17 November ~ F. Claassens “Just for [redacted] and giggles.”

Paul Erdős is arguably one of the most colorful mathematicians of the 20^th century. In his lifetime he wrote 1525 articles with 511 collaborators in his lifetime. (That’s about 18 every year if he had started very early.) Beside this massive volume of work he was a very eccentric person, travelling around the world with two suitcases and a vocabulary of his own. Children he called epsilons, women he called bosses and being married he called being captured. When he said a mathematician had “died” he meant the mathematician stopped doing mathematics. From this mind came the concept of “the book”. A book containing the most elegant proofs for mathematical theorems written down by god himself. Inspired by this Martin Aigler and Günter Ziegler created “Proofs from the book”. A book containing the best and the most beautiful mathematics has to offer. I will present an unlikely coupling of Sperner’s Lemma, a theorem in combinatorics, and Brouwer’s world famous fixed point theorem.