“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.”

To make a discovery is not necessarily the same as to understand a discovery.

[George] Uhlenbeck was a highly gifted physicist. One of his remarkable traits was he would read every issue of T%he Physical Review from cover to cover.

I knew all the time I was going to get through the war. It was completely irrational, a silly idea, but I was not going to lie down and get myself killed. I was going to get out of it.

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.

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. …

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

Anyone who claims to be familiar with it all is a confessing liar.’ I believe that all physicists would subscribe to the same sentiments regarding their own professional literature. I do at any rate.

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?

I spent every night until four in the morning on my dissertation, until I came to the point when I could not write another word, not even the next letter. I went to bed. Eight o’clock the next morning I was up writing again.

The rule of the game was never assume that anybody, however honorable, would be able to stand up under torture. If Mr. X, who knew where I was, was caught for some reason, I should move.

There is now more economic comment in the supposedly serious literature than survives from the whole of the thousand years commonly denominated as the Middle Ages …

To make a discovery is not necessarily the same as to understand a discovery. Not only Planck but also other physicists were intially at a loss as to what the proper context of the new postulate really was.

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

[Heisenberg’s seminal 1925 paper initiating quantum mechanics marked] one of the great jumps-perhaps the greatest-in the development of twentieth century physics.

It was not that long ago that people were complaining about two cultures. If we only had it that good. today.

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.