Rudolf Peierls talks about working with intelligence officers to find out what was going on scientifically in Germany during World War II.

Peierls:

I can tell you. It started in a very funny way, because quite early on, I was asked by the intelligence people, not directly, I never talked to them directly but through somebody else, what — what should they do to discover what was going on in Germany along these lines?

And I said, "Well, there are a number of people who would probably be connected with it, and therefore, if you have the possibility of finding out the movements of those people, whether they are away from their university, whether they have lots of visitors and so on, it might help."

So I wrote down a list, starting with the name of Heisenberg, and then an answer came back, "it's peculiar that you should have mentioned his name, Heisenberg, because he lectured in Cambridge in 1939 and we have no record that he ever left the country."

So I was horrified because I thought, if that was the level of our scientific intelligence, then God help us. But the fact is they improved because they put a very good man in charge. Then I decided I would do my own intelligence, from what I could get from publications. And I knew that each semester the physikalische Zeitschrift published a list of the physics lectures at every German university, and that was very informative, because you can't fake that, because it would attract local attention, to say someone was lecturing if he wasn't, and these lists showed that practically all the Germans, the German physicists, were in their normal places lecturing on their normal subjects. Very different from the picture that you would have got from a similar list in this country (England) or in the United States. Not only because of the atomic energy. And so, then, there were some exceptions. Heisenberg for example did not lecture. Then he — then in Leipzig some student wrote a paper, obviously a thesis — he thanked Hund for help and so on, not Heisenberg, although Heisenberg would have been interested in the subject. So Heisenberg either wasn't there or was too busy.

He gave a lecture, a very formal lecture at Vienna, I think — it was old stuff, nothing new to us. So I concluded Heisenberg was up to something.

Then another interesting point was, in the abstracting journal the Physikalische Berichte, there were people who wrote abstracts of papers on nuclear physics and isotope separation, including for example Wirtz.

So I could make a list of names of people who probably were involved. I didn't get them all. But the main impression was, there was some mild work going on, but no crash program.