https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=162.158.158.87&feedformat=atomexplain xkcd - User contributions [en]2021-10-24T07:35:17ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:1167:_Star_Trek_into_Darkness&diff=188258Talk:1167: Star Trek into Darkness2020-03-06T22:31:06Z<p>162.158.158.87: Partially Undo revision 188251 by 162.158.78.52 (talk)</p>
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<div>There has been a considerable amount of debate as to whether the title of this movie should have a colon in it, which would have appeared as "Star Trek: Into Darkness." They eventually decided against the colon, and I wonder if this comic is poking fun at that debate.[[Special:Contributions/169.234.40.187|169.234.40.187]] 00:49, 31 January 2013 (UTC)<br />
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I suspect an allusion to movie title spellings that can be seen on moviez sites, torrent sites etc. -- [[Special:Contributions/193.174.118.70|193.174.118.70]] 08:20, 30 January 2013 (UTC)<br />
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The Associated Press style manual says to capitalize all prepositions that are four letters or more in titles, e.g. Into, Through, etc. --[[User:Prooffreader|Prooffreader]] ([[User talk:Prooffreader|talk]]) 09:54, 30 January 2013 (UTC)<br />
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This could also have to do with WP's MOS of capitalizing "The first word in a compound preposition (e.g. "Time Out of Mind", "Get Off of My Cloud")".<br />
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However, you cannot simply change the title of a page on WP. This requires actually moving the whole page. [[Special:Contributions/84.208.51.23|84.208.51.23]] 14:02, 30 January 2013 (UTC)<br />
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I think there is a capitalization error in the comic. The second to last 's' should be capitalized in order to match the rest of the pattern in "xX_StAr TrEk InTo DaRkNess_Xx". Unless the author is trying to subtly troll us into arguing about that capitalization... [[User:Sayno2quat|Sayno2quat]] ([[User talk:Sayno2quat|talk]]) 14:31, 30 January 2013 (UTC)<br />
:Non-sense, double consonants should never be capitalized! Unless of course you want to use them for structural purposes, like spacing or framing, obviously.--[[User:Pnariyoshi|Pnariyoshi]] ([[User talk:Pnariyoshi|talk]]) 15:05, 30 January 2013 (UTC)<br />
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I believe Cueball's comment, "I have a new favorite edit war," is refering to the title text in this comic http://xkcd.com/878 about the great debate of HO vs. H0. [[Special:Contributions/206.39.12.245|206.39.12.245]] 15:23, 30 January 2013 (UTC)Pat<br />
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"Magnificient"?<br />
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The actual [http://en.wikipedia.org/wiki/Talk:Star_Trek_into_Darkness#xkcd_Mention Talk Page] of the Wikipedia article in question has an item about this comic. --[[User:Prooffreader|Prooffreader]] ([[User talk:Prooffreader|talk]]) 16:32, 30 January 2013 (UTC)<br />
:Oh sweet mother of god. Between that and the spam on this wiki, I think I'll take the spam. '''[[User:Davidy22|<span title="I want you."><u><font color="purple" size="2px">David</font><font color="green" size="3px">y</font></u><sup><font color="indigo" size="1px">22</font></sup></span>]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 11:33, 31 January 2013 (UTC)<br />
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I spent a good portion of last night reading through Wikipedia's talk pages for that. Worth a good laugh. [[Special:Contributions/76.122.5.96|76.122.5.96]] 16:56, 30 January 2013 (UTC)<br />
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Well it obviously should be capitalized. --[[User:Shine|Shine]] ([[User talk:Shine|talk]]) 17:43, 30 January 2013 (UTC)<br />
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:I tried to make a point on wikipedia that Wikipedia itself went out of its way to create a "lowercase first letter" template so that iPod and things of that nature could be capitalized the way the producer styled it, but there's really nowhere to point it as all discussions have closed and been ground to a halt. [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 19:50, 30 January 2013 (UTC)<br />
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But is it really an edit war? Have they been moving the page bach and forth? --[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 00:18, 31 January 2013 (UTC)<br />
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I still feel the most retarded of discussions on Wikipedia is for the Hentai article, where a disturbing majority demand pornography. --[[Special:Contributions/59.167.191.93|59.167.191.93]] 08:05, 31 January 2013 (UTC)<br />
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Just a minor matter of correctness... but shouldn't this page be entitled "1167: Star Trek Into Darkness", with a capital I, you know, since that's the way the movie studio is writing it, even though it doesn't follow MOS? I think someone needs to fix it RIGHT NOW! --boB<br />
:Hey boB, you should fix your username! :P I'm kidding. I think the wiki just follows what is on the xkcd website, which has the lower case "i".--[[User:Pnariyoshi|Pnariyoshi]] ([[User talk:Pnariyoshi|talk]]) 22:45, 31 January 2013 (UTC)<br />
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I wish the Super Bowl Halftime Show could be that talk page being presented in a dramatic on stage performance. wow. Do you think Ian McKellen is available?--[[User:Shine|Shine]] ([[User talk:Shine|talk]]) 19:29, 31 January 2013 (UTC)<br />
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It looks like it's been moved to the capital I. I'd say that it's definitely because xkcd mentioned it. [[Special:Contributions/76.122.5.96|76.122.5.96]]<br />
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: https://twitter.com/wikisignpost/statuses/297188486421831680 :-) --[[User:Mormegil|Mormegil]] ([[User talk:Mormegil|talk]]) 07:56, 1 February 2013 (UTC)<br />
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I wanna be the guy who has to watch the xkcd website for new Wikipedia-related comics and lock the related article as quickly as possible... [[User:Ilinamorato|Ilinamorato]] ([[User talk:Ilinamorato|talk]]) 15:44, 1 February 2013 (UTC)<br />
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Perhaps it is worth noting that the argument over whether to include a section about the debate and the following xkcd mention is now growing on the talk page and already has a couple thousand words of debate. {{unsigned|24.114.22.89}}<br />
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:That reminds me of the time that I was reading my Encyclopedia Britannica and happened across the section on the Titmouse and it mentioned the debate the editors were having on whether to include a joke about {{w|Tufted_Titmouse|Titmice}} and {{w|tit_(bird)|tits}} being cousins of sorts. Oh Wait.... --[[User:Shine|Shine]] ([[User talk:Shine|talk]]) 23:06, 1 February 2013 (UTC)<br />
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Maybe someone who has seen Contact wants to add some comment about the meaning of the quote or why it is relevant/funny? –[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 18:45, 18 February 2013 (UTC)<br />
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This may be obvious to others, but I don't know why the ~*~ symbol is used for the alternate capitalization. Can someone explain what the meaning of those characters is? [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 19:06, 22 May 2015 (UTC)<br />
:I think it is making fun of old AIM profiles and similar username choices, usually with 'random' capitalization and xX or ~*~* , examples: [1] http://img.ifcdn.com/images/60a97877d77df653f3c29a9f78f342958c00b864d68eda6a6324cafda44ffc69_1.jpg , http://knowyourmeme.com/memes/katy-t3h-pengu1n-of-d00m , https://img.buzzfeed.com/buzzfeed-static/static/2015-07/1/16/enhanced/webdr04/enhanced-20005-1435781306-7.jpg --[[Special:Contributions/108.162.221.91|108.162.221.91]] 19:29, 12 June 2016 (UTC)<br />
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I don't know if the title text was changed from what it was originally, but on xkcd.com it says "factions sprang up..." not "crackers..." -[[Special:Contributions/108.162.246.174|108.162.246.174]] 20:18, 27 May 2015 (UTC)<br />
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Must be the capital "I". That's final! Everything else is plainly stupid! If you like your franchise, then let the movies have beautiful titles. If you use lower-case "i", it's ugly. Btw I'm not a fan of Star Trek. And I don't want to join the war(s). I'm gone. Bye! {{unsigned ip|162.158.85.117}}<br />
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Seems there was an edit war about the page title before there was even a film title. Anyway the [Ii]nto debate starts from the first talk archive and it keeps going: https://en.wikipedia.org/wiki/Talk:Star_Trek_Into_Darkness/Archive_1#Title_redux --[[Special:Contributions/162.158.75.16|162.158.75.16]] 21:14, 22 May 2018 (UTC)<br />
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It’s still happening. The edit war still rages. [[User:Netherin5|“That Guy from the Netherlands”]] ([[User talk:Netherin5|talk]]) 13:07, 13 November 2019 (UTC)<br />
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May I suggest: Star Trek |nto Darkness</div>162.158.158.87https://www.explainxkcd.com/wiki/index.php?title=Talk:553:_Pirate_Bay&diff=186498Talk:553: Pirate Bay2020-01-27T12:52:48Z<p>162.158.158.87: he is wonderful, but...</p>
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<div>"Just some stats..."... here are some reasons why TPB is down sometimes - and how long it usually takes to fix: "Tiamo gets *very* drunk and then something crashes: 4 days "Anakata gets a really bad cold and noone is around: 7 days "The US and Swedish gov. forces the police to steal our servers: 3 days".. yawn." <br />
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The piratebay IS...<br />
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I would consider unremovable Hungarian subtitles to be an [http://tvtropes.org/pmwiki/pmwiki.php/Main/Unishment Unishment]; even if I can not ignore the subtitles, I would end up learning Hungarian! I like learning languages! [[User:Greyson|Greyson]] ([[User talk:Greyson|talk]]) 17:20, 1 July 2014 (UTC)<br />
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The transcript says that Cueball is the one standing, staring at the fence. However, it also lists Cueball as talking. Error or do I just have bad eyesight? {{unsigned ip|199.27.133.128}}<br />
:It says that one of the Cueballs is standing, it doesn't specify which one is talking. Also logically it's not a fence, it's cell bars. -Pennpenn [[Special:Contributions/108.162.250.162|108.162.250.162]] 01:22, 19 August 2015 (UTC)<br />
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Someone translate every sentence in the Explain to Hungarian and put it after every English sentence. It must be checked frequently to make sure nobody removes the Hungarian.[[User:International Space Station|International Space Station]] ([[User talk:International Space Station|talk]]) 21:11, 12 January 2016 (UTC)<br />
:See, this would probably get you banned, but I think it would be hilarious. Should I just use Google Translate, or do we have a Hungarian we can use? [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 15:45, 29 March 2017 (UTC)<br />
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:There you go [[Special:Contributions/172.68.226.100|172.68.226.100]] 18:41, 20 June 2017 (UTC) Bálint<br />
::I've removed that translation because this wiki tries to ''explain in English'' the content of the comics. And Hungarian is just an example, an example for a language the vast majority doesn't understand. Finnish, Czech, or Polish would be the same. So I've added this meaning to the end of the explanation. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:32, 21 June 2017 (UTC)<br />
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Could it be that "seeded generously" is supposed to be a pun about sexual promiscuity? [[Special:Contributions/108.162.237.250|108.162.237.250]] 13:24, 24 May 2016 (UTC)<br />
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:That was my first impression. {{unsigned ip|162.158.75.39}}<br />
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:It was most definitely not. [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 15:45, 29 March 2017 (UTC)<br />
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If you put a colon between "unremovable" and "Hungarian" in the title text, then it sounds like the sentence is unremovable and it is Hungarian subtitles. It is possible that Randall left a colon out (however, unlikely) [[User:625571b7-aa66-4f98-ac5c-92464cfb4ed8|625571b7-aa66-4f98-ac5c-92464cfb4ed8]] ([[User talk:625571b7-aa66-4f98-ac5c-92464cfb4ed8|talk]]) 15:20, 7 March 2017 (UTC)<br />
:Thanks for bringing this up. I've set the incomplete tag. The real pun focuses on other portals (back in 2009 when the comic was released) and their bad quality. And that's not only about subtitles nobody understands.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:18, 7 March 2017 (UTC)<br />
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The Cueball that does the talking, and thus is the prodigy of the comic<br />
i don't think prodigy means what you think it means. do you mean "protagonist"? --[[Special:Contributions/162.158.158.87|162.158.158.87]] 12:52, 27 January 2020 (UTC)</div>162.158.158.87https://www.explainxkcd.com/wiki/index.php?title=Talk:1570:_Engineer_Syllogism&diff=185975Talk:1570: Engineer Syllogism2020-01-14T17:26:03Z<p>162.158.158.87: </p>
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<div>Note the link with 592. [[User:Halfhat|Halfhat]] ([[User talk:Halfhat|talk]]) 11:41, 28 August 2015 (UTC)<br />
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The link to 592 is tenuous at best, and is certainly no foreshadow of this comic. Please stop making up connections just be cause it makes the xkcd "universe" loop back to itself. This is clearly related to the events of the past week, August 24-28 2015. This should be included as future readers will not realize the publication date and its significance.[[Special:Contributions/173.245.56.140|173.245.56.140]] 14:42, 28 August 2015 (UTC)<br />
:You need to go read the title text for 592 again. It is far from a tenuous connection. Randall regularly comes back to themes, and engineers diving into the stock market is literally in the title text of 592. The link is valid. [[Special:Contributions/173.245.55.171|173.245.55.171]] 19:17, 28 August 2015 (UTC)<br />
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Despite all the numbers around it, stock market is actually made of PEOPLE. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 12:18, 28 August 2015 (UTC)<br />
:But, but... if the universe is made of math... and people are part of the universe... aren't people made of numbers? [[Special:Contributions/188.114.98.214|188.114.98.214]] 14:02, 28 August 2015 (UTC)<br />
::But that just shifts the fallacy: math is (a lot) more than numbers, and Cueball doesn't have access to most of the numbers describing the world's investors anyway. [[Special:Contributions/108.162.216.157|108.162.216.157]] 14:04, 28 August 2015 (UTC)<br />
:::And even if something is completely described by numbers, it doesn't necessarily have to be predictable. 'Chaos' teaches us this.--[[Special:Contributions/108.162.229.210|108.162.229.210]] 14:15, 28 August 2015 (UTC)<br />
::::<nowiki><pedantry></nowiki>Well, randomness teaches us this. {{w|Chaos theory|Chaos}} just teaches us that you might need near-perfect information to make decent predictions.<nowiki></pedantry></nowiki> [[Special:Contributions/108.162.216.157|108.162.216.157]] 02:02, 29 August 2015 (UTC)<br />
The title text appears to be a pun on the financial and programming definitions of 'crash'. In the same way that an overconfident or unconsciously incompetent programmer might make changes to a complex piece of software which cause it to crash, Cueball has invested so poorly that the entire market has crashed. {{unsigned ip|141.101.98.219}}<br />
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Now that you mention the chinese stock market crash, have you considered the chinese political class is made most of engineers [http://singularityhub.com/2011/05/17/eight-out-of-chinas-top-nine-government-officials-are-scientists/]? This would explain the tooltip text. {{unsigned ip|162.158.23.204}}<br />
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It's worth note that '''this is also true of economists'''. Unlike mere mathematicians, economists suffer under the delusion that they directly understand how economic activity works and are able to predict its outcomes. But they fail, as Hayek notes in [[Wikipedia: The Counter Revolution of Science|The Counter Revolution of Science]], to understand or even take into account the [[Wikipedia:praxeology|human action]] and motivation<ref>[https://www.youtube.com/watch?v=d0nERTFo-Sk Fear the Boom and Bust: Keynes vs. Hayek - The Original Economics Rap Battle!]<br/><small>I'll begin in broad strokes / Just like my friend Keynes / His [[Wikipedia:The General Theory of Employment, Interest, and Money|Theory]] conceals the Mechanics of Change / That simple equation¹ / <br />
Too much aggregation / Ignores human action / and motivation.<br/><small>¹<code>(C+I+G=Y)</code></small></small></ref> that actually controls economic activity. This weakness, an unscientific [https://mises.org/library/pretense-knowledge pretense of knowledge], is revealed by the fact that they are almost universally abysmal economic investors. The one famous exception to this was [[Wikipedia:John Maynard Keynes|Keynes]], who made a fortune off of stocks, but who also was machiavellian enough to advocate for economic ideas he did not believe in. According to his friend and fellow Nobel laureate [[Wikipedia:Friedrich Hayek|Friedrich Hayek]], Keynes pushed for stimulus spending for political reasons, and was planning to reverse his position when his untimely death intervened. —[[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 18:30, 21 November 2019 (UTC)<br />
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There is also an element here of the fact that engineers understand mathematics in a framework of science that others have worked out. Solving a problem in mechanics might feel similar to solving a problem in the stock market, except that Newton/Lagrange already worked out the science, so you just have to do the math. For the stock market the science isn't worked out. Scientists can come a cropper because they lack the engineering sense to be practical in a real world application, while engineers come a cropper because they assume a system rather than discovering it. When scientists and engineers collaborate then the result is sometimes some of the most successful investing firms on the planet.</div>162.158.158.87https://www.explainxkcd.com/wiki/index.php?title=Talk:1047:_Approximations&diff=183829Talk:1047: Approximations2019-11-28T20:47:25Z<p>162.158.158.87: </p>
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<div>The US population estimate is now off by 7 million, although 2018 just started. Even so, in December 2017, it would have been 4 million off. [[User:625571b7-aa66-4f98-ac5c-92464cfb4ed8|625571b7-aa66-4f98-ac5c-92464cfb4ed8]] ([[User talk:625571b7-aa66-4f98-ac5c-92464cfb4ed8|talk]]) 00:54, 19 January 2018 (UTC)<br />
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: Off by 7 million out of 7-8 billion means that it's accurate to one part in 1,000. That's consistent with it's location in the chart -- next to other values that are accurate to 1 in 1,000. {{unsigned|Redbelly98}}<br />
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The world population estimate is still accurate to within .1 billion. [[Special:Contributions/162.158.63.28|162.158.63.28]] 13:41, 5 May 2017 (UTC)<br />
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They're actually quite accurate. I've used these in calculations, and they seem to give close enough answers. '''[[User:Davidy22|<span title="I want you."><u><font color="purple" size="2px">David</font><font color="green" size="3px">y</font></u><sup><font color="indigo" size="1px">22</font></sup></span>]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 14:03, 8 January 2013 (UTC)<br />
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I only see a use for the liters in a gallon one. The rest are for trolling or simple amusement. The cosine identity bit our math team in the butt at a competition. It was painful. --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 05:27, 17 August 2013 (UTC)<br />
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Annoyingly this explanation does not cover 42 properly, it does not say that Douglas Adams got the number 42 from Lewis Carroll, who is more relevant to the page because he was a mathematician named Charles Lutwidge Dodgson. He was obsessed with the number forty-two. The original plate illustrations of Alice in Wonderland drawn by him numbered forty-two. Rule Forty-Two in Alice in Wonderland is "All persons more than a mile high to leave the court", There is also a Code of Honour in the preface of The Hunting of the Snark, an extremely long poem written by him when he was 42 years old, in which rule forty-two is "No one shall speak to the Man at the Helm". The queens in Alice Through the Looking Glass the White Queen announces her age as "one hundred and one, five months and a day", which - if the best possible date is assumed for the action of Through the Looking-Glass - gives a total of 37,044 days. With the further (textually unconfirmed) assumption that both Queens were born on the same day their combined age becomes 74,088 days, which is 42 x 42 x 42. --[[Special:Contributions/139.216.242.254|139.216.242.254]] 02:43, 29 August 2013 (UTC)<br />
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:: This explanation covers 42 adequately, and would probably be made slightly worse if such information were added. The very widely known cultural reference is to Adams's interpretation, not Dodgson's original obsession. Adding it would be akin to introducing the MPLM into the explanation for the hijacking of Renaissance artists' names by the TMNT. I definitely concede that it does not cover 42 exhaustively, but I think it can be considered complete and in working order without such an addition. If it really irks you, be bold and add it! --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 00:37, 30 August 2013 (UTC)<br />
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::: Additionally, the Lewis Carroll idea is only one of several theories about where Douglas Adams got the number from. [[Special:Contributions/162.158.158.87|162.158.158.87]] 20:47, 28 November 2019 (UTC)<br />
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"sqrt(2) is not even algebraic in the quotient field of Z[pi]" is not correct. Q is part of the quotient field of Z[pi] and sqrt(2) is algebraic of it. The needed facts are that pi is not algebraic, but the formula implies it is in Q(sqrt(2)). --DrMath 06:47, 7 September 2013 (UTC)<br />
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13/15 is a better approximation to sqrt(3)/2 than is e/pi. Continued fraction approximations are great! --DrMath 07:23, 7 September 2013 (UTC)<br />
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How could he forget 1 gallon ≈ 0.1337 ft³?! [[Special:Contributions/67.188.195.182|67.188.195.182]] 00:51, 8 September 2013 (UTC)<br />
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Worth mentioning that Wolfram Alpha now officially recognizes the [http://www.wolframalpha.com/input/?i=e%5E-%28%281%2B8%5E%281%2F%28e-1%29%29%29%5E%281%2Fpi%29%29 White House switchboard constant] and the [http://www.wolframalpha.com/input/?i=%287%5E%28e-1%2Fe%29-9%29*pi%5E2 Jenny constant]. [[Special:Contributions/86.164.243.91|86.164.243.91]] 18:28, 8 October 2013 (UTC)<br />
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Maybe we should add the [Extension:LaTeXSVG LaTeX extension] to make it easier to transcribe these equations. -- [[Special:Contributions/108.162.219.220|108.162.219.220]] 23:02, 16 December 2013 (UTC)<br />
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;Protip - Does anyone see the correct equation?<br />
Maybe this is just an other Wolfram Alpha error, like we recently have had here: [[1292: Pi vs. Tau]]. All equations still look invalid to me.<br />
*''√2 = 3/5 + π/(7-π)'': is impossible because √2 is an irrational number and no equation can match.<br />
*''cos(π/7) + cos(3π/7) + cos(5π/7) = 1/2'': could only match if ''cos(x) + cos(3x) + cos(5x) = 1/2'' would be valid, because ''π/7'' is also an irrational number.<br />
*''γ = e/3<sup>4</sup> + e/5 or γ = e/54 + e/5'': would mean that a sum of two irrational numbers do fit to the Gamma Constant. Impossible.<br />
*''√5 = 13 + 4π / 24 - 4π'': √5 and π are irrational numbers, there is no way to match them in any equation like this.<br />
*''Σ 1/n<sup>n</sup> = ln(3)<sup>e</sup>'': doesn't make any sense either.<br />
Maybe [[:Category:Comics featuring Miss Lenhart|Miss Lenhart]] can help.<br />
--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:41, 17 December 2013 (UTC)<br />
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cos(π/7) + cos(3π/7) + cos(5π/7) = 1/2 is exactly correct. <br />
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Let a=π/7, b=3π/7, and c=5π/7, then <br />
(cosa+cosb+cosc)⋅2sina=2cosasina+2cosbsina+2coscsina=sin2a+sin(b+a)−sin(b−a)+sin(c+a)−sin(c−a)=sin(2π/7)+sin(4π/7)−sin(2π/7)+sin(6π/7)−sin(4π/7)=sin(6π/7)=sin(π/7)=sina<br />
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Hence, cos(π/7) + cos(3π/7) + cos(5π/7) = sin(π/7) / 2sin(π/7) = 1/2<br />
[[Special:Contributions/108.162.216.74|108.162.216.74]] 01:57, 16 January 2014 (UTC)<br />
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:What is this: sin(6π/7)=sin(π/7) ? A new math is born... --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:49, 16 January 2014 (UTC)<br />
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::Actually it does. My proof is geometric: the sines of two supplementary angles (angle a + angle b = π (in radians)) are equivalent because they necessarily have the same x height in a Cartesian plane. Look on a unit circle, or even a sine function. Also, Calculus and most other mathematics use radians over degrees because they make the functions simpler and eliminate irrationality when a trig function shows up, but physics uses degrees because it's easier to understand and taught first. Anonymous 01:27, 13 February 2014 (UTC)<br />
::As an aside, just how far along in math are you? Radian measure is taught in high school (at least the good ones). Anonymous 13:24, 13 February 2014 (UTC)<br />
:::Sure, I was wrong at my last statement. sin(6π/7)=sin(π/7) is correct by using the radian measure. But just change π/7 to π/77 would give a very different result on that formular here. I still can't figure out why PI divided by the number 7 should be that unique, PI divided by 77 should be the same. My fault is: I still can't find the Nerd Sniping here. And we all do know that Randall did use wrong WolframAlpha results here. According to the last question: I'm very well on Math, that's because I want to understand this. This is like 0.999=1. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 22:01, 13 February 2014 (UTC)<br />
::::Ah, I see. I think it has to do with the way e^i*π breaks down, as one of the answers shown in the corresponding link explains, but other answers rely on various angle identities (including the supplementary sines one in the proof above). Anonymous 03:10, 14 February 2014 (UTC) (PS, have you checked [[545]] lately? I answered your question there, too)<br />
:::::As per the derivation from january 16 , you can use any a,b,c that satisfies this set of equations: 2 a = b - a, a + b = c- a, c + a = π - a. This is due to the fact that sin(x) = sin(π-x), and what was derived the 16th. [[Special:Contributions/173.245.53.199|173.245.53.199]] 12:38, 21 February 2014 (UTC)<br />
:::: Dgbrt: If not convinced by the proofs linked to in the "explanation" part, you might want to try this: [http://www.wolframalpha.com/input/?i=sum_%28k%3D0%29%5E38+cos%281%2F77+%282+k%2B1%29+pi%29]. I'm sure you'll find inspiration for similar formulas using PI over [any odd integer]. Your assumption that Randall used WolframAlpha for this very identity is probably wrong. This is a very well-known formula that appears in many high school books, and I am pretty sure it is part of Randall's culture. And this has nothing to do with 1=1. As for your original post,<br />
::::*√2 = (√2-1)/((4-2)π/2-π)+1 : Is this what you call "matching an equation" to √2?<br />
::::*So what you mean is that if an equation is true for an irrational number, then it must be for any real number? Like, (√2)^2 = 2, but because √2 is irrational, then x^2=2 (for all x?)<br />
::::*This one's a bit tough. You will probably agree that γ-√2 is irrational. And so is √2. What about their sum?<br />
::::*Well, maybe it doesn't to you. But is Σ n<sup>-2</sup> = π^2/6 any better? Well, this one is true (using Fourier's expansion of the rectangular function). <br />
::::Finally,<br />
::::*√2 = 3/5 + π/(7-π) is false because it would imply that π is an algebraic number<br />
::::*cos(π/7) + cos(3π/7) + cos(5π/7) = 1/2 is true, and proven by many<br />
::::*γ = e/3<sup>4</sup> + e/5 seems false. But there doesn't seem to be a quick way to disprove.<br />
::::*Σ 1/n<sup>n</sup> = ln(3)<sup>e</sup> seems false, but I can't see why. [[Special:Contributions/108.162.210.234|108.162.210.234]] 09:15, 11 May 2014 (UTC)<br />
::Dgbrt, yes, sin(6π/7)=sin(π/7). Simple proof: sin(6π/7)=sin(π-π/7)=sin(π)cos(-π/7)+cos(π)sin(-π/7)=0*cos(-π/7)+(-1)*(-sin(π/7))=0+sin(π/7)=sin(π/7) [[Special:Contributions/108.162.215.89|108.162.215.89]] 02:34, 20 May 2014 (UTC) <br />
;So, still incomplete?<br />
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Where's our (in)complete judge? [[Special:Contributions/199.27.128.186|199.27.128.186]] 19:21, 18 December 2013 (UTC)<br />
:The protip is still a mystery. I'm calling for help a few lines above. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:16, 18 December 2013 (UTC)<br />
::The cosine one, in radians, is correct [[Special:Contributions/141.101.88.225|141.101.88.225]] 12:54, 28 April 2014 (UTC)<br />
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The 'Seconds in a year' ones remind me of one of my favorite quotes: "How many seconds are there in a year? If I tell you there are 3.155 x 10^7, you won't even try to remember it. On the other hand, who could forget that, to within half a percent, pi seconds is a nanocentury" -- Tom Duff, Bell Labs. [[User:Beolach|Beolach]] ([[User talk:Beolach|talk]]) 19:14, 17 April 2014 (UTC)<br />
:Please do not change former discussions. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 23:57, 17 April 2014 (UTC)<br />
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;cos(pi/7) + cos(3pi/7) + cos(5pi/7) = 1/2 ???<br />
Why the hell the divider seven makes the difference?<br />
*cos(pi) + cos(3*pi) + cos(5*pi) = -3<br />
*cos(pi/8) + cos(3*pi/8) + cos(5*pi/8) = 0.92387953251128675612818318939678828682241662586364...<br />
So why the "magic" prime number seven produces this exact result? I know radians and π/7 is just a small part of a circle which is 2π. One prove claims that sin(6π/7) equals to sin(π/7); my best calculator can't show a difference. Of course sin(6π) equals to sin(π), in radians, BUT sin(6π/8) is NOT equal to sin(π/8). So if the number 7 plays a magic rule here this would be "one of the", no... the BIGGEST mystery in mathematics forever. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 23:03, 16 May 2014 (UTC)<br />
:Dgbrt, please see my answer from 11 May 2014 up there. Any odd integer will do, as long as you sum enough of cos(pi/[thing]). <br />
:*Let's try with 5 : cos(pi/5) + cos (3pi/5) = 1/2.<br />
:*With 9 : cos(pi/9)+ cos(3pi/9) + cos (5pi/9) + cos(7pi/9) = 1/2<br />
: No big mystery around here. Just a beautiful formula :) I think there are similar formulas with cosines and even integers. I'll post them here if I have time. [[User:Varal7|Varal7]] ([[User talk:Varal7|talk]]) 09:56, 17 May 2014 (UTC)<br />
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::You mixing up to different equations and even not prove them. If there is any prove to a mathematician I would accept and include a proper explain for non math people here. We still have to find a prove. And I do not trust my calculators, we just have to explain why even cos(pi/5) + cos (3pi/5) is also nearly the same. This issue is still not explained. So please give us a explain. And a PROTIP: This does not work with Integers, PI is infinite--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 17:55, 17 May 2014 (UTC)<br />
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:::Okay. If I understood what you said.<br />
:::* I mix up different topics. -> True. From now on, we'll just focus on the cosine one.<br />
:::* You ask for a proof/explanation. -> My opinion is those are two different requests. Maybe that's why you use the distinction between math people/not math people. For a proof, please read further. What I exposed above are just other "fun experiments" we could do. e.g : [http://www.wolframalpha.com/input/?i=cos%28pi%2F11%29%2Bcos+%283pi%2F11%29+%2B+cos+%285pi%2F11%29+%2B+cos+%287pi%2F11%29%2Bcos+%289pi%2F11%29].<br />
:::* You do not trust your calculators -> Great. I don't either. (Well more accurately, I trust mine to 10^-8, so I would definitely not use it to prove any of the discussed equations in PROTIP). That's why we'll prove the formulas we assert.<br />
:::* "This does not work with integers" -> Well, I got myself misunderstood. It would probably have been better if I had said: the following formula is true for all integer n. sum_{k=0}^{n-1}{cos((2k+1)*pi/(2n+1)). But It's harder to read, so just say. Choose any odd integer, say N=2n+1. Then start the following sum. cos(pi/N) + cos(3pi/N) + … and stop when the numerator is cos((N-2)pi/N). Then the result is 1/2. And that's what we'll prove, a few lines down from here.<br />
:::*"Pi is infinite" -> That's a common misconception. What you mean is, Pi is irrational. (Fun fact: Pi is a transcendental number. Quite difficult theorem. Lindeman proved it in 1882. Hence, if we identify the real number x with the Q-vector space Q[x], it would make sense to say that "x is infinite" because, the Q-vector space Q[x] is indeed of infinite dimension. But then, that's not what mathematicians do). I think Vi Hart made a video where she addresses this issue (or was it someone else?). Anyway, I might come to that point some other time in the future.<br />
:::Okay, so now let's first prove the protip formula. Well first, here is the link that the explainxkcd wiki points to: [http://math.stackexchange.com/questions/140388/how-can-one-prove-cos-pi-7-cos3-pi-7-cos5-pi-7-1-2]. Most of them are correct. Some are more ugly than others. I'll adapt the last one.<br />
::: We need a [http://en.wikipedia.org/wiki/Complex_number complex numbers]. (I choosed this because I think explainxkcd readers are fine with this. See comic [http://explainxkcd.com/179/ 179]). I will be using dots to show the steps of my proof. Please allow me an extra level of indent for clarity's sake.<br />
:::'''Proof'''<br />
:::: *Let z be a primitive 14-th [http://en.wikipedia.org/wiki/Root_of_unity root of unity] (the reader doesn't need to understand the 3 last words). Just say z = exp(i*pi/7) = cos(pi/7) + i sin(pi/7). Using [http://en.wikipedia.org/wiki/Euler%27s_formula Euler's formula].<br />
:::: *We have z^14-1 = (exp(i*pi/7))^14-1 = exp(i*2pi) - 1 = 0. Using exponential law for integer powers, as seen in this article: [http://en.wikipedia.org/wiki/De_Moivre%27s_formula De Moivre's formula].<br />
:::: *Now let's factor: z^14-1 = (z^7-1)(z^7+1) = (z^7-1)(z+1)(z^6-z^5+z^4-z^3+z^2-z+1) = (z^7-1)(z+1)*Phi_14(z). where Phi_14(X)= X^6-X^5+X^4-X^3+X^2-X+1, (see [http://en.wikipedia.org/wiki/Cyclotomic_polynomial cycltomic polynomial]). Now, because z^7-1 = (exp(i*pi/7))^7-1 = exp(i*pi)-1 = -2. And because z is not -1, the two first factors are not 0 so, Phi_14(z) = 0, which is already a pretty awesome equality.<br />
:::: *Note that exp(i*pi/7)*exp(i*6pi/7)= exp(i*pi)=-1. So the inverse of z is -exp(i*6pi/7). But we also know that it is exp(-i*pi/7). Well. That was just a fancy way to prove that exp(-i*pi/7) = - exp(i*6pi/7). Good enough. The same holds for exp(-i*3pi/7) = exp(i*14pi/7)*exp(-i*3pi/7)=exp(i*11pi/7)=exp(i*7pi/7)*exp(i*4pi/7)=-exp(i*4pi/7). And the exact same calculation shows that exp(-i*5pi/7)=-exp(i*2pi/7). Alright.<br />
:::: *Now, use that for any x, we have cos(x) = (exp(ix)+exp(-ix))/2. See [http://en.wikipedia.org/wiki/Euler%27s_formula#Relationship_to_trigonometry here]. Let's calculate twice the sum of the left hand side. 2(cos(pi/7)+cos(3pi/7)+cos(5pi/7))= exp(i*pi/7) + expi(-i*pi/7) + exp(3pi/7) + exp(-3pi/7) + exp(5pi/7) +exp(-5pi/7) = exp(i*pi/7)-exp(i*2pi/7)+exp(i*3pi/7)-exp(i*4pi/7)+exp(i*5pi/7)-exp(i*6pi/7) = -Phi_14(z) +1 = 1.<br />
:::: * So dividing both sides by 2, we get what we want. Pfew. <br />
::: '''Why is 7 so special? Well it isn't.''' Let's prove it for 9. <br />
::::* Let z = exp(i*pi/9) = cos(pi/9) + i sin(pi/9). We have z^18-1 = 0, and z^9-1 and z+1 are not 0, so using the same factorisation, Phi_18(z) = z^8-z^7+z^6-z^5+z^4-z^3+z^2-z+1 = 0. <br />
::::* Hence, the conclusion follow from: 2(cos(pi/9) + cos(3pi/9) + cos(5pi/9) + cos(7pi/9)) = exp(i*pi/9) + exp(-i*pi/9) + exp(i*3pi/9) + exp(-i*3pi/9) + exp(i*5pi/9) + exp(-i*5pi/9) + exp(i*7pi/9) + exp(-i*7pi/9) = -Phi_18(z)+1 = 1. <br />
::: Well, well. I hope you kinda see the pattern. Dgbrt, I know you hate typos, and I'm pretty sure that in this long text lay many of them. So I apologize, and I will correct them later. The following paragraph was posted after I started my text but before I finished mine. It wasn't signed so I will just leave it down there. It's another valid straightforward proof. Oh. And Friendly TIP: Don't say protip when you're not pro. [[User:Varal7|Varal7]] ([[User talk:Varal7|talk]]) 21:50, 17 May 2014 (UTC)<br />
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The valid identity cos(pi/7)+cos(3pi/7)+cos(5pi/7)=1/2 was correctly proved by the writer at 108.162.216.74 above. For a different proof, consider the complex number z = cos(pi/7)+i sin(pi/7) corresponding to rotation of the complex plane by pi/7 radians, i.e., 1/14th of a full rotation. It satisfies z^{14} -1 = 0 (z to the fourteenth is one). Dividing by z-1 gives z^{13} + z^{12} + ... + z + 1 = 0. The same argument, starting with z^2 corresponding to 1/7th of a full rotation, gives z^{12} + z^{10} + ... z^2 + 1 = 0. Taking the difference, we get z^{13} + z^{11} + ... + z^3 + z = 0. Looking only at the real parts, we get cos(13pi/7) + cos(11pi/7) + cos(9pi/7) + cos(7pi/7) + cos(5pi/7) + cos(3pi/7) + cos(pi/7) = 0. Here cos(13pi/7) = cos(pi/7), cos(11pi/7) = cos(3pi/7) and cos(9pi/7) = cos(5pi/7), since cos is even and 2pi-periodic. Finally cos(7pi/7) = -1, so 2(cos(pi/7) + cos(3pi/7) + cos(5pi/7)) - 1 = 0, which you can rewrite as the desired identity. All of this can be clearly visualized using a regular 14-gon, so a proof with pictures is possible. {{unsigned ip|141.101.81.216}}<br />
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;99 is sexual reference?<br />
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In first explanation it says: "99^8 and 69^8 are sexual references". 69 I understand, but what would 99 refer too? <br />
--[[Special:Contributions/173.245.53.167|173.245.53.167]] 17:38, 18 May 2014 (UTC)<br />
: see [[487: Numerical Sex Positions]][[Special:Contributions/141.101.70.181|141.101.70.181]] 15:33, 20 July 2014 (UTC)<br />
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I'd add pi = (9^2 + (19^2)/22)^(1/4) [[Special:Contributions/198.41.230.73|198.41.230.73]] 02:41, 13 May 2015 (UTC)<br />
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'''Yet another proof of cos(π/7) + cos(3π/7) + cos(5π/7) = 1/2''' — Use the multi-angle formula cos(7θ) = 64(cos θ)^7 − 112(cos θ)^5 + 56(cos θ)^3 − 7(cos θ),<br />
and assume cos(7θ)=−1; then 7θ=π, 3π, 5π, 7π, etc.<br />
Let x=cos θ, then x = cos(π/7), cos(3π/7), cos(5π/7), cos(7π/7), etc.<br /><br />
Now one could actually solve 64x^7 − 112x^5 + 56x^3 − 7x + 1 = (x+1)(8x^3 − 4x^2 − 4x + 1)^2 = 0,<br />
but it’s easier to argue that cos(π/7), cos(3π/7), cos(5π/7) are the 3 roots of the cubic equation 8x^3 − 4x^2 − 4x + 1,<br />
and so (using the relationship of the roots and the coefficients) their sum is −(−4)/8 = 1/2.<br />
[[User:Yosei|Yosei]] ([[User talk:Yosei|talk]]) 08:19, 17 February 2019 (UTC)</div>162.158.158.87https://www.explainxkcd.com/wiki/index.php?title=2210:_College_Athletes&diff=1807822210: College Athletes2019-10-02T16:02:07Z<p>162.158.158.87: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2210<br />
| date = October 2, 2019<br />
| title = College Athletes<br />
| image = college_athletes.png<br />
| titletext = Their signature play is the three-point combinator, a recursive offense which is guaranteed not to halt and continues accumulating points until the buzzer.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a Steph Curry. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}<br />
<br />
[[Ponytail]] is reading from her phone about the [https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201920200SB206 California Fair Pay to Play act], which was signed into law on September 30, 2019, two days before this comic was released. It gives college athletes the rights to their name and face (images) for financial gain, in contrast to {{w|NCAA}} rules which require that athletes be unpaid.<br />
<br />
[[White Hat]], thinks this is a good thing, but then [[Cueball]] claims that his state has passed an even better law which ''gave college players rights to use the names and images of any California athletes''. Note that Cueball's state is thus not California, so it is very weird they can use names from another state.<br />
<br />
Ponytail doesn't believe him but he ''curries'' on claiming that all members of his school's basketball team thus have changed their name to {{w|Steph Curry}}, after the NBA Player who plays for the {{w|Golden State Warriors}}, a Californian team. Cueball explains in particular, that only one player copied the name from the NBA player, then another member of the team copied the name from that player, and so on. <br />
<br />
This is of course an error, since they only had right to use names of California athletes, and as this is another state than California, they could not have used the law to use the name of one of their fellow team mates. Mistake by Randall, or Cueball that is just making a joke...<br />
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Because as it turns out in his final remark, all this has only been the setup for his grand joke, when he tells Ponytail that this process is known as "Currying". This is a play on both the name "Curry" used here, as well as the mathematical procedure called {{w|currying}}, named after mathematician {{w|Haskell Curry}}. This is very typical Cueball, and Ponytail almost fell for it, and thus claims that she hates him!<br />
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Currying is when a multi-variable function is broken down into a sequence of single-variable functions, each of which outputs a new function until the final variable is consumed. For example, the function f(x,y,z) can be curried into f(x)(y)(z), where f is a function that consumes x and produces a function f(x), which in turn consumes y, yielding the function f(x)(y), and that in turn is a function f(x)(y) which consumes the parameter z to finally produce f(x)(y)(z), which is equal to the original f(x,y,z). This is not commonly used in most areas of math except for foundational logic but it is widely used in functional programming.<br />
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When Cueball says ''a team made up entirely of Steph Currys'', White Hat questions what the plural form should be, and is it instead should have been ‘''Stephs Curry''’? This is referring to the pluralization of phrases where a noun is followed by a modifier of some sort, such as ''attorneys general'', ''parts unknown'', ''heirs apparent'', ''mothers-in-law'', and so on. In these cases, plurals are formed by pluralizing the noun parts of the phrases; however, some of these are rare or foreign enough that speakers of English don't always identify them correctly and pluralize the last word instead, e.g. *''attorney generals''.<br />
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The title text is a computer science joke, saying that the Steph Currys basketball team's signature play is the "three-point combinator", a joke on the {{w|three-point play}} in basketball, and a type of {{w|Fixed-point_combinator#Y_combinator|fixed-point combinator}} called the [https://rosettacode.org/wiki/Y_combinator Y Combinator], introduced by Haskell Curry. The description of "three-point combinator" is dense with word play that relates to the Y Combinator, which is used to implement {{w|recursive}} methods in functional programming languages, has notable properties relating to halting (see: the {{w|Halting_problem|Halting Problem}}), and has a common form in which a second argument is used as a counter that is increased by one with each recursive call until termination. "Signature play" may also be a play on words, as currying transforms a {{w|Type_signature#Method_signature|method signature}}.<br />
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In this case, when this move is performed, it will just keep accumulating points, as it is guaranteed it cannot halt and will not stop until the time runs out and the buzzer that ends the game is activated. Such a move can of course not be a part of a real basketball game, and more of a nod to the Golden State Warriors' reputation as a high-scoring, nearly-unstoppable offense widely-known for three-point shooting.<br />
<br />
==Transcript==<br />
:[Cueball, Ponytail and White Hat are having a conversation. Ponytail is checking her phone.]<br />
:Ponytail: Oh, huh. California passed a law giving college athletes full rights to their names and images.<br />
:White Hat: Good, I think?<br />
<br />
:[Cueball holds his hand up in a fist, while Ponytail, holding her phone down, and White hat looks at him.]<br />
:Cueball: That's nothing. '''''Our''''' state gave college players rights to use the names and images of '''''any''''' California athletes.<br />
:Ponytail: It did not.<br />
<br />
:[In a frame-less panel Cueball holds his hands out, Ponytails phone is gone and White Hat puts a hand to his chin.]<br />
:Cueball: Sure it did!<br />
:Cueball: That's how our school fielded a basketball team made up entirely of Steph Currys.<br />
:White Hat: Or is the plural "Stephs Curry"?<br />
<br />
:[Cueball holds both hands up in front of him. Ponytail has her arms down but she is balling her hands into fists.]<br />
:Cueball: They didn't all copy the original Steph, though. One player got the rights to his name, then the next player got it from them, and so on.<br />
:Cueball: This process is known as "currying".<br />
:Ponytail: ...I hate you so much.<br />
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{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Math]]<br />
[[Category:Sport]]<br />
[[Category:Basketball]]</div>162.158.158.87