"Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory. As philosopher of science Karl Popper has emphasized, a good theory is characterized by the fact that it makes a number of predictions that could in principle be disproved or falsified by observation. Each time new experiments are observed to agree with the predictions the theory survives, and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or modify the theory."

“Thus it seems that even God is bound by the uncertainty principle, and can not know both the position, and the speed, of a particle. So God does play dice with the universe. All the evidence points to him being an inveterate gambler, who throws the dice on every possible occasion.”

“On seeing the Enterprise's warp engine while visiting the set of Star Trek: The Next Generation (where he would briefly play himself in the 1993 episode Descent, Part I), Hawking smiled and said: I'm working on that.”

“I regard [the many worlds interpretation] as self-evidently correct. [T.F.: Yet some don't find it evident to themselves.] Yeah, well, there are some people who spend an awful lot of time talking about the interpretation of quantum mechanics. My attitude — I would paraphrase Goering—is that when I hear of Schrödinger's cat, I reach for my gun.”

“I imagine what happens to human consciousness when we die is much like turning off a computer. I don’t believe in a heaven for computers. I think the after-life is a fairy story for people afraid of the dark.”

““Quiet people have the loudest minds”安靜的人，心裡最是波濤起伏。（霍金手稿）”

“I am discounting reports of UFOs. Why would they appear only to cranks and weirdos?”