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.

There is a special sadness in achievement, in the knowledge that a long-desired goal has been attained at last, and that life must now be shaped toward new ends.

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.

I have a fantasy where Ted Turner is elected President but refuses because he doesn't want to give up power.

The only way to define your limits is by going beyond them.

Science can destroy religion by ignoring it as well as by disproving its tenets. No one ever demonstrated, so far as I am aware, the nonexistence of Zeus or Thor, but they have few followers now.

I sometimes wonder how we spent leisure time before satellite television and Internet came along…and then I realise that I have spent more than half of my life in the ‘dark ages’!