The key to having an interesting life is to always say "yes" to anything crazy.

Humanity looks to me like a magnificent beginning but not the final word.

The point of fact is, just in simple ways, you can see how much better things have gotten. I mean, when I was a child, I lived in England, and England was just amazingly polluted. We didn't use that word. We just said it was it all covered with soot.

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.

I mean science was blamed for all the horrors of World War I, just as it's blamed today for nuclear weapons and quite rightly.

The marketplace judges technologies by their practical effectiveness, by whether they succeed or fail to do the job they are designed to do.

It's not going to be just humans colonizing space, it's going to be life moving out from the Earth, moving it into its kingdom. And the kingdom of life, of course, is going to be the universe.