Ernest Mark Henley, an internationally acclaimed University of Washington physics professor and administrator, died 27 March 2017 at age 92. He was well-known for his theoretical research and for his professional service for the American Physical Society (APS) and other committees.
Henley’s research career began in the postwar era as physicists sought to understand how the universe’s fundamental particles interact with one another. Through a combination of his theoretical work and experiments determining the interactions of leptons and quarks, his research helped physicists assemble the Standard Model, today’s framework of fundamental particles and forces.
Henley was born in Germany on 10 June 1924. He earned his undergraduate degree in electrical engineering from the City College of New York in 1944 and a doctoral degree in physics from the University of California, Berkeley in 1952. After short terms as a research associate at Stanford University and lecturer at Columbia University, Henley joined the UW faculty in 1954 as an assistant professor. He was promoted to associate professor in 1957 and full professor in 1961. Before becoming dean of the College of Arts & Sciences, Henley served as chair of the UW Faculty Senate from 1971 to 1972 and chair of the Department of Physics from 1973 to 1976. He was a central force in creating the UW Institute for Nuclear Theory and served as its inaugural director from 1990 to 1991. Henley became a professor emeritus in 1995.
Henley devoted a great deal of his time to professional service. He served on many committees of APS. He was a member of the Program Committee of the APS Division of Nuclear Physics 1969-73, the Panel on Public Affairs 1975, the Nominating Committee 1976-78, the Committee on International Freedom of Scientists 1975-78, the Publications Committee 1983-85, Executive Committee 1984. He was the vice chairman 1978-79 and chairman 1979-80 of the APS Division of Nuclear Physics, and president of APS in 1992. He also was a committee member of the National Academy of Sciences, the Nuclear Science Advisory Committee, the advisory committees for Stanford and Taiwan universities, the Program Review Committee for the Los Alamos Meson Physics Facility, and TRIUMF’s Experimental Evaluations Committee.
Henley received many awards. In 1989 the APS awarded him the Tom W. Bonner Prize in Nuclear Physics. He was elected to the National Academy of Sciences in 1979 and the American Academy of Arts & Sciences in 1995. Also he was a Fellow of APS and the American Association for the Advancement of Science. He was also a Frank B. Jewett (1952-53), NSF (1958-59), John Simon Guggenheim (1967-68), and NATO (1976-77) fellow.
With regard to his research, Henley published articles with collaborators in a number of area of theoretical physics, with many focused on symmetries. Most of these articles were related to CP and time-reversal violations, but in his early research he and his collaborators studied isospin and SU(3) flavor symmetry violation. A great deal of his research used QCD sum rules, such as research on cosmological phase transitions (quantum chromodynamic phase transition and electroweak phase transition). His final research was on neutrino oscillations: CP violation and possible time-reversal violation, parameters needed for neutrino oscillation theory, and analytical theory of neutrino oscillations in matter. Experiments suggested by Henley and performed by colleagues at the UW Nuclear Physics Laboratory—now the Center for Experimental Nuclear Physics and Astrophysics—revealed new details about symmetries and uncovered conditions when subatomic particles deviate from symmetry.
Henley continued his physics research until 2014, writing with collaborators on a diverse set of topics including using QCD sum rules to extract hadronic properties and studies of CP violation and neutrino oscillations. He was also a prolific writer of influential books, publishing five.
Henley came to Los Alamos National Laboratory many times to plan and carry out theoretical research with theoretical physicists from various universities, including Taipei, Taiwan. Often he brought his wife Elaine, who is a distinguished physician in Seattle.
The science community, his students, research collaborators, family, and friends in many nations will long remember his contributions to physics, education, and international freedom of scientists.