Aviation is the branch of engineering that is least forgiving of mistakes.

Atoms are weird stuff, behaving like active agents rather than inert substances. They make unpredictable choices between alternative possibilities according to the laws of quantum mechanics. It appears that mind, as manifested by the capacity to make choices, is to some extent inherent in every atom. The universe is also weird, with its laws of nature that make it hospitable to the growth of mind. I do not make any clear distinction between mind and God. God is what mind becomes when it passes beyond the scale of our comprehension.

The universe in some sense must have known that we were coming.

I am acutely aware of the fact that the marriage between mathematics and physics, which was so enormously fruitful in past centuries, has recently ended in divorce.

Computer models of the climate....[are] a very dubious business if you don't have good inputs.

Humanity looks to me like a magnificent beginning but not the final word.

I think it's much better to have your eyes open, but on the other hand, of course it can do harm if you tell people look, there's all these terrible things you can do and then some idiot may go ahead and do it.