At Stephen Hawking's 70th birthday symposium we talked to Astronomer Royal Martin Rees, some of Hawking's former students, and his graduate assistant.
What's a multiverse? What's the future for intelligent life? And what happened 380,000 after the Big Bang. At Stephen Hawking's 70th birthday conference we talked to physicists David Spergel and Raphael Bousso to find out more.
Are the unchanging numbers that define our universe really unchanging?