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Robert F. Christy (1916-2012) was a Canadian-American theoretical physicist

Christy’s doctoral advisor at the University of California, Berkeley was Robert Oppenheimer, but Christy’s initial involvement with the Manhattan Project came at the Metallurgical Lab at the University of Chicago. Originally, Christy was tasked to work on theoretical design, but Nobel prize-winning physicist Enrico Fermi took notice of the young Canadian’s work and invited him to contribute to the experimental design of Chicago Pile-1. Christy remained at Chicago to witness the first self-sustaining nuclear reaction in history on December 2, 1942. Afterwards, he was invited by Oppenheimer to work in Los Alamos with Hans Bethe on the design of the atomic bomb.

It was here that Christy was credited with his biggest accomplishment; the successful blueprint and construction of an atomic weapon with a solid-core of plutonium, as opposed to the hollow-core that was more likely to fizzle upon detonation. Edward Teller had theorized the concept of a solid-core, but it was Christy that made it a reality. The solid core was dubbed a “Christy pit,” a term that remains in use today. Christy’s contribution to the Manhattan Project was great enough that his fellow scientists used the term “Christy gadget” as a euphemism for the atomic bomb.

After the war, Christy would take a position at the California Institute of Technology (Caltech) on the recommendation of Oppenheimer. Caltech became his academic home for the remainder of his career. In 1973, he re-married, to a fellow phyisicist Inge-Juliana Sackmann

Following Edward Teller’s testimony in the Oppenheimer security hearing in 1954, Christy found himself in the public light after refusing to shake Teller’s hand. Christy and Teller had actually lived together in Chicago for a short time, but following the trial, their relationship was strained, and remained that way for decades. 

Robert F. Christy's Timeline
1916 May 14th Born Robert Frederick Cohen (his family later changed their surname to Christy) in Vancouver, Canada.
1935 Received B.A. in physics and mathematics with first degree honors from the University of British Columbia (UBC)
1937 Received M.A. in physics from UBC, writing a thesis entitled, "Electron attachment and negative ion formation in oxygen.
19381941 Attended the University of California, Berkeley as a doctoral student of Robert Oppenheimer. Completes his Ph.D. in 1941 with a dissertation entitled, "Cosmic-ray burst production and the spin of the mesotron.
1942 Joined the Manhattan Project in Chicago and is recruited by Enrico Fermi to work on the world's first nuclear reactor.
1942 Dec 2nd Witnessed the first controlled nuclear reaction in history as Chicago Pile-1 goes critical for the first time.
1943 Transferred to the Los Alamos Laboratory and assigned to work in the Theoretical Division under Hans Bethe.
1944 Sep Designed the "Christy pit," allowing for a solid core of plutonium to be used in the implosion-type atomic bomb.
1945 Jul 16th A Christy pit is used in the first nuclear detonation at the Trinity test site in New Mexico.
1946 Feb Lived in the same household as Edward Teller for a short time while working at the University of Chicago.
1946 Accepted a position at the California Institute of Technology (Caltech) and remains there for the rest of his academic career.
1954 Refused to shake Teller's hand after Teller testified in the Oppenheimer security hearing.
1967 Earned the Royal Astronomical Society's Eddington Medal for explaining why Cepheid variable stars pulsate.
2012 Oct 3rd Died in California at the age of 96.

Robert Christy's Los Alamos ID badge photo

Juliana and Robert. 

Robert and Juliana on their wedding day, August 4, 1973. 

Robert Christy at the California Institute of Technology. He briefly served as the acting president here from 1978 to 1979.

Robert photographed in 1970.

Robert photographed in 1970.

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