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.
The furore around the MMR vaccine and autism has shown that vaccination can be an emotive issue. We talk to an expert about the math used to make sure it's safe.
Time is a problem, not just for you and me, but also for philosophers. What exactly is time? Why does it have a direction? And was there a beginning of time? Find out more in this podcast.