History is but the record of the public and official acts of human beings. It is our object, therefore, to humanize our history and deal with people past and present; people who ate and possibly drank; people who were born, flourished and died; not grave tragedians, posing perpetually for their photographs.

You stop planetary exploration, those people who do that extraordinary work are going to have to go do something else.

Everybody remembers numbers and computers remember numbers. People remember procedures and computers certainly remember procedures. But the other thing that's still important is that your perception as a human is affected subtly by all this stuff that you can't quite articulate. You run your life according to all this stuff that's happened to you. All of your memories affect everything you do whereas with a computer, there's adaptive software and things, but it's more literal.

Burning carbon-based substances like oil, gas, and especially coal, produces billions of tons of extra carbon dioxide each year. Methane gas from cows and pigs and other animals on our large farms ends up in the atmosphere as well, trapping more of the sun's energy as heat.

I hope climate science becomes the big thing. And then what I want is electrical engineers to solve the world's energy problems, energy distribution problems. I want mechanical engineers to make better transportation systems. I want chemical engineers to develop better solar panels, and so on.

I always say when you see that old black-and-white footage of the rocket on the launch pad and it falls over and explodes, that's because people had slide rules. Not having the decimal point is a real drawback. You want the decimal point, take it from me.

Evolution is the fundamental idea in all of life science, in all of biology. The key to our being here now is time, 4.54 billion (Earth) years of time. Nuclear fission wasn't discovered until long after Charles Darwin and Alfred Russell Wallace published their original books and papers, for example. Our ability to measure atomic masses wasn't developed until long after their deaths. These features of nature enabled us to reckon the age of the Earth and compare it with speciation rates here.