explain xkcd - User contributions [en]

Talk:1245: 10-Day Forecast

2025-04-03T18:19:48Z

Bebidek: Added a comment

You might think Tuesday's image could be anything, even cacti. I did, until I read these comments and zoomed in. Now I think it looks like Jamiroquai's mascot, the guy with the horned helmet. {{unsigned|101.162.84.101}}

Can't believe multi mention of apocalypse but no mention of my first guess (due to -), that place below.
[[User:Monteletourneau|Monteletourneau]] ([[User talk:Monteletourneau|talk]]) 07:00, 1 August 2013 (UTC)

Any possible significance of people seeming having longer legs that usuall on "monday" frame? Also, why should that "tuesday" figure be {{w|antichrist}}? Looks more like {{w|Loki_(comics)|Loki}} to me (although if it SHOULD be Loki he would probably look even more similar). And "sunday" frame looks more like {{w|Bee}}s that {{w|Locust}}, but it's true I never heard of plague of bees :-). (On the other hand, if {{w|Plagues of Egypt|Plague of locusts}} would be referenced, one would expect the other plagues as well.) Also note that if that should reference {{w|Book of Revelation|Christian Apocalypse}}, it should include more horses. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:16, 31 July 2013 (UTC)
:I think the "legs" thing is indicating they're floating up due to the {{w|Rapture}}. --[[User:Druid816|Druid816]] ([[User talk:Druid816|talk]]) 10:26, 31 July 2013 (UTC)
:It's also possible that we're looking at a reference to the Doctor Who episodes "The Impossible Planet" and "The Satan Pit" in which the Tenth Doctor encounters "the devil" on the remnant of a planet orbiting a black hole. If that's the case, we could be looking at some spaghettification on Monday. --[[User:NHBradson|NHBradson]] ([[User talk:NHBradson|talk]]) 16:41, 5 August 2013 (UTC)
I think that we should remove the 'the rapture' explaination because they don't look like the illustrations on Wikipedia which are angels carrying people to heaven and this is people's legs growing very long i.e not the same.[[User:Obscure xkcd reference|Obscure xkcd reference]] ([[User talk:Obscure xkcd reference|talk]])

Also, WHY negative zip codes? -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:53, 31 July 2013 (UTC)
:It may be a reference to [http://tvtropes.org/pmwiki/pmwiki.php/Main/MinusWorld Minus Worlds], implying that the ZIP codes are levels in a video game and the negative ones are glitches, although that's a stretch. [[Special:Contributions/38.108.195.69|38.108.195.69]] 13:41, 31 July 2013 (UTC)

The person in the tuesday picture reminded me of the Rabbit "Frank" from Donnie Darko / S. Darko. --[[Special:Contributions/95.33.125.63|95.33.125.63]] 10:33, 31 July 2013 (UTC)
:If he is, it may mean that negative zip codes are located in a [http://www.donniedarko.org.uk/explanation/ Tangent Universe] --[[User:Danroa|Danroa]] ([[User talk:Danroa|talk]]) 11:02, 31 July 2013 (UTC)
:To me he looks more like Hellboy with horns (in apocalypse mode). His right hand seems to also be larger than his left.[[Special:Contributions/37.130.227.133|37.130.227.133]] 17:02, 5 August 2013 (UTC)

I think that it's actually Megan that says the title text, and not Cueball, mainly because the title text is agreeing with what Cueball said ("Oh, definitely not"). If Cueball were to confirm his own sentence, it wouldn't make sense. {{User:Grep/signature|11:20, 31 July 2013}}

Isn't Sunday a plague of flies? And, judging by the curvature of the earth (I assume) on Tuesday One, wouldn't the character be the size of Galactus? With horns like Galactus? I think it makes sense that it's Galactus. And Monday is just a weird day, just like in my zip code. [[Special:Contributions/67.60.145.86|67.60.145.86]] 13:36, 31 July 2013 (UTC)

: I assume he's just standing on a hill.[[Special:Contributions/153.31.113.20|153.31.113.20]] 18:53, 31 July 2013 (UTC)

What's a zip code? [[Special:Contributions/80.2.179.200|80.2.179.200]] 14:15, 31 July 2013 (UTC)
: Seriously? See {{w|ZIP code}}. [[User:Wwoods|Wwoods]] ([[User talk:Wwoods|talk]]) 15:09, 31 July 2013 (UTC)
:: Not so off-the-wall. The zip code is an American-only thing. Might be worth a mention for non-American readers. [[User:Vyzen|Vyzen]] ([[User talk:Vyzen|talk]]) 16:21, 31 July 2013 (UTC)
:::Strongly disagree with that statement. I live in Israel and we have and use zip codes. [[Special:Contributions/95.35.56.169|95.35.56.169]] 17:42, 31 July 2013 (UTC)
::::Well, here in the UK we use {{w|Postcodes_in_the_United_Kingdom|Postcodes}} that are alphanumeric in nature but pretty much have the same purpose behind them. Although thanks to US imports on TV/films I think most people know that the US call theirs ZIP Codes, even if not that it's a simple number (like I believe most of European postcodes are). However, it doesn't harm to give the link referencing it (as has been done) for anyone who really doesn't know or just appreciates a push towards a bit of [[214|Wikicreep]]. (Which I've just self-inflicted on myself by reading down the Postcode article... Forsooth! Hoist by my own {{w|petard}}!) [[Special:Contributions/178.98.215.19|178.98.215.19]] 19:19, 31 July 2013 (UTC)
:::::Uhhh, your Postcodes are a horror for programmers, just because the length vary. The first official implementation for this was during {{w|WWII}} in Germany, the UK did implement this in the range of 1959-1974, and the US did start this system in 1963. But there are still many countries not using this system (like Ireland), which is just a double horror for programmers.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:18, 31 July 2013 (UTC)
::::::Start with "m/(\w+) (\w+)/" and then subdivide into branches according to $1's further matching? At each stage checked for more specific validity (and even existence!). If not that, "m/[A..Z]{1,2}\d{1,2}[A..Z]? \d[A..Z]{2}/i" should work if you want just a single test (with ()s around elements for the geographic validation checking part). Ok, so it's not "\d{howevermany}", then check it exists on the database, but it'd do for starters, and personally I relish such programming challenges... ;) [[Special:Contributions/178.98.215.19|178.98.215.19]] 11:36, 1 August 2013 (UTC)
::::Jumping in late, but it would be very odd for Israel to use ZIP codes, which are a US Government program (the Zone Improvement Program=ZIP) program. Maybe Israelis who speak American English use the acronym, but I doubt it's the official name. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 13:26, 22 November 2021 (UTC)

:Something like "YKK". [[Special:Contributions/121.72.110.10|121.72.110.10]] 23:30, 31 July 2013 (UTC)

Doesn't the Monday guy sort of look like ''{{w|The Scream}}''?
[[User:Wwoods|Wwoods]] ([[User talk:Wwoods|talk]]) 15:09, 31 July 2013 (UTC)

Did anyone else try to put in a negative zipcode because of this? I think Google should use this as one of the easter eggs they're so fond of. [[Special:Contributions/138.162.8.57|138.162.8.57]] 16:14, 31 July 2013 (UTC)
: at weather.com a negative ZIP code gets you a "can't find" type result with Cancun, Mazatlan and Amsterdam offered as suggestions for where you were interested in. (I tried ZIPs from 10012 to 98072, same result for all I tried). Google Maps just ignores the negative and gives correct results. [[Special:Contributions/67.51.59.66|67.51.59.66]] 17:48, 31 July 2013 (UTC)

Does anyone agree that Randall is playing with the fact that 10day forecast are very inaccurate. We can trust 3, max 4 days of accuracy. After that, is pretty meaningless since the divergence of the models is a likely scenario. No?[[User:Claudionico|cinico]] ([[User talk:Claudionico|talk]])
: Agree [[Special:Contributions/153.31.113.20|153.31.113.20]] 18:53, 31 July 2013 (UTC)
: I often say that the "five day forecast" is fiction after two days. --[[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 19:17, 31 July 2013 (UTC)

The forecast shows much more than expected from a normal "weather forecast". I like that. Sebastian --[[Special:Contributions/178.26.118.249|178.26.118.249]] 19:34, 31 July 2013 (UTC)

What happens to time, when the world ends? It is a 10-day-forecast. That coincides with 10 image frames. We have the days of the week at the bottom of the frames, which are an independent scale, because there is more than one frame for Tuesday. Interpretation/Assumption: 10 days (the forecast) is subjective for the people being in each location (here: ZIP code). Days of week and generally dates are a global reference time. So in these hells time locally stretches for eternity and this day will never end. But from an outside view time goes on normally.
Megan says they are all like that. That does not sound like it would be a special occasion to be there, when the world ends, or having found a ZIP number, where the world ends some days from now. Possible solution: Like a function with several poles the world could end at every location with negative ZIP about every week. Sebastian --[[Special:Contributions/178.26.118.249|178.26.118.249]] 19:49, 31 July 2013 (UTC)

:The fact that the "negative ZIP" universe ends while the normal one keeps going, points again to my theory (above) that this is a reference to Donnie Darko, Frank the rabbit (not the antichrist), and where negative ZIPs are for [http://www.donniedarko.org.uk/explanation/ Tangent Universes]. However I'm not a Donnie Darko expert (I think I started to understand it now reading that website, and the one time I watched it was in theaters...) and I'm not able to provide a theory for the bees/locusts... --[[User:Danroa|Danroa]] ([[User talk:Danroa|talk]]) 12:47, 1 August 2013 (UTC)

What about negative people, or negative areas where everyone is negative. Doom and Gloom, end of the world type of deal. Seems like a lot of negative people are always talking about the end of the world, and that negative zip code and what's occurring sounds exactly like how the end of the world is pictured. She says all negative zip codes are like that.{{unsigned|Glitch}}

Do certain zip codes not have Amazon Prime? [[User:Bugefun|Bugefun]] ([[User talk:Bugefun|talk]]) 01:45, 1 August 2013 (UTC)
: From the [http://www.amazon.com/gp/help/customer/display.html/?nodeId=201118050 website]: Nearly all addresses in the continental U.S. are eligible. Explicitly excluded are Alaska, Hawaii, Puerto Rico, P.O. Boxes, APO/FPO addresses. [[User:Odysseus654|Odysseus654]] ([[User talk:Odysseus654|talk]]) 03:19, 1 August 2013 (UTC)
:Amazon needs to add "Negative ZIP codes excluded" on that page. --13:59, 1 August 2013 (UTC)

"Megan, however, assumes that the negative zip code represents an actual geographical location, and that the weather forecaster is showing an accurate forecast for the area. She further states that, since all negative zip codes produce similar forecasts, that all negative zip codes represent actual geographical locations for which the weather is like that."
: I think that's reading too much in the comic; I wouldn't say she's making such an assumption. [[Special:Contributions/84.197.94.196|84.197.94.196]] 21:11, 1 August 2013 (UTC)

Is it necessarily a reference to the rapture? I mean, it seems to me that it could be poking fun at the twilight zone, or maybe parodying horror in general. --[[User:AlixeTiir|the amazing alixetiir]] ([[User talk:AlixeTiir|talk]]) 03:18, 2 August 2013 (UTC)

Is it just me or can you kinda see a demonic face with horns in the static for the second "Tuesday"? --[[Special:Contributions/208.84.194.188|208.84.194.188]] 03:24, 2 August 2013 (UTC)

:That's probably just {{w|Pareidolia|Pareidolia}}. --[[User:AlixeTiir|the amazing alixetiir]] ([[User talk:AlixeTiir|talk]]) 03:59, 2 August 2013 (UTC)

It might be related to something someone said above, about long-term forecasts being inaccurate, the impossible nature of the integer (entered in the zip code) might cause the prediction function to go wild. This inaccurate forecast theory would be supported by how the first few days appear normal, where as the further it goes, the crazier it gets. My rendition of the comic would be that when entering a negative zip code, being an impossible value, it would render a prediction for a chaos-filled world. No end-of-the-world, no Antichrist, just pure chaos. Think of being present in a day where such a massive lightning-filled lightning storm goes on (zapping the ground every few moments), followed by a day where hoards of bees come by in masses, followed by some impossible to imagine occurrence that causes people to be so deformed (as far as you can tell, the could be deformed like that all the time in the chaotic universe). Then the day after some mysterious creature shows on the horizon, like in a horror film... I think this is supported by the Monday and (fire) Tuesday panels showing a bit too specific scenarios, as if someone took pictures of the occurrences.
But I do come to think it's either the prediction function going haywire the further it gets, or that Minus World thing [[Special:Contributions/38.108.195.69|38.108.195.69]] mentioned (which isn't very far-fetched). After all, Randall knows his computing and maths and it would be assumed he simply made references to such instances of giving a function wrong input and receiving a crazily unpredictable output. [[Special:Contributions/79.179.106.35|79.179.106.35]] 08:34, 2 August 2013 (UTC)

The person on the second Tuesday is supposed to be the Antichrist? I thought it was just a girl with really long pigtails like some kind of Pipi Long-stocking sort of thing where they have a mind of their own or something. I also thought the gravity was just turned off on Monday. I had the feeling There was some kind of apocalypse thing going on though.[[Special:Contributions/72.193.171.120|72.193.171.120]] 08:05, 4 August 2013 (UTC)

The hover text mentioning "...they don't have Amazon Prime" is probably a comedic extrapolation that, since there are no negative prime numbers, there couldn't be an Amazon Prime in a negative zip code. [[Special:Contributions/24.217.105.50|24.217.105.50]] 05:49, 5 August 2013 (UTC)
: A negative prime number is just ðe oppoſite of a prime hth. Oðerwise, ðe fact ðat -2*-1 = 2 becomes a problem. Unleſs you just ignore negatives entirely, whiĉ is ðe reaſonable approaĉ. [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 01:59, 14 September 2016 (UTC)

Personaly i see one of the angels from evangelion on earth surface into the Tuesday box. Not seeing this obvious référence in this thread make me write amoung far more clever comentaries...{{unsigned|82.245.232.105}}

At least in part, this is a Jurassic Park reference. In the book, they discuss how the origin of chaos theory began with the inability to predict weather beyond three days. Given that the weather gets crazy after three days, this just makes sense!{{unsigned ip|75.75.1.95}}

IMO the Tuesday guy is obviously HellBoy in his stick-man form as the world is destroyed. I do not see his crown however.--[[Special:Contributions/108.162.219.18|108.162.219.18]] 20:45, 21 May 2014 (UTC)

I þink it'd be beſt to rewrite ðis article wiþout ſtatiŋ ðat it's probably juſt a prank by ðe programmers- it defeats ðe humor too muĉ, and it'd be more entertainiŋ(/horrifyiŋ) if it is properly interpreted to be a correct forecaſt, just of ðe wrong place. Beſides, xkcd has ʃown us ðat its world is a bit more bizarre and ſupernatural ðan ours on /more/ ðan one occaʒon; haviŋ a world where weaðer is simple, predictable, ðere aren't ſwarms of fleʃ-mites, water (I aſſume ðat's just normal O^2H) falls from ðe sky, and days don't repeat after cataſtrofic occurrences like ðe recent Siksþ Return in Hexadectober 1443+194i [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 01:59, 14 September 2016 (UTC)
:What??? [[Special:Contributions/162.158.214.58|162.158.214.58]] 17:51, 18 July 2017 (UTC)
:: Allow me to try a quick translation of whatever [[User:Hppavilion1|Hppavilion1]] is talking about: "I think it'd be best to rewrite this article without stating that it's just a prank by the programmers, it defeats the humor too much and it'd be more entertaining/horrifying if it is properly interpreted to be a correct forecast just of the wrong place. Besides, xkcd has shown us that its world is a bit more bizarre and supernatural than ours on more (emphasized) than one occasion; having a world where weather is simple, there aren't swarms of flesh-mites, water (I assume that's just normal H20) falls from the sky and days don't repeat after catastrophic occurences like the recent ???? Return in Hexadectober" no idea what a Siksb is nor why he believes there is a sixteenth month--[[User:Lackadaisical|Lackadaisical]] ([[User talk:Lackadaisical|talk]]) 18:38, 18 July 2017 (UTC)

Jeez this comic is kind of scary, actually. [[Special:Contributions/172.70.189.134|172.70.189.134]] 03:27, 22 October 2022 (UTC)

The negative ZIP code might not be Cueball's mistake, but the result of system expecting American notation. No one said that the comic happens in the US. Some countries (e.g. Poland) use notation with hyphen, like 31-324. If the system is worldwide, but its creator didn't take this into account, and the system for some reason interprets entered code as mathematical expression (which is alarming itself), a valid Polish code may become a negative number. Alternatively, this might happen in the US, but Cueball is not American and is used to different notation. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 18:19, 3 April 2025 (UTC)

== What is Monday ==

Monday doesn't seem like the rapture to me.[[Special:Contributions/172.68.189.139|172.68.189.139]] 18:32, 18 November 2019 (UTC)

Agreed. I can't really explain the panel, though, besides "weird giant creatures". They look like they're in pain, maybe? Qoiuoiuoiu (talk) 00:18, 9 June 2022 (UTC)

Also agreed. Monday seem less like "Rapture" and more like "Time/space warping or possible spaghettification" to me.

== Table ==

We need a table explaining the days [[User:MysticalMHM1|MysticalMHM1]] ([[User talk:MysticalMHM1|talk]]) 20:55, 10 May 2022 (UTC)

Talk:2183: Icon Swap

2025-03-30T20:41:30Z

Bebidek: Added a comment

Re: hovertext: That's a really brilliant marketing campaign, right there... {{unsigned|162.158.126.46}}

I'm not sure if it would have any marketing effect, but it definitely sounds as good idea. It doesn't need to be that clever at first either - just posting random sentence from next page is not that likely to be interesting, but even with 2% of success it would help a lot. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:07, 31 July 2019 (UTC)

I wouldn't be very surprised to see a book where each chapter actually started with a breaking news story.
The reader would generally be following the protagonist around, but the articles would show what the rest of the world knows and so either show that something the reader knows is not widely known, or fill the reader in on events that are part of the plot, but where the protagonist was not present.
[[User:Baldrickk|Baldrickk]] ([[User talk:Baldrickk|talk]]) 09:35, 1 August 2019 (UTC)

Here's an idea. What if there was no "book" at all, but the story was pushed to your device in real-time coinciding with the unfolding of the plot. The push could happen either night or day depending on what is going on in the story. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 12:57, 1 August 2019 (UTC)

https://knowyourmeme.com/memes/twitter-reenactments?full=1

That’s a series of apps named Lifeline.

I wonder whether I could do a similar thing, but with redirecting "xkcd.com" address to the ebook site... [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 20:41, 30 March 2025 (UTC)

Talk:217: e to the pi Minus pi

2025-01-21T18:55:39Z

Bebidek: Added comment about the situation being unlikely

Asserting that the programmers' algorithms truncated to three decimal digits is an unsupported and unnecessary extrapolation. Most floating-point implementations use binary, not decimal, and 19.999099979 ''looks'' very much like a rounding error in binary floating-point that has accumulated over several operations. [[User:Daddy|Daddy]] ([[User talk:Daddy|talk]]) 12:39, 29 April 2013 (UTC)
:Fixed. [[User:Xhfz|Xhfz]] ([[User talk:Xhfz|talk]]) 22:57, 16 August 2013 (UTC)

The "not good at math" might be too harsh, if they've (tried to) read the floating point spec. Depending on precision and rounding regime and order of operations, I could easily imagine the "equation" to be true ... and therefore a test that you were rounding "properly", even when it wasn't intuitive.

The third bullet-point above needs changing... (9^2+(19^2/22))=97.4090909091 which is close to pi to the fourth power, so it should be (as noted in the text) (9^2+(19^2/22))^1/4 [[User:Squirreltape|Squirreltape]] ([[User talk:Squirreltape|talk]]) 19:27, 25 February 2014 (UTC)
:Actually, in-case you didn't notice, it says "∜(9² + 19²/22)", not just the sum on its own. I checked the sum on my calculator, and it is equal to what the page is saying. "∜(9² + 19²/22)" means "4th root of (9^2+19^2/22)" (What the title text is saying), or on Windows Calculator, "(9^2+19^2/22) yroot(4)" (Basically what the sum is saying). So, the 3rd bullet point is correct. --[[User:Katavschi|Katavschi]] ([[User talk:Katavschi|talk]]) 22:48, 23 April 2014 (UTC)

It says above that (π + 20)^i ≈ -i, but this should be (π + 20)^i ≈ -1. Proof: π + 20 ≈ e^π => (π + 20)^i ≈ (e^π)^i = e^(πi) = -1.

The ACM competitions are famous for being under tight time pressure. Making your own team waste time would absolutely get you kicked out (and make enemies) [[User:Danshoham|Mountain Hikes]] ([[User talk:Danshoham|talk]]) 04:40, 23 September 2015 (UTC)

One thing seems odd: during contests like ICPC, you usually don't (read: practically never) implement 'floating-point handlers' by yourself. In fact, you rarely need to use floating-point at all, but if you do, you use ready-made and well-tested implementation built into the language/processor. So, while it is possible that they would need their own implementation, I consider it really unlikely. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 18:55, 21 January 2025 (UTC)

;"If they thought about the mathematics"

hm, are you saying it is obvious that e^ pi - pi is not 20? How would you know without approximating it? The sum of two irrationals is not necessarily irrational. [[Special:Contributions/162.158.34.194|162.158.34.194]] 01:58, 26 October 2015 (UTC)
:approximate e^pi using slightly bigger numbers than e and pi (say e: 2.7183 and pi: 3.1416) and subtract a value that is slightly smaller than pi (say 3.1415). The result is less than 20 and a upper limit for e^pi - pi [[Special:Contributions/141.101.93.49|141.101.93.49]] 19:59, 22 August 2016 (UTC)

the title text was close; the real identity is e^(π - 2) = π [[Special:Contributions/173.245.52.165|173.245.52.165]] 05:39, 7 April 2021 (UTC)

The approximation in the title text(the first quantity) is an approximation provided by Ramanujan. [[User:Sarah the Pie(yes, the food)|Sarah the Pie(yes, the food)]] ([[User talk:Sarah the Pie(yes, the food)|talk]]) 21:09, 22 February 2022 (UTC)

== Not a coincidence ==

In the "Explanation" section, it says that "the title text pokes fun at ''another'' coincidence". This implies that what came before was a coincidence (without ever actually explicitly saying so). As already mentioned in the trivia section, this was indeed what was believed when the comic was published, but it is no longer true (an explanation for eπ − π ≈ 20 was found in 2023; it is a simple consequence of π ≈ 22/7). The text should be updated accordingly. Relevant discussion about this can be found on {{w|Talk:Mathematical_coincidence#Explaining_e^%CF%80_%E2%88%92_%CF%80_%E2%89%88_20|this Wikipedia talk page}}, [https://pastebin.com/VzqPG5Gk here], and in the update eventually made to the [https://mathworld.wolfram.com/AlmostInteger.html Mathworld website] (the original source for much of this article). [[Special:Contributions/172.71.250.8|172.71.250.8]] 13:57, 22 April 2024 (UTC)
:That there is some (quite complicated) derivation of eπ − π ≈ 20 is neat, but that doesn't make it 'not a coincidence'. The fact that π ≈ 22/7 is also a coincidence anyway. [[Special:Contributions/162.158.74.118|162.158.74.118]] 19:03, 22 November 2024 (UTC)

Talk:3026: Linear Sort

2024-12-18T16:35:07Z

Bebidek: Added comment about Timsort.

First in linear time![[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 13:28, 18 December 2024 (UTC)

Due to the fact that O(nlog(n)) outgrows O(n), the Linear Sort is not actually linear. [[Special:Contributions/162.158.174.227|162.158.174.227]] 14:21, 18 December 2024 (UTC)
:If your sleep() function can handle negative arguments "correctly", then I guess it could work. [[Special:Contributions/162.158.91.91|162.158.91.91]] 16:27, 18 December 2024 (UTC)

That was fast... [[User:CalibansCreations|'''Caliban''']] ([[User talk:CalibansCreations|talk]]) 15:35, 18 December 2024 (UTC)

Do I even want to know what Randall's thinking nowadays? [[User:Definitely Bill Cipher|⯅A dream demon⯅]] ([[User talk:Definitely Bill Cipher|talk]]) 16:02, 18 December 2024 (UTC)

The title text would be more correct if Randall used e.g. Timsort instead of Mergesort. They both have the same worst-case complexity O(n*log(n)), but the former is linear if the list was already in order, so best-case complexity is O(n). Mergesort COULD also be implemented this way, but its standard version is never linear. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 16:35, 18 December 2024 (UTC)

3026: Linear Sort

2024-12-18T16:21:24Z

Bebidek: Mentioned about BogoSort + corrected typo.

{{comic
| number = 3026
| date = December 18, 2024
| title = Linear Sort
| image = linear_sort_2x.png
| imagesize = 385x181px
| noexpand = true
| titletext = The best case is O(n), and the worst case is that someone checks why.
}}

==Explanation==
{{incomplete|Created in Θ(N) TIME by an iterative Insertion Sorter working on a multidimensional array - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
A common task in programming is to sort a list, a list being a collection of related elements of data that are stored in a linear fashion. There are dozens of algorithms that have been created through the years, from simple to complex, and each has its own merits with regards to how easy it is to understand / implement vs. how efficiently it operates on the data.

The efficiency of an algorithm is measured in terms of O(), commonly referred to as "Big-O", which classifies the amount of time needed to execute the algorithm with respect to the size of the data. Specifically, the Big-O assignment describes the change in execution time when the size of the data set changes (typically, when it doubles). There are various measures of efficiency, such as:
<ul><li>O(1) - Constant, which means the execution time is independent of the size of the data</li>
<li>O(n) - Linear, which means the execution time varies in direct proportion to the size of the data</li>
<li>O(n log n) - "n log n", usually assigned to the fastest sorting algorithms</li>
<li>O(n2) - Quadratic", meaning the execution time is proportional to the square of the size of the data.</li></ul>
It can be proven that the best general-purpose sorting methods are "n log n". Thus, a sorting algorithm in linear time does not actually exist.

In computer science, the complexity of a problem can be described using {{w|Big O Notation}}. Operations generally take longer when they act on more elements (notated as "n"). A linear algorithm would be very simple: each element would take a short amount of time on its own, so the time it takes would be a multiple of the size of the list. For instance, if it takes one second to look at a picture, it would take ten seconds to look at ten pictures. So "look at a list of pictures" is a linear operation and would be described as having complexity O(n).

Sorting is more complex. The time it takes to sort a list of items grows quickly as you add more items to the list. The complexity of sorting algorithms generally ranges from O(n^2) to O(n*log n). For example, one way to sort is to look at all the values to find the first item, then look at all the values to find the second item, and so on until you've positioned every item in the right place. If "looking at a number" takes one second, then you could sort a list of 2 numbers in 4 seconds: look at both numbers, then look at them a second time. Sorting 3 numbers would take 9 seconds: look at all 3 numbers 3 times to find the right position. Sorting a deck of cards this way would take 52*52 seconds = about 45 minutes. You can probably read a card more quickly than that, but the point is that the amount of time it takes to sort a list grows faster the more items you are looking at. This is not the most efficient way to sort, but it gets the job done.

The 'linear' sort here uses the less efficient {{w|merge sort}} rather than linear taking linearithmic, or O(n * log n) time. It does not matter, however, because it `sleep()`s for 1e6 (1 million) seconds per item in the list by sleeping for that length of time minus the time it actually took -- converting it by brute force to linear time that is so slow that it will not overcome the O(n * log n) term for large datasets. It's linear because it's guaranteed to take a million seconds for every element in the list (regardless of how long that actual sort really took); double the list size doubles the number of millions of seconds it takes. No matter how inefficient the actual sort method is, it is very unlikely it would take longer than a million seconds per element (unless some super inefficient algorithm is used, e.g. BogoSort). It should be noted that for sufficiently large lists, Mergesort will take longer than the 1e6 seconds, at which point the sorting algorithm will stop being linear anyway. However, this issue will only arise at impractically huge lists.

The title text refers to the {{w|Best, worst and average case|best and worst case}} of the sort. The joke is that by making the "best case" linear so bad that it is worse than the worst case, the real best case is someone just trusting that a "linear sort" is best and not questioning why it's so slow. The worst case now is someone investigating how it's possible a sort could be taking a million seconds per element and discovering the deception in the code.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[The panel shows five lines of code:]
:function LinearSort(list):
::StartTime=Time()
::MergeSort(list)
::Sleep(1e6*length(list)-(Time()-StartTime))
::return

:[Caption below the panel:]
:How to sort a list in linear time

{{comic discussion}}

[[Category:Programming]]

Talk:1373: Screenshot

2024-12-04T03:08:55Z

Bebidek: Adding a comment about Android plugin.

Guys I feel so strange right now, I woke up thinking "My battery is low, I need a charger but wait ... A new xkcd comic!" I have uploaded my screenshot : http://imgur.com/kjK1S1B
[[Special:Contributions/108.162.219.54|108.162.219.54]] 09:45, 26 May 2014 (UTC)bluelightzero
:I plugged in my phone but it's not charging??! http://imgur.com/xCaPvxX --[[Special:Contributions/108.162.215.65|108.162.215.65]] 22:00, 27 May 2014 (UTC)
Because I can:
http://i.imgur.com/2ezU88G.png
[[User:International Space Station|International Space Station]] ([[User talk:International Space Station|talk]]) 17:26, 19 April 2016 (UTC)

That subreddit made me feel dirty. And all this after seeing some long "friendzone" rants on Imgur. [[Special:Contributions/108.162.237.218|108.162.237.218]] 10:10, 26 May 2014 (UTC)

For completeness: http://imgur.com/YLNKqlC
15:53, 26 May 2014 (UTC) {{unsigned ip|173.245.54.12}}

Although I personally prefer Android phones for their OS flexibility, I don't think the "Android has longer battery life than iPhone" comment is needed in the explanation. It feels very opinionated, out of place and dubious (battery life essentially depends on usage.) That comment distracts from the main point of the comics. The comment the screenshot is of an iPhone and the phone itself is an Android is quite relevant since both status bars are vastly different (something that a casual reader might not realize), yet the phone owner is still confused by the screenshot's battery icon. If someone wants to reword that in the description better than I could do, please help yourself. [[User:Ralfoide|Ralfoide]] ([[User talk:Ralfoide|talk]]) 17:56, 26 May 2014 (UTC)
:The iPhone vs Android jab in the explanation was totally trolling, lame. Android phones as a rule have much inferior battery life to iPhone over the span of the day - and the reason for that are design decisions in making of iOS vs Android. For example iOS is total nazi in not allowing background processes to run (spare ones actively playing music or GPS, plus limited time downloads). On Android OTOH, apps relish attaching themselves to the many system hooks, to be launched/notified on changes - so as practical matter you always have Maps, Play store, Google Play Services and user apps leeching on the battery. Android has advantages over iOS (there are many thing you can do that are verboten in iOS) - but battery life, as well as privacy control are not one of them. Please let the explanation be w/o getting into platform war - it is about being OCD, not mobile OSes. {{unsigned ip|199.27.128.167}}

I don't think that's what "photobomb" means. [[Special:Contributions/108.162.218.107|108.162.218.107]] 20:14, 26 May 2014 (UTC)

:I disagree. I found the usage quite ingenious. [[Special:Contributions/188.114.99.189|188.114.99.189]] 04:20, 13 November 2015 (UTC)

My read on this is he's distracted from the call for help, "Help, my battery won't charge! See!", because the attached image shows a low battery, killing his respect for the sender. Maybe that's just me. [[Special:Contributions/108.162.221.51|108.162.221.51]] 23:13, 26 May 2014 (UTC)
:I agree; I interpreted the title text as the message that someone is trying to send to Randall. [[User:Diszy|Diszy]] ([[User talk:Diszy|talk]]) 05:27, 27 May 2014 (UTC)

Some of the reason for this is the android sdk is used to create these screenshots.
The sdk contains some virtual machines and these have the battery detect as being low.
This seems to be done on purpose as you could query the charge of your phone in an app and having this set to in the middle makes it easier to test your app.
It is much easier to take a photo with the sdk than to use real hardware as phones will be different and you will have other applications running that you don't want to be included in the screen shot.
[[Special:Contributions/108.162.249.224|108.162.249.224]] 03:38, 27 May 2014 (UTC)
: …except it isn’t! iPhones don’t get to use the Android SDK, and they have screenshot functionality since day one. Modern Android phones also have that capability. And no, making screenshots on the VMs is not easier: the SDK requires proficiency with Android, computers in general and much more; you can’t have the texts that you want to have a screenshot of on the VM; it’s generally slow and worthless. Such screenshots are created with physical phones, of people too lazy to charge their phones. —Chris Warrick/[[Special:Contributions/141.101.88.216|141.101.88.216]] 15:43, 27 May 2014 (UTC)

Why is this still incomplete? [[User:MrGameZone|0100011101100001011011010110010101011010011011110110111001100101]] ([[User talk:MrGameZone|talk page]]) 08:38, 10 June 2014 (UTC)
:The "First draft" reason is removed. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:24, 10 June 2014 (UTC)
Wait... why is my battery so low?[[Special:Contributions/162.158.79.119|162.158.79.119]] 17:32, 26 March 2017 (UTC)

Great. Now I can't help thinking about a hypothetical, dumb Android plugin "fixing" the issue from the tittle text. It would detect such screenshots in your library and try to "charge their batteries" using power from an actual (host) smartphone battery. To be exact, it would waste some power (e.g. by doing lots of unnecessary calculations in background) while slowly modifying the photos, increasing their battery readings, until they're not full. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 03:08, 4 December 2024 (UTC)

Talk:230: Hamiltonian

2024-12-04T02:17:31Z

Bebidek: Added comment about likely peer reaction.

I don't agree with the title's explanation. IMO the title refers to the fact the "sudden rush of perspective" happens to Cueball also when he is making love, but starts to think about the algorithms. {{unsigned ip|‎37.128.6.132}}

Fixed. [[User:Tenrek|Tenrek]] ([[User talk:Tenrek|talk]]) 08:56, 1 January 2014 (UTC)

When in math class, he walks out, likely offending his peers, because his mind is occupied with thoughts of love. When making love, he offends his partner because his mind is occupied with math. Some perspective! [[User:Danshoham|Mountain Hikes]] ([[User talk:Danshoham|talk]]) 01:28, 25 September 2015 (UTC)
:"... offending his peers"? This comic appears to happen in an academic environment (judging by the topics involved). Maybe the teacher would get offended (it depends on person) but not his classmates. They would probably be somewhat between confused and laughing (the situation has a great inside meme potential...), maybe also concerned (especially if their teacher was known to be serious about such things), but surely (at least according to my college experience) not offended. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 02:17, 4 December 2024 (UTC)

I always thought that the talk about the algorithm providing an "optimal result in all cases" was the reason Cueball left - he decided to apply the algo to his life somehow in a way that he would always find a positive outcome, such as love. That also made the end panel funnier for me because as he found a flaw in the algorithm, he self-fulfilled it by interrupting his romance, thus ruining the "optimal path in all cases". Could be wrong here... [[Special:Contributions/108.162.237.254|108.162.237.254]] 03:54, 2 April 2016 (UTC)

There's an anecdote about the mathematician Carl Friedrich Gauß, who is said to have jumped out of the bed in the middle of his wedding night, to write down some proof he just found... [[Special:Contributions/162.158.203.144|162.158.203.144]] 19:39, 29 April 2016 (UTC)

Talk:356: Nerd Sniping

2024-12-04T00:59:20Z

Bebidek: Putting in question whether the physicist was killed.

Just because the problem contains an infinite series (or parallel) doesn't mean that it's unsolvable. It's tricky, certainly, and getting the "true" answer involves some rather heavy math, but it's not impossible. Indeed, Google shows that it's already been answered. [[Special:Contributions/76.122.5.96|76.122.5.96]] 20:42, 20 September 2012 (UTC)

I've always had an issue with this problem for one simple reason. In an infinite set of resistors, there is no space to apply a charge, thus there is no resistance. Ohm's law states Resistance = Voltage / I(current). So, in a system where there is no current (creating a divide by zero error), and there is no voltage (no change in electron work capacity, because we don't have a way to excite the electrons, because there is no power) Resistance is incalculable. [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 22:22, 20 September 2012 (UTC)
:We live in 3 dimensions, just place a battery above the grid with wires going to the 2 points. --[[Special:Contributions/84.197.34.154|84.197.34.154]] 22:59, 24 October 2012 (UTC)
::Not everybody does... --[[Special:Contributions/85.159.196.14|FlatlandDweller]] 11:08, 15 November 2012 (UTC)
::: baDumpBump! [[Special:Contributions/172.68.142.89|172.68.142.89]] 16:22, 28 June 2018 (UTC)
::I believe the OP is referencing the issue that an infinite circuit could not hold a current. Connecting a battery would only work for a finite grid. In addition, the orientation of the battery in physical space has no relation to its behavior in a circuit, only the points of connection matter. Think about what the battery is doing to generate a current. How does electric potential apply over an infinite grid? Even moving it through a magnetic field won't work as the flux will be uniform across each cross section. You can't rotate an infinite grid either...{{unsigned|Flewk}}
: This is an idealized version of the general problem of determining the resistance between two points in a volume of some material. Like, say, two electrode tips in a liquid electrolyte? Getting a mathematically exact solution in this situation requires integrating over an infinity of paths, even when the liquid volume is finite. Add in the fact that there are no perfect insulators, and you'll have to consider arbitrarily long paths, too. [[Special:Contributions/162.158.203.15|162.158.203.15]] 03:46, 19 April 2021 (UTC)

:Just crocodidoodle the battery to the pencil lines as and where required for an infinity of varieteediddly.[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 18:51, 20 January 2015 (UTC)

This problem is "unsolvable" only if you try to just use the basic methods for finite networks.
There is a page on this at [http://mathpages.com/home/kmath668/kmath668.htm http://mathpages.com/home/kmath668/kmath668.htm] that reports that the cited points have a resistance of '''4/pi - 1/2''' ohms (.773234... ohms).
The 1/2 ohm resistance between adjacent nodes is actually well known.
[[User:Divad27182|Divad27182]] ([[User talk:Divad27182|talk]]) 05:05, 5 October 2012 (UTC)

:Solution here as well: http://mathworld.wolfram.com/news/2004-10-13/google/ [[User:Potie15|Potie15]] ([[User talk:Potie15|talk]]) 03:50, 18 March 2013 (UTC)

Nowhere it is said that the problem is unsolvable, just that it is interesting. Of course, the sniping is more effective if the problem is also difficult to solve, because otherwise the victim would get over it quickly. [[User:Dargor17|Dargor17]] ([[User talk:Dargor17|talk]]) 17:47, 16 June 2013 (UTC)

That method for parallel resistors is wrong. You don't divide resistances by the number of paths, you sum the reciprocals and then take the reciprocal of that. The method described only works if every resistor has the same value. While that's true in this problem, it's misleading to pass that off as a method that works for all cases. --[[Special:Contributions/173.245.55.60|173.245.55.60]] 03:32, 1 April 2014 (UTC)
:Good point. I made some slight alterations to clarify that we are assuming the resistors are equal. It seems a better solution than getting into the more complex version of the problem. --[[User:BlueMoonlet|BlueMoonlet]] ([[User talk:BlueMoonlet|talk]]) 12:20, 1 April 2014 (UTC)

The real question is: why did the physicist cross the road? --[[User:Alcatraz ii|Alcatraz ii]] ([[User talk:Alcatraz ii|talk]]) 00:53, 29 September 2014 (UTC)

:to get to the other sine. Or if you want a punchline specific to physics (sine is a math concept technically)... Brownian motion--[[User:Twisted Code|Twisted Code]] ([[User talk:Twisted Code|talk]]) 20:25, 30 March 2023 (UTC)

Amazing. From the first comment the discussion is diverted from discussing the comic, to discussing the problem presented in the comic. The commentators have been nerd sniped by a demonstration of nerd sniping. Randall is just that good. [[Special:Contributions/108.162.216.86|108.162.216.86]] 17:55, 30 April 2014 (UTC)

"Sniping" might also be a pun or have a deliberately dual meaning in this context, referring to both a sniper and a [http://en.wikipedia.org/wiki/Snipe_hunt snipe hunt] (do kids still practice the latter?). The former makes sense if Black Hat's purpose is to actually rid the world of physics and math nerds (consistent with his characteristic misanthropy and cynicism), but the latter also fits the theme of merely distracting a nerd with an impossible task, which the title text suggests may have been Randall's motivation for the strip. (On a side note, the Wikipedia article reveals that the terms sniper and snipe hunt have a common origin, which makes twice in the last month it's resolved a long-standing etymological puzzle for me. The other case united the multiple, seemingly unrelated meanings of minute <nowiki>["tiny" vs. time]</nowiki> and second <nowiki>[ordinal vs. time]</nowiki>; see [http://en.wikipedia.org/wiki/Sexagesimal#Notation sexagesimal].) [[Special:Contributions/173.245.54.182|173.245.54.182]] 01:40, 18 June 2014 (UTC)

:I've been led to believe that 'minute' means 'tiny amount of time', 'second' is 'secondary tiny amount of time', and , I quote "Real snipe (a family of shorebirds) are difficult to catch for experienced hunters, so much so that the word "sniper" is derived from it to refer to anyone skilled enough to shoot one." from the snipe hunt wiki page. [[Special:Contributions/141.101.104.4|141.101.104.4]] 23:45, 27 September 2014 (UTC)

Why doesn't someone solder together a thousand one ohm resistors into a grid then use an ohmmeter to measure the resistance? Then repeat with smaller and smaller grids to see if there's any effect on the measurement. If the resistance does not change, or at least doesn't change until the grid size gets quite small, then the "infinite" term in the problem is a 'red herring' to mislead. Pointless, useless, irrelevant etc information in problems is a common tactic for gauging the ability to recognize and reject such data. [[Special:Contributions/199.27.133.122|199.27.133.122]] 00:35, 18 November 2014 (UTC)

Incidentally, should this page mention that what if 113 (I don't know how to do links, sorry) contains a picture of this comic? [[Special:Contributions/108.162.216.65|108.162.216.65]] 23:36, 24 February 2015 (UTC)
:Yes I will do so. Have just referred to another what if where he is mentioning nerd sniping. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:40, 16 February 2016 (UTC)

[[Special:Contributions/141.101.98.34|141.101.98.34]] 12:17, 22 May 2015 (UTC) Am I the only one concerned with the fact that this poor guy was still on a crosswalk? The truck should have stopped. [[Special:Contributions/141.101.98.34|141.101.98.34]] 12:17, 22 May 2015 (UTC)
:No you are not, and good point --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:40, 16 February 2016 (UTC)

When the number of parallel resistors increase, the equivalent resistance decreases. So, in an infinite grid, wouldn't it approach zero? [[User:UrubuSelvagem|UrubuSelvagem]] ([[User talk:UrubuSelvagem|talk]]) 03:43, 28 September 2015 (UTC)
:They are also in series. For each parallel group, there is, in fact a corresponding group in series. {{unsigned|Flewk}}

It is not directly relevant to the discussion of the comic, but this needs to be posted here. Perhaps the best nerd snipe ever actually achieved and a nearly perfect match for the comic (my professor put it in the lecture notes for my group theory class):
"Coxeter came to Cambridge and he gave a lecture, then he had this problem ... I left the lecture room thinking. As I was walking through Cambridge, suddenly the idea hit me, but it hit me while I was in the middle of the road. When the idea hit me I stopped and a large truck ran into me ... So I pretended that Coxeter had calculated the difficulty of this problem so precisely that he knew that I would get the solution just in the middle of the road ... One consequence of it is that in a group if a^2=b^3=c^5= (abc)^-1, then c^610=1."
(J.H. Conway, Math. Intelligencer v. 23 no. 2 (2001))
I did a search, and the entire passage can be read [https://books.google.ca/books?id=aFHyUfFUVIwC&pg=PA22&lpg=PA22&dq=Coxeter+came+to+Cambridge+and+he+gave+a+lecture,+then+he+had+this+problem+...++Ileft+the+lecture+room+thinking.+As+I+was+walking+through+Cambridge,+suddenly+theidea+hit+me,++but+it+hit+me+while+I+was+in+the+middle+of+the+road.++When+the+ideahit+me+I+stopped+and+a+large+truck+ran+into+me+...++So+I+pretended+that+Coxeter+hadcalculated+the+difficulty+of+this+problem+so+precisely+that+he+knew+that+I+would+getthe+solution+just+in+the+middle+of+the+roa&source=bl&ots=CgmxTG2n0w&sig=ohqqBGtJrpuQFeiCPPusMVsQUV4&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMIy4KdnPakyAIV0ZeICh2OGghP#v=onepage&q=Coxeter%20came%20to%20Cambridge%20and%20he%20gave%20a%20lecture%2C%20then%20he%20had%20this%20problem%20...%20%20Ileft%20the%20lecture%20room%20thinking.%20As%20I%20was%20walking%20through%20Cambridge%2C%20suddenly%20theidea%20hit%20me%2C%20%20but%20it%20hit%20me%20while%20I%20was%20in%20the%20middle%20of%20the%20road.%20%20When%20the%20ideahit%20me%20I%20stopped%20and%20a%20large%20truck%20ran%20into%20me%20...%20%20So%20I%20pretended%20that%20Coxeter%20hadcalculated%20the%20difficulty%20of%20this%20problem%20so%20precisely%20that%20he%20knew%20that%20I%20would%20getthe%20solution%20just%20in%20the%20middle%20of%20the%20roa&f=false here] perhaps it is even possible that this event is the inspiration for this comic? The inclusion of the "large truck" is almost too perfect. [[Special:Contributions/108.162.240.217|108.162.240.217]] 23:45, 2 October 2015 (UTC)
:I have now added this story in a new trivia section. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:40, 16 February 2016 (UTC)

I know a solution that use random walks. :) {{unsigned ip|141.101.95.153}}

I really like this comic. It says a lot about Black Hat, but so much more about Randall :-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:40, 16 February 2016 (UTC)

So, *that's* how they did Gaudi in! I always suspected a plot; now I see the method. [[Special:Contributions/172.68.142.89|172.68.142.89]] 16:30, 28 June 2018 (UTC)

Solution: ~0.7729906038309804 ohm. [[User:GcGYSF(asterisk)P(vertical line)e|GcGYSF(asterisk)P(vertical line)e]] ([[User talk:GcGYSF(asterisk)P(vertical line)e|talk]]) 20:36, 4 September 2021 (UTC)

Can't speak for Black Hat's (or Randall's) jurisdiction, but over here a vehicle not stopping for someone on a zebra crossing (especially, but also not taking some basic actions to avoid ''any'' unexpected hazard in ''any'' road, including not going too fast to do so) would be an actual driving offence. Obviously someone stepping out from behind parked vehicles, or wildlife randomly crossing busy roads without regard for 'human' common sense, would be mitigation and probably become a no-fault situation, but someone clearly stood in an empty road (let alone upon a marked crossing point) should not be a surprise to even a looming juggernaut being responsibly driven. The regressive anti-pedestrian laws in the US might somehow {{tvtropes|LookBothWays|excuse this hollywood trope}}, but it still always bothers me when a character (gloating antagonist/doomed love-interest/whoever) gets suddenly side-slammed by a vehicle that nobody (we, they, the 'safe on the sidewalk' observers) had seen/heard until the moment before the impact (if that), but whose driver ''also'' appears to have been oblivious. And where there's no obvious sign of brakes used, vehicle and victim usually dissapearing just as rapidly off the opposite side of the shot, possibly remains so. (Does not apply to malicious side-swipes, obviously, where vehicle-as-a-weapon is invoked by whoever has gained off-screen control of the 'weapon', either to {{tvtropes|SurpriseCarCrash|kick off a villainous attack}} or for a co-protagonist to interupt an {{tvtropes|EvilGloating|attempted pre-mortem evil gloat}}...) [[Special:Contributions/172.70.90.48|172.70.90.48]] 09:38, 23 January 2024 (UTC)

:I don't think the comic is meant to imply that running over pedestrians is legal or desirable. [[Special:Contributions/172.71.150.156|172.71.150.156]] 20:41, 20 November 2024 (UTC)

I created some YouTube Video that details how the problem can be solved (also exploring some paths that do not work): Here is the gitlab page for that https://gitlab.com/mooond/grid-of-1ohm-resistors and here is the youtube playlist (the solution is mostly in chapter III): https://www.youtube.com/playlist?list=PLoGRr8ff1uXESrWh6z0BNTYpc4Y-hlBOm

Why should we assume that the physicist was actually hit by the truck? We only see him stopping in the middle of a street and the truck braking hard. Black Hat has clearly created a dangerous situation here, but has not necessarily killed. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 00:59, 4 December 2024 (UTC)

1442: Chemistry

2024-11-24T23:43:14Z

Bebidek: Changed 'coal' into 'graphite' as allotrope of carbon

{{comic
| number = 1442
| date = November 3, 2014
| title = Chemistry
| image = chemistry.png
| titletext = These are all sans-serif compounds. Serif compounds are dramatically different and usually much more reactive.
}}

==Explanation==
This comic is a classic example of taking an absurd premise, and applying correct science to it, to see how different the conclusion is to the real world.

The idea of Typographic Chemistry presented in this comic is a play on Douglas [[Hofstadter]]’s {{w|Typographical Number Theory}} and [http://smallshire.org.uk/sufficientlysmall/2013/05/12/typogenetics-in-f-part-i/ Typographical Genetics], which are featured in {{w|Gödel, Escher, Bach}}. While Hofstadter's typographical systems are designed to model aspects of real genetics and number theory, Randall abuses this notion by inventing a typographical system which bears no resemblance to real chemistry.

Chemical bonding is a well-known subject which explains the formation of {{w|molecule}}s from {{w|atom}}s. This comic refers to three {{w|chemical element}}s: carbon (C), hydrogen (H), and oxygen (O). In real chemistry, the formation of bonds between atoms depends on the number of valence electrons each atom has, and how accessible those electrons are for bonding. The comic jokingly replaces valence electron theory with a theory that the number of bonds an atom can form depends on the number of {{w|Leaf vertex|leaf vertices}} possessed by the chemical symbol's letter. A leaf vertex is a vertex having only one edge connecting to one other vertex. "H" for example, the chemical symbol of hydrogen, has 4 leaf vertices. This is shown in the comic by the four half-circles placed at each leaf vertex of the "H". Thus, in the comic's theory, elemental hydrogen can form 4 bonds. Oxygen, however, having the chemical symbol "O", has no leaf vertices, and according to the comic's theory should not bond to anything, and is therefore inert.

Of course, the theory is completely inconsistent with observed chemistry. While the comic declares oxygen is inert and forms no bonds, this is not really the case: the two unpaired valence electrons in a lone oxygen atom make oxygen reactive, and oxygen atoms readily form molecules. Diatomic oxygen, O2, makes up about 20.9% of Earth's atmosphere, and is essential for aerobic life, including human life. Similarly, a water molecule consists of an oxygen atom tightly bonded to two hydrogen atoms.

By observing real chemical compounds, chemists have deduced that hydrogen atoms really have 1 valence electron, carbon 4 and oxygen 6, allowing hydrogen to have up to 1 bond, carbon up to 4, and oxygen up to 2. Thus carbon can have up to four bonds, and really is {{w|graphite|often found}} in {{w|diamond|crystalline form}} in nature (diamonds and graphite are {{w|allotropy|allotropes}} of carbon); oxygen can have up to 2 bonds, and can combine with carbon to form CO2 (instead of C2H in the comic). [[Randall]] thus gives to "typographic" hydrogen qualities that belong in real-life to carbon, since "typographic" hydrogen can have 4 bonds. Similarly, "typographic" carbon is ascribed properties belonging to real-life oxygen. "Typographic" oxygen takes on the properties of the real-life noble gases (like helium, neon, and argon), which form no bonds and are inert.

While the {{w|ethynyl radical}}, which has the structure ∙C≡C–H, does have the formula C2H, there is no molecule with the C–H–C structure in nature. The word "mydrane" is a whimsical neologism for this fictional substance: the "hydr-" prefix for hydrogen is changed to "mydr-" (a prefix which does not exist) and combined to the "-ane" suffix for {{w|alkane}}s (simple hydrocarbon molecules). Perhaps Randall named this compound "mydrane" to declare ownership of it ("my-" as in "mine"). Another reasonable assumption is that the word is a portmanteau of methyl (Me- is the prefix for 1 carbon chains attached to a functional group) and hydrogen with the -ane suffix for alkanes; the nomenclature stems from (di-)m(ethyl) (h)ydr(ogen) -ane, which would form mydrane. Technically, the nomenclature would be "dimethyl" since there are two "methyl" groups attached to the functional group (i.e. hydrogen in this case). It would, however, not be uncommon to drop a di- from a compound name if it's redundant (only one possible compound, e.g. dimethyl ether which sometimes is referred to as methyl ether) or makes a clumsy name ("dimydrane" could make it sound as if there are two mydrane groups).

The title text points out that the theory as presented only applies to sans-serif text. A {{w|serif}} is a small line across the end of each stroke. "H", for instance, has four serifs, each with two leaf vertices. Thus hydrogen in a serif font would be able to form 8 bonds making it, according to the comic's theory, "more reactive".

==Transcript==
:[A large capital letter "H", with faint gray circles drawn on the ends of each of the four legs.]
:Hydrogen can form four bonds. It readily bonds with itself, and often exists as a crystal.
:[A lattice of several H's, all "bonded" together at the ends of their legs in a crisscross, meshlike pattern, labeled:]
:Crystalline hydrogen

:[A large capital letter "C", with faint gray circles drawn on both ends of the arc.]
:Carbon can only form two bonds. It readily bonds with hydrogen to form C2H (mydrane) or itself.
:[Image of a C and an inverted C, linked at their endpoints, labeled:]
:C2
:[Image of two C's linked with an H between them, labeled:]
:C2H

:[A large capital letter "O".]
:Oxygen is inert, forming no bonds...
:[Image of several lone O's, none connected to anything, labeled:]
:Monatomic oxygen gas.

:[Caption at bottom:]
:Typographic chemistry

{{comic discussion}}
[[Category:Chemistry]]

1659: Tire Swing

2024-10-24T17:28:23Z

Bebidek: Changed 'with three tires' to 'without all its tires', as there's no reason to assume that the truck was 4-wheeled.

{{comic
| number = 1659
| date = March 23, 2016
| title = Tire Swing
| image = tire_swing.png
| titletext = If we find one of those tire dumps, the next time he tries to get his truck back we can just retreat and let him have it.
}}

==Explanation==
In this comic, [[Jill]] and another girl have just completed a {{w|tire swing}}, a common makeshift {{w|swing (seat)|swing}} is created by hanging a car {{w|tire}} from a length of rope, typically tied to the branch of a tree as in the comic. The other girl might at first look like she has hair like [[Megan]] but not quite as she is revealed upon zoom in to have curly hair. That they are rather small kids can be seen from the size of the tire compared to them. (They could be the same as the girls in the last panel of [[1580: Travel Ghost]]).

In the second panel of this comic Jill muses that there are huge tire dumps filled with nothing but old tires that have no use. In the last panel, Jill continues that maybe they should use a tire from such a dump next time they make a tire swing. The presumption is that perhaps they used a brand-new tire, or a tire from some other source. This is confirmed by the other girl's response (and also by the title text, see below) which makes it clear that the tire they used was in fact stolen from a guy's vehicle. The last reply from Jill suggests the victim put up a fight and they had to take the tire by force. So, these two small girls actually fought an adult man over his truck and won the fight.

Vehicle tires have a limited lifespan. The natural end of their life is when the pattern of raised treads on the circumference of the tire, which promote traction on wet roads, are worn down to a point where they are no longer effective enough, or after 6-10 years (sunlight causes the rubber to degrade, so the tire becomes prone to cracking and unsafe, even if it appears to be in good condition). Tires can also become damaged in other ways, such as puncture.

{{w|Tire recycling|Used tires}} are a notable ecological problem for a number of reasons (e.g., their size, the quantity produced, their relatively short lifespan, and the fact that they are difficult and slow to break down and contain a number of components that are ecologically problematic). A tire swing represents a functional use for otherwise useless old tires. The number of tires (it is estimated that 259 million tires are discarded annually) makes them attractive targets for recycling. More than half of used tires are ultimately simply burned for their fuel value (which prevents them from sitting in landfills indefinitely, but this may even be worse as it releases otherwise locked up carbon thus releasing this into the atmosphere and making {{w|global warming}} even worse). Some steel mills that use electric arc furnaces will mix shredded tires with their scrap when charging the furnace for both the carbon value and fuel value, in place of the coal that would otherwise be used.

The comic is thus clearly [[Randall|Randall's]] attempt to draw attention to this huge ecological problem, as he so often before has done with other climate change/global warming related comics. (Climate change, especially global warming, is a [[:Category:Climate change|recurring theme]] in xkcd). So while this is not the joke of the comic, it could be the point of it.

He also suggests another way to use old tires. It should be noted that used tires are not necessarily safe to use as a kids' toy as they could become sharp/frayed along the edges and stones and other hard/sharp objects may have become stuck in the tires (even going all the way through), during its life span, or worn thin enough to tear apart mid-swing (when the stresses on the swing material would be at their peak). So, tires bought for use as a swing may even be made from a new tire, but not necessarily of the same solid type as those used for cars. Used tires reused for a swing should be inspected for the problems mentioned above.

The title text goes further, suggesting that they actually stole the victim's entire truck - possibly just to harvest the tire needed for the swing - and that he unsuccessfully attempted to recover the truck, so they probably did fight him. He put up enough of a fight that they do not wish to fight him again (so he at least survived). Further, since the girls expect him to try again (maybe recovering the truck without all its tires), they apparently still have the truck. One of the girls suggests that if they could find one of these tire dumps, then they could take a tire from there, make a new swing, and then just walk or run away from the truck when the guy comes back, letting him have it if he really wants it so bad.

The reason Jill made this swing could be that she wishes to become a {{w|cosmologist}} as a reference back her meeting a cosmologist on a tire swing in [[1352: Cosmologist on a Tire Swing]].

Note that {{w|Calvin and Hobbes}}, which has often been [[:Category:Calvin and Hobbes|referenced in xkcd]], has done the same to Calvin's father as the girls did to the guy (though without the violence) in a [http://assets.amuniversal.com/bcb737d0b98e013340c2005056a9545d similar comic].

This was the first of two Wednesdays in a row where Randall used two children to make a reference to an environmental issue, the second being [[1662: Jack and Jill]] about {{w|hydraulic fracturing|fracking}} also with Jill.

==Transcript==
:[Jill and a girl with long curly hair, are standing under a large leafless tree as Jill adjusts a tire swing hanging from the largest of the branches of the tree. The tire hangs so high that the small girls only reach up to just above the center of the tire which has a diameter of more than half the height of the girls.]
:Jill: OK, looks good.

:[Zoom in on the girls so only the tire swing can be seen, and nothing of the tree. They both look at the tire.]
:Jill: I read that there are these huge dumps everywhere full of millions of old tires that no one knows what to do with.

:[Same setting but Jill looks up at the tree (outside the frame).]
:Jill: We should use one of those next time.
:Curly haired girl: Yeah. That guy was real mad.
:Jill: I would ''not'' want to fight him again.

{{comic discussion}}

[[Category:Comics featuring Jill]] 
[[Category:Climate change]]
[[Category:Kids]]

Talk:538: Security

2024-06-17T20:45:20Z

Bebidek: Add comment about why RSA is not a good choice here.

I was in a flea market one time when I saw a booth who sold wrenches. They were priced starting at $2. There were even $5 wrenches!
Yes; I did this in response to this comic strip. No; I did not buy one. (I have no need to "crack" a computer. I just wanted to prove that there is a $5 wrench.)
[[User:Greyson|Greyson]] ([[User talk:Greyson|talk]]) 02:15, 3 November 2012 (UTC)
(Oops... I forgot to log on... I feel... scared.)
[[User:Greyson|Greyson]] ([[User talk:Greyson|talk]]) 02:15, 3 November 2012 (UTC)

Remember [https://what-if.xkcd.com/22/ the other comic], talking about how much does your time spent to pick up a penny cost? This applies here too! It's not just $5 for the wrench, there is also the time of the guy who will be hitting with it! Although of course the wrench is amortizable over multiple secret extraction sessions, unless it gets bent too much out of shape. [[Special:Contributions/108.162.246.5|108.162.246.5]] 20:57, 31 January 2014 (UTC)

I went to the flea market and bought a $5 wrench, then used it to beat the password out of 2^5 nerds. I just wanted to prove that there is a $5 wrench and that it's reasonable to amortize it over multiple extraction sessions. The wrench is still in good shape, even to use as a wrench. [[Special:Contributions/108.162.215.115|108.162.215.115]] 18:26, 28 January 2015 (UTC)

Why does everyone imagine that the "crypto nerd" will be a "him"? This gendered language is simply reinforcing the sexist stereotypes that serve as the cultural foundation for rape and other symptoms of this sexist worldview. I'm changing this to "him or her"... {{unsigned|Vctr}}
:The text of the comic refers to the cryptonerd being a him. Please check yourself before you wreck yourself. [[Special:Contributions/108.162.221.99|108.162.221.99]] 18:07, 1 May 2015 (UTC)
:: It says in the comic that the 'crypto nerd' is a 'him': "'''His''' laptop is encrypted". --[[Special:Contributions/108.162.216.118|108.162.216.118]] 15:45, 5 July 2020 (UTC)
Same concept as [[416: Zealous Autoconfig]]. [[User:Shanek|Shanek]] ([[User talk:Shanek|talk]]) 12:31, 1 May 2015 (UTC)
:BTW "him or her" leaves out gender-nonconforming people and is also is unnecessarily clunky - "they" is usually a better choice. It's great that you want to reduce the use of gendered language on the internet, though. Just be careful not to go overboard; there's a difference between identification and unnecessarily gendered language. [[User:DownGoer|DownGoer]] ([[User talk:DownGoer|talk]]) 01:42, 4 September 2023 (UTC)

What would happen if the owner of the computer used deniable cryptography with some decoy message? -- [[Special:Contributions/173.245.48.141|173.245.48.141]] 08:35, 15 July 2015 (UTC)
:As pointed out by the wikipedia article, deniable cryptography might either fool the attackers, or make them keep beating you even after you give them the real password. [[Special:Contributions/198.41.235.179|198.41.235.179]] 22:48, 13 October 2015 (UTC)

Surely if he's encrypting his PC, he should be using something like 256-bit AES/Rijndael, as it's more secure? [[User:Walale12|Walale12]] ([[User talk:Walale12|talk]]) 10:11, 24 July 2015 (UTC)

I doubt the crypto "nerd"'s nerdiness. RSA is not generally used for disk encryption. It relies on the computation of large primes, a task infeasible for data of such size. Instead, AES is used. [[Special:Contributions/108.162.250.163|108.162.250.163]] 13:54, 15 January 2016 (UTC)
:Quite often, disk encryption is done in two steps: Instead of generating key directly from passphrase, random symmetrical key is generated and used for actual encryption of whole disk, then encrypted by key generated from passphrase and stored ON the disk. That allows to change the passphrase without reencrypting whole disk. While the algorithm used for encrypting disk could be and often is AES, it's possible to use RSA for the second step. And breaking 4096bit RSA would still be quicker than breaking 256bit AES. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:35, 15 July 2019 (UTC)
::The main problem with RSA being used here is that RSA is an asymmetric cipher. That kind of cryptography is useful when you have two or more parties that have different roles, for example one of them can only encrypt and the second one can only decrypt. But when it comes to disc encryption (even in the two-step variant), there is only one party (the computer owner) so the only reasonable solution is a symmetric cipher (e.g. AES). Technically, RSA could be used here, but that would be very artificial and would be a clear sign that our "nerd" doesn't really understand the difference.[[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 20:45, 17 June 2024 (UTC)

Lol. The spelling "wench"
:My game is up! Drat! ;)
:Please sign your comments. - Also this article has been vandalized few times, to change wrench->wench. I now notice that the title text here also says so. On the original page it says wrench. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:15, 14 August 2019 (UTC)

Talk:2818: Circuit Symbols

2024-05-24T21:19:15Z

Bebidek: Added comment

The direct link to the comic is getting a 404 error. But it appears at the xkcd.com home page. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 01:31, 22 August 2023 (UTC)
:The link is working now. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 02:33, 22 August 2023 (UTC)

Randall is symbolizing sheep with a coil because ... wool takes a helical shape. See https://commons.wikimedia.org/wiki/Wool#/media/File:Royal_Winter_Fair_Wool.jpg. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 02:33, 22 August 2023 (UTC)
:I think it's meant to be a little prince reference; it's a "box with three holes" [[Special:Contributions/172.71.222.76|172.71.222.76]] 06:07, 11 December 2023 (UTC)
The title text is probably a reference to the classic novella "The Scarlet Letter" by Nathaniel Hawthorne (a common classroom reading in the US). In this novella, a young Puritan woman "sins" by having a child out of wedlock. She is punished by having to wear the letter A (for adultery). [[User:Comsmomf|Comsmomf]] ([[User talk:Comsmomf|talk]]) 02:54, 22 August 2023 (UTC)

Can someone with more wiki-foo than me please put the actual images for the symbols in a new first column? [[User:Blackbearnh|Blackbearnh]] ([[User talk:Blackbearnh|talk]]) 03:01, 22 August 2023 (UTC)

:The easy way to do this might be with the [https://www.mediawiki.org/wiki/Extension:SpriteSheet SpriteSheet extension], but maybe that's more trouble than it's worth. Any admin thoughts about installing it? [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 02:22, 25 August 2023 (UTC)

I tried, unsuccessfully, to learn if there were "Scarlet Letters" that represented other sins ['A' is mentioned to be for 'Adultery', Maybe 'O' for Onanism?] [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 03:41, 22 August 2023 (UTC)
:From what I understand, ‘BJ’ had its fair share of supporters. [[Special:Contributions/172.70.210.247|172.70.210.247]] 04:47, 22 August 2023 (UTC)

What exactly does "the opposite of capacitors" mean in this context? I'm not that familiar with EE, but from my limited understanding of inductors this is an incorrect and confusing statement. [[Special:Contributions/172.70.126.79|172.70.126.79]] 08:07, 22 August 2023 (UTC)

:They are the conjugate complex (so the sentence is kind of half-true), if you consider complex impedances. Sebastian --[[Special:Contributions/172.68.110.169|172.68.110.169]] 08:56, 22 August 2023 (UTC)

:Behaviorally the description makes sense, capacitors behave the same way regarding voltage vs. current as inductors behave regarding current vs. voltage and vice versa. Capacitors can "instantaneously" allow a spike in the current flowing through the circuit path that they are placed in, while the voltage across a capacitor can't change instantaneously and requires time to change incrementally (with a corresponding decline over time in the current flowing). Inductors "instantaneously" allow the voltage across their terminals to spike, but the current flowing through it can't change instantaneously and requires time to change incrementally (with a corresponding decline in the voltage across the inductor). Capacitors can act as a sort of "shock absorber" (no pun intended) or low-pass frequency filter for voltages, as inductors can for current. So they are very much considered complementary and the "essentially the opposite of capacitors" comment does pretty much make sense to EEs. But yes, it's not a particularly illuminating description without that background, and the description isn't really valid regarding their physical makeup or what makes them tick, just their role in a circuit. [[Special:Contributions/172.71.146.213|172.71.146.213]] 09:32, 22 August 2023 (UTC)

:Incapacitors [[Special:Contributions/172.70.85.108|172.70.85.108]] 16:48, 25 August 2023 (UTC)

The "overpass" is troubling me, as a map fan. Dependant upon the conventions of any given map illustrator this could easily be more an ''underpass'' (main road being the || track, lesser track being the — that sneaks beneath it) or a 'green bridge' (road is the — and the bridge 'symbol' is the || with no actual route using the space between its edges) or a minor road intersection of an uncrossable dual carriageway (each || is a directional way, separated by central reservation, and a historic road/lane is given T-junction access to/from the adjacent direction of travel, but no local flyover to access the opposite continuation/direction, probably have to use other flyovers/turning points above and below this snapshot). Or it's just a regular major/minor crossroads (track-level horizontal/E-W, more main road vertically/N-S) and is entirely at-grade so not involving a bridge at all. But all very much will rely upon the publisher's/renderer's choice of map-symbolism. [[Special:Contributions/172.70.91.95|172.70.91.95]] 11:27, 22 August 2023 (UTC)

:What's your hope? That Randall will edit his comic? -- [[User:Dtgriscom|Dtgriscom]] ([[User talk:Dtgriscom|talk]]) 11:41, 22 August 2023 (UTC)
::No more than I wish he'd use IEC resistors rather than the US zigzags. Just highlighting that (in isolation) there's so easily an alternate inference, dependent upon what notation/symbology you're most exposed to. [[Special:Contributions/172.70.162.199|172.70.162.199]] 16:36, 22 August 2023 (UTC)
:I appreciated the map trivia, personally [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:18, 22 August 2023 (UTC)
::Cheers, though I can't help but think that I explained it badly. And without much reason to. [[Special:Contributions/172.70.162.199|172.70.162.199]] 16:36, 22 August 2023 (UTC)

:I added the joke about needing a citation-needed joke. Please remove if you don't feel it was needed after all.

:Where I live the distinction between underpass and overpass is more about whether the bridge is at grade, and excavation has been done for the other road to pass under (i.e. under the ground level) or the bridge is above grade and the road it crosses over is at grade. --[[Special:Contributions/162.158.63.159|162.158.63.159]] 11:28, 25 August 2023 (UTC)
::From my perspective, you also need to consider flyovers (bridges rising above grade, usually more minor or singular carriageways compared to the at-grade main road with or without median-separated carriageways). If the main route rises over the minor (which remains at-grade, more or less) with clear over-ground construction, it's just a road-bridge. An underpass need not be subterrainean, and often can be an at-grade "original" route (typically pedestrian) beneath the embankmented new major road (or other route, e.g. rail) that was engineered across it, in the same subtle manner as a culvert. Or even what you'd now term the stretch of road "bridged" (or tunnelled) beneath the building of a cross-highway shopping centre, like some towns do in order to sustain an inner ringroad and a large footprint shopping centre.
::In general, if the 'over' road doesn't really notice the 'under' (it's still mostly the same grass verging, maybe briefly slightly higher crash-barriers on top of whatever embankment-guarding barriers already exist but no clear 'bridge' details) then I'd just name the underpass as such, as everything on that is definitely going to know that it is diving under the upper route
::It can be complicated. The {{w|File:No pedestrians (geograph 5985118).jpg|extended runway seen here}} is possibly at-grade overpass, w.r.t the whole airport "level" (equivalent to a by-pass embankment?), while the road looks sunken (as can be seen by how much the pedestrian side-portal need not be). It could be a runway on an overpass, though I'd say the road is an underpass (with a possible argument that it was always a cut'n'cover tunnel, or passing under ''really'' long bridge). [[Special:Contributions/172.70.90.138|172.70.90.138]] 17:46, 25 August 2023 (UTC)

With a capacitor you can build a low-pass filter. It can be used in signal processing like audio devices to filter out noise. [[Special:Contributions/172.70.243.218|172.70.243.218]] 21:01, 22 August 2023 (UTC)

I think the Battery/Baettry/Batttttttttery joke is probably a reference to the oreo/oreoreo/etc meme that can be seen at https://i.kym-cdn.com/photos/images/original/001/839/727/d7f.jpg . [[Special:Contributions/172.70.38.170|172.70.38.170]] 13:58, 23 August 2023 (UTC)Bumpf
:Feel free to add that to the page! --[[User:FaviFake|FaviFake]] ([[User talk:FaviFake|talk]]) 20:44, 23 August 2023 (UTC)
:To me the last one sounds like hoe Metallica sings battery in the song ‘Battery’

The electricity in a wave pool citation needed is the first properly funny one I've seen in quite a while - I approve. [[Special:Contributions/172.70.85.135|172.70.85.135]] 16:49, 25 August 2023 (UTC)

The capacitor explanation is a bit of a mess at the moment, with pronouns lacking any apparent referent. I'm going to clean it up to the best of my ability, but since I only know things from the civil engineering side and not the electrical engineering side, it will almost certainly need someone who actually understands capacitors to give it a once or twice over.[[Special:Contributions/162.158.174.197|162.158.174.197]] 15:55, 29 August 2023 (UTC)

I'm surprised that NPN transistor was used for the Trolley Problem instead of PNP. It would make a lot more sense because the PNP symbol has an arrow pointing towards the center, which corresponds nicely with the trolley heading towards a fork. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 21:19, 24 May 2024 (UTC)

Talk:1109: Refrigerator

2024-04-23T13:59:55Z

Bebidek: Add opinion about the design

I'm saying this is a bad idea for a fridge. Don't mistake me, I'm an xkcd-fan just like you. But Randall obviously has never seen a full fridge. I mean "full" like packed full with no space for fresh food. That here only works for empty/medium filled refrigerator. And that would be a waste of energy, see sustainable etc. (I have my fridge currently offline). Besides that doesn't solve the more urgent problem in most households: the freezer compartment, which is almost always full. But yeah, I know, this is just for fun. {{unsigned ip|162.158.83.144}}

I would argue that this is also a reference to {{w|The Incredible Machine}} and friends, where many levels revolve around conveyor belts and things on top of them that stir certain actions. [[User:Kaa-ching|Kaa-ching]] ([[User talk:Kaa-ching|talk]]) 10:46, 17 September 2012 (UTC)
: Not a chance. The conveyor belts don't look like the ones in that game, nor is there anything else in the refrigerator that has anything to do with that game. [[Special:Contributions/108.28.72.186|108.28.72.186]] 23:00, 30 August 2013 (UTC)

The main problem with this design is that the bad food needs to land softly otherwise it could splash\spatter over the good food. [[User:SaintGerbil|SaintGerbil]]([[User talk:User:SaintGerbil|talk]]) 12:17, 17 September 2012 (UTC)

I thought an alternative design for the fridge could be to have the middle conveyor belt attached to the right, leaving a gap on its left and obviously it would move toward the left. This way we could put food on the topmost belt on its left side and the food would travel along that belt then drop onto the middle one, then travel to the bottom belt and finally fall into the BAD bin. Of course we'd have to relabel all belts accordingly. [[User:DelendaEst|DelendaEst]] ([[User talk:DelendaEst|talk]]) 12:27, 17 September 2012 (UTC)

:The only problem with that is that different foods spoil at different rates (e.g. carrots last for about 2 months while milk is a week at best). The 3 shelves moving at different speeds seems to account for this. --[[User:Joehammer79|Joehammer79]] ([[User talk:Joehammer79|talk]]) 13:38, 18 September 2012 (UTC)

::I disagree. I'm with DelendaEst. I presume the premise is that you initially place the food at the appropriate place. Milk might start at the 2-week mark on the shelf, whereas juice might start at the 4 week mark, and ketchup might start at the many month mark. Randall has designed it so you put the food on the relevant shelf. In the left-right-left right scenario, the top shelf might run 3 months to 1 month, and take two months to roll from left to right. Then the second shelf could be 1 month to 1 week, and take approximately 3 weeks to roll from right to left. The bottom shelf would take 1 week to roll from left to right into the "bad" bin. You would just have to put stuff down based on initial expiration date. Ketchup might go on the top-left, while milk might go in the middle of the second shelf, etc. In Randall's version, the food at "2 days" on the top shelf, the second shelf and the door shelf should all reach the bad bin at the same time. Thus, it could all have been on one shelf. [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 19:22, 19 September 2012 (UTC)

Most of the stuff I find gone bad is in the bottom two drawers where it has become forgotten, like a half bag of lettuce.--[[User:DanB|DanB]] ([[User talk:DanB|talk]]) 14:19, 17 September 2012 (UTC)

Sorry Randall: so much for brilliant... there's a bug in your design. Look at the top rack in the door. There is a chute that would prevent food from falling past when the door is closed. It would need to be rotated 90 anticlockwise in order to work. [[Special:Contributions/207.225.239.130|207.225.239.130]] 21:30, 17 September 2012 (UTC)
*I see a space -[[User:Shine|Shine]] ([[User talk:Shine|talk]]) 02:00, 18 September 2012 (UTC)

::I think the anon user is pointing out that the little "ramp" below the door belt would actually roll food into the side wall of the fridge when the door is closed. The ramp should be oriented from the wall of the door towards the back of the fridge (when the door is closed) instead of towards the side wall. so the food rolls from the door back into the fridge and the "bad" bin, rather than rolling into the side wall of the fridge. [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 19:25, 19 September 2012 (UTC)

:::And Shine is pointing out that the middle and bottom shelves doesn't go all the way to the edge of the door. The fridge is designed so that the "BAD" bin is as long as the width of the body shelves plus the width of the door shelves. That way, the food from the top shelf of the door will fall between the middle/bottom shelves and the side wall, and into the front end of the "BAD" bin. [[Special:Contributions/72.169.224.103|72.169.224.103]] 17:55, 5 December 2012 (UTC)

The problem I see is that you would have to place the food back exactly where you took it from, or a little to the right. It still works, but you would have to be very precise. Maybe keep some markers to put on the conveyor belt to mark where the food came from. This way, you'd know where to put the food back.[[Special:Contributions/75.69.96.225|75.69.96.225]] 21:33, 11 October 2013 (UTC)

:Or you could install spigots on everything so you never have to pick anything up. Maple syrup, spigot, chicken soup, spigot, miso soup with tofu, spigot.[[Special:Contributions/173.245.55.24|173.245.55.24]] 20:19, 6 June 2014 (UTC)

"Epitaph of Stevinus" should writely be known as the epitaph of Stevin's next of kin.[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 18:59, 20 January 2015 (UTC)

Of course, if your timing was bad something would drop from the door-conveyor while the door was open, splattering almost-spoiled food on the floor. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 19:09, 12 October 2021 (UTC)

The real (and unfortunately unfixable) problem with this design is that expiration dates are not trustworthy. In many cases the food is still perfectly good long after it 'expires'. The only way is to check it yourself. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 13:59, 23 April 2024 (UTC)

Talk:697: Tensile vs. Shear Strength

2024-03-13T17:59:45Z

Bebidek: Added my thought that the elevator could have been saved

Does anyone know the tensile vs. shear strength of nanotubes? [[User:Djbrasier|Djbrasier]] ([[User
talk:Djbrasier|talk]]) 20:33, 3 September 2013 (UTC)

"but it can be cut with a simple pair of pruning shears (also a pun on shear strength)" - I don't know the precise etymology of the word shears, but I would assume they are called such precisely because they operate on a shearing principle. While it is fair to assume that the use of the words 'pruning shears' is intentional (rather than 'scissors' or similar) , I wouldn't call it a pun (exploiting multiple meanings of words). --[[User:Pudder|Pudder]] ([[User talk:Pudder|talk]]) 16:07, 11 September 2014 (UTC) (Retroactively signed)

I agree, it's not a pun. I'm going to change that.
[[User:Spiral phi|Spiral phi]] ([[User talk:Spiral phi|talk]]) 19:32, 27 August 2014 (UTC)

I can't immediately think of any other rhyming comics. Are there any others? --[[User:Pudder|Pudder]] ([[User talk:Pudder|talk]]) 16:07, 11 September 2014 (UTC)
:At least [[206: Reno Rhymes]], [[491: Twitter]] and [[805: Paradise City]], and probably others. [[User:Pelosujamo|Pelosujamo]] ([[User talk:Pelosujamo|talk]]) 17:32, 23 September 2014 (UTC)

Though the thing would have buckled before all this could even have a chance to happen [[Special:Contributions/108.162.254.71|108.162.254.71]] 16:22, 11 October 2014 (UTC)

:Buckling is specifically a failure under compressive load. I'm assuming we are looking at a cable under tensile load caused by centrifugal force. (The old swinging a bucket on a rope trick). Wikipedia has an interesting {{w|Space Elevator}} article. --[[User:Pudder|Pudder]] ([[User talk:Pudder|talk]]) 12:23, 12 December 2014 (UTC)

Aargh! The first line lacks a syllable... E.g. THEN after countless engineers...[[User:Mumiemonstret|Mumiemonstret]] ([[User talk:Mumiemonstret|talk]]) 10:31, 17 October 2014 (UTC)

I'm pretty sure the 3rd line's been changed; when I first read it, it ended with either "turns to tears" or "ends in tears". Can anyone confirm? [[User:Promethean|Promethean]] ([[User talk:Promethean|talk]]) 19:03, 31 May 2015 (UTC)

More accurate to refer to punched holes in terms of being stress concentrators than in terms of cross-section reduction. Sharp corners can reduce stress to failure massively while only marginally reducing cross-sectional area [[Special:Contributions/108.162.216.18|108.162.216.18]] 16:09, 24 December 2015 (UTC)

In reality, I believe that any space elevator would be nearly perfectly balanced, to the point that it would not even need to necessarily be connected to the ground. That is of course why a space elevator in and of itself is possible and why a material with great tensile strength is needed, as it would be perfectly balanced. {{unsigned ip|108.162.245.170}}
: Attaching to the ground provides stability to some designs. It does not need to be perfectly balanced as the moving cargo will be changing the center of mass anyway. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 00:21, 29 October 2021 (UTC)

I'm pretty sure you guys missed the reference to Burma Shave. The setup of the text is identical to the "burma shave" campaign (4 rhyming lines + "Burma Shave"). In this case Pruning Shears is used instead of Burma Shave which sounds quite similar (this is why he choose that over "scissors" or similar). See comic 491 for another reference. [[Special:Contributions/188.114.102.169|188.114.102.169]] 15:11, 24 August 2016 (UTC) msx80

The Burma Shave connection is weak. The signs used only three or four syllables per line and just one rhyme (e.g., "Ben met Anna / Made a hit / Neglected beard / Ben Anna split"), and the "Burma Shave" was on a fifth, separate sign, not part of the rhyme. [[User:Gmcgath|Gmcgath]] ([[User talk:Gmcgath|talk]]) 20:23, 25 October 2016 (UTC)

I find it cool there is a melody "Cerebral Plumbing" by Rom di Prisco, which fits the pattern of the poem. [[Special:Contributions/141.101.104.201|141.101.104.201]] 07:21, 28 July 2019 (UTC)

It’s written in Common Meter (mostly) which means that it fits to quite a number of tunes (especially if one is prepared to force the syllables a bit). The second line is the main one to break a little from this but with a bit of effort it can be sang to O Little Town or Bethlehem or even the Original Pokemon Theme.

I can't see how these holes were supposed to ruin the whole project. Apparently, the elevator was still in one piece (although probably couldn't be used). All they had to do is to raise the base a couple of meters (the banner doesn't seem that high) so that the damaged region of the ribbon is not relevant (possibly they could even cut the ribbon right above it). Surely, it will cost a lot, but not quite as much as a new elevator. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 17:59, 13 March 2024 (UTC)

Talk:790: Control

2024-03-11T13:13:29Z

Bebidek: Added an alternative explanation of Megan having 8 limbs.

Soon followed by psychologists recommending the tested drug as a depressant after looking at the results of the trials. '''[[User:Davidy22|{{Color|#707|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 02:21, 24 April 2013 (UTC)

This has always bothered me: If LSD Lysergic Acid Diethylamide, why isn't it LAD? What's so special about the S in LySergic that it beats out the A in Acid? Anonymous 01:06, 5 December 2013 (UTC)

: It is from the German "Lysergsäure-diethylamid" where "säure" refers to the acidity. [[Special:Contributions/108.162.240.6|108.162.240.6]] 14:39, 8 December 2013 (UTC)

::Ah, that makes sense. Anonymous. 00:10, 12 January 2014 (UTC)

LSD invokes hallucinations, not delirium. By definition, you know when you're hallucinating. Just saying. [[Special:Contributions/108.162.249.111|108.162.249.111]] 00:21, 22 January 2014 (UTC)
:: People who do insane things like jump off a building or flee from hallucinations while on LSD are usually those who had it slipped to them without their knowledge. The reason most people who are tripping aren't fooled by the things their poorly filtered mind brings up is that they're aware it's happening, not that it's not convincing. If you think you're sober, those impressions are entirely believable. They are not even really a hallucination, but in fact are the triggering of memories by sensory stimulus or thoughts. LSD blocks part of your brain's normal chemical filtering of memories and thoughts, which would keep you from being distracted by only slightly-relevant thoughts. — [[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 21:33, 28 October 2019 (UTC)
: Hallucinations are, in fact, indistinguishable from reality, like delirium. LSD-like effects, where things feel real but you know they aren't are sometimes called pseudohallucinations. Delirants like belladona, datura, mandrake or even nutmeg are more likely produce true hallucinations, usually of the unpleasant kind. [[User:GuB|GuB]] ([[User talk:GuB|talk]]) 13:56, 23 October 2015 (UTC)

: If you are not aware that you have been given a drug that would cause hallucinations, and are going in to have the size of your rash analyzed, you have no expectation of perceiving things that aren't real to help cue you in to what is happening

:: Saying 'LSD does not cause delirium' might make sense when reading wikipedia or someone's sanitized lab report, but "OH GOD SPIDERS" is not a very abnormal response to the drug. [[User:Singlelinelabyrinth|Singlelinelabyrinth]] ([[User talk:Singlelinelabyrinth|talk]]) 03:15, 25 July 2020 (UTC)

There is an argument that, when doing tests on humans, who leave the lab and do things that may accidentally or by design affect the data (say, a person being given the placebo rather than a drug for blood sugar, blood pressure, etc who happens to start walking more at work because they are moved to a less centrally located desk, the term "comparison group" should be used instead of "control group," because they can compare the two data sets but not control for all variables [[User:Katt3|Katt3]] ([[User talk:Katt3|talk]]) 17:48, 19 September 2016 (UTC)Katt3

I always thought the multiple arms were to show motion. [[Special:Contributions/173.245.54.41|173.245.54.41]] 05:32, 2 May 2016 (UTC)

: An alternative explanation (which was actually my first thought) is that what we see is Megan's perception of herself. Not only does she see spiders around her, but she also sees some features of spiders (having 8 legs/limbs) in her own body. [[User:Bebidek|Bebidek]] ([[User talk:Bebidek|talk]]) 13:13, 11 March 2024 (UTC)