There is nothing so big nor so crazy that one out of a million technological societies may not feel itself driven to do, provided it is physically possible.

When I listen to the public debates about climate change, I am impressed by the enormous gaps in our knowledge, the sparseness of our observations and the superficiality of our theories.

It's amazing how much progress there's been in China, and also India. Those are the places that really matter - they're half of the world's population. They're the places where things are enormously better now than they were 50 years ago. And I don't see anything that's going to stop that.

Science is a human activity, and the best way to understand it is to understand the individual human beings who practise it. Science is an art form and not a philosophical method. The great advances in science usually result from new tools rather than from new doctrines. ... Every time we introduce a new tool, it always leads to new and unexpected discoveries, because Nature's imagination is richer than ours.

Dropping of the atomic bomb was the main subject of conversation for many years and so people had very strong feelings about it on both sides and people who thought it was the greatest thing they'd ever done and people who thought it was just an unpleasant job and people who thought they should have never done it at all, so there were opinions of all kinds.

For me too, the periodic table was a passion. ... As a boy, I stood in front of the display for hours, thinking how wonderful it was that each of those metal foils and jars of gas had its own distinct personality.

Science and religion are, of course, two different ways of looking at the universe; and it's the same universe with two different windows.