Despite all that education and experience can do, I retain a certain level of unsophistication that I cannot eradicate and that my friends find amusing. In fact, I think I sometimes detect conspiratorial plottings among my friends to protect me against my own lack of sophistication. I don't mind. I suspect that I am never quite as unsophisticated as they think I am, but I don't mind.

When, however, the lay public rallies round an idea that is denounced by distinguished but elderly scientists and supports that idea with great fervor and emotion - the distinguished but elderly scientists are then, after all, probably right.

Having no unusual coincidence is far more unusual than any coincidence could possibly be.

When asked for advice by beginners. Know your ending, I say, or the river of your story may finally sink into the desert sands and never reach the sea.

At two-tenths the speed of light, dust and atoms might not do significant damage even in a voyage of 40 years, but the faster you go, the worse it is--space begins to become abrasive. When you begin to approach the speed of light, hydrogen atoms become cosmic-ray particles, and they will fry the crew. ...So 60,000 kilometers per second may be the practical speed limit for space travel.

I do not use airplanes. They strike me as unsporting. You can have an automobile accident-and survive. You can be on a sinking ship-and survive. You can be in an earthquake, fire, volcanic eruption, tornado, what you will-and survive. But if your plane crashes, you do not survive. And I say the heck with it.

I never considered myself a patriot. I like to think I recognize only humanity as my nation.