string theory

The final part of Professor Jim Al-Khalili’s documentary series shows how the world we think we know turns out to be a tiny sliver of an infinitely weirder universe than which we could have conceived. (56 min, 6 segments)

Physicists calculate the likely existence of universes other than our own. Find out why they think we exist within a multiverse and what that means. (44 min, 5 segments)

BBC Horizon explores time travel from a few different perspectives. (9:12 min)

Scientists now believe there may really be a parallel universe - in fact, there may be an infinite number of parallel universes, and we just happen to live in one of them. Parallel Universes, a 2002 BBC documentary, is presented here in 5 video parts (45 min total).