Copenhagen - Michael Frayn [50]
The failure to separate U235 also held up the reactor programme, and therefore the prospect of producing plutonium, because they could not separate enough of it even for the purposes of enrichment (increasing the U235 content of natural uranium), so that it was harder to get the reactor to go critical. The construction of the reactor was further delayed because Walther Bothe’s team at Heidelberg estimated the neutron absorption rates of graphite wrongly, which obliged the designers to use heavy water as a moderator instead. The only source of heavy water was a plant in Norway, which was forced to close after a series of attacks by Norwegian parachutists attached to Special Operations Executive, American bombers, and the Norwegian Resistance. Though perhaps, if a crash programme had been instituted from the first day of the war, enough heavy water might have been accumulated before the attacks were mounted.
If, if, if .… The line of ifs is a long one. It remains just possible, though. The effects of real enthusiasm and real determination are incalculable. In the realm of the just possible they are sometimes decisive.
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Anyone interested enough in any of these questions to want to sidestep the fiction and look at the historical record should certainly begin with:
Thomas Powers: Heisenberg’s War (Knopf 1993; Cape 1993)
David Cassidy: Uncertainty: The Life and Science of Werner Heisenberg (W H Freeman 1992)
Abraham Pais: Niels Bohr’s Times (OUP 1991)—Pais is a fellow nuclear physicist, who knew Bohr personally, and this, in its highly eccentric way, is a classic of biography, even though Pais has not much more sense of narrative than I have of physics, and the book is organised more like a scientific report than the story of someone’s life. But then Bohr notoriously had no sense of narrative, either. One of the tasks his assistants had was to take him to the cinema and to explain the plot to him afterwards.
Werner Heisenberg: Physics and Beyond (Harper & Row 1971)—In German, Der Teil und das Ganze. His memoirs.
Jeremy Bernstein: Hitler’s Uranium Club, the Secret Recordings at Farm Hall, introduced by David Cassidy (American Institute of Physics, Woodbury, New York 1996)
or the British edition of the transcripts:
Operation Epsilon, the Farm Hall Transcripts, introduced by Sir Charles Frank. (Institute of Physics Publishing 1993)
Also relevant:
Heisenberg: Physics and Philosophy. (Penguin 1958)
Niels Bohr: The Philosophical Writings of Niels Bohr (Oxbow Press, Connecticut 1987)
Elizabeth Heisenberg: Inner Exile (Birkhauser 1984)—In German Das politische Leben eines Unpolitischen. Defensive in tone, but revealing about the kind of anguish her husband tended to conceal from the world; and the source for Heisenberg’s ride home in 1945.
David Irving: The German Atomic Bomb (Simon & Schuster 1968)—in UK as The Virus House (Collins 1967). The story of the German bomb programme.
Paul Lawrence Rose: Heisenberg and the Nazi Atomic Bomb Project (U of California Press 1998)
Records and Documents Relating to the Third Reich, II German Atomic Research, Microfilms DJ29-32. (EP Microform Ltd, Wakefield) living’s research materials for the book, including long verbatim interviews with Heisenberg and others. The only consultable copy I could track down was in the library of the Ministry of Defence.
Archive for the History of Quantum Physics, microfilm. Includes the complete correspondence of Heisenberg and Bohr. A copy is available for reference in the Science Museum Library. Bohr’s side of the correspondence is almost entirely in Danish, Heisenberg’s in German apart from one letter.
Leni Yahil: The Rescue of Danish Jewry, (Jewish Publication Society of America, Philadelphia 1969)
There are also many interesting sidelights on life at the Bohr Institute in its golden years in:
French & Kennedy, eds: Niels Bohr, A Centenary Volume (Harvard 1985)
and in the memoirs of Hendrik Casimir, George Gamow, Otto Frisch, Otto