Robert “Bob” Finkelstein, professor emeritus in the department of physics and astronomy in the UCLA College, died peacefully Aug. 27 in Los Angeles. He was 104 years old.
Finkelstein conducted pioneering research in elementary particle theory, calculating the decay rates of the pi-meson and muon particles. During his long career, he contributed to general relativity, the theory of weak interactions and models for elementary particles based on the mathematical description of knots.
In 1948, he joined the faculty at UCLA, where he worked until his retirement in 1986.
“Although UCLA was very much in its infancy when I first came to it, I was convinced that it would become a major university,” he recalled in 2016. “The future looked very promising.”
In his research, Finkelstein worked on a broad range of topics in particle physics, and in recent years, he continued to publish research on the application of knot theory for particle physics.
“He has one of the longest records of scientific authorship,” said David Saltzberg, professor and chair of the physics and astronomy department, “spanning the 80 years from his first publication in 1940 to his most recent paper submitted in 2020.”
Saltzberg added: “Bob was a familiar face in the department. I always enjoyed speaking to him about his life and work and appreciated his kind demeanor. We are grateful to Bob, not only for his career and friendship but also for creating numerous graduate fellowships.”
One such fellowship is the Finkelstein Fellowship, which was created and augmented over the years by Finkelstein and his wife, Norma.
Born and raised in Pittsfield, Massachusetts, Finkelstein attended Dartmouth College, where he took a physics class with G.F. Hull, who, with E.L. Nichols, was the first (along with P. Lebedev in Russia) to measure the pressure of light. In his paper “My Century of Physics,” Finkelstein wrote, “The world would learn sometime later about the diabolical importance of the pressure of light in enabling the hydrogen bomb.” He graduated from Dartmouth as salutatorian in 1937.
He then attended Harvard, where he earned his doctorate in physics in 1941, working with John Hasbrouck Van Vleck and co-authoring a paper that Van Vleck considered important enough to reference in his Nobel Prize talk.
The day after his final doctoral exam, Finkelstein took the train to Washington, D.C., to join physicist Francis Bitter’s group in the U.S. Navy, where he also worked with leading mathematicians including Marshal Stone and Joseph Doob. Finkelstein later transferred to a group that worked with shock waves and detonation theory, and he found an analytic solution to a shockwave problem that Subrahmanyan Chandrasekhar had previously solved numerically.
“At about that time Einstein had agreed to serve as a consultant to our group but did not want to travel to Washington,” Finkelstein wrote. “There had to be a liaison person, and I was given that opportunity. Since Einstein did not know me, there had to be someone to introduce us. It then happened that I was introduced to Einstein by John Von Neumann, one of the most important mathematicians of all time, and who had also become a consultant to our group. It was a very great experience for a new Ph.D. to be introduced to Einstein by Von Neumann!”
After World War II, Finkelstein wrote to J. Robert Oppenheimer and Wolfgang Pauli to apply for a postdoctoral position. Oppenheimer, a highly influential theoretical physicist and UC Berkeley professor, worked on the Manhattan Project during WWII that developed the first nuclear weapons and later worked to avert nuclear proliferation and a nuclear arms race with the Soviet Union, and opposed the development of the hydrogen bomb.
“When Oppenheimer accepted me, the Yukawa theory was still very young,” Finkelstein wrote, “and mesons coming from an accelerator had yet to be observed.”
His research with Oppenheimer led to the 1947 paper “The Gamma Instabilities of Mesons.” They later worked together at the Institute for Advanced Study, where Finkelstein studied the quantization of unitary field theories.
“Bob never stopped working,” said his UCLA colleague Ernest Abers, professor emeritus of physics. “He walked the halls of UCLA’s physics department for seven decades. When he came here, it was a small, quiet place. He was one of the leaders who turned it into the major research and teaching center for physics it is today. He was the glue that held the theoretical particle physics group together — loved and respected by everyone who knew him. He was a good leader, a loyal friend and always good company.
“Bob was quiet and self-effacing. He exercised his considerable authority through quiet discussion, rather than public shouting matches,” Abers said. “Soft-spoken, figuratively and literally, he nevertheless held strong convictions about physics, politics, the university and, by example, how one should live life. He jogged for several miles almost every day along the palisades in Santa Monica.”
Finkelstein was an excellent teacher, and the Academic Senate awarded him a campuswide Distinguished Teaching Award in 1969, Abers added.
“He often taught without notes, and had a talent for making complex concepts accessible,” said Ana Cristina Cadavid, a professor of physics at Cal State Northridge, who was Finkelstein’s last doctoral student. “He had high expectations for the dozens of doctorate students he mentored, and was always supportive and available to them.”
Finkelstein recently discussed his life and career in an oral history for the American Institute of Physics.
Finkelstein is survived by Norma; their children, Michael and Ruth; and grandchildren Joshua and Alicia.
Those who wish to donate in memory of Finkelstein can contribute to the chair’s discretionary fund. These donations will be allocated to the Finkelstein Fellowship fund.