George Braxton Pegram (October 24, 1876 – August 12, 1958) was an American physicist who played a key role in the technical administration of the Manhattan Project.
By 1918, he was Dean of the Faculty of Applied Sciences but he resigned in 1930 to relaunch his research activities, performing many meticulous measurements on the properties of neutrons with John R. Dunning.
[4] During the summer break in 1905, he worked for the United States Coast and Geodetic Survey on measuring the Earth's magnetic field at its observation stations.
Pegram was awarded a John Tyndall Fellowship for this purpose in 1907, and went to Germany, where he attended lectures at the Humboldt University of Berlin given by Max Planck and Walther Nernst.
In his travels he visited some twenty European universities,[6] and he met Florence Bement, a Wellesley College graduate from Boston.
They renewed their acquaintance after they returned to the United States, and were married at her aunt's home in West Newton, Massachusetts on June 3, 1909.
[9] In 1917 and 1918, Pegram served on a committee established by the National Research Council headed by the President of Columbia University, Nicholas Murray Butler, with Michael I. Pupin as its secretary, that created a quartz piezo-electric sound detector for locating submerged submarines.
Pegram was intimately involved in its design, insisting on a structure without load bearing internal walls, so that it could be reconfigured over time, and with large two-storey lecture theatres.
He attempted to expose his physics students to ideas from Europe, inviting Hendrik Lorentz, Larmor, Planck, Max Born and Werner Heisenberg to visit Columbia.
[19] Other scientists working at Columbia in 1939 included Herbert L. Anderson, Eugene T. Booth, G. Norris Glasoe, Francis G. Slack and Walter Zinn, making it one of the world's most important centers for nuclear physics.
At Columbia, Enrico Fermi and John R. Dunning were quick to verify Hahn's and Strassmann's results, and there was a lively debate over whether uranium-235 or its more abundant uranium-238 isotope was primarily responsible.
[24] In March 1939, Fermi, Szilard and Eugene Wigner met with Pegram in his office, and urged that their results be brought to the attention of the government.
[25] Echoing sentiments his father had articulated back in 1911,[26] Pegram informed Hooper that uranium chain reaction might "liberate a million times as much energy per pound as any known explosive.
[31] Pegram attended the Advisory Committee on Uranium meeting on April 27, along with Fermi, Szilard and Wigner where the prospects for a chain reaction were discussed.
On May 14, he was able to report that Szilard and Fermi had found that graphite indeed had a small neutron absorption cross section, and would make an effective moderator.
[30] Pegram brought in members of the football team to stack graphite blocks,[32] and purchased uranium from the Eldorado Mining and Refining Limited in Canada.
Fermi recalled that: We went to Dean Pegram, who was then the man who could carry out magic around the University, and we explained to him that we needed a big room.
He scouted around the campus and we went with him to dark corridors and under various heating pipes and so on, to visit possible sites for this experiment and eventually a big room was discovered in Schermerhorn Hall.
The United States' entry into World War II following the Japanese attack on Pearl Harbor gave the project a new urgency when the S-1 Committee next met on December 18, 1941.
After the war, scientists there had access to the research reactors at the government-sponsored Argonne National Laboratory, and Fermi and Urey were lured away to Chicago.
Even the quintessential New Yorker Rabi was tempted to leave rather than return to Columbia from his wartime work at the MIT Radiation Laboratory.
On January 16, 1946, Pegram convened a meeting of representatives of 16 different colleges, universities, hospitals and research institutions like the Bell Telephone Laboratories.
The meeting drafted a request to the director of the Manhattan Project, Major General Leslie R. Groves, Jr., asking him to establish a regional research laboratory near New York City.
In response, Groves sent Colonel Kenneth Nichols to meet with Pegram and Rabi and their opposite numbers from Princeton University, Hugh S. Taylor and Henry D. Smyth on February 8.
[42] Finding a site that was both accessible and remote proved to be a challenge, but eventually one of found at Camp Upton on Long Island.