"I was talking to a guy who was a philosopher, and he said, 'But you're just describing the world, you're not explaining it.' And I said, 'Yeah, that's what science is. We describe it. We don't explain…"

"The thing that bothers me is that I can tell that the students don't understand. They are taught to remember things, but they don't understand."

"The greatest joy is to understand how nature works."

"Why do you suppose that, when you are not speaking English, you speak with an accent?"

"I'm not interested in being a guru. I'm interested in understanding the world."