were married in a Calvinist church. He returned to England in September 1934. Mici had been a student in Pittsburgh, and wanted to return to the United States. Her chance came in 1935, when, thanks to George Gamow, Teller was invited to the United States to become a professor of physics at George Washington University, where he worked with Gamow until 1941. At George Washington University in 1937, Teller predicted the Jahn–Teller effect, which distorts molecules in certain situations; this affects the chemical reactions of metals, and in particular the coloration of certain metallic dyes. Teller and Hermann Arthur Jahn analyzed it as a piece of purely mathematical physics. In collaboration with Stephen Brunauer and Paul Hugh Emmett, Teller also made an important contribution to surface physics and chemistry: the so-called Brunauer–Emmett–Teller (BET) isotherm. Teller and Mici became naturalized citizens of the United States on March 6, 1941. When World War II began, Teller wanted to contribute to the war effort. On the advice of the well-known Caltech aerodynamicist and fellow Hungarian émigré Theodore von Kármán, Teller collaborated with his friend Hans Bethe in developing a theory of shock-wave propagation. In later years, their explanation of the behavior of the gas behind such a wave proved valuable to scientists who were studying missile re-entry. Manhattan Project Los Alamos Laboratory In 1942, Teller was invited to be part of Robert Oppenheimer's summer planning seminar, at the University of California, Berkeley for the origins of the Manhattan Project, the Allied effort to develop the first nuclear weapons. A few weeks earlier, Teller had been meeting with his friend and colleague Enrico Fermi about the prospects of atomic warfare, and Fermi had nonchalantly suggested that perhaps a weapon based on nuclear fission could be used to set off an even larger nuclear fusion reaction. Even though he initially explained to Fermi why he thought the idea would not work, Teller was fascinated by the possibility and was quickly bored with the idea of "just" an atomic bomb even though this was not yet anywhere near completion. At the Berkeley session, Teller diverted discussion from the fission weapon to the possibility of a fusion weapon—what he called the "Super", an early concept of what was later to be known as a hydrogen bomb. Arthur Compton, the chairman of the University of Chicago physics department, coordinated the uranium research of Columbia University, Princeton University, the