Aron Bernstein, professor emeritus of physics and longtime anti-nuclear proliferation activist, died on Jan. 14 after a short battle with cancer. He was 88.
Aron Bernstein joined MIT in 1961, and taught a broad range of physics courses from first-year to graduate level for 40 years. A member of The Hadronic Physics Group in the Laboratory for Nuclear Science, his research was in intermediate energy physics, including nuclear and particle physics, with an emphasis on studying the basic structure of matter. He was also active in the anti-nuclear weapons movement with the Council for a Livable World, the Union of Concerned Scientists, and the Nuclear Weapons Education Project.
“Aron was one of those rare beings — a thoughtful scholar, a good and cheerful person, and someone who worked with a lightness of being to make the world a better place,” said Jim Walsh, a senior research associate in MIT’s Security Studies Program, who worked with Aron in the classroom and on the board of the Council for a Livable World. “He was a gentle soul, but also a persistent, if humble, instigator. He had a deep commitment and boundless energy for university students and for efforts to eliminate nuclear weapons.”
Born April 6, 1931, he grew up in Brooklyn and Queens, the son of Abraham and Lillian (Dashevsky) Bernstein, and the older brother of Grace. His father owned an engraving business specializing in mercury-and-glass thermometers. A physics major at Queens College, he was inspired by his professor Banesh Hoffman, who had worked with Albert Einstein. Bernstein recalled Hoffman promising an instant A if the class could solve a difficult math problem. “Aron and one of his friends worked on it for days,” recalled Bernstein’s wife, Susan Goldhor. “They took it very seriously and they actually came up with a solution. I don’t know if he got an A, but from the professor’s viewpoint there was an elegant solution, and theirs was a cobbled-together solution. Aron was like that, he would work on something and would not give up.”
However, Bernstein was stumped by foreign languages, which was a requirement, so he switched to Union College, where he received a bachelor’s in physics in 1953. He then pursued his doctorate at the University of Pennsylvania, where he recalled a memorable colloquium featuring MIT Professor Victor “Viki” Weisskopf. “His physical intuition made a vivid impression on me, and I still remember him rubbing his fingers together to show his pleasure at getting to the nub of things,” said Bernstein.
After receiving his PhD in 1958, Bernstein became a postdoc at Princeton University. He recalled asking his advisor Donald Hamilton to let him attend a summer program on nuclear physics in Colorado that featured Weisskopf. “I decided to present a project I’d done with my fellow postdoc Max Brennan,” Bernstein recalled. “I remember pacing the streets the evening before, wondering what Viki would ask me. After a few hours pacing around, I realized that Viki would say, ‘Very nice, but please explain how it works.’ I would then smile and explain on my fingers. Amazingly, that’s exactly what happened.”
Soon after, Bernstein was drawn to interview at MIT. “He sort of fell in love with MIT and Cambridge,” recalled his wife. “He had a dream that was linked to MIT, where he was on the subway and every single person had a white coat and was a scientist.”
He started in 1961 as an assistant professor of physics, and used accelerators around the world to study the structure of atomic nuclei by looking at reactions started by beams of particle accelerators. His first accelerator at MIT was the Markle cyclotron, an atom-smasher built in 1938 for nuclear and medical research, and newly refurbished. Bernstein saw it as an underutilized workhorse, and used its 30 MeV alpha particle beam to perform low-energy nuclear physics experiments. “We could get a lot of experiments done with the cyclotron,” he said. “We were quite active using a solid-state detector, so we had decent resolution. We made a lot of physics hay, so to speak, with this beam.”
When Bernstein and four others came up for tenure in the mid-’70s, he had Weisskopf in his corner. “All four (other) physics candidates for promotion that year were turned down, but I was the one Viki successfully fought for,” recalled Bernstein.
Bernstein was an experimental nuclear scientist but also worked on the theoretical side of physics. He collaborated with multiple laboratories at home and abroad, including France as a Guggenheim fellow, Germany as a Humboldt fellow, and in an exchange program with the physics and political science departments at Oxford’s Baliol College.
“He covered a lot of ground,” said his colleague, professor of physics Robert Redwine. “He was highly esteemed.” Redwine and Bernstein wrote papers together, and alternated on round-the-clock shifts for weeks during accelerator experiments, most often at the former Bates Linear Accelerator Center in Middleton, Massachusetts. “We would work rather intensely together,” Redwine said.
Bernstein organized an internationally recognized chiral dynamics workshop in 1994. After the first two workshops, he stepped back to serve on its advisory committee. “He spent a lot of time to make sure it was useful, not just a bunch of senior people talking, and it was so successful they are still held every three years,” said Susan. “His attitude was ‘Let the young people run it.’ Some people are always angling to be senior author or to get more credit. Aron didn’t care about that. He only cared about the physics and mentoring young people.”
Bernstein’s family used to tease him for not winning a Nobel prize like many of his physics colleagues. But as the saying goes, to be rich in friends is to be poor in nothing. And Bernstein had a talent for making friends among colleagues, students, and others around the world. After his death, Susan received condolence emails from many of Bernstein’s former students and colleagues, and they all expressed how much he had touched their lives.
“Aron was the colleague I talked the most with about physics and also learned from the most about science,” said one former colleague, Haiyan Gao. “Aron's passion for physics is contagious and tremendously inspiring. He has always been so nurturing to young scientists and extremely generous in sharing his physics insight, knowledge, and wisdom.”
“He was a dedicated classroom teacher who knew what he was talking about,” said Redwine. “He really liked to connect to people. He was good at making what he was saying relevant to you.”
Victor F. Weisskopf Professor of Physics Alan Guth was an MIT first-year in 1964 when he took Bernstein’s 8.01 class, and he also chose Bernstein for his junior lab 8.14 (Experimental Physics II). That project extended into a senior thesis, and then a master's thesis. “From the beginning of this project, Aron made me feel for the first time like I was a physicist, and not just a student,” said Guth. “He always made the people he was speaking to feel important. When I was still an undergraduate, but had started working with him, he always invited me to the meetings of his research group, treating me like any other member of the group.”
Bernstein’s former grad student and Jefferson Lab worker Peter Bosted recalled Bernstein’s “twinkle in his eye” and his generosity with his time. Bernstein’s former grad student Itaru Nakagawa said that “research with Aron was a joy for me.” Bernstein’s postdoc Cesar Fernandez-Ramirez said, “Aron became a mentor to me and showed me how I should conduct myself as a scientist and a human being. The world is a better place, thanks to people like him.”
Bernstein was a member of Phi Beta Kappa and Sigma Xi, and a fellow of the American Physical Society and the American Association for the Advancement of Science. He retired from the physics department in 2001 after 40 years.
Nuclear arms control activist
Bernstein never retired from keeping an eye on the hands of the Doomsday Clock. “The disarmament project is his capstone project, because it married his political and research passions,” said his son, Dan Bernstein MCP ’86. “He was really a peace activist.”
Among those he teamed up with were fellow peace advocates Weisskopf and Phil Morrison, both Manhattan Project veterans; future Nobel laureate and professor of physics Henry Kendall; microbiologist Salvador “Salva” Luria; Center for Theoretical Physics founder Herman Feshbach; and professor of linguistics Noam Chomsky.
“I was always aware of the fact that if I had been 20 years older, I would have been in the Manhattan Project,” Bernstein said. “I was fortunate in my career to have worked closely with, and to have been inspired by, three such extraordinary people as Viki, Salva, and Phil. I regularly got phone calls from Salva commanding me to “get your head out of the cyclotron and come to my office and do something important. Viki … was a tremendous sounding board and a moral force that I greatly benefitted from.”
In 1969, Bernstein helped form the Union of Concerned Scientists and participated in its “Scientists Strike for Peace,” which disrupted research and classes to protest U.S. and MIT involvement in the Vietnam War. The strike led MIT to the divestment of the Instrumentation Laboratory (now Draper Laboratory), a U.S. Department of Defense contractor.
“The organizers were distressed, on the one hand, with the low level of political engagement of the scientific community, and more specifically with the role of military research on university campuses,” Bernstein wrote in a 50-year retrospective on the strike.
Years later, Bernstein joined a similar campaign to reject research funds for work related to President Ronald Reagan’s “Star Wars” space-based missile defense system.
He served on the National Advisory Board of the Council for a Livable World, an organization aimed at educating Congress on issues of arms control. “He was quick to offer advice, and just as quick to offer and provide help,” said Executive Director John Tierney.
Bernstein chaired a Federation of American Scientists chapter at MIT and the MIT Faculty Disarmament Study Group, and was the advisor to a student group on arms control, MIT’s Global Zero.
Bernstein and his contemporaries grew up prepared for a Russian nuclear attack, practicing classroom duck-and-cover exercises, and working in buildings set up with basement bomb shelters. But he soon became aware that his post-Cold War students didn’t quite understand this nuclear threat. He gathered a group of volunteers, including Redwine and Los Alamos weapons program veteran Mike Hynes, to launch the Nuclear Weapons Education Project. The idea was to supplement curriculums to increase nuclear-weapon literacy, and to set up a website to share information.
In his final years, Bernstein continued to visit universities, and cultivated a network of physicists around the country on behalf of this project. “We were still having meetings and discussions on this a few months ago,” said Redwine. “It became more difficult for him because of health reasons, but he was still involved.” Guth added that Bernstein possessed an “inexhaustible concern for helping to make the world a better place.”
Bernstein married Marlene Reshall in 1956, and raised two children, Dan and Amy. The couple divorced in 1975.
His family benefited from Bernstein’s ability to combine his work with travel and a love of the outdoors. In 1968, he took them on his sabbaticals to France and New Mexico. When China opened up to the West in the late ’70s, he not only wanted to make connections with Chinese physicists, he took Dan with him, with detours to Japan, India, Germany, and England. Wherever he traveled for work, he’d find a spot to go hiking. He enjoyed living in Cambridge, Massachusetts, so he could bike to work and take his family sailing on the MIT boats, and family time was spent snowshoeing, cross-country skiing, or sailing.
Bernstein met second wife Susan Goldhor through mutual friends. “I thought he was kind of cute and had a really nice smile,” she recalled. Susan, a biologist with an interest in mycology, recalled Bernstein joking that “I did mushrooms, and he did mushroom clouds.” On their first date, they hiked the White Mountains. Then they planned a longer hike. “I didn’t have the right socks, and I got blisters. These were big hikes every day. I was really having a hard time, I was in pain, I was exhausted, and so I complained to Aron about this. Aron hated whiners, so he wrote me a letter afterward that it wasn’t going to work out, that he wasn’t going to deal with whiners. He was a very, very straightforward person — he didn’t play games.”
She convinced him that she wasn’t actually a whiner, and he took her to a Mozart concert at Jordan Hall. Bernstein loved music, “nothing later than Schubert, and preferably a lot earlier— I couldn’t get him to go to a Mahler concert.” They married in 1990. Hiking was a shared passion, and they bought a vacation home in the White Mountains. “We hiked in summer, fall, and winter — I remember hiking in a blizzard. Until Aron was 86, we were still hiking and snowshoeing together. The hikes got shorter but the pleasure was still there.”
And he was still biking into MIT until the last couple of years, to work on his anti-nuclear projects or meet with friends.
Bernstein “was the kind of person to whom it is quite difficult to say no, even when you should,” said Walsh. “He cared about you, the person sitting across from him in his office, and cared about the fate of humanity, and both are the better for it.”
“Aron was certainly one of the most wonderful people I've known,” said Guth. “His dedication to helping to build a better world was unbounded.”
Bernstein is survived by his wife, Susan Goldhor; daughter Amy Bernstein; son Dan Bernstein and daughter-in-law Efrat Levy; and three granddaughters, Dara, Meirav, and Tali.
The Department of Physics is planning a memorial celebration later this year in honor of Aron Bernstein.