In a recent interview conducted by TIME, Stephen Hawking talks briefly about Einstein, relativity, and black holes:
The field equations of his theory of relativity imply that a large star or cloud of gas would collapse in on itself and form a black hole. Einstein was aware of this but somehow managed to convince himself that something like an explosion would always occur to throw off mass and prevent the formation of a black hole. What if there was no explosion?
He also mentions fusion power as a scientific advancement he’d like to see in his lifetime. 🙂