The point of fact is, just in simple ways, you can see how much better things have gotten. I mean, when I was a child, I lived in England, and England was just amazingly polluted. We didn't use that word. We just said it was it all covered with soot.

The important thing is that we now have the tools to sequence all kinds of animals and plants and microbes - as well as humans. It is not important that we didn't actually finish the human sequence yet.

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.

The reason why new concepts in any branch of science are hard to grasp is always the same; contemporary scientists try to picture the new concept in terms of ideas which existed before.

Walking the streets of Tokyo with Hawking in his wheelchair ... I felt as if I were taking a walk through Galilee with Jesus Christ [as] crowds of Japanese silently streamed after us, stretching out their hands to touch Hawking's wheelchair. ... The crowds had streamed after Einstein [on Einstein's visit to Japan in 1922] as they streamed after Hawking seventy years later. ... They showed exquisite choice in their heroes. ... Somehow they understood that Einstein and Hawking were not just great scientists, but great human beings.

Most of the papers which are submitted to the Physical Review are rejected, not because it is impossible to understand them, but because it is possible. Those which are impossible to understand are usually published.

I have the freedom to do what I want... bright people to talk to every day.