It's not going to be just humans colonizing space, it's going to be life moving out from the Earth, moving it into its kingdom. And the kingdom of life, of course, is going to be the universe.

The technologies which have had the most profound effects on human life are usually simple.

Computer models of the climate....[are] a very dubious business if you don't have good inputs.

It's better to get mugged than to live a life of fear.

If we had a reliable way to label our toys good and bad, it would be easy to regulate technology wisely. But we can rarely see far enough ahead to know which road leads to damnation. Whoever concerns himself with big technology, either to push it forward or to stop it, is gambling in human lives.

Science was blamed for all the horrors of World War I, just as it's blamed today for nuclear weapons and quite rightly. I mean World War I was a horrible war and it was mostly the fault of science, so that was in a way a very bad time for science, but on the other hand we were winning all these Nobel Prizes.

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