"What one fool can do, another can."

"The only way to do something is to do it. Not to talk about it, not to plan it, but to do it."

"I don't believe in miracles, because I believe in science."

"I asked him once, 'How do you tell when a mathematical argument is correct?' He said, 'If it's beautiful, it's correct.'"

"The thing that I cannot understand is what I cannot create. And I can't create a universe. So I don't understand the universe."