The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense must have known that we were coming.

Thanks to the discoveries of astronomers in the twentieth century, we now know that the heat death is a myth. The heat death can never happen, and there is no paradox.

I am acutely aware of the fact that the marriage between mathematics and physics, which was so enormously fruitful in past centuries, has recently ended in divorce.

From my childhood it has been my conviction that men would reach the planets in my lifetime . . . this conviction . . . rests on two beliefs, one scientific and one political: (1) there are more things in heaven and earth than are dreamed of in our present-day science. And we shall only find out what they are if we go out and look for them. (2) it is in the long run essential to the growth of any new and high civilization that small groups of people can escape from their neighbors and from their governments, to go and live as they please in the wilderness.

A good cause can become bad if we fight for it with means that are indiscriminately murderous. A bad cause can become good if enough people fight for it in a spirit of comradeship and self-sacrifice. In the end it is how you fight, as much as why you fight, that makes your cause good or bad.

I think we're doing pretty well. It's clear the media, of course, always gives you the bad news.

The idea that global warming is the most important problem facing the world is total nonsense and is doing a lot of harm.