Re: [math-fun] Best proof that sqrt(2) is irrational?

Bill Gosper: "Years ago, Conway said, perhaps on this list, that he was working on a book of Extreme Proofs. His version of this one was to cut (or fold) a square of paper along the diagonal..." Michael Reid: "So it's possible that this proof is several millenia old." According to Miller & Montague, Stanley Tennenbaum discovered Conway's 'origami' proof in the 1950's: http://web.williams.edu/go/math/sjmiller/public_html/math/papers/irrationali... According to < http://www.qedcat.com/proofs/geometricproof.html >, it may go back even further, mentioning a 'numerical' version in 'A Course of Modern Analysis' by Whittaker & Watson (1927).