I have lived much of my life among molecules. They are good company.

The great questions are those an intelligent child asks and, getting no answers, stops asking.

I think I know what is bothering the students. I think that what we are up against is a generation that is by no means sure that it has a future.

It would be a poor thing to be an atom in a universe without physicists, and physicists are made of atoms. A physicist is an atom's way of knowing about atoms.

There's life all over this universe, but the only life in the solar system is on earth, and in the whole universe we are the only men.

A scientist should be the happiest of men.

The concept of war crimes is an American invention.