Famed astrophysicist Stephen Hawking believes humans are capable of time travel -- and he's not afraid to let everyone know.
Claiming he is not as concerned about being labelled crazy as he once was, Hawking has publicly aired his second startling theory in two weeks, after last week claiming it was "entirely reasonable" to assume aliens existed.
Preparing for the debut of his Discovery documentary, Stephen Hawking's Universe, which screens next week, Hawking said he believed humans could travel millions of years into the future and repopulate their devastated planet.
Hawking said once spaceships were built that could fly faster than the speed of light, a day on board would be equivalent to a year on Earth. That's because -- according to Einstein -- as objects accelerate through space, time slows down around them.
Which also means that Hawking's theory only applies to moving forwards through time.
