Lincoln Wolfenstein (February 10, 1923, Cleveland, Ohio – March 27, 2015, Oakland, California) was an American particle physicist who studied the weak interaction. Wolfenstein was born in 1923 and obtained his PhD in 1949 from the University of Chicago. He retired from Carnegie Mellon University in 2000 after being a faculty member for 52 years. Despite being retired, he continued to come into work nearly every day. Wolfenstein was a particle phenomenologist, a theorist who focused primarily on connecting theoretical physics to experimental observations. In 1978, he noted that the presence of electrons in Earth and Solar matter could affect neutrino propagation. This work led to an eventual understanding of the MSW effect, which acts to enhance neutrino oscillation in matter. Wolfenstein received the 2005 Bruno Pontecorvo Prize from The Scientific Council of the Joint Institute for Nuclear Research (JINR), for his pioneering work on the MSW effect. He was elected to the National Academy of Sciences in 1978. He was a founding member of the original Pittsburgh SANE (Committee for a Sane Nuclear Policy) and a member of the Union of Concerned Scientists. In 1986, Wolfenstein was awarded the New Person Award by the Thomas Merton Center in Pittsburgh for his work in pursuit of nuclear disarmament: He led a lifetime of advocating for responsible science as well as for individual rights and liberties. In 1992, Wolfenstein was awarded the American Physical Society's J.J. Sakurai Prize for Theoretical Particle Physics for "his many contributions to the theory of weak interactions, particularly CP violation and the properties of neutrinos". See also Cabibbo–Kobayashi–Maskawa matrix (Wolfenstein parameters) Carnegie Mellon University MSW effect (Mikheyev–Smirnov–Wolfenstein effect) Trimaximal mixing References External links Lincoln Wolfenstein's profile at Carnegie Mellon University Oral history interview, conducted 19 April 1997 by the American Institute of Physics Barry R. Holstein, "Lincoln Wolfenstein", Biographical Memoirs of the National Academy of Sciences (2016) 1923 births 2015 deaths American physicists Particle physicists Carnegie Mellon University faculty Members of the United States National Academy of Sciences J. J. Sakurai Prize for Theoretical Particle Physics recipients Fellows of the American Physical Society University of Chicago alumni