Keeping an active mind has been vital to my survival, as has been maintaining a sense of humor.
Stephen HawkingI am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.
Stephen HawkingIf it [the universe] was expanding fairly slowly, the force of gravity would cause it eventually to stop expanding and then to start contracting. However, if it was expanding at more than a certain critical rate, gravity would never be strong enough to stop it, and the universe would continue to expand forever.
Stephen Hawking