Time travel was once considered scientific heresy, and I used to avoid talking about it for fear of being labelled a 'crank.'

So remember to look up at the stars and not down at your feet. Try to make sense of what you see and hold on to that childlike wonder about what makes the universe exist.

We think we have solved the mystery of creation. Maybe we should patent the universe and charge everyone royalties for their existence.

I want my books sold on airport bookstalls.

A model is a good model if first it interprets a wide range of observations in terms of a simple and elegant model, and second if the model makes definite predictions that can be tested, and possibly falsified, by observation.

I’m not religious in the normal sense. I believe the universe is governed by the laws of science. The laws may have been decreed by God, but God does not intervene to break the laws.

Computers double their performance every month.