage of flights over water or uninhabited areas, rather than cities.

According to [[1070: Words for Small Sets]], a few is referring to "anywhere from 2 to 5". Currently, there are 1.9 billion children in the world, so assuming on average that one cookie is left for Santa for each child and that Santa eats one in every 5 cookies, he consumes 380 million cookies in two 48 hour periods. Due to the convenience of time zones, approximately 48 hours from when a day starts in Kiritimati until it ends in Hawaii; also, most western Christians, including Roman Catholics and Protestants, observe Christmas almost two weeks before Eastern Orthodox Christians do. According to Google, a chocolate-chip cookie contains approximately 140 kilocalories, therefore Santa consumes 53.2 billion kilocalories in the period of 2 days, or 26.6 billion kilocalories per day. As the average human daily intake is 2500 kilocalories per day, Santa has eaten 10,640,000 times the amount of daily kilocalories required by one human over the period of two days, an amount otherwise sufficient to last for over 59,111 years for a human, and producing 20 million pounds of feces. However, if we consider the dietary requirements of both Santa and the flying reindeer, and the kilocalories that reindeer would burn flying around the world carrying 1.9 billion toys, the cookies might not be sufficient. If the 1 in 5 cookies are not sufficient energy intake, Santa could probably eat every cookie left for him, which amounts to 266 billion kilocalories in the period of 2 days.

On a side note, this amount of energy is enough to power several thousand homes for a year.

==Transcript==
:Megan: Say Santa eats a cookie at every few houses. That's hundreds of tons. By the end of the night, he should be a hulking seven-story behemoth.
:But he's not.

:Cueball: What are you...
:Megan: Does Santa poop in our houses?

:Cueball: No way.
:Megan: That mass must be going somewhere.
:Cueball: He has that magic bag...
:Megan: You think he poops in the bag of ''presents''?

:Cueball: Maybe instead of pooping in every few houses, he waits, and then in a few houses, he poops a ''lot''.
:Megan: What if no one's been ''that'' naughty?
:Cueball: He picks at random. The needs of the many...

==Trivia==
*Although this is the only "real" Christmas comic to come out around Christmas, the next comic could be seen as a possible item that would be on xkcd fans Christmas wishlist... the [[xkcd Phone 2]].

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

1648: Famous Duos

2024-01-08T00:23:13Z

172.69.134.16: /* Explanation */

{{comic
| number = 1648
| date = February 26, 2016
| title = Famous Duos
| image = famous_duos.png
| titletext = The Romeo and Butt-Head film actually got two thumbs up from Siskel and Oates.
}}

==Explanation==
In popular culture (the term is loosely used in this case) there are many '''famous duos''', such as {{w|Calvin & Hobbes}} (six-year-old boy and his toy tiger, from the cartoon strip with the same name) or {{w|David & Goliath}} (famous past King of Israel and giant, {{w|Biblical}} characters from the {{w|Book of Samuel}} in the {{w|Old Testament}}). (See the [[#Trivia|trivia section]] regarding an on-line list of duos).

In this table, [[Randall]] describes a fictional {{w|Many-worlds interpretation|parallel universe}} where the same names are used in different combinations — instead of Calvin, it is now Thelma (from the movie ''{{w|Thelma & Louise}}'') who is paired up with Hobbes, and Calvin is instead paired off with the King, from ''{{w|Anna and the King}}''. In all cases the one mentioned first on the list is also mentioned first in our universe, so it is always of the form Calvin and the King, never Calvin and Anna. There are 24 duos, and all 48 partners are mentioned (they go through four [[#Cycles|cycles]]). (In the title text of [[1644: Stargazing]] from the week before this comic, there is an indirect reference to parallel universes/{{w|multiverse}}).

The humor of this comic comes from the ridiculousness of the pairings, and the reader's imagination of the stories that are created with the pairs. See the whole [[#List of real duos|list of real duos]] as well as the [[#List of alternative duos|list of alternative duos]] below, with more detailed explanations.

In the title text, alternative movie ''Romeo and Butt-Head'' is mentioned, the fifth entry on the list. This is a combination of the famous {{w|Shakespeare}} play ''{{w|Romeo and Juliet}}'' and ''{{w|Beavis and Butt-Head}}''. ''{{w|Romeo and Juliet}}'' has been filmed many times; most recently in ''{{w|Romeo + Juliet}}'' from 1996 with {{w|Leonardo DiCaprio}} and {{w|Claire Danes}} in the leading roles. {{w|Butt-Head}} is the less stupid one (of the very stupid duo) from the animated TV series ''{{w|Beavis and Butt-Head}}'' (and a {{w|Beavis and Butt-Head Do America|film}}). As Romeo and Juliet is one of the best known love stories and Butt-Head is one of the most disgusting teens ever depicted on the big screen (only overtaken by {{w|Beavis}}), the combination could create disturbing pictures in people's heads (especially in the heads of anyone who may identify themselves with Juliet).

In the alternative universe, when this movie was released, it got the best possible review of two thumbs up from the critics ''Siskel and Oates''. {{w|Gene Siskel}} was paired with {{w|Roger Ebert}}, when they reviewed movies as the famous duo {{w|Siskel and Ebert}}. They were widely known for the "thumbs up/thumbs down" review summaries, with their best combined review being ''Two Thumbs Up'', one from each of them. Coincidentally, or perhaps not, they actually gave {{w|''Beavis & Butthead Do America''}} ''Two Thumbs Up''.

In the alternative universe Siskel and his partner gives the film a (surprising) two thumbs up, but Ebert has been replaced with Oates. This is a reference to John Oates of {{w|Hall & Oates}}, a famous American musical duo from Philadelphia.

There also exists a comedy duo named {{w|Garfunkel and Oates}}, formed by Riki Lindhome and Kate Micucci, who chose the "Garfunkel and Oates" name by combining the second names from both ''Hall & Oates'' and ''{{w|Simon and Garfunkel}}'' (the latter duo is mentioned in the main comic). Although this exact combo would not be possible in the xkcd version, as the "real universe" combo takes the second names from two duos rather than the first name from one and the second name from another (as in this comic), there may definitely be a deliberate reference to this group as well which has taken the parallel universe idea into our universe.

===List of real duos===
*See the list of [[#List of alternative duos|alternative duos]] below.
*In this list the ''partner index'' indicates whom the second from the duo is linked with in the comic
**So in the case with Thelma (index 1) and Louise (partner index 3), this means that Louise is paired up with Batman (index 3).
**Thelma is paired up with the Hobbes who has partner index 1.
{| class="wikitable sortable"
|-
|+ Famous duos in this universe
|-
! scope="col" | Name
! scope="col" class="unsortable" | pairing
! scope="col" | Partner
! scope="col" class="unsortable" | Explanation
! scope="col" | Name index
! scope="col" | Partner index
|-
| Thelma
| and
| Louise
| ''{{w|Thelma & Louise}}'' is a famous road trip film from 1991.
| 1
| 3
|-
| When Harry
| Met
| Sally
| ''{{w|When Harry Met Sally...}}'' is a romantic comedy film from 1989.
| 2
| 16
|-
| Batman
| and
| Robin
| {{w|Batman}} and {{w|Robin (comic)|Robin}} are comic book characters (first appearance for Batman was in 1939, Robin the year after). There have been several {{w|Batman_in_film#Films|films}} including one called ''{{w|Batman & Robin (film)|Batman & Robin}}'' from 1997. A new Batman film ''{{w|Batman v Superman: Dawn of Justice}}'' had its release date three weeks after the release of this comic (2016-02-26).
| 3
| 4
|-
| {{w|Mark Antony|Antony}}
| and
| {{w|Cleopatra}}
| {{w|Mark Antony#Antony and Cleopatra|Antony and Cleopatra}} are historical figures who had an affair and three children together after the death of {{w|Julius Caesar}} up to Anthony's death 30 BC. Their combined names are best known from the play ''{{w|Antony and Cleopatra}}'' by {{w|Shakespeare}}.
| 4
| 12
|-
| Romeo
| and
| Juliet
| {{w|Romeo and Juliet}} are characters from Shakespeare's famous romantic tragedy, from 1597, made into several {{w|Romeo and Juliet on screen#Significant feature releases|major films}}.
| 5
| 24
|-
| {{w|Bonnie and Clyde#Bonnie Parker|Bonnie}}
| and
| {{w|Bonnie and Clyde#Clyde Barrow|Clyde}}
| {{w|Bonnie and Clyde}} were American criminals who traveled the central United States with their gang during the Great Depression until their death on May 23, 1934. They are well known from the film ''{{w|Bonnie and Clyde (film)|Bonnie and Clyde}}''.
| 6
| 7
|-
| {{w|Pinky and the Brain#Pinky|Pinky}}
| and
| {{w|Pinky and the Brain#Characters|the Brain}}
| Two mice from ''{{w|Pinky and the Brain}}'', an American animated TV series from the 1990s.
| 7
| 20
|-
| {{w|Paul Simon|Simon}}
| and
| {{w|Art Garfunkel|Garfunkel}}
| {{w|Simon & Garfunkel}} is a very famous musical duo from the 1960s. (See also explanation for the title text).
| 8
| 22
|-
| Beauty
| and
| the Beast
| {{w|Beauty and the Beast}} are fairy tale characters from a French book from 1740, today best known from the {{w|Beauty and the Beast (1991 film)|Disney film}} from 1991.
| 9
| 10
|-
| {{w|Beavis}}
| and
| {{w|Butt-head}}
| ''{{w|Beavis and Butt-Head}}'' is an animated TV series from the 1990s shown on {{w|MTV}}.
| 10
| 5
|-
| {{w|Rocky the Flying Squirrel|Rocky}}
| and
| {{w|Bullwinkle J. Moose|Bullwinkle}}
| A flying squirrel and a moose known from the ''{{w|The Rocky and Bullwinkle Show}}'', an American animated TV series from the 1960s.
| 11
| 2
|-
| {{w|Bud Abbott|Abbott}}
| and
| {{w|Lou Costello|Costello}}
| {{w|Abbott and Costello}} is a famous American comedy duo whose work in vaudeville and on stage, radio, film and television made them the most popular comedy team during the 1940s. They are known for their famous {{w|Who's on First}} sketch.
| 12
| 17
|-
| Dr. Jekyll
| and
| Mr. Hyde
| Not really a duo, {{w|Dr. Jekyll and Mr. Hyde (character)|Dr. Jekyll and Mr. Hyde}} are the two sides of a well known character from the book ''{{w|Strange Case of Dr Jekyll and Mr Hyde}}'' written by the Scottish author {{w|Robert Louis Stevenson}} in 1886. It has been adapted into several {{w|Adaptations_of_Strange_Case_of_Dr._Jekyll_and_Mr._Hyde#Film|films}}.
| 13
| 15
|-
| {{w|Samson}}
| and
| {{w|Delilah}}
| Not really a duo, Samson and Delilah are Biblical characters from the {{w|Book of Judges}} (chapters 13-16). Samson was given supernatural strength by God in order to combat his enemies. However, Samson had two vulnerabilities: his attraction to untrustworthy women, and his hair, without which he was just a normal man. These vulnerabilities ultimately proved fatal for him when Delilah had him reveal the secret of his hair, which she subsequently cut off. Then she handed him over to be captured by the Philistines, who gouged his eyes out and brought him to imprisonment in Gaza. He died while in capture but on his own terms. Delilah had not explained why he was no longer strong, so his hair had been allowed to grow out again. When he got it all back, he used his power to destroy a temple he was led into, taking many enemies with him in death.
| 14
| 11
|-
| {{w|Butch Cassidy}}
| and
| the {{w|Sundance Kid}}
| They are historical criminals who died in 1908. They were notorious American train and bank robbers with the {{w|Butch Cassidy's Wild Bunch}} gang in 1899-1901. They were made famous by the film ''{{w|Butch Cassidy and the Sundance Kid}}'' from 1969.
| 15
| 23
|-
| Bill
| and
| Ted’s Excellent Adventure and Bogus Journey
| {{w|Bill & Ted (franchise)|Bill & Ted}} are characters from the two films ''{{w|Bill & Ted's Excellent Adventure}}'' (1989) and ''{{w|Bill & Ted's Bogus Journey}}'' (1991). The two titles are spread out on the two new pairings for Bill and Ted, in recognition that this duo is mainly known for these two films, although there also is a {{w|Bill & Ted's Excellent Adventures (1990 TV series)|spin-off animated series}} from 1990-1991.
| 16
| 6
|-
| {{w|David}}
| and
| {{w|Goliath}}
| Not really a duo, David and Goliath were biblical adversaries best known from "small" David's defeat of giant Goliath in the story {{w|David#David_and_Goliath|David and Goliath}}. David later became the second king of Israel, according to the {{w|Books of Samuel}}, and according to the {{w|New Testament}}, an ancestor of {{w|Jesus}}.
| 17
| 8
|-
| {{w|Sherlock Holmes}}
| and
| {{w|Dr. Watson}}
| Characters from {{w|Arthur Conan Doyle}}'s famous books (from 1887-1927) which have been made into numerous {{w|Adaptations of Sherlock Holmes#Film|films}}. In 2009 and 2011, a new {{w|Sherlock Holmes (2009 film)|series of movies}} has been released with {{w|Robert Downey Jr.}} and {{w|Jude Law}} as the two characters. There have also been several TV series.
| 18
| 19
|-
| Jay
| and
| Silent Bob
| {{w|Jay and Silent Bob}} is a strange duo from {{w|View Askew Productions|View Askew's}} film universe, first seen in the film {{w|Clerks}} from 1994. A film called {{w|Jay and Silent Bob Strike Back}} was later released in 2001. The director of these movies, {{w|Kevin Smith}} plays Silent Bob, who of course rarely speaks, but when he finally does it often becomes a long defining monologue. Jay (played by {{w|Jason Mewes}}) talks all the time!
| 19
| 18
|-
| {{w|Anna Leonowens|Anna}}
| and
| the {{w|Mongkut|King}}
| Recently made famous by the 1999 film ''{{w|Anna and the King}}'', based on the 1944 novel ''{{w|Anna and the King of Siam (novel)|Anna and the King of Siam}}'' by {{w|Margaret Landon}}. The Langdon novel was based on two memoirs written by Anna Leonowens in 1870 and 1872, from her experience as royal governess for King Mongkut's children and language secretary for the King from 1862-1867.
| 20
| 21
|-
| {{w|Calvin (Calvin and Hobbes)|Calvin}}
| and
| {{w|Hobbes (Calvin and Hobbes)|Hobbes}}
| ''{{w|Calvin and Hobbes}}'' is a comic series by {{w|Bill Watterson}} that ran from 1985-1995. Calvin is a six-year-old boy and Hobbes is Calvin's stuffed tiger and best friend, who becomes a living anthropomorphic tiger in Calvin's private fantasy world. They have been [[:Category:Calvin and Hobbes|featured regularly]] in xkcd, most prominently in the "duo" comic: [[409: Electric Skateboard (Double Comic)]].
| 21
| 1
|-
| Timon
| and
| Pumbaa
| {{w|Timon and Pumbaa}} are characters from ''{{w|The Lion King}}'' film (1994) and they also have their own {{w|The Lion King 1½|film from 2004}} and a {{w|Timon & Pumbaa (TV series)|TV series}} that ran from 1995-1999. There have been [[:Category:The Lion King|many references]] to ''The Lion King'' in xkcd, for instance the comment in the final panel of [[1504: Opportunity]], is from the original movie.
| 22
| 14
|-
| {{w|Mary Kate Olsen|Mary Kate}}
| and
| {{w|Ashley Olsen}}
| Known as the {{w|Mary-Kate_and_Ashley_Olsen|Olsen twins}}, these {{w|Twin#Dizygotic_.28fraternal.29_twins|fraternal twin}} actresses born in 1986 have been on TV since they were infants (on ''{{w|Full House}}'' from 1987) and began starring together in TV, film, and video projects, which enabled them to join the ranks of the wealthiest women in the entertainment industry at a young age. They have previously been the pun of the joke in [[362: Blade Runner]].
| 23
| 13
|-
| {{w|Mario}}
| and
| {{w|Luigi}}
| In the {{w|Mario (franchise)|''Mario'' series of video games}}, which started with the 1983 game ''{{w|Mario Bros.}}'', Mario and his brother Luigi are the main characters. ''Mario'' games have been referenced in several xkcd comics, such as [[151: Mario]] and the comics in the {{w|''Mario Kart''}} [[:Category:Mario Kart|category]].
| 24
| 9
|}

===List of alternative duos===
*See the list of [[#List of real duos|real duos]] above.
{| class="wikitable"
|-
|+ Famous Duos in a nearby parallel universe
|-
! scope="col" | Duo name
! scope="col" | Explanation
|-
| Thelma and Hobbes
| In this essay [http://www.exampleessays.com/viewpaper/207623.html Political Philosophies in Thelma and Louise] the sentence ''Thelma and Hobbes's Total Sovereign Authority'' can be found. In this case it is a reference to {{w|Thomas Hobbes}} as the essay is an analysis of Thelma and Louise's actions and the decision they make in comparison to the political philosophies of Thomas Hobbes and {{w|Jean Jacques Rousseau}}. Hobbes was an English philosopher, best known today for his work on political philosophy. He also developed some of the fundamentals of European liberal thought, which could be said to be relevant for the movie.
|-
| When Harry met Bullwinkle
| {{w|Billy Crystal}} who played Harry in When Harry Met Sally... also has an uncredited cameo part as a mattress salesman in the movie {{w|The Adventures of Rocky and Bullwinkle}} (see the list of uncredited actors on [http://www.imdb.com/title/tt0131704/combined IMDb]). In this real action movie, Rocky and Bullwinkle ends up in the real world, where it thus becomes likely that Billy who played Harry ends up meeting Bullwinkle "in real life".
|-
| Batman and Louise
| This duo's name comes rather close to the real duo {{w|Clark Kent}} and {{w|Lois Lane}} especially since the film {{w|Batman v Superman: Dawn of Justice}} was set for release three weeks after the release of this comic in February 2016.
|-
| Antony and Robin
| There is a book called ''[http://www.amazon.com/Shakespeares-Antony-Cleopatra-English-Literature/dp/0713155884 Shakespeare's "Antony and Cleopatra"] written by a Robin Lee.
|-
| Romeo and Butthead
| It would be quite a different story if either Butt-head should replace Juliet or if Romeo should replace Beavis... (Note Butt-Head is spelled with a hyphen, but has been misspelled in the comic.)
|-
| Bonnie and Ted's excellent adventure
| There was not much excellent about the adventure for Bonnie as {{w|Ted Hinton}} was a Dallas County, Texas, deputy sheriff, the youngest of the posse that ambushed and killed Bonnie and Clyde in 1934. That they could have had an excellent adventure in an alternative universe becomes clear from this segment from his history on Wikipedia: "Ted Hinton was also once acquainted with young Bonnie Parker while she was working in Marco's Cafe in Dallas. Because of her good looks, many of the male customers would flirt with her. Hinton was always gentlemanly and treated Bonnie with respect. Hinton admitted in a later biography that he had a crush on Bonnie, which made it difficult for him as one of the men on the team sent to kill her and her lover, Clyde."
|-
| Pinky and Clyde
| As can be seen in the table above this refers to Pinky the mouse from Pinky and the Brain and Clyde from Bonnie and Clyde. But {{w|Ghosts (Pac-Man)#Pinky|Pinky}} and {{w|Ghosts (Pac-Man)#Clyde|Clyde}} are also the names of the pink and orange {{w|Pacman}} ghosts in this universe. They are, however, not a duo as there are {{w|Ghosts (Pac-Man)|four ghosts}} ({{w|Ghosts (Pac-Man)#Blinky|Blinky}} and {{w|Ghosts (Pac-Man)#Inky|Inky}} being the two others).
|-
| Simon and Goliath
| Goliath begins with G as Garfunkel. Simon was the shorter of the duo thus fitting as David vs. Goliath.
|-
| Beauty and Luigi
| No direct relation to either Mario or the Beast. However, each story has had a less-popular adaptation that takes place in the sewers of New York City: the 1993 {{w|Super Mario Bros. (film)|''Super Mario Bros.'' film}} and the 1987-1990 {{w|Beauty and the Beast (1987 TV series)|"Beauty and the Beast" TV series}}. Of course, Mario and Luigi are beast hunters rather than beasts.{{citation needed}}
|-
| Beavis and the Beast
| Beavis starts with the same three letters as Beauty, just like Beast does.
|-
| Rocky and Delilah
| There is a book called ''[http://www.bensonink.com/delilahsdaughters.html Delilah's Daughters]'', by Angela Benson, where Delilah Monroe's (note the closeness to Munroe) late husband is called Rocky. (See also [https://www.youtube.com/watch?v=XsIvBLuiiRs Rocky and Delilah] on YouTube...)
|-
| Abbot and Cleopatra
| Abbot starts with an A as does Anthony. Cleopatra starts with a C as does Costello.
|-
| Dr. Jekyll and Ashley Olsen
| In the Robert Louis Stevenson story, Dr. Jekyll has a sinister alter-ego in Mr. Hyde just like twins are (almost) the same persons. Though the Olsen twins are not {{w|Twin#IdenticalTwins|identical twins}}, as children the two shared the role of Michelle Tanner on the U.S. sitcom ''Full House''. Jekyll and Hyde are two people in one body, while Mary Kate and Ashley were, in a way, one person in two bodies. There are only three switches in this cycle. Butch Cassidy takes Mr. Hyde and the other Olson twin takes The Sundance Kid. This means that both twins are paired with a man instead of as in real life with a woman.
|-
| Samson and Pumbaa
| Samson has several letters in common with Timon but Samson is a huge man where Timon is a very small animal compared to the other main characters in The Lion King film.
|-
| Butch Cassidy and Mr. Hyde
| See above explanation for Dr. Jekyll and Ashley Olsen.
|-
| Bill and Sally's Bogus Journey
| In this [http://www.rogerwhitney.com/casestudy/ case study] regarding retirement we ''meet Bill and Sally'' (as Sally met Harry). It could be said to be a ''bogus journey'' as it is just a case study.
|-
| David and Costello
| As Costello was the smaller of Abbot and Costello this does not match up with David vs. a Goliath as it did with Goliath vs small Simon.
|-
| Sherlock Holmes and Silent Bob
| This is the only case of a direct switch between two duos. Dr. Watson usually listen to the musings of Sherlock Holmes and Silent Bob is, as his name indicates, mainly silent. Jay talks all the time.
|-
| Jay and Dr. Watson
| See explanation above for their respective real universe partners (the only case of a direct switch between two duos).
|-
| Anna and the Brain
| The Brain desires to take over the world; the King is ruler of his domain.
|-
| Calvin and the King
| Although it is Calvin's fantasy that decides what happens, it is Hobbes that behaves like the King in their relationship at least when it comes to displaying physical strength to determine who decides.
|-
| Timon and Garfunkel
| Timon is put together with Garfunkel, which makes it a close match to Simon and Garfunkel.
|-
| Mary-Kate and the Sundance Kid
| See above explanation for Dr. Jekyll and Ashley Olsen.
|-
| Mario and Juliet
| Mario would have no issue with balconies. His name has some similarities with Romeo. Also, like Romeo, he is an Italian stereotype.
|}

===Cycles===
*There are four cycles.
*The cycles listed below are sorted like explained this example from the longest cycle:
**It starts with "Thelma" (from Thelma and Louse), who is paired with "Hobbes". Hobbes is then shown diagonally down in the next entry below, Calvin and Hobbes, thus leading from "Hobbes" to "Calvin", who is similarly paired with "the King" leading to Anna and so on, until "Batman" is paired with "Louise", completing the cycle.
* First cycle: length 15
Thelma & Louise
Calvin & Hobbes
Anna & the King
Pinky & the Brain
Bonnie & Clyde
Bill & Ted
Harry & Sally
Rocky & Bullwinkle
Samson & Delilah
Timon & Pumbaa
Simon & Garfunkel
David & Goliath
Abbot & Costello
Antony & Cleopatra
Batman & Robin

* Second cycle: length 4
Romeo & Juliet
Beavis & Butthead
Beauty & the Beast
Mario & Luigi

* Third cycle: length 3
Dr. Jekyll & Mr. Hyde
Mary-Kate & Ashley Olsen
Butch Cassidy & the Sundance Kid

* Fourth cycle: length 2
Sherlock Holmes & Dr. Watson
Jay & Silent Bob

* Assigning an index starting with 1 (= Thelma & Louise) to 24 (= Mario & Luigi), they can be written as:

(1, 21, 20, 7, 6, 16, 2, 11, 14, 22, 8, 17, 12, 4, 3)
(5, 10, 9, 24)
(13, 23, 15)
(18, 19)

==Transcript==
:[Caption above the panel:]
:Famous Duos in a nearby parallel universe

:[A list with 24 duos with a gray “and" between the two names (in one case it is a “met") and three times there is a gray word before (once) or after (twice) the names. The list is centered with the “and" in the middle disregarding the length of the names on each side:]
:{|
|-
| style="text-align:right;" | Thelma
| and
| Hobbes
|-
| style="text-align:right;" | When Harry
| met
| Bullwinkle
|-
| style="text-align:right;" | Batman
| and
| Louise
|-
| style="text-align:right;" | Antony
| and
| Robin
|-
| style="text-align:right;" | Romeo
| and
| Butthead
|-
| style="text-align:right;" | Bonnie
| and
| Ted's excellent adventure
|-
| style="text-align:right;" | Pinky
| and
| Clyde
|-
| style="text-align:right;" | Simon
| and
| Goliath
|-
| style="text-align:right;" | Beauty
| and
| Luigi
|-
| style="text-align:right;" | Beavis
| and
| the Beast
|-
| style="text-align:right;" | Rocky
| and
| Delilah
|-
| style="text-align:right;" | Abbot
| and
| Cleopatra
|-
| style="text-align:right;" | Dr. Jekyll
| and
| Ashley Olsen
|-
| style="text-align:right;" | Samson
| and
| Pumbaa
|-
| style="text-align:right;" | Butch Cassidy
| and
| Mr. Hyde
|-
| style="text-align:right;" | Bill
| and
| Sally's Bogus Journey
|-
| style="text-align:right;" | David
| and
| Costello
|-
| style="text-align:right;" | Sherlock Holmes
| and
| Silent Bob
|-
| style="text-align:right;" | Jay
| and
| Dr. Watson
|-
| style="text-align:right;" | Anna
| and
| the Brain
|-
| style="text-align:right;" | Calvin
| and
| the King
|-
| style="text-align:right;" | Timon
| and
| Garfunkel
|-
| style="text-align:right;" | Mary-Kate
| and
| the Sundance Kid
|-
| style="text-align:right;" | Mario
| and
| Juliet
|}

==Trivia==
*Here is a ranked list with [http://www.ranker.com/list/best-duos-of-all-time/ariel-kana The Best Duos of All Time].
**When this comic came out there was still less than 300 duos on the list.
**16 of the 24 in the comic, and one of the two mentioned in the title text was on this list.
**Below the ranking refers to where they were on the list Sunday after the release of the comic (on Friday).
**The index refers to the index from the table above with the [[#List of real duos|list of real duos]].
:{| class="wikitable sortable"
|-
|+ Ranking (on 2016-02-28) of famous Duos
|-
! scope="col" | Rank
! scope="col" | Duo
! scope="col" | Index
|-
| 2 || Batman and Robin|| 3
|-
| 8 || Holmes and Watson|| 18
|-
| 11 || Simon and Garfunkel|| 8
|-
| 22 || Thelma and Louise|| 1
|-
| 23 || Pinky and The Brain|| 7
|-
| 24 || Hall and Oates|| 26 Title text
|-
| 31 || Butch Cassidy and the Sundance Kid|| 15
|-
| 35 || Calvin and Hobbes|| 21
|-
| 41 || Jay and Silent Bob|| 19
|-
| 46 || Dr. Jekyll and Mr. Hyde|| 13
|-
| 71 || Abbott and Costello|| 12
|-
| 79 || Beauty and the Beast || 9
|-
| 85 || Antony and Cleopatra|| 4
|-
| 99 || Beavis and Butt-head|| 10
|-
| 106 || Mary-Kate and Ashley Olsen|| 23
|-
| 110 || Romeo and Juliet|| 5
|-
| 206 || Rocky and Bullwinkle|| 11
|-
| N/A || When Harry Met Sally...|| 2
|-
| N/A || Samson and Delilah || 14
|-
| N/A || Bill & Ted|| 16
|-
| N/A || David and Goliath || 17
|-
| N/A || Anna and the King || 20
|-
| N/A || Timon and Pumbaa || 22
|-
| N/A || Mario and Luigi || 24
|-
| N/A || Siskel and Ebert || 25 Title text
|}

{{comic discussion}}
[[Category:Charts]]
[[Category:Video games]]
[[Category:Calvin and Hobbes]]
[[Category:The Lion King]]

2872: Hydrothermal Vents

2023-12-25T18:21:59Z

172.69.134.16: /* Explanation */

{{comic
| number = 2872
| date = December 25, 2023
| title = Hydrothermal Vents
| image = hydrothermal vents 2x.png
| imagesize = 330x459px
| noexpand = true
| titletext = Benthic Santas weren't even discovered until the 1970s, but many scientists now believe Christmas may have originally developed around hydrothermal vents and only later migrated to the surface.
}}

==Explanation==
{{incomplete|Created by SANTA'S REMAINS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic was released on Christmas day, in the morning. In the belief of many children, Santa Claus had just finished his annual trip around the world. This comic makes a joke on that by saying that here are "benthic Santas", meaning there are Santas that deliver gifts underwater. The joke here is that many say Santa goes down chimneys, and that hydrothermal vents were evolved to trick Santa into entering them, believing they were chimneys, and thus getting killed by getting digested by the vents, as seen in the comic. There are many things that are very strange mentioned.{{citation needed}} There are no actual humans living down deep in the sea, and fish and other undersea creatures are unlikely to know what "Santa" is or understand the concept of Christmas.{{citation needed}} In addition, the comic shows the remains of many "Santas". However, according to stories, there is only 1 Santa.
The title text is referring to abiogenesis [https://en.wikipedia.org/wiki/Abiogenesis], the origin of life. It was thought non-living matter combined into living cells in shallow water through the energy supplied from the sun and lightnings. At least, amino acids can be synthesized this way, as proven by the Miller–Urey experiment [https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment]. A new explanation places the origin of life on hydrothermal vents, as it's rich in chemicals and rocks there serve as catalysis, with energy coming from earth's heat.

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

{{comic discussion}}

Talk:2835: Factorial Numbers

2023-10-05T13:11:56Z

172.69.134.16: lost

Number systems aren't real math, at least not serious math. They're an affectation. 99.9% of math is number-system-independent, so nobody should care about them. [[Special:Contributions/172.70.46.108|172.70.46.108]] 22:30, 29 September 2023 (UTC)

: Of course it's "real math." There aren't that many applications, but so what? Math isn't about applications. Besides, there are some. Maybe not specifically for factorial base, but for some place systems. The only thing "dirty" about decimal is the arbitrariness of ten. Considering place systems in general is just considering special kinds of sums. Certainly, "serious" mathematicians are interested in proving numbers normal in specific bases, or in every base. [[User:EebstertheGreat|EebstertheGreat]] ([[User talk:EebstertheGreat|talk]]) 01:55, 30 September 2023 (UTC)

: A great deal of interesting maths can be found in and around the various arrangements of digits in numbers systems, surely. AzureArmageddon 07:54, 30 September 2023 (UTC)

I thought this was a complete joke, until coming here. The "factorial number system" exists?! [[Special:Contributions/162.158.90.249|162.158.90.249]] 22:38, 29 September 2023 (UTC)
:Yup, complete news to me too... What's REALLY weird: the night before this comic I was tutoring a friend's daughter in math, and I happened to teach her what factorials are! (News to me there's a number system, though)... [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:59, 1 October 2023 (UTC)

I wanted to add a link to a converter, but the one I found is https://www.dcode.fr/factorial-base which is quite ugly with lots of adds and a bit counter-intuitive.--[[User:Pere prlpz|Pere prlpz]] ([[User talk:Pere prlpz|talk]]) 23:42, 29 September 2023 (UTC)

This needs simplifying a bit. Came here because I had no idea what was going on, and after a quick scroll through the prose, the main thing I learned was "it's 'cause you're dumb". May be true but I still don't get what Randall's factorial system is....[[User:Alcatraz ii|Alcatraz ii]] ([[User talk:Alcatraz ii|talk]]) 01:25, 30 September 2023 (UTC)

Factorial base also allows to finitely represent all rational numbers - no constant base is capable of that! [[Special:Contributions/172.68.238.76|172.68.238.76]] 01:55, 30 September 2023 (UTC)
: Unless you use a division sign. But yes, only radix numerals of a variable base with infinite series of factors of every prime can even theoretically finitely represent arbitrary rationals without invoking existential quantifiers. [[Special:Contributions/172.71.147.26|172.71.147.26]] 06:43, 30 September 2023 (UTC)

I feel like Michael when Oscar is trying to explain what a “surplus” is.[[Special:Contributions/162.158.186.241|162.158.186.241]] 04:12, 30 September 2023 (UTC)
:Bruh, same, and I'm a stats major. This "explanation" sorely needs a couple paragraphs of ELI5 introductory exposition for English majors between the first and second sentences. [[Special:Contributions/172.69.134.16|172.69.134.16]] 13:11, 5 October 2023 (UTC)

== The warning is complete nonsense, just remove it ==

bots cant be escorted out of somewhere just remove the stupid warning [[Special:Contributions/162.158.203.109|162.158.203.109]] 04:28, 30 September 2023 (UTC)

: you must be new here - [[Special:Contributions/108.162.216.143|108.162.216.143]] 15:51, 30 September 2023 (UTC)

: The nonsense is part of the fun. AzureArmageddon 07:52, 30 September 2023 (UTC)

::im deleting it {{unsigned ip|162.158.203.80|11:16, 30 September 2023}}‎

:::Premature elision. Still has a purpose (as does signing your contributions here). [[Special:Contributions/172.71.178.208|172.71.178.208]] 14:58, 30 September 2023 (UTC)
:::<nowiki>*</nowiki>sigh* As has been stated, you MUST be new here. The "incomplete" tag goes on new comics while their descriptions are still in flux. When the bot creates the empty description page, it does so with the Incomplete warning, labelled with its name. On the first edit, someone ALWAYS changes the name to some silly gag that's related to the comic, often pretending it's the name of the bot that created the page for us. In this case the comic shows Cueball being escorted out, so the joke is the bot is being escorted out. If you're not going to have a sense of humour, why are you here? Just leave the editing to others in the meantime. :) (Oh, and as the user above noted, make sure to end your comments with <nowiki>~~~~</nowiki> (4 tildes), like it says at the top of the editing text box you type in). :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:13, 1 October 2023 (UTC)
:Okay, now the Incomplete warning needs to stay up forever. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:13, 1 October 2023 (UTC)

:In case you weren’t aware, this wiki has a tradition of humor. This is one of its examples. [[Special:Contributions/172.68.58.134|172.68.58.134]] 12:56, 2 October 2023 (UTC)

== The "adic" part of factor-adic numbers ==

It's not explicitly mentioned in the comic but the "adic" in the name "Factor''adic''™" implies that the number system extends the factorial number system by being in some way "adic" as discussed in [https://youtube.com/watch?v=tRaq4aYPzCc this YouTube video on the Veritasium channel] and so negative numbers would have a truly wacky representation that violates the intent of the title text's pronouncement by requiring an infinitely long representation requiring infinite digits (1, 2, 3, 4, ..., 9, A, B, C, ..., ''infinite digits''). AzureArmageddon 08:00, 30 September 2023 (UTC)

: The "adic" in factoradic doesn't actually relate to p-adic numbers of any kind. Rather, both factoradic and p-adic numbers use the suffix -adic to refer to the concept of adicity, which is "The number of arguments or operands a function or operation takes" according to Wiktionary. Each place value of a p-adic number had p possibilities, and each place value in the factoradic system has a number of possible arguments determined by the factorial of the place. Factoradic would be better called "factorary" since it's more similar to ordinary n-ary number systems, but I guess it just isn't. [[Special:Contributions/172.69.205.130|172.69.205.130]] 20:43, 30 September 2023 (UTC)

:: Ah, today I learned. AzureArmageddon 15:35, 1 October 2023 (UTC)

== Title text ==
The title text references that 10! = 3,628,800 (base 10), and so for numbers greater than or equal to that, you would have to add a tenth digit in order to display them in this system. The question is asking whether you would then proceed to using letters of the alphabet such as one does in [https://en.wikipedia.org/wiki/Hexadecimal hexadecimal] to which the reply is that numbers above this amount are simply illegal. The trouble comes when you try to write down the number 10 * 10! = 36,288,000 (base 10) in this system. For 10!, the notation is 1000000000 , so 9 * 10! would be 9000000000, and then to get 10 * 10!, you would have to write A000000000 because 10 * 10! < 11!. In fact, since this is the first "illegal" number, you could "legally" allow up to 10 * 10! - 1 = 36,287,999 (base 10) in the system (which would be written as 9987654321 = 9 * 10! + 9 * 9! + 8 * 8! + ... + 2 * 1! + 1 * 1!) without the need to introduce any letters. I also want to point out that the reference in the comic to 9 being reserved for big numbers is due to no number needing a 9 to write it down in this system until 9 * 9! = 3265920 which is written 900000000. Since numbers above 10! are not allowed, this means that only the 9! digit is legally allowed to hold a 9, and it only applies to numbers in that high range of 3265920 to 3628799.[[Special:Contributions/172.71.166.230|172.71.166.230]] 15:01, 30 September 2023 (UTC)
:I feel the current in-Explanation explanation about that already covers this, with the addition of the validity that the digit that could need to be >9 could still be any digit 0..9 without needing to invoke the 11th digit. (Maybe a few tweaks, but not sure what you're trying to add here.) [[Special:Contributions/172.70.86.148|172.70.86.148]] 15:13, 30 September 2023 (UTC)

== Radix Economy ==
Someone got in there just before I did, about (from a quick scan of what's been added) "economical" use of Factorial-based variable radices. (I was planning both the test code and the explanation for this, whilst travelling.) My short way of putting it is that (apart from values of zero or one, which represent identically in Factorial-based notation to any other notation in base of 2+) the Factorialised method initially is using up 'places' quicker until the point at which it has reached a 'magnitude' equal to its base-normal 'original' (i.e. only when there are N glyphs made available under Factoradic notation does it not rush through the 'magnitude' quicker than the base-N number). And ''then'', it needs to work up into the more 'efficient' higher-order digits in order to pull back the disadvantages of its lower-order ones and equal, then be shorter than, any given value's respective base-N form. 
Now, I've done some very rough calculations (started hitting numbers for which I really need to convert everything into high-precision large-number data types, which needs me to rewrite one or two elements of my existing code) and looked at the successive changes of magnitude, in each base, and checked the calculated Factoradic length (with the assumption that there are enough extended glyphs to represent every digit singly, unlike the comic Title Text speculation). 
By my reckoning, Base-2 is more efficient at 20fact (compare with 1002, =410); Base-3 breaks better at
3111fact (100003, =81); Base-4: 540220fact (10000004, =4096); Base-5: 533340021fact (10000000005, =1953125); Base-6: 90967344000fact(1000000000006, =362797056); Base-7: 7ABAA086002001fact(1000000000000007, =678223072849); Base-8: D73A256860540220fact(100000000000000008, =281474976710656); Base-9: B1HEA65678836651220fact(100000000000000008119, =1350851717672992000) ...but at this point, the conversion of decimal to its base-9 form (and that powers of 9 should ''never'' have trailing zeros!) shows I may very well have hit a limit to normal large-number precision, so I really can't trust the subsequently derived base-10 values. 
But, in case anyone wants it, the following is my (Perl, but should be easily convertible into most medium-to-high level code dialevts) en-Factoriadialising function.
sub factadic { my ($n,$place)=(@_,1);
return () unless $place;
if ($n>=fact($place+1)) { return factadic($n,++$place) }
my $digit=0; my $base=fact($place);
while ($n>=$base) { $digit++; $n-=$base; }
my @return=($digit,factadic($n,$place-1));
return @return;
}
You call it as <code>factadic(''<value>'')</code>. Or <code>factadic(''<value>'',''<minimum_digits>'')</code> to start with the assumption of at least a minimum number of digits, but it'll start by shifting the default minimum of 1 into the <script>$place</script> variable if you don't give it that (there are other ways that you can/must do that, of course), and it will still always expand that to the degree necessary in the first phase of 'diving in' as far as it needs to in order to agree with the <code>fact()</code> function (factorial calculator, a trivial coding issue that I only use here like this because I alreadu set it up for another bit of code). 
It returns an array (@-variable, in Perl) of digits, in standard most-to-least-significance order, that you can convert to a glyphwise notation in any way that you wish (or do a string conversion within the function, at each stage of building it up). ...and I'm presenting a ''slightly'' less optimised version of it here (some of the Perl-tricks I originally used don't translate well into some non-Perl) and, yes, the <code>while ($n>=$base)</code> loop could be done using modulus and integer-division, but it's a fairly trivial part of the looping process. 
If you have any ''real'' problems with it, it's probably going to be if you're hitting any recursion-depth limits (especially as it uses roughly twice as many recursive calls as the eventual notation-length it produces). I also have a 'stack-based' version (loops round as it shifts in enough 'slots', then works back down again assigning the place-values) which avoids such trouble, but that's coded in a slightly esoteric Perlish way that I'm not sure most of you'd appreciate. ;) [[Special:Contributions/141.101.76.77|141.101.76.77]] 20:25, 30 September 2023 (UTC)
: Probably a double precision floating point accuracy limitation, you can only get up to 2^53 = 9007199254740992 before many modern programs start getting numerically fuzzy. But what weirds me out is you seem to have gotten 1350851717672992900 out of what should have been 9^19 = 1350851717672992089, instead of a nearby float of 1350851717672992768 or 1350851717672993024. What is it with things rounding to decimal like that? [[Special:Contributions/172.71.147.84|172.71.147.84]] 11:43, 1 October 2023 (UTC)
::One 'solution' is to <code>use Math::BigFloat</code> (or similar), in the Perl, and make hold such sensitive and large-tending values. Alternately, implement an array of digits in a raw manner (can be of entirely arbitrary base, explicitly, plus arbitrarily long; well, as long as one doesn't hit ''other'' data limits!) and make your own long-division/etc algorithms. Or pack bitwise/bytewise data as a 'string', with suitable overloaded/replacement mathematical functions. But it all adds extra coding effort, of course. And I rarely share my various hacked-together bits of Perl, because they either work but look horrible or they don't work (and probably look strange, even to me - hence why I've failed to discover why they don't work!). [[Special:Contributions/172.71.98.87|172.71.98.87]] 19:39, 1 October 2023 (UTC)
: Just analyzed the growth rate; For base x, the length can be estimated by 1/2+e*x-e-1.487*ln(x). Maybe a more sniped nerd can get more precision, or even an exact solution; but this is within a digit of the result up to around base 10^13, and then I start running into precision problems in general, so I'm just putting this here as a good enough guess. [[Special:Contributions/172.71.146.129|172.71.146.129]] 13:20, 1 October 2023 (UTC)

Factorial numbers is new to me... It sounds more like a coding system than a number system, LOL! "The door code is 4503 in factorial! Figure it out!" (I'd write this on the bottom of the comments as usual, but I don't want to get mixed up with that ill-thought out and unsigned coding sample Algorithm and table that I KNOW must be mangled when published because the wiki refuses to honour single Newlines. Clearly the author didn't take a peek at what it looks like when published EDIT: Correction, wow, the wiki spotted the code and marked it as such automatically (for now), wow!) :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:59, 1 October 2023 (UTC)

All the stuff about economy / efficiency doesn't seem to really have any direct relation to the comic, so I'd suggest it doesn't really belong in the explanation, but should be confined to the comments, or at least to a trivia section. Not least because it dives off into a lot of technical stuff that ''itself'' requires explanation for a significant part of the readership. As it is, it's doing more to confuse than to explain.[[Special:Contributions/172.70.85.218|172.70.85.218]] 09:02, 2 October 2023 (UTC)
:I sort of agree, in that I had planned something similar about 'notation economy' as a Trivia-like addendum, before others got there before me. But there could at least be something to be said that by reserving higher-digits(/dissalowing them in lower values), Cueball/Randall is sacrificing conciseness for (one idea of) aestheticism. (And that's without going into 'how much storage it takes to store each digit', which I wasn't going into. So rather than the idealised radix being base-'e', I would have said the idealised base was whatever base-number exceeded the highest value, so it was just one (different) single squiggle for ''everything''. Obviously, there's necessary entropy in the choice of differentiatable squiggles/encoding, though, which is why I also appreciate the current Explanation's blurb.) [[Special:Contributions/172.70.90.52|172.70.90.52]] 10:15, 2 October 2023 (UTC)

NiceGuy1 the wiki uses standard markdown, if you preface with 6 spaces, it will automatically recognize it as a code snippit. I appologize if my contribution was ill-thought out, though i have gone back and signed it. [[User:Drinkcoffeeandcode|Drinkcoffeeandcode]] ([[User talk:Drinkcoffeeandcode|talk]]) 20:06, 4 October 2023 (UTC)

== Factoradic Algorithms ==

there are several ways to compute the factoradic of a base 10 number, depending on the choice of language
the length of the program will be demonstrably bigger. Dynamically typed languages, like perl can likely
perform this in one or two lines, where as a language like c++ will be longer.

The simplest algorithm is to generate the digits from right to left one at time by dividing the number by a per-iteration-incrementing radix starting from 2 (because 1 is simply '0', we start from 2), taking the result and repeating until the quotient reaches zero:

#include <iostream>
#include <algorithm>
using namespace std;
int factoradic(int num) {
string digits;
int radix = 2;
while (num != 0) {
digits.push_back(((num % radix)-'0'));
num /= radix++;
}
reverse(digits.begin(), digits.end());
return atoi(digits.c_str());
}

Using Randall's values we can confirm it is correct:

int main(int argc, char* argv[]) {
for (int i = 21; i < 26; i++)
cout<<i<<" - "<<factoradic(i)<<endl;
for (int i = 5038; i < 5042; i++)
cout<<i<<" - "<<factoradic(i)<<endl;
for (int i = 999998; i < 1000002; i++)
cout<<i<<" - "<<factoradic(i)<<endl;
return 0;
}

max@laptop:~/$ ./factoradic
21 - 311
22 - 320
23 - 321
24 - 1000
25 - 1001
5038 - 654320
5039 - 654321
5040 - 1000000
5041 - 1000001
999998 - 266251210
999999 - 266251211
1000000 - 266251220
1000001 - 266251221

Came back to sign code sample after seeing NiceGuy1's comment. [[User:Drinkcoffeeandcode|Drinkcoffeeandcode]] ([[User talk:Drinkcoffeeandcode|talk]]) 20:02, 4 October 2023 (UTC)

I would love to have some kind of explanation as to why this number system exists/what it's used for in the real world. (Even if that explanation is just "there's no practical purpose, mathematicians just love doing this stuff".) [[Special:Contributions/172.70.134.87|172.70.134.87]] 14:55, 2 October 2023 (UTC)

Would it be too much of a fandom crossover to edit / annotate the last word of the explanation (at time of commenting, the word "senary") to "seximal"? Or, given that we are discussing intentionally silly base systems, just the '''right''' amount of a fandom crossover? [[Special:Contributions/172.71.242.176|172.71.242.176]] 08:14, 5 October 2023 (UTC)

2730: Code Lifespan

2023-01-27T16:42:26Z

172.69.134.16: /* Explanation */ typo

{{comic
| number = 2730
| date = January 27, 2023
| title = Code Lifespan
| image = code_lifespan_2x.png
| imagesize = 377x307px
| noexpand = true
| titletext = Surely (no one/everyone) will (recognize how flexible and useful this architecture is/spend a huge amount of effort painstakingly preserving and updating this garbage I wrote in 20 minutes)
}}

==Explanation==
{{incomplete|Created by a BOT PROGRAMMED 50 YEARS AGO. Do NOT delete this tag too soon.}}

In the first panel, [[Ponytail]] painstakingly future-proofed her code, but all in vain, as it will never be reused again. In the second panel, she decided that future-proofing would be unneccessary, as she assumes nobody would reuse her code that far in the future anyway. This feels like a {{w|Catch-22}} situation for developers.

The title text proposes four permutations of sentences that software developers may consider, which given the context of the comic, usually start out as these two hoped-for ideals:
* Surely everyone will recognize how flexible and useful this architecture is. And,
* Surely no one will spend a huge amount of effort painstakingly preserving and updating this garbage I wrote in 20 minutes.
However, reality often falls short of such hopes, in that insufficient numbers of people recognize code intended for re-use, and far more people than intended will attempt to maintain and adapt sloppy work. The latter sometimes happens because the corner-cutting peculiarities of hasty work are often seen as far deeper necessities than they actually are.

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

[Two situations are depicted between Ponytail and Cueball.]

[Situation 1:]

Ponytail: It took some extra work to build, but now we'll be able to use it for all our future projects.

Caption below the panel: How to ensure your code is never reused

[Situation 2:]

Ponytail: Let's not overthink it; if this code is still in use '''''that''''' far in the future, we'll have bigger problems.

Caption below the panel: How to ensure your code lives forever

{{comic discussion}}

2719: Hydrogen Isotopes

2023-01-05T14:24:43Z

172.69.134.16: /* Explanation */ reword

{{comic
| number = 2719
| date = January 2, 2023
| title = Hydrogen Isotopes
| image = hydrogen_isotopes_2x.png
| imagesize = 442x250px
| noexpand = true
| titletext = Oops, All Neutrons is also known as Neutral Quadrium, Nydnonen, and Goth Tritium.
}}

==Explanation==
{{incomplete|Created by a BREAK ROOM DE BROGLIE MICROWAVE USER. Do NOT delete this tag too soon.}}

{{W|Hydrogen}} is the simplest of the chemical atoms, usually consisting of an electron orbiting a lone proton, but with two other naturally occurring {{w|isotope}}s. This comic shows real and humorously fictional forms of hydrogen, generally depicted according the {{w|Discovery of the neutron#Proton–neutron model of the nucleus|Chadwick model}} of the atom; see [[2100: Models of the Atom]] for details.

{| class="wikitable"
! "Isotope"
! Real?
! Description
|-
|Hydrogen
|Yes
|Hydrogen-1 is the most common isotope of hydrogen, with one proton and one electron, shown with the electron orbiting the proton. It is also known as protium.
|-
|Deuterium
|Yes
|{{w|Deuterium}} is the second most common isotope of hydrogen, with one electron and both a neutron and proton in its nucleus. About one of every 6,760 hydrogen atoms in seawater is deuterium. Its chemical symbol is D or [[2614: 2|2H]], and it's also called heavy hydrogen or hydrogen-2.
|-
|Tritium
|Yes
|{{w|Tritium}} is the third most common isotope of hydrogen, with an electron orbiting a nucleus of one proton and two neutrons, for an atomic mass of about three {{w|Dalton (unit)|daltons}}. It is radioactive with a half-life of about twelve years, and is very rare (but not as rare as unbound "instant hydrogen" neutrons.) It's also designated hydrogen-3, with the symbol T, or more often, 3H.
|-
|Ium
|Only in the lab
|This is a free electron orbiting around nothing. Following the naming of the heavier hydrogen isotopes (a prefix designating the number of {{w|nucleons}} is followed by the suffix "-ium"), the lack of a nucleus is designated here by the absence of a prefix. A free electron will not circle around nothing but will react to electromagnetic fields when suitably configured. A {{w|Penning trap}} can confine electrons to move in circles.
|-
|Wheelium
|No
|This fictional form consists of a proton, electron, and neutron orbiting around nothing, shaped similarly to a wheel. The neutron could bind to the proton, but will more likely {{w|Elastic_scattering#Nuclear particle physics|elastically scatter}} away.
|-
|Instant hydrogen (ready in 15 minutes)
|Yes, but rare[https://radioactivity.eu.com/phenomenon/neutronic_radiation]
|This is just a single neutron. An unbound neutron will decay into a proton, an electron, and an antineutrino, with a mean lifetime of just under fifteen minutes. The proton and electron ''can'' form into a hydrogen atom, but that [https://van.physics.illinois.edu/ask/listing/1207 only happens about four times in a million.] The name is likely a reference to "instant" food such as noodles which are reduced for convenience and can be quickly reconstituted.
|-
|Hydrogen (maximum strength)
|No
|This fictional isotope consists of a proton, an electron, and what appear to be at least 14 neutrons. This isotope's proton would not be bound to all the neutrons. It would immediately decay by {{w|Nuclear drip line|dripping}} most all of them away, producing a large amount of energy. "Maximum strength" may be a reference to over-the-counter medicines containing the largest quantity of active ingredients permitted.
|-
|Oops, All Neutrons
|Extremely unlikely
|This fictional form consists of four neutrons, with one orbiting around a group of three. As the existence of {{w|tetraneutron|tetraneutrons}} is still uncertain, their possible configurations are unknown. But the depicted configuration is very unlikely given the characteristics of fundamental forces. The name is likely a reference to an American breakfast cereal called {{w|Cap'n Crunch#Variations|Oops! All Berries}}, which has also been referenced in [[2256]].
|}

The title text provides three other names for Oops, All Neutrons: 1. "Neutral Quadrium": {{w|Isotopes_of_hydrogen#Hydrogen-4|Quadrium}} is the extremely rare artificial isotope hydrogen-4, with a proton and three neutrons.[https://www.chem.ccu.edu.tw/~hu/Web_Lib/articles/Muonium+H2_Science_2011.pdf][https://www.lenr-canr.org/acrobat/GodesRcontrolled.pdf] The proton and electron have been replaced with neutrons. 2. "Nydnonen" is the word "hydrogen" with three consonants replaced by the letter 'n' so it has four of them representing the four neutrons. 3. "Goth Tritium": All the particles in the depiction are black, resembling typical {{w|gothic fashion}}, and in the same configuration as the particles of tritium.

==Transcript==
:[Eight drawings of different versions of hydrogen atoms are shown. They are arranged in two rows of four. The depictions use the planetary model version with for instance a negative electron (with a "-" written inside a small circle) orbiting a positive proton (with a "+" written inside a larger circle) and a black neutron depicted as a circle of the same size as the neutron, as in the second atom - Deuterium. Each has a label underneath. Here, they are listed in reading order:]
:[An electron orbiting a proton:]
:Hydrogen

:[An electron orbiting a proton connected with a neutron:]
:Deuterium

:[An electron orbiting a proton connected with two neutrons, so they form a triangle:]
:Tritium

:[An electron orbiting nothing:]
:Ium

:[An electron a proton and a neutron all orbiting on the same circle around nothing. They are placed equidistant from each other forming a large triangle:]
:Wheelium

:[A single neutron:]
:Instant Hydrogen (ready in 15 minutes)

:[An electron orbiting a proton connected with many neutrons, 13 visible with six touching the proton which are in front. Four more are close to those six and mostly shown and then three are only just visible behind the others. Looking closely there are also two smaller dots near the edge indicating at least two more, for 15 that can be seen. And several more would be behind the visible neutrons if this forms a spherical shape. The electrons orbit just barely goes around the outer neutrons:]
:Hydrogen (maximum strength)

:[Four neutrons arranged like the particles in Tritium with a neutron orbiting a triangle of neutrons.]
:Oops, all neutrons

{{comic discussion}}

[[Category:Charts]]
[[Category:Physics]]
[[Category:Chemistry]]

2719: Hydrogen Isotopes

2023-01-04T06:05:53Z

172.69.134.16: /* Explanation */ reword

{{comic
| number = 2719
| date = January 2, 2023
| title = Hydrogen Isotopes
| image = hydrogen_isotopes_2x.png
| imagesize = 442x250px
| noexpand = true
| titletext = Oops, All Neutrons is also known as Neutral Quadrium, Nydnonen, and Goth Tritium.
}}

==Explanation==
{{incomplete|Created by a BREAK ROOM DE BROGLIE MICROWAVE USER. Do NOT delete this tag too soon.}}

{{W|Hydrogen}} is the simplest of the chemical atoms, usually consisting of a lone electron orbiting a lone proton. This comic shows real and humorously fictional forms of hydrogen, generally depicted according the {{w|Discovery of the neutron#Proton–neutron model of the nucleus|Chadwick model}} of the atom; see [[2100: Models of the Atom]] for details.

{| class="wikitable"
! "Isotope"
! Real?
! Description
|-
|Hydrogen
|Yes
|Hydrogen-1 is the most common {{w|isotope}} of hydrogen, with one proton and one electron, shown with the electron orbiting the proton. It is also known as protium.
|-
|Deuterium
|Yes
|{{w|Deuterium}} is the second most common isotope of hydrogen, with one electron and both a neutron and proton in its nucleus. About one of every 6,760 hydrogen atoms in seawater is deuterium.
|-
|Tritium
|Yes
|{{w|Tritium}} is the third most common isotope of hydrogen, with one electron and a nucleus of one proton and two neutrons, for an atomic mass of about three {{w|Dalton (unit)|daltons}}. It is radioactive with a half-life of about twelve years, and is very rare (but not as rare as unbound "instant hydrogen" neutrons.)
|-
|Ium
|Not as shown
|This isotope depicts one electron orbiting around nothing. Heavier hydrogen isotopes are named from a prefix designating the number of {{w|nucleons}} followed by the suffix "-ium" (which is also {{w|systematic element name|used to name newly discovered elements}} before they are given a proper name, e.g. {{w|unununium}} for element 111) so no nucleus is designated with no prefix. A free electron will not circle around nothing, but instead will gain momentum towards positive electric field potentials including those created by moving magnetic fields.
|-
|Wheelium
|No
|This fictional form consists of a proton, electron, and neutron orbiting around nothing, shaped similarly to a wheel. The neutron could bind to the proton, but will more likely {{w|Elastic_scattering#Nuclear particle physics|elastically scatter}} away.
|-
|Instant hydrogen (ready in 15 minutes)
|Yes, but rare
|This is just a single neutron. An unbound neutron will decay into a proton, an electron, and an antineutrino, with a mean lifetime of about 14 min, 39.6 s (half-life = about 10 min, 11 s). The antineutrino will carry away momentum, while the proton and electron ''can'' form into a hydrogen atom. However, this [https://van.physics.illinois.edu/ask/listing/1207 only happens about four times in a million.] The name is likely a reference to "instant" meals (e.g. instant noodles) which are typically reduced for convenient storage, and can be quickly reconstituted.
|-
|Hydrogen (maximum strength)
|No
|This fictional isotope consists of a proton, an electron, and what appear to be at least 14 neutrons. This isotope's proton would not be bound to all the neutrons. It would immediately decay by {{w|Nuclear drip line|dripping}} most all of them away, producing a large amount of energy. "Maximum strength" may be a reference to over-the-counter medicines containing the greatest legal quantity of active ingredients.
|-
|Oops, All Neutrons
|Maybe
|This fictional form consists of four neutrons, a {{w|tetraneutron}}, with one orbiting around a group of three. The name is likely a reference to an American breakfast cereal called {{w|Cap'n Crunch#Variations|Oops! All Berries}}.

The title text provides three other names of this form: 1. "Neutral Quadrium": Quadrium is an extremely rare isotope of hydrogen with four nucleons, a proton and three neutrons.[https://www.chem.ccu.edu.tw/~hu/Web_Lib/articles/Muonium+H2_Science_2011.pdf][https://www.lenr-canr.org/acrobat/GodesRcontrolled.pdf] The proton and electron have been replaced with neutrons, making a fictional neutral atom. 2. "Nydnonen" is likely a derivation of "hydrogen" with three of its consonants replaced with the letter 'n' so it has four of them representing the four neutrons. 3. "Goth Tritium": All the particles in the depiction are black, resembling typical {{w|gothic fashion}}, and in the same configuration as the particles of tritium.
|}

{{notice2|The Mountain View, California Public Library is hosting an online chat with [[Randall Munroe]] Tuesday, January 31 at 11am Pacific. [https://libraryc.org/mountainviewlibrary/22032 Register here to send your question(s) to the moderators.]|image=Crystal Project Agt announcements.png}} 

==Transcript==
:[Eight drawings of different versions of hydrogen atoms are shown. They are arranged in two rows of four. The depictions use the planetary model version with for instance a negative electron (with a "-" written inside a small circle) orbiting a positive proton (with a "+" written inside a larger circle) and a black neutron depicted as a circle of the same size as the neutron, as in the second atom - Deuterium. Each has a label underneath. Here, they are listed in reading order:]
:[An electron orbiting a proton:]
:Hydrogen

:[An electron orbiting a proton connected with a neutron:]
:Deuterium

:[An electron orbiting a proton connected with two neutrons, so they form a triangle:]
:Tritium

:[An electron orbiting nothing:]
:Ium

:[An electron a proton and a neutron all orbiting on the same circle around nothing. They are placed equidistant from each other forming a large triangle:]
:Wheelium

:[A single neutron:]
:Instant Hydrogen (ready in 15 minutes)

:[An electron orbiting a proton connected with many neutrons, 13 visible with six touching the proton which are in front. Four more are close to those six and mostly shown and then three are only just visible behind the others. Looking closely there are also two smaller dots near the edge indicating at least two more, for 15 that can be seen. And several more would be behind the visible neutrons if this forms a spherical shape. The electrons orbit just barely goes around the outer neutrons:]
:Hydrogen (maximum strength)

:[Four neutrons arranged like the particles in Tritium with a neutron orbiting a triangle of neutrons.]
:Oops, all neutrons

{{comic discussion}}

[[Category:Charts]]
[[Category:Physics]]
[[Category:Chemistry]]

2719: Hydrogen Isotopes

2023-01-04T05:13:53Z

172.69.134.16: /* Explanation */ tighten

{{comic
| number = 2719
| date = January 2, 2023
| title = Hydrogen Isotopes
| image = hydrogen_isotopes_2x.png
| imagesize = 442x250px
| noexpand = true
| titletext = Oops, All Neutrons is also known as Neutral Quadrium, Nydnonen, and Goth Tritium.
}}

==Explanation==
{{incomplete|Created by a BREAK ROOM DE BROGLIE MICROWAVE USER. Do NOT delete this tag too soon.}}

{{W|Hydrogen}} is the simplest of the chemical atoms, usually consisting of an electron 'orbiting' a single and unaccompanied proton. The comic depicts this, as well as other forms of hydrogen, in the [[2100: Models of the Atom|general form]] of the Chadwick model ({{w|Discovery of the neutron#Proton–neutron model of the nucleus|or similar}}) of the atom. Starting with essentially factual figures, before moving into typical xkcd humour, the eight forms depicted are as follows:

{| class="wikitable"
! "Isotope"
! Real?
! Description
|-
|Hydrogen
|Yes
|Hydrogen-1 is the most common {{w|isotope}} of hydrogen, with one proton and one electron, shown with the electron orbiting the proton. It is also known as protium.
|-
|Deuterium
|Yes
|{{w|Deuterium}} is the second most common isotope of hydrogen, with one electron and both a neutron and proton in its nucleus. About one of every 6,760 hydrogen atoms in seawater is deuterium.
|-
|Tritium
|Yes
|{{w|Tritium}} is the third most common isotope of hydrogen, with one electron and a nucleus of one proton and two neutrons, for an atomic mass of about three {{w|Dalton (unit)|daltons}}. It is radioactive with a half-life of about twelve years, and is very rare (but not as rare as unbound "instant hydrogen" neutrons.)
|-
|Ium
|In a way
|This isotope depicts one electron orbiting around nothing. The name relates to the fact that the two heavier isotopes are named from a prefix designating the number of {{w|nucleons}} followed by the suffix "-ium", a naming scheme that is also used to identify newly detected (exotic/heavy) elements before they are given a proper name (for example, [https://www.collinsdictionary.com/de/worterbuch/englisch/unununium unununium for element 111]); this scheme is now applied to the case where there is literally nothing in the center. While there is no physical reason for a single electron to circle around nothing, a free electron can perfectly well exist on its own, and may be described by a localized probability distribution ([https://en.wikipedia.org/wiki/Wave_packet wave packet]) in much the same way as orbitals describe the bound states around a nucleus. In this sense, "ium" would be just another word for "free electron".
|-
|Wheelium
|No
|This fictional form consists of a proton, electron, and neutron orbiting around nothing, shaped similarly to a wheel. The neutron would either bind to the proton, or much more likely, be {{w|Elastic_scattering#Nuclear particle physics|elastically scattered}} away.
|-
|Instant hydrogen (ready in 15 minutes)
|Yes, but rare
|This is just a single neutron. An unbound neutron will decay into a proton, an electron, and an antineutrino, with a mean lifetime of about 14 min, 39.6 s (half-life = about 10 min, 11 s). The antineutrino will carry away momentum, while the proton and electron ''can'' form into a hydrogen atom. However, this [https://van.physics.illinois.edu/ask/listing/1207 only happens about four times in a million.] The name is likely a reference to "instant" meals (e.g. instant noodles) which are typically reduced for convenient storage, and can be quickly reconstituted.
|-
|Hydrogen (maximum strength)
|No
|This fictional isotope consists of a proton, an electron, and what appear to be at least 14 neutrons. This isotope's proton would not be bound to all the neutrons. It would immediately decay by {{w|Nuclear drip line|dripping}} most all of them away, producing a large amount of energy. "Maximum strength" may be a reference to over-the-counter medicines containing the greatest legal quantity of active ingredients.
|-
|Oops, All Neutrons
|Maybe
|This fictional form consists of four neutrons, a {{w|tetraneutron}}, with one orbiting around a group of three. The name is likely a reference to an American breakfast cereal called {{w|Cap'n Crunch#Variations|Oops! All Berries}}.

The title text provides three other names of this form: 1. "Neutral Quadrium": Quadrium is an extremely rare isotope of hydrogen with four nucleons, a proton and three neutrons.[https://www.chem.ccu.edu.tw/~hu/Web_Lib/articles/Muonium+H2_Science_2011.pdf][https://www.lenr-canr.org/acrobat/GodesRcontrolled.pdf] The proton and electron have been replaced with neutrons, making a fictional neutral atom. 2. "Nydnonen" is likely a derivation of "hydrogen" with three of its consonants replaced with the letter 'n' so it has four of them representing the four neutrons. 3. "Goth Tritium": All the particles in the depiction are black, resembling typical {{w|gothic fashion}}, and in the same configuration as the particles of tritium.
|}

{{notice2|The Mountain View, California Public Library is hosting an online chat with [[Randall Munroe]] Tuesday, January 31 at 11am Pacific. [https://libraryc.org/mountainviewlibrary/22032 Register here to send your question(s) to the moderators.]|image=Crystal Project Agt announcements.png}} 

==Transcript==
:[Eight drawings of different versions of hydrogen atoms are shown. They are arranged in two rows of four. The depictions use the planetary model version with for instance a negative electron (with a "-" written inside a small circle) orbiting a positive proton (with a "+" written inside a larger circle) and a black neutron depicted as a circle of the same size as the neutron, as in the second atom - Deuterium. Each has a label underneath. Here, they are listed in reading order:]
:[An electron orbiting a proton:]
:Hydrogen

:[An electron orbiting a proton connected with a neutron:]
:Deuterium

:[An electron orbiting a proton connected with two neutrons, so they form a triangle:]
:Tritium

:[An electron orbiting nothing:]
:Ium

:[An electron a proton and a neutron all orbiting on the same circle around nothing. They are placed equidistant from each other forming a large triangle:]
:Wheelium

:[A single neutron:]
:Instant Hydrogen (ready in 15 minutes)

:[An electron orbiting a proton connected with many neutrons, 13 visible with six touching the proton which are in front. Four more are close to those six and mostly shown and then three are only just visible behind the others. Looking closely there are also two smaller dots near the edge indicating at least two more, for 15 that can be seen. And several more would be behind the visible neutrons if this forms a spherical shape. The electrons orbit just barely goes around the outer neutrons:]
:Hydrogen (maximum strength)

:[Four neutrons arranged like the particles in Tritium with a neutron orbiting a triangle of neutrons.]
:Oops, all neutrons

{{comic discussion}}

[[Category:Charts]]
[[Category:Physics]]
[[Category:Chemistry]]

Talk:2716: Game Night Ordering

2022-12-27T01:16:56Z

172.69.134.16: Idea

Should we create a category for comics about game night? It can contain at least this and https://xkcd.com/2486/. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:32, 26 December 2022 (UTC)
:I'm not going to oppose it, but keep in mind that it would overlap with [[:Category:Board games]]. --[[Special:Contributions/172.70.178.48|172.70.178.48]] 22:50, 26 December 2022 (UTC)
::We absolutely need a general [[:Category:Games]] because we have e.g. roleplaying games under Board games. Does anyone know how to edit in a superclass category? The last time I ever did anything sophisticated with Mediawiki categories was like 2008. [[Special:Contributions/172.71.154.38|172.71.154.38]] 23:39, 26 December 2022 (UTC)

The rules would seem to be similar to the card game Cheat (or, at least, the version we used to play). Using an ordinary wholly-dealt pack of cards (for any number of players), it was a "blind bid and discard" game whereby each player has to state "<one to four> <card value>s" (or more than four, with merged packs, each of which might be whole or partial) was going on the discard pile, such that the card value was within one (-1, =, +1, with standard wrapping ...>10>J>Q>K>A>2>...) of the prior stated discard. And ''something'' had to be discarded, whether or not the player could technically do so. The forfeit for not continuing play ''or'' challenging, within a generally acceptable thinking time, was the same for either being successfully challenged (you stated you put down two threes, but on checking the dump pile you discarded two sevens) or for the person who wrongly challenged... to pick up the discard pile and be so much further from the ultimate goal of ending up with zero cards (the first the winner, optionally the second, third, etc to do so to earn further ranks just for the sake of continuing/last-ranking the one who ended up as the only one still with cards). - I presume this game just applies the same penalty (buying the food) to anyone who dithers over whether to challenge anything or 'play their own hand'. There doesn't need to be anything more complicated to it. Unless there's also an 'empty hand' winning state, that I can't discern from the brief discourse given in the comic. But it seems more geared to finding the eventual 'loser' (the one who pays up) than any single beneficiary. [[Special:Contributions/162.158.34.230|162.158.34.230]] 23:17, 26 December 2022 (UTC)
:If there is a link for Cheat you should add it. [[Special:Contributions/172.70.206.150|172.70.206.150]] 23:20, 26 December 2022 (UTC)
::Well, I think there's far too many variations... Though, surprisingly, it does look like {{w|Cheat (game)}} actually describes ''my'' learnt version quite well. But I don't think I see any 'time out' penalties mentioned there, and that was the key part of the "play or challenge, don't dither, or you lose" bit to my (sorry, rather long) description above... [[Special:Contributions/162.158.34.230|162.158.34.230]] 23:27, 26 December 2022 (UTC)
::: Never apologize for verbosity on talk; devote that energy to brevity on main. [[Special:Contributions/172.71.154.156|172.71.154.156]] 23:41, 26 December 2022 (UTC)
::(Plus there's the inverted "loser finder" rather than "winner finder" primary nature of the gameplay. It makes the methodology of play a bit too different.) [[Special:Contributions/162.158.34.231|162.158.34.231]] 23:30, 26 December 2022 (UTC)

We should make a payment service for providing crowdfunded rewards to the best contributors to explanations. [[Special:Contributions/172.69.134.16|172.69.134.16]] 01:16, 27 December 2022 (UTC)

Talk:2709: Solar System Model

2022-12-11T03:44:39Z

172.69.134.16: I'm dumb, please explain the comic in simpler words please.

Like the [https://outerwilds.fandom.com/wiki/Quantum_Moon Quantum Moon] from Outer Wilds. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 06:30, 10 December 2022 (UTC)

The lead sentence needs correcting: ELECTRONS orbit the nucleus, not ATOMS orbit the nucleus
([[User talk:ArtK|talk]]) 08:54, 10 December 2022 (UTC)[[Special:Contributions/172.70.210.49|172.70.210.49]] 08:56, 10 December 2022 (UTC)
:Fixed. —[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&printable=yes printable version] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&action=info page information] | [https://www.explainxkcd.com/wiki/index.php/Special:WhatLinksHere/User:While_False what links there] | [https://www.explainxkcd.com/wiki/index.php?title=Special:RecentChangesLinked&days=30&from=&target=User%3AWhile_False related changes] | [https://www.google.com Google search] | current time: {{CURRENTTIME}}) 09:10, 10 December 2022 (UTC)

Also, the electrons ORBIT, not REVOLVE.
([[User talk:ArtK|talk]]) 09:01, 10 December 2022 (UTC)[[Special:Contributions/172.70.210.49|172.70.210.49]] 09:01, 10 December 2022 (UTC)
: You can fix that yourself? click the edit button and replace it. That's... the whole point of wikis i'm pretty sure. [[Special:Contributions/162.158.79.83|162.158.79.83]] 14:36, 10 December 2022 (UTC)Bumpf

When I first read the comic, I was confused about Randall (Ms. Lenhart) describing quantum orbitals correctly. See, I knew the real history of science, so my brain autocorrected it to read that we used to think ''electrons'' had elliptical orbits. I had to look three times before I even saw the inversion. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 16:28, 10 December 2022 (UTC)

Someone should add something about [https://en.wikipedia.org/wiki/Lyapunov_time Lyapunov time], and how orbits are unpredictable on longer timescales.[[Special:Contributions/162.158.146.175|162.158.146.175]] 16:59, 10 December 2022 (UTC)

([[User:pinkdoesstuff|talk]]) 3:42, 10 December 11 (UTC)
Someone PLEASE explain this to me like I'm five? The explanation confused me :(

2708: Mystery Asterisk Destination

2022-12-09T16:48:16Z

172.69.134.16: /* Explanation */ comma

{{comic
| number = 2708
| date = December 7, 2022
| title = Mystery Asterisk Destination
| image = mystery_asterisk_destination_2x.png
| imagesize = 288x248px
| noexpand = true
| titletext = If you ever see the † dagger symbol with no unmatched footnote, it means the writer is saying the phrase while threatening you with a dagger.
}}

==Explanation==
{{incomplete|Created by a BOT.* Do NOT delete this tag too soon.†}}

This comic pertains to the use of asterisks and other symbols for footnotes or endnotes. It jokes that when an asterisk appears after a word without a corresponding footnote, it refers to this comic. Missing footnotes can be frustrating, and this comic may provide closure for some readers, similar in spirit to [[391: Anti-Mindvirus]], and opposite to the tension created by the unmatched parenthesis in [[859: (]].

The title text jokes that unmatched instances of † (the dagger symbol, also used for footnotes) are threats being made by the author to the reader with a physical dagger. As of this writing, it states "If you ever see the † dagger symbol with no '''''un'''''matched footnote...", forming a double negative. This is likely a typo intended as "...no matching footnote."

An unpaired asterisk or dagger often does not refer to a footnote, and thus does not constitute a mystery. Examples include programming languages and mathematical expressions using asterisks such as for the multiplication operator, or dates of birth and death which are sometimes indicated with an asterisk or dagger respectively.

==Transcript==
:[A blank panel with text at the bottom.]
:'''*'''Whenever you see a mystery asterisk that doesn't have a matching footnote, it points here.

{{comic discussion}}

2708: Mystery Asterisk Destination

2022-12-07T20:15:46Z

172.69.134.16: /* Explanation */ move italics to likely mistake and bold

{{comic
| number = 2708
| date = December 7, 2022
| title = Mystery Asterisk Destination
| image = mystery_asterisk_destination_2x.png
| imagesize = 288x248px
| noexpand = true
| titletext = If you ever see the † dagger symbol with no unmatched footnote, it means the writer is saying the phrase while threatening you with a dagger.
}}

==Explanation==
{{incomplete|Created by a BOT* - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
A little treat from Randall to XKCD readers, offering closure to a situation where none is ordinarily found (along the vein of [[391: Anti-Mindvirus]]). Perhaps to make up for the [[859|unmatched parenthesis he willingly set loose onto the world eleven years ago]].

Any good feelings about this closure are short-lived, however, as the title text then reveals that unmatched instances of † (a dagger; a symbol for a secondary footnote) are in fact threats being made with an actual dagger.

The title text, as of writing, says "If you ever see the † dagger symbol with no '''''un'''''matched footnote[...]", forming a double negative. This may be a typo.

==Transcript==
:[A blank panel with some text at the bottom.]
:'''*'''Whenever you see a mystery asterisk that doesn't have a matching footnote, it points here.

{{comic discussion}}

Talk:2708: Mystery Asterisk Destination

2022-12-07T20:10:02Z

172.69.134.16: better but still

ChatGPT explanation:
: The xkcd comic is a humorous reference to the use of asterisks in written text to indicate a footnote or additional information. In this case, the asterisk in the comic is not accompanied by a corresponding footnote, and instead, the text at the bottom of the panel explains that the asterisk points to this explanation. The joke is that the explanation itself is not particularly useful or illuminating, as it simply states that the asterisk points to this very explanation.
Mediocre at best. Trying again after removing the space after the asterisk from the transcript, and including the title text:
:This xkcd comic is a reference to the use of asterisks and other symbols in footnotes and endnotes to indicate a reference or explanation. In this case, the comic shows a blank panel with a note at the bottom that says "Whenever you see a mystery asterisk that doesn't have a matching footnote, it points here." This is a humorous way of saying that when an asterisk appears in a piece of text without a corresponding footnote, it is pointing to the explanation provided in this comic.

:The title text adds an additional layer of humor by saying that if a writer uses the "dagger" symbol (also known as a "†" symbol) without a corresponding footnote, it means that the writer is threatening the reader with a physical dagger. This is meant to be a tongue-in-cheek joke about the potential dangers of reading footnotes.
Better but still flawed. The prompt prefix I used in front of the transcript was, "Explain the following xkcd comic. The title text should be explained in a separate paragraph.\n\n" [[Special:Contributions/172.69.134.16|172.69.134.16]] 20:10, 7 December 2022 (UTC)

2702: What If 2 Gift Guide

2022-11-27T18:59:56Z

172.69.134.16: /* Explanation */

{{comic
| number = 2702
| date = November 23, 2022
| title = What If 2 Gift Guide
| image = what_if_2_gift_guide_2x.png
| imagesize = 500x878px
| noexpand = true
| titletext = BABIES OR LITERATURE BUT NOT BOTH: Baby shoes
}}

==Explanation==
{{incomplete|Created by an OUT-OF-CONTROL HANDHELD NEUTRINO CYLINDER FOR TEENS. Do NOT delete this tag too soon.}}

[[Randall]] is again promoting his new book, ''[https://xkcd.com/what-if-2/ What if? 2]'', and starts by explaining the kind of recipient who might appreciate it, basically anyone who is into science or anything in the Universe... So basically anyone.

Then he also gives both direct and humorously indirect instructions of how to obtain the book for them, the latter method making a jocular (but not completely wrong) presumption that almost any text-input widget leads to some relevant search-engine result. Also the entire comic is a link to the what if? 2 page on xkcd that he writes the link to in the comic. As always clicking anywhere on the image will take you there (so also if you actually click on the link).

He also suggests some other tongue-in-cheek gift ideas for several other subtypes of gift-receiver. Most of which are, in keeping with the What If ethos, somewhat dangerous or impractical. A number directly reference things previously mentioned or depicted by xkcd.

{| class="wikitable"
|+
|-
! Interest !! Gift Idea !! Explanation
|-
| Engineering || The {{w|International Prototype of the Kilogram|platinum cylinder}} formerly used to identify the kilogram || This is an object of historical relevance of which only six exist, making it a very expensive or illegal gift. With the {{w|2019 redefinition of the SI base units|redefinition of the SI base units}} in 2019, {{w|2019_redefinition_of_the_SI_base_units#Kilogram|the kilogram}} is now defined using only natural constants rather than a physical standard. It took some time before this last SI unit was redefined, 3 years prior to this comic's release. The old prototypes are no longer as important as they were when they were actually used to define the kilogram. But they are still historical artifacts with enormous value, even apart from the value of a kilogram of platinum (about $32 000 at time of writing).
|-
| Biology || The genomes of the scientists who headed the human genome project || The "International Human Genome Sequencing Consortium," as the {{w|Human Genome Project}} team was known, involved scientists from twenty institutions in six countries. In the US, it was initially led by DNA structure co-discoverer {{w|James Watson}} who was succeeded by {{w|Francis Collins}}. In the UK, the project was led by {{w|John Sulston}}. The teams from other countries' institutions were less prominent and performed substantially less work on the initial sequencing. James Watson's genome was sequenced in 2007. The genome of {{w|Craig Venter}}, the CEO of {{w|Celera Genomics}}, was used as the exemplar for Celera’s sequence. While the “race” between Celera and NIH was declared a tie by then-President Clinton, in actuality, Celera had some 85+% coverage while NIH was about 50%.
|-
| Physics || A beam of neutrinos delivered through the earth by the LHC || {{w|Neutrino}}s interact very weakly with other particles, to the point that they almost always pass straight through matter completely unaffected. This means that particle accelerators can send neutrinos to any other point on Earth by aiming the particle beam into the ground, and the neutrinos pass straight through the Earth. This point is referenced in the What-If article "{{what if|73|Lethal Neutrinos}}". The low interactivity of neutrinos would also mean that the recipient would be unable to perceive their gift, making this a poor present for anyone except the small proportion of physics aficionados who already have a neutrino detector on-hand.
|-
| Animals || Surprise wildlife encounter (gift-wrapped box with a bobcat inside) || This is a reference to [https://www.explainxkcd.com/wiki/index.php/Category:Bobcats xkcd's rich history of mailing boxed bobcats to people]. This gift would place the recipient in a perilous situation, and, although definitely a wildlife encounter, is not a good gift.{{Citation needed}}
|-
| Law || A vacation to that area of Idaho where you can commit crimes with impunity due to a court district boundary error || This refers to the "{{w|Zone of Death (Yellowstone)|Zone of Death}}", a 50-square-mile area of Yellowstone National Park that is in the physical boundaries of Idaho, but in the legal jurisdiction of Wyoming. Because a jury in the United States must be composed of residents of the same district ''and'' state in which the crime was committed, but no one lives in this small area of a National Park, anyone who committed a crime here could not (according to a legal theory not fully tested in the courts) receive a trial, and thus could not legally be punished for said crime in any circumstance. This is an interesting legal loophole, but going to this area does not provide any more value than hearing about it, and could scare your law-enthusiast friend.
|-
| Chemistry || A necklace of element samples whose symbols spell out the recipient's name (note: names like "Katherine" and "Brandon" may cause radiation accidents.) || Novelty necklaces are a common and innocuous gift, and using element symbols in place of the same letter is a common gimmick, such as in the title of Breaking Bad. However, making an object out of whatever element sample corresponds to someone's name could have unpredictable results - some elements in their pure form are too brittle or have too low a melting point for such an application, although placing the samples in some kind of small container could work around this problem; some are unsafe. "Katherine" would be made from Potassium (highly reactive), Astatine (rare, '''radioactive''' and has a short half-life), Hydrogen (gaseous at room temperature, flammable), Erbium, Iodine (sublimes into a gas at room temperature), and Neon (gaseous at room temperature). "Brandon" would be made from Boron, Radium ('''radioactive'''), Neodymium, Oxygen (gaseous at room temperature), and Nitrogen (gaseous at room temperature). The problems with element samples could be partially alleviated by allowing compounds rather than pure elements, but the radioactivity would still be a problem, and neon does not form compounds and as such is always gaseous. Additionally, the letters J and Q do not appear in the periodic table symbols, while M does not appear on its own, so a name like John, Quinn, or Mike would be problematic.
|-
| Puzzles || Two goats and a new car || This is a reference to the the "{{w|Monty Hall problem}}", in which a game show contestant can win only one of the three items. (See [[1282: Monty Hall]] for another cartoon inspired by this problem.) This gift places the recipient within a puzzle which is typically discussed hypothetically, rather than happening in real life. Although many people would consider a new car a ''great'' gift, those who would appreciate a gift of a goat are more uncommon.
The problem that the recipient would have would likely be how to transport the two goats - it'd be difficult to fit both into a compact car at once, but one can't be left behind unattended (especially not with [[2348: Boat Puzzle|a cabbage or a wolf]]).
|-
| Technology || Cybiko® wireless handheld computer for teens (2000) || This is a direct callback to [[2699: Feature Comparison|one of the previous week's comics]], which humourously suggested that this device is a better option than most of the current popular communication technologies. While an interesting example of the history of communication technology and coming from a time when experimentation was common and standards were few, it isn't very useful now, because it is no longer supported, has a communication range of 100 meters (sending text messages via radio) and one can only use it to communicate with users of the same device. However, technology enthusiasts could find it interesting as a collectors' item, so by all means it is one of the most plausible gift ideas on this list.
|-
| Space || Webb telescope personal photoshoot || The Webb telescope belongs to NASA, the ESA and the CSA, and is currently very far from Earth. It is designed to capture distant space objects in previously unseen detail. If the photoshoot implies photographing a nearby human, it is not designed to do this, even if the difficulties of sending a human about a million miles to it's location could be overcome. On the other hand, if it means photographing the recipient on the earth's surface, Webb would have to point at the warm Earth and expose its optics to the Sun, permanently crippling the telescope ([https://webb.nasa.gov/content/about/faqs/faqLite.html Which is forbidden by NASA.]) and it would not have sufficient resolution to make out the subject in any case. These circumstances make it a highly impractical gift, to all intents and purposes to the point of impossibility.

On the other hand, a gift experience of being allowed to take your own snapshot of Webb in position, perhaps with a [https://www.dailymail.co.uk/sciencetech/article-10442913/James-Webb-Space-Telescope-seen-Earth-settles-orbit.html robotic telescope], might be an attractive gift to a space enthusiast! So might a chance to use the Webb telescope to take pictures of whatever celestial objects one chooses, as time on the Webb telescope is very carefully allocated.
|-
| Literature || Stephen King's writing desk (he's still using it so you'll have to fight him) || {{w|Stephen King}} is an author lucky enough to have legendary status while still alive. The desk of an author that has died would become an object of historic significance and would likely be either kept for exhibition or auctioned by their respective estate, but as Stephen King is still alive, he would probably object to his desk being subjected to the same.
|-
| Philosophy || Out-of-control trolley || This is another gift that places the recipient in the situations that they like discussing hypothetically. This refers to the {{w|trolley problem}}, which places stress on the person forced to make the decision, and exists to make them examine their morals. Facing someone with the hypothetical problem is already not a good gift, but [https://www.youtube.com/watch?v=1sl5KJ69qiA forcing them to live through it in real life] is a terrible gift. (See [[1455: Trolley Problem]] for another cartoon inspired by this problem.)
|-
| Psychology || A nice gift with a note saying you don't expect anything in return || This is perhaps the most viable option on this list. This kind of gift giving could induce the Benjamin Franklin effect, causing the gift giver to like the recipient more. It could also be used to manipulate the recipient by increasing pressure to reciprocate. This would cause them stress, making it a bad gift, but a psychologist would hopefully understand it to be a joke.
|-
| (Title text) Babies or literature but not both || Baby shoes || This is a reference to the six-word story {{w|For sale: baby shoes, never worn}} which is often attributed to Ernest Hemingway. Someone with babies, such as expecting or new parents would find baby shoes as a valuable gift for their child. Someone interested in literature would see the reference to a famous work. But someone who understands the reference would possibly also be sad if they simultaneously actually enjoyed babies or have children of their own (since the story implies the seller was expecting a baby but there was an accident). So if they are into both then find another gift.
|}

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

What If? 2 Gift Guide

What if? 2 makes a good gift for anyone who's into science, absurd ideas, or just the universe in general. To order, go to xkcd.com/whatif2, or just type "what if 2" into some random box on your device; it will probably work.

Here are some other gift ideas for hard-to-shop-for science enthusiasts:

Interest - Gift Idea

Engineering - The platinum cylinder formerly used to define the kilogram 
Biology - The genomes of the scientists who headed the human genome project 
Physics - A beam of neutrinos delivered through the earth by the LHC 
Animals - Surprise wildlife encounter (gift-wrapped box with a bobcat inside) 
Law - A vacation to that area of Idaho where you can commit crimes with impunity due to a court district boundary error 
Chemistry - A necklace of element samples whose symbols spell out the recipient's name (note: names like "Katherine" and "Brandon" may cause radiation accidents.) 
Puzzles - Two goats and a new car 
Technology - Cybiko® Wireless Handheld Computer for Teens (2000) 
Space - Webb telescope personal photoshoot 
Literature - Stephen King's writing desk (he's still using it so you'll have to fight him) 
Philosophy - Out-of-control trolley 
Psychology - A nice gift with a note saying you don't expect anything in return. 

{{comic discussion}}

[[Category:Book promotion]]
[[Category:Science]]
[[Category:Biology]]
[[Category:Physics]]
[[Category:Animals]]
[[Category:Bobcats]]
[[Category:Chemistry]]
[[Category:Space]]
[[Category:Telescopes]]
[[Category:Photography]]
[[Category:Comics featuring real people]]
[[Category:Psychology]]

2699: Feature Comparison

2022-11-17T01:25:51Z

172.69.134.16: /* Explanation */

{{comic
| number = 2699
| date = November 16, 2022
| title = Feature Comparison
| image = feature_comparison_2x.png
| imagesize = 740x470px
| noexpand = true
| titletext = Below the Web, and the Dark Web, a shadowy parallel world of Cybiko users trade messages on the Translucent Neon Plastic Web.
}}

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

This is comparing different remote communication services.



Mesh Networking is the ability for users to have P2P connections, and talk without a centralized server.
The Cybiko is able to have wireless message delivery because it communicates to other devices via radio hence the ability to operate with any internet connectivity at all.


The “Cybiko® wireless handheld computer for teens (2000)” is described in Wikipedia’s article {{w|Cybiko}}. Additional information about it is available at [http://cultureandcommunication.org/deadmedia/index.php/Cybiko the Dead Media Archive], as the device has not been manufactured since 2003. The Cybiko has two-way communication capabilities along with built-in games and music player capabilities.

The chart suggests that the Cybiko has an advantage over all of the other ten communication services listed, as it has all eight of the features listed in the table, whereas none of the other services under consideration have move than five of the features.

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

:[A table with checkmarks to indicate which features various messaging services have. Each column is labeled with a service name and its logo beneath, except that for the last column, the device's longer name is written higher than all the other services' names, with an arrow pointing to a drawing of the device below it.]

{| class="wikitable"
|-
!
! Twitter
! Discord
! Mastodon
! FB
! Slack
! Signal
! IRC
! Tumblr
! Reddit
! SMS
! Cybiko® wireless handheld computer for teens (2000)
|-
! Direct messages
| ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓
|-
! Group chats
| ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || || ✓ || || ✓
|-
! File transfer
| || ✓ || ✓ || ✓ || ✓ || ✓ || ✓ || || ✓ || || ✓
|-
! Built-in games
| || ✓ || || ✓ || || || || || || || ✓
|-
! User-run instances
| || ✓ || || || ✓ || || ✓ || || ✓ || || ✓
|-
! Doesn't require central server
| || || || || || || ✓ || || || || ✓
|-
! Mesh networking
| || || || || || || || || || || ✓
|-
! Wireless message delivery works without internet
| || || || || || || || || || ✓ || ✓
|-
|}

{{comic discussion}}

1579: Tech Loops

2022-11-16T18:48:25Z

172.69.134.16: /* Description of the boxes */

{{comic
| number = 1579
| date = September 18, 2015
| title = Tech Loops
| image = tech_loops.png
| titletext = And when I think about it, a lot of "things I want to do" are just learning about and discussing new tools for tinkering with the chain.
}}

==Explanation==
The comic is about how much time a geek might spend on a computer just to maintain the system itself, rather than actually using it for something relevant. This can in the worst cases go all the way up to the point where maintaining the system becomes the main goal. Often the operating system (OS) needs periodic updates, which might break some apps which in turn need to be updated; apps themselves might need to be updated, which can create all sort of incompatibilities which the geek then needs to spend time fixing. One term for this is "{{W|dependency hell}}".

Most people consider computers as tools to achieve something else — e.g. to surf the web, play games, read news or balance their bank account — and they would rather not have to spend lots of time on maintaining the OS or the computer if they can avoid it.

Here, however, [[Randall]] finds he's spending most of the time using his computer just for the sake of maintaining the OS or the hardware on said computer. It's tools for the sake of tooling, rather than tools as helpers to build something else.

A hardware equivalent would be the {{w|RepRap Project}}: get a 3D printer and end up spending all the time printing 3D parts for itself instead of creating something else like toys or art.

An alternative interpretation is how a simple task can get maddeningly tricky because of the inherent complexity of the system. An example of this appears in [[949: File Transfer]], where the simple task of sending a file from one computer to another gets practically impossible despite having all kinds of {{w|Cloud computing|cloud}} tools available, many of them designed to perform much more complex tasks with one simple click. In this view, the box labeled "things I actually want to use my computer for" could refer to simple actions like transferring a file and all the rest of the graph are unsuccessful tiring attempts to solve the problem by installing increasingly complex tools which end up not solving the simple problem properly. This is similar to this [http://www.pfccheatsheet.com/fnpgmr90.htm traditional programming joke].

In the title text Randall realizes that what he really wishes to do it often only to learn about and discussing new tools to improve the chain. So in this way it is for sure only a system to support itself. But on the other hand, then the box with things he actually wishes to use the computer for, is then not disconnected from the rest, but an integral part of it all.

Other comics about the same concept are [[349: Success]] and [[763: Workaround]].

==Description of the boxes==
There are 18 boxes in the chart, but only 12 different texts. 16 of the boxes are interconnected. Two are not connected to any other boxes.

Here is a list of all the items explained individually:
*Tool: In this context, a tool is mostly any general purpose computer program. Typical tools are text editors and calendar applications. Randall is presumably spending all his time installing and maintaining tools but never using them for their intended purpose.
**There are two tools which both are related to the updater and both have one entry and one exit. The first tool has an entry from the most active library (most arrows) and the second has an exit to the VM.
*Updater: An application designed to automatically download and install new versions of an already installed program. Referenced in [[1197: All Adobe Updates]]. The time spent in updating an application can't be used to get productive work from the application.
**The updater has one entry from a tool, but also exits to another tool. Two other exits goes to the most active library (most arrows) and to the repository which is the only box without exits.
*{{w|Repository (version control)|Repository}}: For programmers a repository is a database where programs are stored. All modifications of the programs are preserved for posterity, in the same way as the Wikipedia {{w|Help:Page history|View history}} tab.
**There are three entries, but this box has no exits. Thus the information stored here never leaves; this means the programs stored in the repository are not used.
*{{w|Library (computing)|Library}}: In this context, a library is a part of a computer program which is developed separately, with the idea that the library will be used for more than one program and therefore saving effort, as the library has to be developed only once. Often, programs require specific versions of specific libraries that can or can not be available. A typical example of a library often required and not always available is Microsoft's {{w|Framework Class Library}}, more known as {{w|.NET Framework}}.
**There are six libraries. Four of them has one entry and one exit arrow and twice one library exits only to another library. The top left is the most active with two entries and three exits making it the second busiest box in the chart. But most important is the bottom right library that starts everything since this is the only of the interconnected boxes that does not itself have any entry. From this library you can reach all the other connected boxes starting from its only connection: Awful hack from 2009.
*VM: A {{w|Virtual machine}} is a computer program designed to emulate a complete computer. Probably a reference to [[1305: Undocumented Feature]], combined with the next item "Chat client".
**It has two entries as it obviously both need a tool and a hardware workaround to function. It exits to the chat client already mentioned.
*Chat client: an {{w|Online chat}} program, probably a reference to [[1305: Undocumented Feature]], combined with the previous item "VM".
**It has two entries, one from the most active library (most arrows) and one from the already mentioned VM. It exits to the repository which is the only box without exits.
*IRC for some reason: {{w|Internet Relay Chat}}.
**It is connected in a loop (entry and exit) only with Awful hack from 2009.
*Custom settings: Some programs (and especially web sites) assume a fixed setup in the user's computer. Many web pages even state plainly that they are only intended to work in one single browser with some settings enabled. This is a nuisance for users, and it becomes helplessly burdensome when the user must install several programs requiring different settings.
**Is connecting two libraries, exiting to the most active library (most arrows).
*Hardware workaround: Sometimes a problem can be solved by hardware changes. Removing TV tuner or telephone modem cards, changing an USB device from one port to another, opening and closing the CD tray, etc. are operations that, in many cases, have led to solving a problem; most of the time with no one knowing exactly why such an operation should or could have any effect in the computer's behavior.
**Has one entry from the most active library (most arrows) and two exits to VM and Awful hack from 2009
*Awful {{w|Kludge|hack}} from 2009: An example of an awful hack can be found in [[1479: Troubleshooting]]. When an awful hack is necessary, it is often because less awful alternatives do not exist; so awful hacks tend to remain useful for many years. An example can be the 256-character limit in the Windows path for a file, which has been inherited from MS-DOS (way, way before 2009) and is still there up to Windows 10.{{Actual citation needed}}
**This is the most busy box with three entries and three exits. It has an entry from the only box that does not it self have any entries, the bottom right library. Another entry is from the Hardware workaround. It also form a simple entry exit loop with IRC for some reason, that box is not connected to any other boxes. And finally it exits to two libraries. One of these leads to the most active library (most arrows). From this hack all connected boxes can be reached, except the library that only has entry into the hack.
*{{w|Dynamic-link library|DLL}} needed by something: Although "DLL" is a term used by Microsoft Windows, all modern operating systems use dynamic libraries, each with its own name. A dynamic library is a part of a program which is not loaded when the program starts, but rather it's attached "dynamically" to the running process when it is needed. This has the advantage that the dynamic library is not loaded at all if it's not needed, and also several processes which need the same dynamic library can share the same copy in memory.
**This box only leads to two question marks, and not to any of the other items. Modern computers have dozens of DLL files, the actual use of which is not often obvious even to tech-savvy people.
*Things I actually want to use my computer for: All the other stuff is thus only there to make it possible to use the computer for these purposes.
**But this box is not in any way related to all the tools libraries etc. mentioned here above. Which are thus in reality not needed at all.

==The tech loops==
:The flow chart described:
:→ means supports (key)
: 
:Things I actually want to use my computer for [isolated box with no links into or out of, by any of the following]
:
:DLL needed by something → ? [two exits to unknowns]
:
:Library (1) → Awful hack from 2009 →
::Awful hack from 2009 → IRC for some reason → Awful hack from 2009 → (Loop)
::Awful hack from 2009 → Library (2) → Library (3) → Repository
::Awful hack from 2009 → Library (4) → Library (5) → Custom Settings → Library (6) →
:::Library (6) → Chat Client → Repository
:::Library (6) → Hardware Workaround →
::::Hardware Workaround → VM → Chat Client → Repository
::::Hardware Workaround → Awful hack from 2009 → (Loop)
:::Library (6) → Tool (1) → Updater →
::::Updater → Repository
::::Updater → Library (6) → (Loop)
::::Updater → Tool (2) → VM → Chat Client → Repository
:
:(Note the Repository node leads to nowhere)

==Transcript==
:[A flow chart 18 boxes linked (or not) with arrows going in several different directions. At the top is an arrow pointing to the right with text under. The rest of the text in the chart is written inside the boxes.]
:[Under arrow:]
:Supports

:[Going from the top below the tip of the arrow and reading left to right and top to bottom the following text is written in the boxes that all are in some way connected with each other. The number of arrows going in and out of each box is noted behind the text in square brackets as [in, out]:]
:Updater [1, 3]
:Tool [1, 1]
:Tool [1, 1]
:Repository [3, 0]
:Library [1, 1]
:Library [2, 3]
:Library [1, 1]
:Chat Client [2, 1]
:VM [2, 1]
:IRC for some reason [1, 1]
:Custom Settings [1, 1]
:Hardware Workaround [1, 2]
:Library [1, 1]
:Awful hack from 2009 [3, 3]
:Library [1, 1]
:Library [0, 1]

:[The last box in the lower middle is not connected to any other boxes but has two exit arrows pointing to two questionmarks.]
:DLL needed by something [0, 2]
:?
:?

:[Box alone at the top right corner, with no connections:]
:Things I actually want to use my computer for [0, 0]

:[Caption below the panel:]
:Every now and then I realize I'm maintaining a huge chain of technology solely to support itself.

==Trivia==
*In the [http://www.explainxkcd.com/wiki/images/archive/2/2b/20150921141046%21tech_loops.png first version] of this comic is said "soley" instead of "solely" in the caption. This was corrected later on the release day.

{{comic discussion}}
[[Category:Flowcharts]]
[[Category:Programming]]
[[Category:Logic]]
[[Category:Computers]]
[[Category:Philosophy]]

2694: Königsberg

2022-11-05T13:30:24Z

172.69.134.16: /* Explanation */ copyedit

{{comic
| number = 2694
| date = November 4, 2022
| title = Königsberg
| image = konigsberg_2x.png
| imagesize = 448x343px
| noexpand = true
| titletext = At first I thought I would need some gold or something to pay him, but then I realized that it was the 18th century and I could just bring a roll of aluminum foil.
}}

==Explanation==
{{incomplete|Created by a WOLF, TWO GOATS, AND THREE BAGS OF GRAPH NODES. Do NOT delete this tag too soon.}}

[[File:Konigsberg bridges.png|frame|right|{{w|Königsberg}}, Prussia in Euler's time, showing the Pregel river and its seven bridges. The Baltic port city is now Kaliningrad, a Russian exclave. Only five of the bridges remain.[https://goo.gl/maps/ChdBoeQMr3AQPi446] ]]

This comic is about the {{w|Seven Bridges of Königsberg}}, a seminal {{w|graph theory}} problem solved by the famous mathematician {{w|Leonhard Euler}}.[https://www.maa.org/press/periodicals/convergence/leonard-eulers-solution-to-the-konigsberg-bridge-problem] {{w|Graph (discrete mathematics)|Graphs}} are a data structure common in many algorithmic problems in computer science. The problem was to devise a path through the city that would cross each of the seven bridges exactly once, without crossing the river forks any other way. In 1736, Euler proved that there was no such possible path. This result is considered to be the first theorem of graph theory and the first proof in the theory of networks[http://www-personal.umich.edu/~mejn/courses/2004/cscs535/review.pdf] — a subject now generally regarded as a branch of {{w|combinatorics}} — and presaged the development of {{w|topology}}. Combinatorial problems of other types had been considered since antiquity.

[[Cueball]] attempts to cheat on the final exam in his algorithms class by traveling back in time to commission the construction of an eighth bridge before Euler could learn of the problem, allowing a trivial solution that would remove the rationale for further analysis. He hopes that this would alter his present-day timeline in such a way that the test becomes easier because graph theory might never have been developed.

With the addition of the eighth bridge, it's possible to cross each bridge exactly once, starting at the north bank and ending on the central eastern bank, or vice-versa. However, there is still no way to traverse each bridge exactly once and return to the starting point, because the altered graph would have an {{w|Eulerian trail|Euler trail}} but not an Euler cycle. Thus the problem might still have been sufficiently interesting to spark Euler's curiosity. Adding a ninth bridge connecting the north bank to the east island would render the problem completely trivial. Without the seven bridges problem, Euler could have focussed on a different foundation for graph theory, possibly resulting in an even harder examination in Cueball's time.

The title text alludes to the fact that ordinary {{w|aluminum foil}}, which was not commercially available until 1911, would have been a tremendously valuable curiosity in the 18th century, which didn't even have {{w|tin foil}}. Aluminum itself was a highly priced metal before the 1880s, when methods were developed to cheaply refine it. Famously, the {{w|Washington Monument}} was constructed with a tip made of pure aluminum due to its great value and conductive capacity. Aluminum had not even been extracted in its pure form at the time of Euler, and was only known in compounds such as {{w|alum}}, so it would have been unique and exotic.

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

:[Cueball, standing next to two men wearing wigs, pointing with a pointer at a map showing the seven bridges problem, with an extra bridge added in dashed lines]
:Cueball: Lord Mayor of Königsberg, I will reward you handsomely if you construct this bridge before my friend Leonhard arrives.

:[Caption below the panel:]
:I tried to use a time machine to cheat on my algorithms final by preventing graph theory from being invented.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring real people]]
[[Category:Math]]
[[Category:Programming]]