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Robert D. Tripp
In Memoriam

Robert D. Tripp

Professor of Physics, Emeritus

UC Berkeley
1927-2020
Robert (Bob) Tripp, Professor Emeritus of Physics and retired Senior Faculty Scientist in the Physics Division at Lawrence Berkeley National Laboratory (LBNL) passed away on June 27th in Berkeley, California. He was born on January 9, 1927 and spent his childhood on a farm near Fresno, California. He entered MIT in the Fall of 1944 but interrupted his studies after one semester to join the U.S. Navy, where he subsequently served as a radar technician on Treasure Island. After his discharge, he returned to MIT, where he obtained a B.S. degree in 1950.  He then came to Berkeley as a graduate student in the Department of Physics. In 1952, he joined the research group of Professor Emilio Segré, and together with Thomas Ypsilantis initiated the first experiments at the 184-inch synchrocyclotron using polarized protons. After receiving his Ph.D. in 1955, he joined the Alvarez group as a postdoctoral fellow and participated in path-breaking experiments with liquid-hydrogen-filled bubble chambers. He helped to design and then used a beam of negative kaons that were stopped in the newly-built 10-inch hydrogen bubble chamber at the Berkeley Bevatron. 

In 1960, Bob was appointed assistant professor in Berkeley’s physics department and over the years he advanced up the academic ladder to become a full professor and senior faculty scientist at LBNL. In the late 1950s and early 1960s, he was one of a group of very talented and productive young LBNL physicists that included M. Lynn Stevenson, Art Rosenfeld, Frank Crawford, and others, who used hydrogen bubble chambers to discover and then characterize many of the resonant states that formed the basis of the quark model of Murray Gell-Mann and Georg Zweig. Over the years, he attracted and influenced several outstanding visitors such as Max Ferro-Luzzi, who became long-time collaborators and close friends. He was a mentor to many, including Lina Galtieri, Janos Kirz, and Charles Wohl.

In the early 1980, along with Herbert Steiner and George Gidal, Bob joined a small group led by Mark Strovink to carry out a search for right-handed currents in the decay of stopped polarized muons at TRIUMF. The limit they obtained was then, and remained for many years, the definitive result. Thereafter, his interests shifted to neutrino-less double beta decay and, together with Robert Kenney and Margaret Alston-Garnjost, he set up an experiment with Mo100 in an unused mine in Idaho. Their limit was competitive with results obtained by others using various materials.

Bob retired from the physics faculty in late 1991 but continued to do research at LBNL. His interest shifted again, this time to astrophysics, where he looked for infrared signals from extinguished supernovae in starburst galaxies, and proposed a two-parameter luminosity correction for type 1a supernovae used to calibrate distant supernovae to measure cosmological expansion parameters. In a novel extension of his astrophysics work, after the Oakland Hills fire of 1991, Bob and Carl Pennypacker invented the FUEGO satellite system to detect fires from geosynchronous orbit. The FUEGO concept was granted a U.S. patent and may be implemented in Australia.

Bob’s scientific undertakings were characterized by a deep knowledge of the underlying physics and his insistence on always fully involving himself in the details of the research issues under investigation. These qualities, along with his good nature and sense of humor, earned him the high respect of his collaborators.

Bob was a dedicated runner who inspired many of his colleagues to join him on four-mile runs through the Berkeley hills. He was also an enthusiastic and accomplished mountaineer and skier, who climbed challenging peaks all over the world, including Denali (Mt. McKinley) in Alaska and Aconcagua in Argentina, the highest peaks in North and South America. Bob also was a wine connoisseur; each year he and a few friends picked grapes and then went to his garden and cellar to make wine, which was almost always very good. Bob’s wife, Susan Ervin-Tripp, an eminent professor of psychology at Berkeley, pre-deceased him in November 2018. He is survived by their three children, Alexander, Katya, and Nicholas.

Herbert Steiner
2020