Really exotic methods of propulsion . . . will have to be devised to get there. How it will be done, I do not know. Whether it will be done, I am not quite certain. But I would bet it can be done.

Had we not pursued the hydrogen bomb, there is a very real threat that we would now all be speaking Russian. I have no regrets.

Really exotic methods of propulsion . . . will have to be devised to get there. How it will be done, I do not know. Whether it will be done, I am not quite certain. But I would bet it can be done.

If not for me, the H-bomb would have been developed in Russia first. In the U.S., we'd now be speaking Russian.

I claim that relativity and the rest of modern physics is not complicated. It can be explained very simply. It is only unusual or, put another way, it is contrary to common sense.

When you come to the end of all the light you know, and it's time to step into the darkness of the unknown, faith is knowing that one of two things shall happen: either you will be given something solid to stand on or you will be taught to fly.

A state-of-the-art calculation requires 100 hours of CPU time on the state-of-the-art computer, independent of the decade.