If there are any gods whose chief concern is man, they can't be very important gods.

I'm sure we would not have had men on the Moon if it had not been for Wells and Verne and the people who write about this and made people think about it. I'm rather proud of the fact that I know several astronauts who became astronauts through reading my books.

Somewhere in me is a curiosity sensor. I want to know what's over the next hill. You know, people can live longer without food than without information. Without information, you'd go crazy.

The intelligent minority of this world will mark 1 January 2001 as the real beginning of the 21st century and the Third Millennium.

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

If such a thing had happened once, it must surely have happened many times in this galaxy of a hundred billion suns.

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.