[On Richard P. Feynman's live demonstration of the rigidity of the O-rings when cold that doomed the space shuttle Challenger, killing seven astronauts:] The public saw with their own eyes how science is done, how a great scientist thinks with his hands, how nature gives a clear answer when a scientist asks her a clear question.

The brain, being analog, is able to grasp images so much better. The brain is just designed for comparing images and some patterns - patterns in space and patterns in time - which we do amazingly well. Computers can do it, too, but not in anything like the same kind of flexibility.

The great advances in science usually result from new tools rather than from new doctrines.

So long as you have courage and a sense of humor, it is never too late to start life afresh.

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'm prejudiced about education altogether. I think it's terribly overrated. It wastes a tremendous amount of time - especially for women, it's particularly badly timed. If they're doing a Ph.D., they have a conflict between raising a family or finishing the degree, which is just at the worst time - between the ages of 25 to 30 or whatever it is. It ruins the five years of their lives.

One factor that has remained constant through all the twists and turns of the history of physical science is the decisive importance of the mathematical imagination.