In this clip from Genius by Stephen Hawking, learn about gravity, general relativity and black holes; and if travelling forward in time is actually possible. Einstein's research in to gravity led him to come up with the theory of general relativity. His theory was that the presence of mass bends or warps the shape of both space and time in its surroundings, and other objects then follow their natural path through this curved space. Einstein said that this warping of spacetime is what creates gravity, but also alters time itself, and that time passes at different speeds depending on how strong the gravity is: the stronger the gravity, the stronger the effect. See how three volunteers apply the theory of general relativity and warped time near a black hole to discover if traveling in to the future would be theoretically possible.