Keyword Dark Matter

Brian Greene is going to let you in on a secret: We've all been deceived. Our perceptions of time and space have led us astray. Much of what we thought we knew about our universe-that the past has already happened and the future is yet to be, that space is just an empty void, that our universe is the only universe that exists-just might be wrong.

Professor Jim Al-Khalili shows how, by uncovering its secrets, scientists have used light to reveal the universe.