We investigate how the vast possibilities in a game of chess compare to the vastness of the observable universe.

Dr James Grime helps us understand the Shannon number – a famous figure on the chess side of the equation - and astronomer Professor Catherine Heymans takes on the entire observable universe.

Presenter: Tim Harford
Producers: Debbie Richford and Nathan Gower
Production Co-ordinator: Brenda Brown
Series Producer: Tom Colls
Sound Mix: Andy Fell
Editor: Richard Vadon