Francis Su is the Benediktsson-Karwa Professor of Mathematics at Harvey Mudd College and the past president of the Mathematical Association of America. In 2013, he received the Haimo Award, a nationwide teaching prize for college math faculty, and in 2018 he won the Halmos-Ford writing award for the highly-acclaimed speech on which this book is based. His work has been featured in Quanta Magazine, Wired, and the New York Times.