Because imaginary time behaves like another direction in space, histories in imaginary time can be closed surfaces, like the surface of the Earth, with no [existential] beginning or end.

There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.

I think the next century will be the century of complexity.

In A Brief History Of Time I used the word "God" like Einstein did as a shorthand for the laws of physics. However, this is not what most people mean by God, so I have decided not to use the term. The laws of physics can explain the universe without the need for a God.

While physics and mathematics may tell us how the universe began, they are not much use in predicting human behavior because there are far too many equations to solve. I'm no better than anyone else at understanding what makes people tick, particularly women.

I like physics, but I love cartoons.

The universe doesn't allow perfection.