http://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=199.27.128.110&feedformat=atomexplain xkcd - User contributions [en]2018-09-20T13:35:32ZUser contributionsMediaWiki 1.30.0http://www.explainxkcd.com/wiki/index.php?title=410:_Math_Paper&diff=69001410: Math Paper2014-06-06T15:39:03Z<p>199.27.128.110: /* Transcript */ Changed to match discussion.</p>
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<div>{{comic<br />
| number = 410<br />
| date = April 14, 2008<br />
| title = Math Paper<br />
| image = math_paper.png<br />
| titletext = That's nothing. I once lost my genetics, rocketry, and stripping licenses in a single incident.<br />
}}<br />
<br />
==Explanation==<br />
This comic is a set up to use the joke about {{w|imaginary friend}}s by taking the concept of "{{w|friendly number}}s" into the complex plane, which comprises numbers that have both a real and an imaginary part. Such a pun is both so obvious and so terrible that Cueball's superiors deem that he has lost the right to carry a "math license". <br />
<br />
This is a recurring theme in earlier xkcd comics, being banned from holding presentations at conferences because said presentations are just elaborate puns. The title text takes the joke a step further, with the added hilarity of making the audience ask just how the hell Cueball was able to work a {{w|striptease}} into a presentation about genetic engineering and astrophysical rocket study. This is what TV Tropes calls a "[http://tvtropes.org/pmwiki/pmwiki.php/Main/NoodleIncident noodle incident]".<br />
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===Math===<br />
An {{w|imaginary number}} is a number that can be written as a real number multiplied by the imaginary unit ''i'', which is defined by its property ''i<sup>2</sup> = -1'' (an impossibility for regular, "real" numbers, for which all squares are positive). The name "imaginary number" was coined in the 17th century as a derogatory term, since such numbers were regarded by some as fictitious or useless, but over time many applications in science and engineering have been found.<br />
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An imaginary number ''bi'' can be added to a real number ''a'' to form a {{w|complex number}} of the form ''a+bi'', where ''a'' and ''b'' are called, respectively, the real part and the imaginary part of the complex number.<br />
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Joel Bradbury has a wonderful explanation of {{w|friendly number}}s on [http://joelbradbury.net/notes/friendly_numbers his site]:<br />
<br />
:What are Friendly Numbers? <br />
:We need first to get define a divisor function over the integers, written σ(n) if you're so inclined. To get it first we get all the integers that divide into n. So for 3, it's 1 and 3. For 4, it's 1, 2, and 4, and for 5 it's only 1 and 5.<br />
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:Now sum them to get σ(n). So σ(3) = 1 + 3 = 4, or σ(4) = 1 + 2 + 4 = 7, and so on.<br />
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:For each of these n, there is something called a characteristic ratio. Now that's just the divisors function over the integer itself: σ(n)/n . So the characteristic ratio where n = 6 is σ(6)/6 = 12/6 = 2.<br />
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:Once you have the characteristic ratio for any integer n, any other integers that share the same characteristic are called friendly with each other. So to put it simply a friendly number is any integer that shares its characteristic ratio with at least one other integer. The converse of that is called a solitary number, where it doesn't share it's characteristic with anyone else.<br />
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:1, 2, 3, 4 and 5 are solitary. 6 is friendly with 28; σ(6)/6 = (1+2+3+6)/6 = 12/6 = 2 = 56/28 = (1+2+4+7+14+28)/28 = σ(28)/28.<br />
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==Transcript==<br />
:[Cueball points to equations on the board.]<br />
:Cueball: In my paper, I use an extension of the divisor function over the Gaussian integers to generalize the so-called "friendly numbers" into the complex plane.<br />
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:Professor: Hold on. Is this paper simply a giant build-up to an "imaginary friends" pun?<br />
<br />
:[Cueball stands speechless for two panels.]<br />
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:Cueball: It <u>MIGHT</u> not be.<br />
:Professor: I'm sorry, we're revoking your math license.<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Banned from conferences]]<br />
[[Category:Public speaking]]</div>199.27.128.110http://www.explainxkcd.com/wiki/index.php?title=259:_Clich%C3%A9d_Exchanges&diff=61343259: Clichéd Exchanges2014-02-28T00:09:34Z<p>199.27.128.110: </p>
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<div>{{comic<br />
| number = 259<br />
| date = May 9, 2007<br />
| title = Clichéd Exchanges<br />
| image = cliched exchanges.png<br />
| titletext = It's like they say, you gotta fight fire with clichés.<br />
}}<br />
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==Explanation==<br />
Another entry into the [[My Hobby]] series.<br />
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"{{w|O RLY?}}" is an Internet meme typically used to express sarcastic agreement with or feigned surprise at a statement. The typical response to "O RLY" is usually "YA RLY", "NO WAI" or "SRSLY?" These exchanges are all just so many SMS abbreviations for "Oh really?", "Yeah really", "No way!", and "Seriously?" respectively<br />
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[[Cueball]]'s response avoids this typical exchange though, instead replying with another cliche: the double entendre. For example:<br />
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:Friend: You're such a messy eater.<br />
:You: Eat her? I hardly know her!<br />
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Such a double entendre makes no sense in the context of an O RLY exchange, and will only serve to derail the conversation.That's really all there is to this comic. Cueball/Randall are bored of cliches, and are finding ways to amuse themselves.<br />
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In the ''title text'' the joke is that the real cliché is that ''you fight fire with fire'', whereas in the comic, Cueball fights a cliché with another cliché.<br />
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==Transcript==<br />
:My Hobby:<br />
:Derailing clichéd exchanges by using the wrong replies<br />
<br />
:Friend: O RLY?<br />
:Cueball: O RLY? I 'ardly know 'er!<br />
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{{comic discussion}}<br />
[[Category:My Hobby]]<br />
[[Category:Comics featuring Cueball]]</div>199.27.128.110