I don't know what's the matter with people: they don't learn by understanding, they learn by some other way — by rote or something. Their knowledge is so fragile!

It's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about we can discuss.

Work as hard and as much as you want to on the things you like to do the best.

So my antagonist said, "Is it impossible that there are flying saucers? Can you prove that it's impossible?" "No," I said, "I can't prove it's impossible. It's just very unlikely." At that he said, "You are very unscientific. If you can't prove it impossible then how can you say that it's unlikely?" But that is the way that is scientific. It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible.

It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management.

I couldn't claim that I was smarter than sixty-five other guys--but the average of sixty-five other guys, certainly!

To develop working ideas efficiently, I try to fail as fast as I can.