On the day we were caught, Lion and I had been talking about writing a memorandum on the fate of the Jewish war children living in hiding or among Du… - Abraham Pais

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. I learned, because there was no interruption. I had access to myself, to my thinking. I wouldn't say that I particularly matured. The thinking was physics thinking. I was just short of twenty-two then. I was in hiding for two years and two months, something like that. In all that time I went out very, very little, just once in a great while, after dark. 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.

I made a discovery, perhaps known to others but new to me: I need not put myself center stage but can rather place myself at the side, like a Greek chorus. As the curtain rises, I can walk to the center and can speak as follows: I wish to tell you of happenings in the twentieth century, as I witnessed them and reflected upon them. You will see me return to center stage, but only occasionally. Once that imagery had gotten hold of me, I went back to Ida and said yes, I shall try.

The ultimate unification of weak and electromagnetic interactions has probably not yet been achieved, but a solid beach-head appears to have been established in terms of local non-Abelian gauge theories with spontaneous symmetry breakdown. As a result, it is now widely believed that weak interactions are mediated by massive vector mesons. Current expectations are that such mesons will be observed within the decade. It is widely believed that strong interactions are also mediated by local non-Abelian gauge fields. Their symmetry is supposed to be unbroken so that the corresponding vector mesons are massless. The dynamics of these 'non-Abelian photons' are supposed to prohibit their creation as single free particles. The technical exploration of this theory is in its early stages.