The energy requirements for interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades. If they want to make contact, they would make contact; if not, they would save their energy and go elsewhere.

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.

On Earth, we are unmanned by our longing for a pastoral past that never really existed; and that, if it had existed, could never exist again...on the Moon, there is no past to long for or dream about. There is no direction but forward.

The significant chemicals of living tissue are rickety and unstable, which is exactly what is needed for life.

You don't have to be able to lay eggs to know when one of them is rotten.

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

Nothing has to be true, but everything has to sound true.