Szilard, Leo

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SZILARD, LEO (1898–1964), Hungarian physicist and extraordinary polymath. He was born in Budapest and studied at the Minta School and at Budapest Technical University (1916–19). His engineering course was disrupted by World War i service in the Austro-Hungarian army (1917) from which he was discharged because of illness. Horthy's antisemitic policies persuaded him to leave Hungary for Berlin (1920) where he gained his Ph.D. in physics from the University of Berlin (1922). He worked in different departments of the University of Berlin and for the German General Electric Company (1922–33) before leaving for England with the rise of the Nazis. He did research at St Bartholomew's Hospital, London, and the Clarendon Laboratory, Oxford University (1933–38) before immigrating to the U.S. He worked at Columbia University, New York, before moving to the University of Chicago (1942). He was appointed professor of biophysics at the university's Institute of Radiobiology and Biophysics (1946) but changed to biology (1947) and started a molecular biology laboratory (1948–53). After a period without formal affiliation except as visiting professor to Brandeis University, Waltham, Mass., he again returned to the University of Chicago as professor of biophysics at the Enrico Fermi Institute for Nuclear Studies (1956–61). He became a resident fellow of the Salk Institute, La Jolla, California (1964–66). Szilard's scientific career began with an outstandingly original thesis on thermodynamics. In Germany he collaborated with Albert *Einstein (1926–33) in designing a novel domestic refrigerator and induction pump, filed patents on the linear accelerator, cyclotron, and electron microscope, taught quantum physics with John von *Neumann, and published his analysis of Maxwell's Demon. In England he conceived and patented (1934) the idea of a neutron chain reaction despite the skepticism of many physicists and was at once aware of the implications. After Hahn and Strassman's discovery of uranium fission, (with Walter Zinn) he showed that neutrons are emitted during this process. His experiments with Enrico Fermi led to the construction of the world's first nuclear reactor. He advised his colleagues in the Manhattan Project on reactor design and correctly predicted that radiation damage to reactor constituents could release stored energy; this accounted for the accident involving Britain's Windscale reactor (1957). He was later a creative contributor to the work on phages (viruses which infect bacteria) which initiated modern molecular biology and an influential theorist in the field of enzyme regulation. His World War i experience and the Japanese invasion of China made Szilard averse to militarism. However his alarm, shared by Eugene *Wigner and Edward *Teller, that the Nazis might develop nuclear weapons persuaded Einstein to write to Roosevelt, thereby initiating the Manhattan Project. Szilard's opposition to political interference with scientific freedom led to conflict with General Groves, the overall Project commander. After Germany's defeat he also expressed moral reservations over using nuclear weapons against Japan. After the war he was prominent among Project scientists opposing military control of atomic energy. He attended the first Pugwash conference (1957) and participated in the Pugwash movement and other movements for world security. His writings included the elegant essays The Voice of the Dolphins (1961). He was elected to membership of the U.S. Academy of Arts and Sciences (1954) and National Academy of Sciences (1961). When he fell ill, he designed the radiation therapy that cured his bladder cancer (1959).

[Michael Denman (2nd ed.)]