Notes to Heisenberg.
As soon as I came to England and learned about the great American
English preparations, I naturally had to
When I came to England in 1943 and was acquainted with the great
American–English preparations, the question of how far Germany had come was
naturally of the greatest importance both for physicists and for government
authorities. I had the opportunity to discuss this question thoroughly both
with the English intelligence service and with members of the English government,
and I naturally reported all of our experiences including in particular the
impression I got both during the visit to Copenhagen by you and Weizsäcker as
well as during Jensen’s.
As the war approached its conclusion and Germany’s position became
ever more difficult, the fear that it should succeed in producing atomic
weapons naturally decreased, nor did their use in the war against Germany
become an issue.
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In that connection I have also been asked how your journey to
Copenhagen was arranged and what authorization you had been given to speak to
me about a question which was surrounded by such great secrecy and held such
great political problems. (1)–(2)
As regards Jensen’s visit to Copenhagen in 1943, the war had
already at that time taken a course quite different from what you and
Weizsäcker expressed as your conviction in 1941. Jensen described the efforts
to increase the production of heavy water in Norway and mentioned in this
connection that, for him and other German physicists, it was only a matter of
an industrial application of atomic energy. At that time, however, I had to be
very cautious and sceptical, partly on the basis of rumours of new German
weapons, partly because of my own difficult position due to the constant surveillance
of the German police.
Of course, it is your account published in Jungk’s book which has
created such keen public interest in all these wartime connections
When I, especially after the publication of Jungk’s book, about
which I have been questioned not only by colleagues in many different
countries, but especially as a consequence of the thorough investigations of
archives, which one from
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I recall that you said in that connection that you did not know
what I thought but that you had worked so closely with it yourself that
(1) (Because
of the great experience that I had in subsequent years through connection with
counterespionage by the secret intelligence service, I fully understand the
reason for such questions.) (2)