It has become part of the accepted wisdom to say that the twentieth century was the century of physics and the twenty-first century will be the century of biology.

I think that the artificial-intelligence people are making a lot of noise recently, claiming that artificial intelligence is making huge progress and we're going to be outstripped by the machines.

The question that will decide our destiny is not whether we shall expand into space. It is: shall we be one species or a million? A million species will not exhaust the ecological niches that are awaiting the arrival of intelligence.

Mathematics is really an art, not a science.

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

That's, of course, the beautiful thing about science - that it's all about things we don't understand, not just the things we do understand.

Aviation is the branch of engineering that is least forgiving of mistakes.