The world is just - it's wonderful when you look at all the detail. It's just amazing.

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.

The glory of science is to imagine more than we can prove.

Climate change is part of the normal order of things, and we know it was happening before humans came.

Mostly I'm just writing books for the public, and so I try to describe for the public what the choices are, what they might have to expect in the future and so by warning people ahead of time maybe you have an effect.

Scientifically speaking, a butterfly is at least as mysterious as a superstring. When something ceases to be mysterious it ceases to be of absorbing interest to scientists. Almost all things scientists think and dream about are mysterious.

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.