There are no wild, seedless watermelons. There's no wild cows... You list all the fruit, and all the vegetables, and ask yourself, is there a wild counterpart to this? If there is, it's not as large, it's not as sweet, it's not as juicy, and it has way more seeds in it. We have systematically genetically modified all the foods, the vegetables and animals that we have eaten ever since we cultivated them. It's called artificial selection.

Rational thoughts never drive people's creativity the way emotions do.

We didn't go to the moon to explore or because it was in our DNA or because we're Americans. We went because we were at war and we felt a threat.

There are books on my shelf that I'm not into. They are things I don't know anything about yet. It's going to lead me off into a new place. The books don't represent an interest; they represent a source of my ignorance.

I'd go back and hang out with Isaac Newton. I'm torn between do I hang out with him or do I bring him into the present to hang out with me. See, that might be terrifying because his head will just explode once he sees everything that was derived from his discoveries, but I'd spend more time with someone who I think is one of the most brilliant minds our species has ever known.

Not only are we in the universe, the universe is in us. I don't know of any deeper spiritual feeling than what that brings upon me.

The value of science is not simply what the next model of the iPod you will buy next week, but its real value comes about when it's time to distinguish reality from everything else. And to be scientifically literate is to be trained in what it is, to recognize your own frailty as a data-taking device.