## Articles

We look at a crafty mathematical device which, among other things, has helped people understand what causes cholera.

How should people arrange themselves for maximal socialising at a safe distance?

It's one of mathematics' most famous results: every "map" can be coloured using at most four colours. What it doesn't usually apply to, however, are real maps.

This puzzle is famous because the accepted answer is counter-intuitive. But is it always correct?

The golden ratio has many amazing properties. But is it really a secret of nature and the epitome of beauty?

With just a few months to go until the UEFA European Cup, here's how you can make your office sweepstake a lot fairer and more exciting.

Nothing, not even light, can escape from a black hole. Or can it? Find out about one of Stephen Hawking's most radical results.

Explore a mystery that intrigued Stephen Hawking until the end of his life.