Kusch, Polykarp

▪ 1994

      U.S. physicist (b. Jan. 26, 1911, Blankenburg, Germany—d. March 20, 1993, Dallas, Texas), was awarded the 1955 Nobel Prize for Physics for his precise work in measuring the electron's magnetic moment, a vital determination that led to revised theories about the interactions of electrons with electromagnetic radiation and to new scientific principles as a basis for quantum electrodynamics; he shared the prize with Willis E. Lamb, Jr., who independently performed related experiments on the hyperfine structure of the hydrogen atom. Kusch immigrated to the U.S. with his family in 1912 and became a citizen in 1922. He graduated (1931) from Case Institute of Technology, Cleveland, Ohio, before earning an M.A. (1933) and a Ph.D. (1936) from the University of Illinois at Urbana-Champaign, where he taught physics from 1931 to 1936. He joined Columbia University, New York City, in 1937, and there, with physicist Isidor I. Rabi, he conducted studies of the effects of magnetic fields on beams of atoms. Kusch remained associated with Columbia until 1972 except for a time during World War II, when he engaged in military research on the applications of vacuum tubes and microwave generators at Westinghouse Electric Corp. (1941-42) and Bell Telephone Laboratories (1944-46). At Columbia he served as chairman of the physics department (1949-52 and 1960-63), director of the radiation laboratory (1952-60), and academic vice president and provost (1969-72). From 1972 until his retirement in 1982, he taught at the University of Texas at Dallas.

* * *

▪ American physicist

born Jan. 26, 1911, Blankenburg, Ger.

died March 20, 1993, Dallas, Texas, U.S.

      German-American physicist who, with Willis E. Lamb, Jr. (Lamb, Willis Eugene, Jr.), was awarded the Nobel Prize for Physics in 1955 for his accurate determination that the magnetic moment of the electron is greater than its theoretical value, thus leading to reconsideration of and innovations in quantum electrodynamics.

      Kusch was brought to the United States in 1912 and became a citizen in 1922. In 1937, at Columbia University, he worked with the physicist Isidor I. Rabi (Rabi, Isidor Isaac) on studies of the effects of magnetic fields on beams of atoms. He spent the wartime years in research on radar and returned to Columbia in 1946 as professor of physics, a position he held until 1972. Among other posts held by Kusch at Columbia were department chairman (1949–52, 1960–63), director of the radiation laboratory (1952–60), and academic vice president and provost (1969–72). In 1972 he took a position as professor at the University of Texas, Dallas, where he remained until his retirement in 1982.

      In 1947, through precise atomic beam studies, Kusch demonstrated that the magnetic properties of the electron were not in agreement with existing theories. Subsequently, he made accurate measurements of the magnetic moment of the electron and its behaviour in hydrogen. In work characterized by great accuracy and reliability, he measured numerous atomic, molecular, and nuclear properties by radio-frequency beam techniques.

* * *