Extreme skepticism and extreme gullibility are two equal ways of not having to think at all. And I don't think I'm the first to say that.

We can trace the elements. They were forged in the centers of high-mass stars that went unstable at the ends of their lives, they exploded, scattered their enriched contents across the galaxy, sprinkled into gas clouds that then collapsed and formed stars and planets and life.

There's an old saying in the space community: 'If God wanted us to be a spacefaring species, he would have given us a moon'.

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.

The most creative people are motivated by the grandest of problems that are presented before them.

People like it when they understand something that they previously thought they couldn't understand. It's a sense of empowerment.

If you are that person, you are more likely to believe that God cured you, this invisible force, creator of the universe, cured you, than that you had three idiotic doctors diagnose you. ... I taught physics to pre-med students who became doctors. Not all of them are smart, I assure you.