Robert Bacher

Robert Fox Bacher (August 31, 1905November 18, 2004) was an American nuclear physicist and one of the leaders of the Manhattan Project.

Bacher was born in Loudonville, Ohio, on August 31, 1905, the only child of Harry and Byrl Fox Bacher.

In 1908, the family moved to Ann Arbor, Michigan, where Harry worked as a banker and Byrl as a voice teacher on the University of Michigan faculty.

Bacher attended the W. S. Perry School, and later Ann Arbor High School.

While there he met Professor Harrison M. Randall, the head of the physics department at the University of Michigan, who encouraged him to study physics.

Bacher entered the University of Michigan, where he joined the Kappa Sigma fraternity and lived in the frat house.

He became the house manager in his sophomore year, but moved back home in his junior year to concentrate on physics.

At Randall's suggestion he applied to the Harvard Graduate School of Arts and Sciences, which he entered in 1926 to study for his doctorate.

His fees were paid by his family, but his father had a heart attack and could no longer afford them, so in 1927 Bacher moved back to Ann Arbor, where he lived at home, and attended the University of Michigan.

He received a Charles A. Coffin Foundation Fellowship from General Electric.

To build up the theoretical physics department at the University of Michigan, Randall recruited four distinguished young physicists to work at Ann Arbor in 1927: Otto Laporte, George Uhlenbeck, Samuel Goudsmit, and David M. Dennison.

The University of Michigan was no longer a backwater in theoretical physics.

Bacher immediately signed up for Goudsmit's course on atomic structure.

Born in Loudonville, Ohio, Bacher obtained his undergraduate degree and doctorate from the University of Michigan, writing his 1930 doctoral thesis under the supervision of Samuel Goudsmit on the Zeeman effect of the hyperfine structure of atomic levels.

After graduate work at the California Institute of Technology (Caltech) and the Massachusetts Institute of Technology (MIT), he accepted a job at Columbia University.

With Goudsmit he investigated the Zeeman effect of hyperfine structure of atomic levels, which became the subject of his 1930 PhD thesis.

On May 30, 1930, Bacher married Jean Dow.

His mother gave them a Ford Model A and the use of the family's lakeside holiday house, where they entertained guests including Paul Ehrenfest and Enrico Fermi.

In 1931, with a National Research Council Fellowship, he spent a year at the California Institute of Technology (Caltech) because Ira Bowen taught there.

At Caltech Bacher attended lectures by Robert Oppenheimer, but spent most of his time at the Mt. Wilson Observatory, which had a better library.

Bacher decided to create a work listing the energy, coupling constant, parity and electron configurations of all the known atoms and ions, working with Goudsmit back in Ann Arbor.

The result was a book, Atomic Energy States as Derived from the Analysis of Optical Spectra (1932), which they dedicated to Randall.

In 1935 he accepted an offer from Hans Bethe to work with him at Cornell University in Ithaca, New York.

It was there that Bacher collaborated with Bethe on his book ''Nuclear Physics.

A: Stationary States of Nuclei'' (1936), the first of three books that would become known as the "Bethe Bible".

In December 1940, Bacher joined the Radiation Laboratory at MIT, although he did not immediately cease his research at Cornell into the neutron cross section of cadmium.

The Radiation Laboratory was organized into two sections, one for incoming radar signals, and one for outgoing radar signals.

Bacher was appointed to handle the incoming signals section.

Here he gained valuable experience in administration, coordinating not just the efforts of his scientists, but also those of General Electric and RCA.

In 1942, Bacher was approached by Robert Oppenheimer to join the Manhattan Project at its new laboratory in Los Alamos, New Mexico.

It was at Bacher's insistence that Los Alamos became a civilian rather than a military laboratory.

At Los Alamos, Bacher headed the project's P (Physics) Division, and later its G (Gadget) Division.

Bacher worked closely with Oppenheimer, and the two men discussed the project's progress on a daily basis.

After the war, Bacher became director of the Laboratory of Nuclear Studies at Cornell.

He also served on the U.S. Atomic Energy Commission, the civilian agency that replaced the wartime Manhattan Project, and in 1947 he became one of its inaugural commissioners.

He left in 1949 to become head Division of Physics, Mathematics, and Astronomy at Caltech.

He was appointed a member of the President's Science Advisory Committee (PSAC) in 1958.

In 1962, he became Caltech's vice president and provost.

He stepped down from the post of provost in 1970, and became a professor emeritus in 1976.

He died in 2004 at the age of 99.