Session E15: Manhattan Project and Beyond

Remembering Los Alamos

Some Recollections Of Life At Los Alamos Before And After Trinity   

Did the Allies Know in 1942 About Nazi Germany's Poor Prospects for an Atomic Bomb?

According to official accounts, the U.S. knew nothing about Nazi Germany's efforts to get an atomic bomb until the end of the World War II, but had feared the worst. As it turned out, the Germans had made little progress. But did someone in the Allied camp know in 1942? In his 1986 book, The Griffin, Arnold Kramish relates how Paul Rosbaud, a spy for MI6, the British secret intelligence service, kept his handlers informed during the War about the German atomic project and reported the decision to give up on a bomb. Kramish's revelations are, understandably, thinly documented and Rosbaud's name can hardly be found independenly anywhere else. But as Samuel Goudsmit's papers in the Bohr Library show, he knew and communicated with Rosbaud from August 1945 on. In 1986, 15 letters exchanged by Goudsmit and Rosbaud were removed by the Government from the Library and eventually placed in the National Archives under classification review. Renewed interest in the Rosbaud story was engendered last year when his family sued MI6 in an English court for the release of the Rosbaud file. So far the spy agency has refused to reveal even that there is such a file. Discovering authoritatively what Rosbaud told the British and what they did with the information is clearly of historical interest.   

Revisiting the 100 Year Old Radioactivity Lectures of Frederick Soddy

Between 1908 and 1922, Frederick Soddy, MA., FRS (Dr. Lee`s Professor of Inorganic and Physical Chemistry, Univ. of Oxford) published four editions of a compendium of his experimental lectures delivered at the University of Glasgow, under the title ``The Interpretation of Radium, and the Structure of the Atom''. Professor Soddy taught his students about `radium writing' and the emanation of radium. He presented a radium clock designed by Professor Strutt; showed students `Pleochroic Halos'; and described the separation of `ionium' from its isotope, thorium. The process of constructing a cohesive logic to empirical observations of this newly discovered phenomenon of radioactivity was a challenging one. Some aspects did not stand the test of time. However, revisiting these lectures after 100 years gives us fascinating insight into the mental processes of the early pioneers in radioactivity.   

Arthur Compton's 1941 Analysis of Explosive Fission in U-235: The Physics

In November 1941 Arthur Compton prepared a report for Vannevar Bush regarding the possibility of explosive fission of U-235. This remarkable report, arguably the parent document of the Los Alamos Primer, presented detailed estimates for the critical mass, expected energy release, efficiency, destructive effects and probable cost of such a weapon. This paper will examine the physics behind Compton's estimates for the critical mass and efficiency of a fission weapon and compare his results to those derived from present-day cross-sections and secondary-neutron numbers. His approach to the efficiency calculation is found to be particularly interesting in that it utilizes some very basic undergraduate physics.   

The Manhattan Project and its Effects on American Women Scientists

There have been many detailed historical accounts of the Manhattan Project, but few have recognized the technical role women scientists and engineers crucially played in the Project's success. Despite their absence from these prominent accounts, recent studies have revealed that, in fact, women participated in every non-combat operation associated with the Manhattan Project. With such extensive participation of women and such a former lack of historical attention upon them, little analysis has been done on how the Manhattan Project might have influenced the prospectus of women scientists after the war. This talk has two aims: 1) to recount some of the technical and scientific contributions of women to the Manhattan Project, and 2) to examine what effects these contributions had on the women's careers as scientists. In other words, I intend offer a preliminary explanation of the extent to which the Manhattan Project acted both as a boon and as a detriment to American women scientists. And finally, I will address what this historical analysis could imply about the effects of current efforts to recruit women into science.   

X-Ray Spectroscopy, The Ellen Richards Prize, and Nuclear Proliferation: The Inspiring Life of Katherine Chamberlain

In 1924, Katherine Chamberlain became the first woman to receive a doctorate in physics from the University of Michigan. As one of the first women in the world to earn a doctorate in physics, Katherine reached a level prominence in the scientific community that few women had achieved. As a scientist, Katherine studied the outer energy levels of various elements using x-ray spectroscopy at the University of Michigan. In her thesis, she showed the potential for x-rays to reduce highly oxidized compounds and in 1925 won the Ellen Richards Prize for the world's best scientific paper by a woman. As an educator, she taught an introduction to photography course for thirty-five years in the hopes of creating new ways to inspire a love for physics in her students. As a community leader, she worked with The United World Federalists and The Michigan Memorial Phoenix Project to find peaceful uses for nuclear energy. Looking at these aspects of Chamberlain's life offers a unique perspective on the physics community of the 1920's, physics education, and the nuclear panic that followed WWII.   

From Alamogordo to the Nuclear Test-Ban Treaty

After W.W.II., the U.S. continued its program for the development of nuclear weapons. Winds carried radioactive debris far beyond the Nevada test site, and these fission products were deposited by rain, to enter the human food chain. The isotopes of greatest concern were Sr90 and I131, that, after ingestion, become concentrated in bone and thyroid respectively. There was a growing public anxiety about possible heath hazards posed by radiation from this fallout. In March 1958, the Greater St. Louis Citizens' Committee for Nuclear Information (C.N.I.) was formed. Among the leaders of C.N.I. were E. U. Condon and Barry Commoner. The aim of C.N.I. was ``to collect and distribute in the widest possible manner information which the public requires to understand the present and future problems which arise from potential large-scale use of nuclear weapons in war; testing of nuclear weapons; and nonmilitary uses of nuclear energy.'' In accordance with its objectives, members of C.N.I. gave many nontechnical talks, where we described the various forms of radiation and what was then known about the biological effects of radiation. Some of our members testified at Congressional committee hearings. We published a newsletter, initially titled \textit{Nuclear Information,} and later \textit{Scientist and Citizen}. In this presentation, I will describe some of the activities of this idealistic organization.