Difference between revisions of "599: Apocalypse"

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search
(Explanation: expanded "not everyone" paragraph)
m (Explanation: ce)
Line 14: Line 14:
 
Thanks to collaboration between mathematicians and other researchers, many people in science and medical research now have Erdős numbers. Not everyone has a (finite) Erdős number, though; people without any chain linking them to Erdős have an Erdős number of infinity (or an undefined Erdős number). For example, most people who are not mathematicians or scientists do not have a finite Erdős number.
 
Thanks to collaboration between mathematicians and other researchers, many people in science and medical research now have Erdős numbers. Not everyone has a (finite) Erdős number, though; people without any chain linking them to Erdős have an Erdős number of infinity (or an undefined Erdős number). For example, most people who are not mathematicians or scientists do not have a finite Erdős number.
  
In this comic, the apocalypse happens. [[Cueball]] quickly writes a math paper and gets everyone from the math dept. to sign it. Then he gets the resurrected Erdős to sign it. This way everyone from the math dept. has an Erdős number of 1.
+
In this comic, the apocalypse happens. [[Cueball]] quickly writes a math paper and gets everyone from the math department to sign it. Then he gets the resurrected Erdős to sign it. This way everyone from the department has an Erdős number of 1.
  
 
Paul Erdős described people who had stopped doing mathematics as "dead."
 
Paul Erdős described people who had stopped doing mathematics as "dead."

Revision as of 01:01, 23 March 2014

Apocalypse
I wonder if I still have time to go shoot a short film with Kevin Bacon.
Title text: I wonder if I still have time to go shoot a short film with Kevin Bacon.

Explanation

According to Wikipedia, Paul Erdős (26 March 1913 – 20 September 1996) was a Hungarian mathematician who published more papers than any other mathematician in history, working with hundreds of collaborators.

There is an in-joke developed among mathematicians called the Erdős number (similar to a Bacon number for film actors, which we'll discuss in a minute). By definition, Erdős has an Erdős number of 0. Everyone who has co-written a mathematical paper with Erdős has an Erdős number of 1. Everyone who collaborated with them (but not Erdős himself) is assigned an Erdős number of 2. In general, if k is the minimal Erdős number of all the people you've written papers with, your Erdős number is k + 1. The Erdős number is the length of the shortest "chain" from you to Erdős.

Thanks to collaboration between mathematicians and other researchers, many people in science and medical research now have Erdős numbers. Not everyone has a (finite) Erdős number, though; people without any chain linking them to Erdős have an Erdős number of infinity (or an undefined Erdős number). For example, most people who are not mathematicians or scientists do not have a finite Erdős number.

In this comic, the apocalypse happens. Cueball quickly writes a math paper and gets everyone from the math department to sign it. Then he gets the resurrected Erdős to sign it. This way everyone from the department has an Erdős number of 1.

Paul Erdős described people who had stopped doing mathematics as "dead."

The title text mentions a similar (and less esoteric) meme called "Six degrees of Kevin Bacon", or simply Bacon numbers. This time, the chain's center is actor Kevin Bacon, and the links are formed by two people appearing in the same movie. Unlike Erdős, Kevin Bacon is not dead, so those of you wishing to get a Bacon number of 1 still have a chance.

One of the mathematical scribbles appearing in panel 5 shows the square root of 163, which may be a reference to Ramanujan's constant.

Transcript

[Scene of meteors showering the darkened earth.]
[Beret Guy is running, with his arms raised in the air.]
Beret Guy: The apocalypse! The skies burn, the seas turn to blood, and the dead walk the earth!
[Cueball and Beret Guy.]
Cueball: The dead what?
Beret Guy: Walk the earth!
[Cueball running.]
Cueball: I have to go.
[Cueball scribbling at a table. Mathematical symbols and equations are above Cueball's head.]
Scribble scribble
[Cueball running, paper and pencil in hand.]
[Cueball opening door labelled "Math dept."]
Cueball: The dead return! Everyone, quick, get your names on here!
[People lining up.]
Female Mathematician: At last!
Male Mathematician: I hope there's still time!
[Cueball running.]
[Cueball at a cemetery.]
Rising dead: Hurrghhh
[Cueball finds a man rising from his grave.]
Cueball: Paul Erdős?
Erdős: Yes?
Cueball: We need you to sign this.


comment.png add a comment! ⋅ comment.png add a topic (use sparingly)! ⋅ Icons-mini-action refresh blue.gif refresh comments!

Discussion

Imagine the result if the ressurected Erdős also appears in that proposed short film with Bacon. They'd both immediately get Erdős–Bacon numbers of 1, for themselves, and then every traditionally Erdős-numbered person and every single Bacon-numbered person would be guaranteed to end up with an Erdős–Bacon number of no more than their existing (Erdős|Bacon) number plus one! It would make a mockery of the entire system!!! ...and that's why the end of the world is a Bad ThingTM 178.105.100.250 18:42, 23 May 2013 (UTC)

(Because there are pedants out there, I wish to immediately acknowledge the intrinsic error in such a statement... Anyone who hasn't acted XOR hasn't co-authored a paper can't get a finite Bacon||Erdős number to add to their finite Erdős||Bacon number, and someone who co-authored a paper with someone who acted with a second Baconised person cannot count that particular link as part of either chain, unless otherwise qualified, and therefore would count for both... Although the intermediary person might get a chance to connect to both if the original guy gets Erdős-connected by a different route. But way to ruin my own joke.)
((Oh, and my Bacon number is no more than 3, by way of an uncredited film appearance alongside Ian McKellan. I haven't checked to see if anyone else that's relevent has less than his presumed value of 2, but I'm not Erdőlised at all yet. Maybe that's my next goal in life. I know someone with an E-number of <=3, but obviously that's not enough to be worthy of geting an EB# of 7 or less for myself. 178.105.100.250 19:15, 23 May 2013 (UTC) ))

Without the title text it could be seen as a reference to Erdös' signature. Erdős used to sign things pgom (poor great old man) then ld (living dead) then ad (archaeological discovery) then ld again (legally dead) then cd (counts dead) so it could be them trying to see if he'd sign living dead. FlyingPiggy -- FlyingPiggy (talk) (please sign your comments with ~~~~)

Because this website does not usually take a position regarding religion or the lack of religion, it may be that the moderator has failed to realize that the explanation section pertaining to the biblical concept of Apocalypse is not universally accepted. Not even close to being universally accepted. There are a number of other theological views from those who believe in the authenticity of the Bible's message which would disagree with this "explanation." 162.158.122.120 17:40, 11 December 2019 (UTC)

I got nerd sniped trying to figure out what the summation in panel 5 (ni=0ik1/i) is supposed to be. It turns out the first term (where i = 0) comes out to 0k/0, which is undefined for all k. It follows that the sum itself is only defined when n < 0, i.e. when it's an empty sum. However, if we cancel the 1/i with a factor of i, we get ni=0ik-1, which is defined when n < 0 or k ≥ 1. Here's an interactive version I made in Desmos. Hhhguir (talk) 23:47, 3 March 2022 (UTC)