Chimpanzees are an evolutionary hair's-width from us.... Now imagine a species on Earth, or anywhere else, as smart compared with humans as humans are compared with chimpanzees. How much of the universe might they figure out?

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.

If we're going to affect policy, or affect attitudes, for me, the adults have always been the target population.

In whatever you choose to do, do it because it's hard, not because it's easy. Math and physics and astrophysics are hard. For every hard thing you accomplish, fewer other people are out there doing the same thing as you. That's what doing something hard means. And in the limit of this, everyone beats a path to your door because you're the only one around who understands the impossible concept or who solves the unsolvable problem.

Without new economies, our old economies get our jobs taken from them because everyone else has figured out how to do it.

We are not figuratively, but literally stardust.

Space enthusiasts are the most susceptible demographic to delusion that I have ever seen.