Stanley Deser, a theoretical physicist who helped illuminate the details of gravity and how it shapes the space-time fabric of the universe, died on April 21 in Pasadena, Calif. He was 92.
His death, at a hospital, was confirmed by his daughter, Abigail Deser.
Physicists have long dreamed of devising a theory of everything — a set of equations that neatly and completely describe how the universe works. By the middle of the 20th century, they had come up with two theories that serve as the pillars of modern physics: quantum mechanics and general relativity.
Quantum mechanics describes how, in the subatomic realm, everything is broken up in discrete chunks, or quanta, such as the individual particles of light called photons. Albert Einstein’s theory of general relativity had elegantly captured how mass and gravity bend the fabric of space-time.
However, these two pillars did not fit together. General relativity does not contain any notion of quanta; a quantum theory of gravity is an ambition that remains unfinished today.
“The problem we face is how to unify these two into a seamless theory of everything,” said Michael Duff, an emeritus professor of physics at Imperial College London in England. “Stanley was amongst the first to tackle this problem.”
In 1959, Dr. Deser, along with two other physicists, Richard Arnowitt and Charles Misner, published what is now known as the ADM formalism (named after the initials of their surnames), which rejiggered the equations of general relativity in a form that laid a foundation for work toward a quantum theory of gravity.
“It’s a bridge toward quantum,” said Edward Witten, a physicist at the Institute for Advanced Study in Princeton, N.J. So far, however, no one has been able to take it to the next step and come up with a unified theory that includes quantum gravity.
The ADM formalism offered additional benefit: It made general relativity equations amenable to computer simulations, enabling scientists to probe phenomena like the space-bending pull of black holes and the universe-shaking explosions when stars collide.
The rejiggered equations split four-dimensional space-time into slices of three-dimensional space, an innovation that allowed computers to handle the complex data and, as Frans Pretorius, a professor of physics at Princeton University, put it, “evolve these slices in time to find the full solution.”
Dr. Deser is perhaps best known for his work in the 1970s as one of the pioneers of supergravity, which expanded an idea known as supersymmetry to include gravity.
From quantum mechanics, physicists already knew that fundamental particles fell into one of two groups. Familiar constituents of matter like electrons and quarks fall into the group known as fermions; while those that carry fundamental forces like photons, the particles of light that convey the force of electromagnetism, are known as bosons.
Supersymmetry hypothesizes an as-yet-undiscovered boson partner for every fermion, and a fermion partner for each boson.
Dr. Deser worked with Bruno Zumino, one of the originators of supersymmetry, to add gravity to the theory, creating the theory of supergravity. Supergravity includes gravitons — the gravitational equivalent of photons — and adds a supersymmetric partner, the gravitino.
Experiments using particle accelerators have yet to turn up evidence of any of these partner particles, but the theories have not been disproved, and because of their mathematical elegance, they remain attractive to physicists.
Supergravity is also a key aspect of superstring theories, which attempt to provide a complete explanation of how the universe works, overcoming shortfalls of quantum gravity theories.
“Stanley was one of the most influential researchers on questions related to gravity over his extremely long and distinguished career,” said Dr. Witten, who has been at the forefront of devising superstring theories.
Stanley Deser was born in Rovno, Poland, a city now known as Rivne and part of Ukraine, on March 19, 1931. As Jews, his parents, Norman, a chemist, and Miriam, fled Poland’s repressive, antisemitic regime in 1935 for Palestine. But prospects for finding work there were dim, and a few months later they moved to Paris.
In 1940, with World War II engulfing Europe, the family narrowly escaped France after Germany invaded.
“They finally realized the danger and decided to leave everything,” Dr. Deser wrote of his parents in his autobiography, “Forks in the Road.” “I rushed with my father to empty our safe. That evening, my mother sewed the coins into a belt of towels, a much-practiced maneuver of refugees, while the rest of us packed a few belongings.”
The family fled to Portugal and 11 months later obtained visas to emigrate to the United States. They eventually settled in New York City, where Norman and Miriam ran a chemical supplies business.
By age 12 Stanley had been promoted to 10th grade, and he graduated from high school at 14. He earned a bachelor’s degree in physics from Brooklyn College in 1949 at 18, then went to Harvard, where he studied under Julian Schwinger, a Nobel Prize laureate. He completed his doctorate in 1953.
After postdoctoral fellowships at the Institute for Advanced Study and the Niels Bohr Institute in Copenhagen, Dr. Deser joined the faculty of Brandeis University in 1958.
The following three years, working on the ADM formalism, provided “the best run of luck that one could possibly hope for,” he wrote in his autobiography.
In an interview last year for Caltech’s Heritage Project, Dr. Deser recalled that he, Dr. Arnowitt and Dr. Misner completed much of the work during summers in Denmark, in a kindergarten classroom. “The nice thing about this kindergarten, it has blackboards,” he said. “Denmark is very good that way.”
Since the blackboards were mounted low for children, “we would crawl and write equations,” Dr. Deser said. “And the papers just poured out.”
Dr. Misner, an emeritus professor of physics at the University of Maryland, said there were parallels between the ADM recasting of general relativity and the quantum field theory of electromagnetism that other physicists were working on, and they were able to apply that experience to general relativity.
The work on supergravity occurred during a stay at the CERN particle laboratory in Geneva where Dr. Zumino worked. “In a period of just three weeks, to our amazement, we had a consistent theory,” Dr. Deser recalled.
He and Dr. Zumino published a paper about supergravity in June 1976. However, another group of physicists — Daniel Freedman, Sergio Ferrara and Peter van Nieuwenhuizen — beat them to the punch, describing supergravity in a paper that had been completed about a month before Dr. Deser and Dr. Zumino submitted theirs.
As a result, Dr. Deser said, sometimes the work that he and Dr. Zumino did was overlooked. In 2019, a Breakthrough Prize in Fundamental Physics — accompanied by $3 million — was awarded to the other team.
“He was understandably upset,” Dr. Duff, the British physicist, said. “I think they could have erred on the side of generosity and included Stanley as the fourth recipient.” (Dr. Zumino died in 2014.)
Dr. Schwarz and Dr. Witten, who were members of the committee that awarded the prize, declined to discuss the particulars of the decision, but Dr. Schwarz said, “It was a purely scientific decision.”
Dr. Deser worked at Brandeis until he retired in 2005. He then moved to Pasadena to be close to his daughter and obtained an unpaid position as a senior research associate at Caltech.
In addition to Abigail, he is survived by two other daughters, Toni Deser and Clara Deser, and four grandchildren.
His wife of 64 years, Elsbeth Deser, died in 2020. A daughter, Eva, died in 1968.
While Dr. Deser was an expert on gravity and general relativity, he was not infallible.
In the Caltech interview, he recalled a paper in which he suggested that gravity could solve some troubling infinities that were showing up in the quantum field theory of electrodynamics.
Other noteworthy physicists had similar thoughts but did not publish them. Dr. Deser did.
“It was garbage,” he said. During a talk at a conference, Richard Feynman, the Nobel Prize-winning physicist who devised much of quantum electrodynamics, “without much difficulty shot me to pieces, which I deserved,” he said.
He added, “Everybody’s entitled to a few strikes.”
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