1. Numbers

What do the proportions of Chartres Cathedral share with the life cycle of the cicada, with how we hear sound, and with the intricately designed nautilus shell? Du Sautoy investigates their sacred numbers and the power of pi.

3. Prediction

While so much of life appears random, Du Sautoy shows how it is really governed by the code of chaos, in which small variations can cause vastly different outcomes, often referred to as the "butterfly effect."