From my childhood it has been my conviction that men would reach the planets in my lifetime . . . this conviction . . . rests on two beliefs, one scientific and one political: (1) there are more things in heaven and earth than are dreamed of in our present-day science. And we shall only find out what they are if we go out and look for them. (2) it is in the long run essential to the growth of any new and high civilization that small groups of people can escape from their neighbors and from their governments, to go and live as they please in the wilderness.

The only way to improve the chances for finding winners is to keep all the choices open and try them all.

Science is not a collection of truths. It is a continuing exploration of mysteries.

The whole point of science is that most of it is uncertain. That's why science is exciting--because we don't know. Science is all about things we don't understand. The public, of course, imagines science is just a set of facts. But it's not. Science is a process of exploring, which is always partial. We explore, and we find out things that we understand. We find out things we thought we understood were wrong. That's how it makes progress.

Theory said one thing and the experiment said something different, so that was the stimulus that started me going, that there was something there to be explained, which wasn't understood and to try to see why that experiment gave the answer it did, so it was a big opportunity for a young student starting to have actually an experiment which contradicted the theory, so that's was my chance to understand that.

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.

New directions in science are launched by new tools much more often than by new concepts. The effect of a concept-driven revolution is to explain old things in new ways. The effect of a tool-driven revolution is to discover new things that have to be explained.