In 1917, the Japanese mathematician Sōichi Kakeya posed what at first seemed like nothing more than a fun exercise in geometry. Lay an infinitely thin, inch-long needle on a flat surface, then rotate ...

In just three pages, a Russian mathematician has presented a better way to color certain types of networks than many experts thought possible. A paper posted online last month has disproved a ...

For anyone fascinated by powers and integers, there’s no shortage of problems to tackle, whether by ingenious logic or massive computer search. In 1769, while thinking about the problem now known as ...