Hayes writes a column in American Scientist, and the thirteen chapters here are taken from it but expand on the original sources, which he’s put up on his web site. They cover a variety of topics in math: prime numbers, random walks, Markov chains, pi, the nature of proof, and more. Chapter four, The Spectrum of Riemannium, was a favourite of mine.
There are many (well, some) popular mathematics books out there aimed at people unsure of math who want some of the interesting groundwork covered again. This one is aimed at people that know some math—not a lot, little is required—but want to explore something new, and are interested in seeing someone try out some ideas and ask, “How does this work?” Every chapter is engaging and intriguing.
This is a delightful work.