David Christian: getting our heads around history

Historian David Christian's work incorporates a history of everything - from the big bang to the first stars, to fossil fuels and mass globalisation. He started a movement called Big History that asks how did we get from The Big Bang to today's staggering complexity of human life; Bill Gates is a fan. David Christian's latest book is called Origin Story - a Big History of Everything. He is speaking at the Auckland Writers Festival.