Nearly 14 billion years ago, a mysterious 'big bang' started a series of processes that created the Earth, and us. We still have much to discover about how we came to exist, and doing so will require powerful new instruments - in space and on the ground - and a deeper knowledge of the links between cosmos and micro-world.
Martin Rees, President of the Royal Society and Astronomer Royal, discusses the evolution of complex systems from simple beginnings. This lecture was part of the Cheltenham Science Festival.