Asteroids have us in our sight. The dinosaurs didn't have a space program, so they're not here to talk about this problem. We are, and we have the power to do something about it. I don't want to be the embarrassment of the galaxy, to have had the power to deflect an asteroid, and then not, and end up going extinct.

When a coincidence seems amazing, that's because the human mind isn’t wired to naturally comprehend probability & statistics.

As important as the civil rights movement was, I think what will rise to the top is that we left Earth in that time.

The caricature of science is that we hold tight to the theories we have, and shun challenges to them. That's just not true. In fact, we hold our highest rewards for those scientists who can prove others wrong. And by the way, they are famous in their own lifetimes. We don't wait until they're dead.

I think that intelligence is such a narrow branch of the tree of life - this branch of primates we call humans. No other animal, by our definition, can be considered intelligent. So intelligence can't be all that important for survival, because there are so many animals that don't have what we call intelligence, and they're surviving just fine.

Santa knows Physics: Of all colors, Red Light penetrates fog best. That's why Benny the Blue-nosed reindeer never got the gig.

Grab something off the shelf that's on the spaceship-an ashtray, it doesn't matter what. Because I can tell you, if they flew here from another galaxy, no matter what you've pulled off the shelf, it'll be unlike anything we have on Earth.