One of the things I learned, one of the strangest things, is how to think. There was nothing else to do. I couldn't see people, or go for a walk in the forest. All I had was my head and my books, and I thought a lot.

Once I even took the train to Utrecht, forty miles from Amsterdam, with my yellow star, this star which I still have. Why did I go? I just wanted to visit some friends. I was a little bit crazy, a little bit insane.

Deliberately or not, every author is of course present in every book he or she writes - even in a scientific text.

A number of current theoretical explorations will turn out to be passing fancies...

One of the absolute rules I learned in the war was, don't know anything you don't need to know, because if you ever get caught they will get it out of you.

Of course, relative citation frequencies are no measure of relative importance. Who has not aspired to write a paper so fundamental that very soon it is known to everyone and cited by no one?

There is not a soul on Earth who can read the deluge of physics publications in its entirety. As a result, it is sad but true that physics has irretrievably fallen apart from a cohesive to a fragmented discipline. ... It was not that long ago that people were complaining about two cultures. If we only had it that good. today.