But one of the coolest things about meteorites is that most were formed four-and-a-half-billion years ago, during the birth of our solar system, when, for reasons not yet known, a cloud of gas and dust was transformed into a sun with circling planets.

The very nature of science is discoveries, and the best of those discoveries are the ones you don't expect.

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.

Ignorance is a virus. Once it starts spreading it can only be cured by reason. For the sake of humanity, we must be that cure.

I'm often asked whether I believe in Global Warming. I now just reply with the question: "Do you believe in Gravity?"

The show [ StarTalk ] was born as a radio program out of a National Science Foundation grant.

I am not the most annoying person to bring to a movie 'cause I basically hold it in and write about it later or tweet about it. The most annoying people to bring to movies, I think we all agree, are those who read the book first.