Frederick Reines

Physicist

• Born: March 16, 1918
• Birthplace: Paterson, New Jersey
• Died: August 26, 1998
• Place of death: Orange, California

Beginning with his codiscovery of the neutrino in 1956, Reines pioneered the developments leading to an understanding of the properties and the interactions of this elementary particle. His subsequent work led to the field of neutrino astronomy and to an understanding of the role played by neutrinos in generating the elements heavier than iron during stellar collapse and explosion.

Early Life

The son of Jewish immigrants to the United States from Russia, Frederick Reines (RI-nuhs) was the youngest of four children and spent much of his childhood in upstate New York. His father, Israel, was a store proprietor. Reines had fond memories of spending time working in his father’s store and enjoying life in a small American town. After the family moved to North Bergen, New Jersey, Reines attended Horace Mann Elementary School. He graduated from Union Hill High School in Union City, New Jersey, where he participated in a variety of extracurricular activities.

Reines loved science and earned a bachelor of science degree in physics from Stevens Institute of Technology in Hoboken, New Jersey, in 1939. Two years later he received his master’s degree from the same institution. In 1940, he married Sylvia Samuels. They reared a son and a daughter. In 1944, he earned his Ph.D. in physics from New York University.

Life’s Work

After earning his Ph.D., Reines worked under famed physicistRichard Feynman in the Theoretical Division of the Los Alamos National Laboratory in New Mexico. In 1945, Reines was appointed as the theory group leader. For the next fourteen years, he helped conduct a number of nuclear bomb tests in the South Pacific and in Nevada to develop a better understanding of the effects of nuclear blasts.

In 1951, Reines teamed with Los Alamos colleague Clyde Cowan, Jr., to search for the elusive neutrino particle that had been proposed by Wolfgang Pauli in 1936. Their first attempts at detecting the massless, neutral-charge neutrino were carried out at the Hanford nuclear facility in Richland, Washington. In 1955, they transferred their experimental operations to the new Savannah River nuclear reactor facility in South Carolina. One year later, using the capture of k-electrons to detect the neutrino, they observed the electron antineutrino. Soon thereafter, Reines focused his attention on gamma ray astronomy and the study of the neutrino’s properties and interactions.

In 1959, Reines was appointed chairman of the Physics Department at Case Western Reserve University in Cleveland, Ohio, where he remained until 1966. While at Case, Reines and fellow researchers were the first to detect neutrinos created in the atmosphere by cosmic rays. In 1966, Reines became the founding dean of the Physical Sciences Department at the University of California, Irvine (UCI). He helped graduate students develop medical radiation detectors, including those used to measure the total radiation delivered to the human body during radiation therapy.

For several years, Reines pursued a program of experiments to test some of the fundamental symmetry principles and associated conservation laws of nature predicted by the Grand Unified Theory (GUT) of elementary particles. These included conservation of lepton number, which would be violated if the decay of an electron or neutrino occurred, and conservation of baryon number, which would be observed in proton decay. This work led to the development of large-scale particle detectors, which have placed stringent limits on the violations of these conservation laws. Based on the measurements of Reines and others, the Supernova 1987A explosion was analyzed to figure out events associated with stellar evolution, particularly the production of elements heavier than iron. Production of these elements is associated with neutrinos bombarding mass that escapes from the supernova.

In 1981, Reines was awarded the J. Robert Oppenheimer Prize. He was also given the National Medal of Science (1985), the Bruno Rossi Prize (1989), the Michelson-Morley Award (1990), the W. K. H. Panofsky Prize (1992), and the Franklin Medal (1992). During his later years, his research concentrated on finding relic neutrinos, the neutrino-Mössbauer effect, limits on the violation of the Pauli exclusion principle, the precise measurement of the universal gravitational constant, exploration of the brain using ultrasound, and developing new particle detectors. In 1995, Reines and Martin Perl, a pioneer in lepton physics, shared the Nobel Prize in Physics. Reines died of natural causes at the age of eighty in 1998.

Significance

Reines played a role in the development of many fundamental scientific discoveries. Through his analyses of nuclear testing data, he outlined the effects associated with nuclear blasts. Turning his efforts to elementary particle physics, he codiscovered the elusive neutrino and helped develop its use as a sensitive probe in particle physics experiments. Neutrinos were used to investigate the weak interactions, the structure of protons and neutrons, and the properties of quarks. He was a pioneer of neutrino astronomy, and the role that the neutrino played in the production of elements heavier than iron during stellar evolution. His later work helped to establish limits for fundamental symmetry principles and conservation laws.

Bibliography

Ananthaswamy, Anil. The Edge of Physics: A Journey to Earth’s Extremes to Unlock the Secrets of the Universe. New York: Houghton Mifflin Harcourt Trade, 2010. The author explores some of the experiments being conducted to gain an understanding of dark matter, dark energy, and quantum gravity, and the roles that neutrinos play in these experiments. Dazzling, high-tech telescopes that are operating or under construction for exploration of outer space are described.

Bettini, Alessandro. Introduction to Elementary Particle Physics. Cambridge, England: Cambridge University Press, 2008. This book presents a clear, insightful description of the standard model of elementary particle physics, which includes contributions made to this field through the work on the neutrino by Reines. The interplay between theoretical and experimental physicists in developing an understanding of the fundamental forces of nature is discussed.

Zuber, Kai. Neutrino Physics. New York: Taylor and Francis, 2003. Zuber recounts the discovery of the neutrino, a discussion of its known properties, and its use in elementary particle experiments. Past, present, and future neutrino experiments and essential developments are described and explored. The diagrams are clear with informative captions.