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Robert Bacher (1905-2004) was an American nuclear physicist. Born in Ohio, he received his bachelor’s and doctorate in physics from the University of Michigan.

After working at the MIT Radiation Laboratory, Bacher was recruited for the Manhattan Project by J. Robert Oppenheimer. He became head of the experimental physics division at Los Alamos in 1943 and the bomb physics division in 1944 and 1945. Bacher was instrumental in keeping Los Alamos a civilian instead of military laboratory. His wife, Jean, and their two children, Andrew and Martha, also lived at Los Alamos.

Bacher was in charge of G (“Gadget,” the bomb’s code name) Division, responsible for designing the implosion-type bomb, known as “Fat Man,” that was used at Nagasaki. He also helped assemble the plutonium core of the “Gadget” for the Trinity test at the McDonald Ranch House in the New Mexico desert. 

He received the Medal of Merit for his work in 1946. After the war, Bacher held a brief position at the United Nations as one of Bernard Baruch’s technical advisors, then was appointed to be a charter commissioner on the Atomic Energy Commission (AEC). He later became a member of President Eisenhower’s Science Advisory Committee, and was vice president and provost at Caltech.

Robert Bacher's Timeline
1905 Aug 31st Born in Loudonville, Ohio.
1926 Received a B.S. in physics from the University of Michigan.
1930 Received his Ph.D. in physics from the University of Michigan.
19341935 Taught at Columbia University.
1935 Joined the faculty at Cornell University, working with Hans Bethe.
1941 Began work at the MIT Radiation Laboratory.
1942 Recruited by J. Robert Oppenheimer to work on the Manhattan Project at Los Alamos.
1943 Directed the experimental physics division at Los Alamos.
19441945 Directed the bomb physics division at Los Alamos.
1945 Became a full professor at Cornell.
19461949 May Appointed a charter commissioner on the Atomic Energy Commission.
1949 Moved to Caltech to work as a division chair of physics, mathematics, and astronomy.
19531955 Member of the President's Science Advisory Committee under Dwight D. Eisenhower.
19571959 Member of the President's Science Advisory Committee under Dwight D. Eisenhower.
1962 Vice-president and provost at Caltech.
1970 Retired from Caltech.
2004 Nov 18th Died in Montecito, California.

Robert Bacher. Photo courtesy of LANL.

Robert Bacher's Los Alamos ID badge photo

Leslie Groves, Richard Tolman and Robert Bacher

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