Science and religion are two windows that people look through, trying to understand the big universe outside, trying to understand why we are here. The two windows give different views, but they look out at the same universe. Both views are one-sided, neither is complete. Both leave out essential features of the real world. And both are worthy of respect.

[On Richard P. Feynman's live demonstration of the rigidity of the O-rings when cold that doomed the space shuttle Challenger, killing seven astronauts:] The public saw with their own eyes how science is done, how a great scientist thinks with his hands, how nature gives a clear answer when a scientist asks her a clear question.

As far as I can see, our concentration of different abilities in one species - there's nothing I can see that in this Darwinian evolution that could've done that. So it seems to be a miracle of some sort.

Lucky individuals in each generation find technology appropriate to their needs.

One of the memorable moments of my life was when Willard Libby came to Princeton with a little jar full of crystals of barium xenate. A stable compound, looking like common salt, but much heavier. This was the magic of chemistry, to see xenon trapped into a crystal.

The laws of nature are constructed in such a way as to make the universe as interesting as possible.

In the long run, the only solution I see to the problem of diversity is the expansion of mankind into the universe by means of green technology... Green technology means we do not live in cans but adapt our plants and our animals and ourselves to live wild in the universe as we find it... When life invades a new habitat, she never moves with a single species. She comes with a variety of species, and as soon as she is established, her species spread and diversify further. Our spread through the galaxy will follow her ancient pattern.