Newton came up with Newton's laws of motion and gravity. They worked. They were working.

To view space as, "Well, let's go to Mars now," or "Let's do this now," maybe we should rethink of space as our backyard and have a suite of launch vehicles that can enable any ambition a person has regarding space. It's the same way you can go to buy a car: I want to go offroading, I'll buy this model. I'm a city driver, that's this model. I want to use less fuel, well, that's this model. They're not selling you one car, you have options. So when I think of space, I think of having options.

I have a very high respect for professional comedians. What they do astonishes me. You have to be really smart and absorb everything, repackage it, bring it back to the person, and make them laugh at themselves. I can make people laugh during my talks because they didn't come to have me make them laugh. It's added value. So my job is way easier than that of a professional comic.

In life and in the universe it's always best to keep looking up.

Science is a fundamental part of our existence.

I want upon death to be buried, just like in the old days, where I decompose by the action of microorganisms, and I am dined upon by any form of creeping animal or root system that sees fit to do so.... I will have recycled back to the universe at least some of the energy that I have taken from it. And in so doing, at the conclusion of my scientific adventures, I will have come closer to the heavens than to Earth.

One of the most significant events in our distant past is still perhaps the greatest mystery: the origins of life itself.