I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong. If we will only allow that, as we progress, we remain unsure, we will leave opportunities for alternatives. We will not become enthusiastic for the fact, the knowledge, the absolute truth of the day, but remain always uncertain … In order to make progress, one must leave the door to the unknown ajar.

Maybe that is why young people make success. They don't know enough.

What I am going to tell you about is what we teach our physics students in the third or fourth year of graduate school... It is my task to convince you not to turn away because you don't understand it. You see my physics students don't understand it... That is because I don't understand it. Nobody does.

Observation, reason, and experiment make up what we call the scientific method.

Science is like sex: sometimes something useful comes out, but that is not the reason we are doing it

The test of all knowledge is experiment.

If it disagrees with experiment, it's wrong.