The test of all knowledge is experiment.

You can always recognize truth by its beauty and simplicity.

I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?' ...Nobody knows how it can be like that.

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.

We need to teach how doubt is not to be feared but welcomed. It's OK to say, "I don't know."

There is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics.

We decided that 'trivial' means 'proved'. So we joked with the mathematicians: We have a new theorem- that mathematicians can prove only trivial theorems, because every theorem that's proved is trivial.