NOVA's "The Fabric of the Cosmos" series continues with "Universe or Multiverse?" episode airing on November 23 at 9 p.m.

In this episode, Brian Greene takes us on a tour of a brave new theory at the frontier of physics: that our universe may not be the only one. Instead, it may be just one of an infinite number of worlds that make up the multiverse. It won’t be easy to prove, but if it’s right, our understanding of space, time and our place in the universe will never be the same.

Watch a preview of this episode below.