## Articles

*fractal*, introduced in the mid 1970's by Benoit Mandelbrot, is now commonly used to describe this family of non-differentiable functions that are infinite in length. Find out more about their origins and history.

We know there is infinitely many primes, but are there infinitely many twin primes?

**David Henwood**explains the role of mathematics in the design of Hi-Fi loudspeakers.

**Geoffrey Grimmett**explains how probability is at the heart of it all.