There's no shortage of people that we can put on, because science touches us all.

Stars die and reborn […] They get so hot that the nuclei of the atoms fuse together deep within them to make the oxygen we breathe, the carbon in our muscles, the calcium in our bones, the iron in our blood. All was cooked in the fiery hearts of long vanished stars. … The cosmos is also within us. We're made of star stuff. We are a way for the cosmos to know itself.

Scientific literacy is an intellectual vaccine against the claims of charlatans who would exploit ignorance.

When you're enlightened, you don't have to reference other people, because you yourself are enlightened. And that's a better Earth. People can make more informed decisions politically, culturally, personally.

Anyone who has wrestled knows that it's the hardest thing in the world to do. Anyone who says something else is the hardest thing has never wrestled. That's what I have found. ... You don't wrestle because it's easy, you wrestle because it's hard. I don't do astrophysics because it's easy, I do it because it's hard. And I juxtapose the two in my mind, body, and soul all the time.

If our solar system is not unusual, then there are so many planets in the universe that, for example, they outnumber the sum of all sounds and words ever uttered by every human who has ever lived. To declare that Earth must be the only planet with life in the universe would be inexcusably bigheaded of us.

Three and a half million years ago our ancestors - yours and mine - left these traces [indicates footprints]. We stood up and parted ways from them. Once we were standing on two feet, our eyes were no longer fixated on the ground. Now, we were free to look up and wonder.