A theory is a good theory if it satisfies two requirements: it must accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements, and it must make definite predictions about the results of future observations.

thus, in a sense, we are all doomed. even if we stay away from black holes

My first popular book, 'A Brief History of Time,' aroused a great deal of interest, but many found it difficult to understand.

There ought to be something very special about the boundary conditions of the universe and what can be more special than that there is no boundary?

All of my life, I have been fascinated by the big questions that face us, and have tried to find scientific answers to them. If, like me, you have looked at the stars, and tried to make sense of what you see, you too have started to wonder what makes the universe exist.

Jesus loves you, but everyone else thinks you're an ass.

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.