"I'm not saying that science has all the answers. I'm saying that science is the only way we're going to get answers."

"Knowing how to think empowers you far beyond those who only know what to think."

"The universe is a dangerous place. It's full of black holes and gamma-ray bursts."

"I'm not afraid of questions. I'm afraid of people who don't ask questions."

"If you're ever feeling small, just remember that you're made of stardust, and you're part of something much bigger than yourself."