I don't believe in astrology; I'm a Sagittarius and we're skeptical.

Even if we never reach the stars by our own efforts, in the millions of years that lie ahead it is almost certain that the stars will come to us. Isolationism is neither a practical policy on the national or cosmic scale. And when the first contact with the outer universe is made, one would like to think that Mankind played an active and not merely a passive role-that we were the discoverers, not the discovered.

... chemistry is a trade for people without enough imagination to be physicists.

The dinosaurs disappeared because they could not adapt to their changing environment. We shall disappear if we cannot adapt to an environment that now contains spaceships, computers - and thermonuclear weapons.

I can never look now at the Milky Way without wondering from which of those banked clouds of stars the emissaries are coming. If you will pardon so commonplace a simile, we have set off the fire alarm and have nothing to do but to wait. I do not think we will have to wait for long.

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.

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