"If you're religious, you already have a book of answers. The problem is, it's not a book of questions."

"I'm not afraid of death. I'm afraid of dying without having lived a full life."

"I'm not a fan of the idea of 'alternative facts.' Facts are facts. There's no alternative to them."

"The universe is full of mysteries. And that's a good thing."

"I'm just trying to get people to think about the universe in a different way."