1942-1975. "The quest for a theory of everything" ; "Our goal is nothing less than a complete description of the universe we live in" ; "Equal to anything" ; "The realization that I had an incurable disease, that was likely to kill me in a few years, was a bit of a shock" ; "The big question was, was there a beginning or not?" ; "There is a singularity in our past"
1970-1990. "These people must think we are used to an astronomical standard of living" ; "Scientists usually assume there is a unique link between the past and the future, cause and effect. If information is lost, this link does not exist" ; "The odds against a universe that has produced life like ours are immense" ; "In all my travels, I have not managed to fall off the edge of the world" ; "It's turtles all the way down" ; "The field of baby universes is in its infancy"
1990-2000. "Is the end in sight for theoretical physics?" ; Between film roles, I enjoy solving physics problems" ; "I think we have a good chance of avoiding both Armageddon and a new Dark Age" ; "It seems clear to me"
2000-2011. "An expanding horizon of possibilities ; "Grandad has wheels" ; "I've always gone in a somewhat different direction" ; "My name is Stephen Hawking : physicist, cosmologist and something of a dreamer."