How do you do it? Horizontally from side to side, or perhaps criss-cross, producing a series of Xs running up your feet? Towards the end of The shoelace book, its author Burkard Polster raises a troubling question. Despite all the here-today, gone-tomorrow vagaries of fashion, and in spite of the huge variety of shoe styles available to us in this golden age of footwear, why does almost everyone lace their shoes in one of these two ways?
I've read several of Paul Nahin's books before (see my review of Dr. Euler's fabulous formula in Plus) and this is no exception to his excellent style. The strategies of pursuit and evasion have fascinated mathematicians for centuries. One of the earliest problems was posed by Frenchman Pierre Bouger in 1732.