The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'

And above all things, never think that you're not good enough yourself. A man should never think that. My belief is that in life people will take you at your own reckoning.

After years of finding mathematics easy, I finally reached integral calculus and came up against a barrier. I realized that this was as far as I could go, and to this day I have never successfully gone beyond it in any but the most superficial way.

I do not fear computers. I fear the lack of them.

There are so many benefits to be derived from space exploration and exploitation; why not take what seems to me the only chance of escaping what is otherwise the sure destruction of all that humanity has struggled to achieve for 50,000 years?

When I sit down at the typewriter, I write. Someone once asked me if I had a fixed routine before I start, like setting up exercises, sharpening pencils, or having a drink of orange juice. I said, "No, the only thing I do before I start writing is to make sure that I'm close enough to the typewriter to reach the keys."

Modern science fiction is the only form of literature that consistently considers the nature of the changes that face us.