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.

It is simple, therefore it is beautiful

Although it is uncertain, it is necessary to make science useful. Science is only useful if it tells you about some experiment that has not been done; it is not good if it only tells you what just went on.

There is one simplification at least. Electrons behave ... in exactly the same way as photons; they are both screwy, but in exactly in the same way.

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.

It is necessary for the very existence of science that minds exist which do not allow that nature must satisfy some preconceived conditions.

It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is if it disagrees with experiment it is wrong. That is all there is to it.