Mathematics poll

[ciphergoth]

Inspired by a similar poll in palmer1984's journal.

About the "proof" question below: examples of the kind of proof I mean would be a proof that there are infinitely many primes, or that the square root of two is irrational, or of Pythagoras's Theorem. A proof in computer science counts too. By "know a proof off by heart" I mean that you'd be able to convince someone of it at a party, if they had the background to follow the proof.

If you know lots of proofs, feel free to choose one you particularly like in the last question...

[Poll #1351621]

Comments

[djm4]

I can also prove that root 2 is irrational. It's a proof I'm particularly partial to as Pythagoras allegedly proved it and then tried to suppress the knowledge, as it offended his mystic sensibilities of the Universe.

[drdoug.livejournal.com]

I like this tale too. I have a dim memory of a smart alec going on a boat trip with Pythagoreans, and casually asking them how long the diagonal of the unit square is. They took it in good humour and merely drowned their impious interlocutor.

[ex-pipistre.livejournal.com]

I thought one of his students proved it and he tried to suppress it by getting his minions to drown the upstart!

Damn, I forgot to put that one on my list.