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.

Everything in my life was luck.

It's as great a part of the human adventure to invent things as to understand them. John Randall wasn't a great scientist, but he was a great inventor. There's been lots more like him, and it's a shame they don't get Nobel Prizes.

The biologists have essentially been pushed aside. Al Gore's just an opportunist. The person who is really responsible for this overestimate of global warming is Jim Hansen. He consistently exaggerates all the dangers.

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.

Intelligence may indeed be a benign influence creating isolated groups of philosopher-kings far apart in the heavens... On the other hand, intelligence may be a cancer of purposeless technological exploitation, sweeping across a galaxy as irresistibly as it has swept across our own planet.

It is our task, both in science and in society at large, to prove the conventional wisdom wrong and to make our unpredictable dreams come true