Scientists have pushed back the horizon of time from the biblical 6,000 years to 4,600,000,000 years for the age of Earth a 760,000-fold increase.

An optimistic view of the future would indicate that before long, the clear necessity of expanding humanity's horizons would cause ... space settlements to be built. The construction would also serve as a great project that not only would be clearly of great benefit, but might induce human cooperation in something large enough to fire the heart and mind, and make people forget the petty quarrels that have engaged them for thousands of years in wars over insignificant scraps of earthly territory.

Titles are an important part of a story and I take considerable care in choosing one. In fact, I cannot start a story until I have chosen a title.

Once you've dissected a joke, you're about where you are when you've dissected a frog. It's dead. Banquets of the Black Widowers (1984), p. 49; comparable to "Humor can be dissected, as a frog can, but the thing dies in the process and the innards are discouraging to any but the pure scientific mind."

In my fiction I am careful to make everything probable and to tie up all loose ends. Real life is not hampered by such considerations.

Science fiction offers its writers chances of embarrassment that no other form of fiction does.

There are limits beyond which your folly will not carry you. I am glad of that. In fact, I am relieved.

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

Of all the cultural aspects of humanity, the only one which is not broken up into national or regional splinters is science. Different nations have different languages, they may have different religions, may have different dietaries, may have different holidays, different ways of thinking, but here's only one science. Interview by Richard Heffner on The Open Mind (19 June 1988); video (25:31)

Science doesn't purvey absolute truth. Science is a mechanism. It's a way of trying to improve your knowledge of nature. It's a system for testing your thoughts against the universe and seeing whether they match. And this works, not just for the ordinary aspects of science, but for all of life. I should think people would want to know that what they know is truly what the universe is like, or at least as close as they can get to it.