You meet an old friend on holiday, you find your colleague shares your birthday, you win the lottery. Exactly how rare are these rare events? David Spiegelhalter investigates in his regular column on uncertainty and risk.

Translating music into geometry

Great educational thinker dies

Abstract ideas better than real-world examples for maths learning

Using sand to create new mathematical models

Mathematics tackles an eternal question

The father of chaos theory dies

Road colouring problem solved

Alexander Grothendiek turns 80

Prestigious mathematics prize goes to group theorists

The first third degree transcendental L-function

Conversations across science and art