So long as the Universe had a beginning, we could suppose it had a creator. But if the Universe is really completely self-contained, it would have neither beginning or end, it would simply be. What place then for a creator?

The thing about smart people is that they seem like crazy people to dumb people.

But a machine that was powerful enough to accelerate particles to the grand unification energy would have to be as big as the Solar System - and would be unlikely to be funded in the present economic climate.

All my adult life people have been helping me.

For millions of years, mankind lived just like the animals. Then something happened which unleashed the power of our imagination. We learned to talk and we learned to listen.

For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not predict how the universe would begin.

If human life were long enough to find the ultimate theory, everything would have been solved by previous generations. Nothing would be left to be discovered.