While there's life, there is hope.

It is said that there's no such thing as a free lunch. But the universe is the ultimate free lunch.

I've noticed that even people who believe in fate look both ways before crossing the street.

In effect, we have redefined the task of science to be the discovery of laws that will enable us to predict events up to the limits set by the uncertainty principle.

I'm here to chew gum and kick some ass, and I'm all out of gum.

If the rate of expansion one second after the Big Bang had been smaller by even one part in a hundred thousand million million, it would have recollapsed before it reached its present size. On the other hand, if it had been greater by a part in a million, the universe would have expanded too rapidly for stars and planets to form.

Then we shall... be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason - for then we would know the mind of God.