There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe there ever was such a time ... On the other hand, I think I can safely say that nobody understands quantum mechanics.

Doubt is clearly a value in science. It is important to doubt and that the doubt is not a fearful thing, but a thing of great value.

As usual, nature's imagination far surpasses our own, as we have seen from the other theories which are subtle and deep.

People who wish to analyze nature without using mathematics must settle for a reduced understanding.

For those who want some proof that physicists are human, the proof is in the idiocy of all the different units which they use for measuring energy.

I have argued flying saucers with lots of people. I was interested in possible. They do not appreciate that the problem is not to demonstrate whether it's possible or not but whether it's going on or not.

In its efforts to learn as much as possible about nature, modern physics has found that certain things can never be "known" with certainty. Much of our knowledge must always remain uncertain. The most we can know is in terms of probabilities.