We do not know how much of the environmental change is due to human activities and how much [is due] to long-term natural processes over which we have no control.

Climate change is part of the normal order of things, and we know it was happening before humans came.

Do not imagine that you have to know everything before you can do anything. My own best work was done when I was most ignorant.

You ask: what is the meaning or purpose of life? I can only answer with another question: do you think we are wise enough to read God's mind?

When World War II came along, which was when I was a teenager, we all expected we would have anthrax bombs and this kind of stuff. We thought it would be a biological war. Fortunately it wasn't and, but it's because the danger is still there and by some miracle we escaped all that, so you never can tell what it going to happen, but biology certainly could be even worse than physics and chemistry.

The world is just - it's wonderful when you look at all the detail. It's just amazing.

There is a great satisfaction in building good tools for other people to use.