"I'm often asked if I believe in UFOs. I'm open to the possibility, but I need evidence. I need the aliens to land on the White House lawn, or at least in my backyard, and say hello."

"You know, the universe is a pretty big place. It's much bigger than people realize. And sometimes, you just gotta look up."

"Imagine a world where people are judged not by the color of their skin, but by the content of their character, and where the content of their character is measured by how much science they know."

"Science is not just a collection of facts, but a way of thinking."

"I think the greatest gift you can give someone is the gift of knowledge."