Gregory Breit

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Interviewed by
Spencer Weart
Interview date
Conducted on the telephone
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In footnotes or endnotes please cite AIP interviews like this:

Interview of Gregory Breit by Spencer Weart on 1975 December 8,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,

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Brief interview focused on secrecy in the 1940s. As member of the National Academy of Sciences, Division of Physical Sciences, Breit expressed the necessity of keeping track of the fission problem through a publications committee headed by Frank B. Jewett. Comments on Manhattan Project scientists (Leo Szilard, Hans A. Bethe).


Asked B. about secrecy ca. 1940. He was a recently elected member of the National Academy of Sciences, and a member of the committee of the Division of Physical Sciences (Richtmyer, chairman) of NAS-NRC. In this committee he proposed that it should keep track of the fission problem. B. had had extended discussions, particularly with Szilard and also with Wigner. He had met both of them in Berlin, which he visited while he was in Zurich. [1]

At the meeting there were various reactions; some were skeptical, e.g. Lee Dubridge, who later told Breit, “you were right, I was wrong.” Breit’s remark was talked about, and the meeting, chaired by Luther P. Eisenhart (Princeton math) picked a committee. Frank B. Jewett became chairman of this committee on publications, and Breit naturally was made chairman of a sub-committee of this committee, for literature on isotopes (he didn’t want to mention uranium).

Breit sent letters to Fermi, Wigner, Urey and others (there was some prejudice against Szilard, so he wasn’t added). These people were trusted without being officially cleared. There were some raised eyebrows at the whole procedure. “I had a hell of a time with Bethe” — somebody in a high position feared he was unreliable.

Breit adds that he went into proximity fuse work during the war. He felt, correctly as it turned out, that the bomb wouldn’t be finished in time to help in the European war. The money could be spent on other things in his magnetic mine work, for example, he found a small appropriation was hard to get and made a big difference. He feels that many Manhattan Project scientists wanted the project for professional reasons they were able to keep on with their scientific interests and to make progress towards their postwar careers. This was very clear when he visited the Chicago Met Lab the young men there clearly tried to put their best foot forward when they made their presentations.