Operation Epsilon was the codename of a program in which Allied forces near the end of World War II detained ten German scientists who were thought to have worked on Nazi Germany's nuclear program. The scientists were captured between May 1 and June 30, 1945, as part of the Allied Alsos Mission, mainly as part of its Operation Big sweep through southwestern Germany. They were interned at Farm Hall, a bugged house in Godmanchester, England (near Cambridge), from July 3, 1945 to January 3, 1946. The primary goal of the program was to determine how close Nazi Germany had been to constructing an atomic bomb by listening to their conversations.
List of scientists
The following German scientists were captured and detained during Operation Epsilon:
- Erich Bagge
- Kurt Diebner
- Walther Gerlach
- Otto Hahn
- Paul Harteck
- Werner Heisenberg
- Horst Korsching
- Max von Laue
- Carl Friedrich von Weizsäcker
- Karl Wirtz
Farm Hall transcripts
The results of the transcripts were inconclusive. On July 6, the microphones picked up the following conversation between Werner Heisenberg and Kurt Diebner, both of whom had worked on the German nuclear project and had been seized as part of the Allied Alsos Mission, Diebner in Berlin and Heisenberg in Urfeld:
- Diebner: "I wonder whether there are microphones installed here?"
- Heisenberg: "Microphones installed? (laughing) Oh no, they're not as cute as all that. I don't think they know the real Gestapo methods; they're a bit old fashioned in that respect."
Most historians have no reason to believe that he was not being genuine, and the attitude of Heisenberg and the other scientists over all the months and especially their reaction to the shattering news of the bomb explosion was so genuine that it is almost inconceivable it was staged.
All of the scientists expressed shock when informed of the atomic bombing of Hiroshima on August 6, 1945. The transcripts seem to indicate that the physicists, in particular Heisenberg, had either overestimated the amount of enriched uranium that an atomic bomb would require or consciously overstated it, and that the German project was at best in a very early, theoretical stage of thinking about how atomic bombs would work. After first puzzling over whether or not the report was genuine, the scientists then contemplated how the bomb was made and why Germany was not able to produce one. Some of the scientists indicated that they were happy that they had not been able to build a nuclear bomb for Adolf Hitler, while some of the others, more sympathetic to the Nazi party, were dismayed at having failed. Otto Hahn, one of those who were grateful that Germany had not built a bomb, chided those who had worked on the German project, saying "If the Americans have a uranium bomb then you're all second-raters."
Some of the scientists had almost nothing to do with the nuclear project. Otto Hahn, for example, had (with his assistant Fritz Strassmann) discovered nuclear fission in December 1938, but otherwise had no participation. Max von Laue was, like Hahn, an ardent anti-Nazi and had not done any work relating to wartime physics. In the transcripts, Otto Hahn contemplates suicide after learning of the bombing of Hiroshima, believing himself personally responsible for the many Japanese victims, while less than two weeks after the announcement Heisenberg had figured out the process by which the bomb was built.
The transcripts were originally sent as reports to British military officers, and were then forwarded to the U.S. War Department, where they eventually made it to General Leslie Groves of the Manhattan Project, as part of Operation Alsos. In February 1992 they were declassified and published.
The events at Farm Hall were dramatised on BBC Radio 4 on 15 June 2010 in "Nuclear Reactions", written by Adam Ganz, son of one of the interpreters, Peter Ganz.
A play "Operation Epsilon" by Alan Brody, largely based on the transcripts, opened on March 7, 2013 in Cambridge, Massachusetts. A staged reading of the play "Farm Hall" by David C. Cassidy, was presented on February 15, 2013 in the Science & the Arts program at The Graduate Center of the City University of New York. A second reading was performed on March 20, 2013 at the annual March meeting of The American Physical Society in Baltimore, Maryland.
- Operation Epsilon: The Farm Hall Transcripts. Sir Charles Frank (introduction). Bristol, Philadelphia, and Los Angeles: Institute of Physics Publishing and University of California Press. November 1993. p. 313. ISBN 978-0-520-08499-5.
- Bernstein, Jeremy (1995). Hitler's Uranium Club: The Secret Recordings at Farm Hall. New York: Springer-Verlag. p. 457. ISBN 978-1-56396-258-5.
- Bernstein, Jeremy (2001). Hitler's Uranium Club: The Secret recordings at Farm Hall (2nd ed.). New York: Springer-Verlag. ISBN 978-0-387-95089-1.
- Goldberg, Stanley; Powers, Thomas (September 1992). "Declassified files reopen "Nazi bomb" debate". Bulletin of the Atomic Scientists 48 (7). pp. 32–40. ISSN 0096-3402.
- Excerpts from the Farm Hall transcripts for August 6, 1945
- Annotated bibliography for Farm Hall from the Alsos Digital Library for Nuclear Issues
- Archival entry for the original transcripts, includes notes on their provenance
- Programme for staged reading of the Farm Hall Transcripts, Royal Society of Edinburgh, 24 April 2009