I am guilty of the great crime of optimism.

A fact is a simple statement that everyone believes. It is innocent, unless found guilty. A hypothesis is a novel suggestion that no one wants to believe. It is guilty, until found effective.

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

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.

Society's emissions of carbon dioxide may or may not turn out to have something significant to do with global warming-the jury is still out.

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 anyone wants a hole in the ground, nuclear explosives can make big holes