In 1736, a Swiss mathematician pondered routes for a sightseeing trip along the Pregel River in Königsberg. In 1880, an Italian painter turned zoologist sought to settle a hotly-contested controversy: whether or not birds protect crops by reducing insect populations. In 1932, the superintendent of a girls' reformatory school in Hudson, New York, hired a sociologist to investigate the cause of a recent wave of runaways. In 1955, a U.S. Army General and a mathematician developed a technique for identifying bottlenecks in the Soviet railway system. And, in 1998, two mathematicians in Ithaca, New York tried to figure out (among other things) why exactly all movie stars seem to be connected by Kevin Bacon.
These puzzles, taking ...
