The history and future of our universe

Professor Brian Greene is one of the world's foremost theoretical physicists. He is the head of Columbia University's Center for Theoretical Physics, and is co-founder and chairman of the World Science Festival. The author of six bestselling books, his most recent, Until the End of Time: Mind, Matter and Our Search for Meaning in an Evolving Universe, explains the cosmos and our quest to find meaning in the face of this vast expanse. Professor Greene says to understand the history of our universe - and it's future - we must understand that humans have only existed in it for a fraction of a fraction of a fraction of its history.