Felix Bloch on learning from war work.

Bloch:

It is, of course, a technical point. Anyway, so I was all ready: I did my work mostly in the evening, my calculations, convincing myself that this should at least be possible; that the size of the signals were big enough. At that point I had learned something about radio techniques, and I knew what a receiver and an antenna was, and I knew what noise was. That was all-important in our game. That was of great importance to the work I was planning then. That's why I said before that I learned more, for me, useful things at the Radio Research Laboratory than in Los Alamos, because I knew very little about radio techniques before I joined this Harvard laboratory.

I may interject that that is probably a rather common experience. People felt that through their war work they came in contact with other fields of science, which they had not been acquainted with before. And I believe at least part of this sudden quick development of physics after the war was due to this phenomenon. It was certainly eminently true in my case, but I'm quite sure other people had the same experience. They had worked in too narrow a field, and now they were forced to go into other things, which they thought they would never use. They did so only because the war required it, and later it turned out it was very important.