Any technology distinguishable from magic is insufficiently advanced.

After their encounter on the approach to Jupiter, there would aways be a secret bond between them---not of love, but of tenderness, which is often more enduring.

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

I have great faith in optimism as a guiding principle, if only because it offers us the opportunity of creating a self-fulfilling prophecy.

We stand now at the turning point between two eras. Behind us is a past to which we can never return... The coming of the rocket brought to an end a million years of isolation... the childhood of our race was over and history as we know it began.

I have encountered a few "creationists" and because they were usually nice, intelligent people, I have been unable to decide whether they were really mad or only pretending to be mad. If I was a religious person, I would consider creationism nothing less than blasphemy. Do its adherents imagine that God is a cosmic hoaxer who has created the whole vast fossil record for the sole purpose of misleading humankind?

In fact, one of the arguments for searching for intelligent life in space, elsewhere, is that we have no evidence that intelligence has any survival value. The most successful creatures on this planet are the cockroaches. They've been around, what is it, 100 million years or so and I suspect they'll still be there 100 million years in the future. Maybe intelligence is an evolutionary aberration which dooms its possessors in the way armor may have doomed some of the dinosaurs.