**Steven J. Brams** uses the Cuban missile crisis to illustrate the Theory of Moves, which is not just an abstract mathematical model but one that mirrors the real-life choices, and underlying thinking, of flesh-and-blood decision makers.

Last October, two mathematicians won £1m when it was revealed that they were the first to solve the Eternity jigsaw puzzle. It had taken them six months and a generous helping of mathematical analysis. **Mark Wainwright** meets the pair and finds out how they did it.

Why can't human beings walk as fast as they run? And why do we prefer to break into a run rather than walk above a certain speed? Using mathematical modelling, **R. McNeill Alexander** finds some answers.

Arguably, the exponential function crops up more than any other when using mathematics to describe the physical world. In the first of two articles on physical phenomena which obey exponential laws, **Ian Garbett** discusses light attenuation - the way in which light decreases in intensity as it passes through a medium.

**Jenni Barker** plots the path from astrophysics to science journalism.