Floyd could imagine a dozen things that could go wrong; it was little consolation that it was always the thirteenth that actually happened.

Nowhere in space will we rest our eyes upon the familiar shapes of trees and plants, or any of the animals that share our world. Whatsoever life we meet will be as strange and alien as the nightmare creatures of the ocean abyss, or of the insect empire whose horrors are normally hidden from us by their microscopic scale.

It is a good principle in science not to believe any 'fact'---however well attested---until it fits into some accepted frame of reference. Occasionally, of course, an observation can shatter the frame and force the construction of a new one, but that is extremely rare. Galileos and Einsteins seldom appear more than once per century, which is just as well for the equanimity of mankind.

I'm sure the universe is full of intelligent life. It's just been too intelligent to come here.

Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living.

It was one thing to have guessed it, another to have had that guess confirmed beyond possibility of refutation.

Moses Kaldor had always loved mountains; they made him feel nearer to the God whose nonexistence he still sometimes resented.