It often happens that I have an idea, but then I try to fill in the intermediate steps and find they don't work, so I have to give it up.
Stephen HawkingScience predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in.
Stephen HawkingWe are entering an increasingly dangerous period of our history. But I'm an optimist.
Stephen Hawking