"I have often been asked: What do you think about God? I have said that we cannot know for sure whether God exists or not. But I don't believe in a personal God."

"I tell my kids: Don't spend all your time at the computer. But then I realize, I do that myself all day."

"The universe is a grand design, but it's not designed by a grand designer."

"In the proof stage, I nearly cut that last sentence of the book. Had I done so, the sales might have been halved."

"We are all time-travelers, heading into the future at the rate of one second per second."