As a theoretician, I am proud to be part of a counter revolution... discovering that quantum field theory language was not dead and finished but had not really been explored thoroughly enough.

The energy requirements for interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades. If they want to make contact, they would make contact; if not, they would save their energy and go elsewhere.

The gravest threat faced by the world is of an extremist group getting hold of nuclear weapons or materials.

That is the way of the scientist. He will spend thirty years in building up a mountain range of facts with the intent to prove a certain theory; then he is so happy with his achievement that as a rule he overlooks the main chief fact of all-that all his accumulation proves an entirely different thing.

It was strange, in a way, because there were no ideas involved in the laser that weren't already known by somebody 25 years before lasers were discovered. The ideas were all there; just, nobody put it together.

Economics is not an exact science. It's a combination of an art and elements of science. And that's almost the first and last lesson to be learned about economics: that in my judgment, we are not converging toward exactitude, but we're improving our data bases and our ways of reasoning about them.