Operation Epsilon

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 weapon/power program. The scientists were captured between May 1 to June 30, 1945 and interned at Farm Hall, a bugged house in Godmanchester, England (near Cambridge), from July 3, 1945 to January 3, 1946. The goal was to determine how close the Germans had been to constructing an atomic bomb, by listening to their conversations.

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:

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. 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."

In the transcripts, Hahn contemplates suicide after learning of the bombing of Hiroshima, believing himself personally responsible, 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.