David Bohm

David Bohm was born in Wilkes-Barre, Pennsylvania, in 1917, the son of a Jewish furniture-store owner whose family had fled the pogroms in Hungary. He took his bachelor's degree at Pennsylvania State University and went to Berkeley for graduate work, where he became one of Robert Oppenheimer's last doctoral students before Oppenheimer left for the Manhattan Project. Bohm's 1943 PhD on neutron-proton scattering was so directly relevant to weapons design that the work was classified before he could publish it — Oppenheimer arranged for Bohm's Berkeley faculty to certify the thesis on his word that it was complete, since they could no longer read it. Bohm joined the Manhattan Project's Berkeley division but, as a member of the Communist Party USA in the late 1930s and a participant in left-wing political circles, was denied access to Los Alamos for security reasons. His Berkeley work on plasma diagnostics (the now-named "Bohm diffusion" coefficient) became foundational to magnetic-confinement fusion.

The McCarthy era reshaped Bohm's life. In 1949, called before the House Un-American Activities Committee to testify against Oppenheimer's Berkeley circle, he refused to name names and pleaded the Fifth Amendment. Princeton, where he had taken an assistant professorship in 1947, declined to renew his contract in 1951; he was unable to find another US academic position despite his abilities and the high regard in which Einstein and others held him. He left for São Paulo in 1951 (where he wrote the 1952 papers on the pilot-wave interpretation of quantum mechanics — Einstein, Schrödinger, and de Broglie all praised the work but Bohm himself was unhappy in São Paulo and the exile poisoned the reception of an already-controversial idea), then Haifa from 1955 to 1957 (where he met and worked with the young Yakir Aharonov), then Bristol from 1957 to 1961, and finally Birkbeck College in London from 1961 until his retirement.

The Bohm-Aharonov 1959 paper *Significance of Electromagnetic Potentials in the Quantum Theory* was written across the Bristol-Brandeis Atlantic divide; the 1952 *A Suggested Interpretation of the Quantum Theory in Terms of Hidden Variables* gives the deterministic pilot-wave (Bohmian mechanics) reformulation of nonrelativistic quantum mechanics. Bohm's later work turned increasingly philosophical: he had long correspondences with the Indian-born philosopher Jiddu Krishnamurti, wrote *Wholeness and the Implicate Order* (1980) on his ideas about the structure of reality, and pursued the implications of nonlocality and wholeness for fields outside physics. He died of a heart attack in London in 1992. Bohmian mechanics, once a fringe pursuit, is now taken seriously by a sub-school of philosophers of physics and a small but committed community of theoretical physicists; the Aharonov-Bohm effect is in every quantum mechanics textbook.