By Anne Levin

Theoretical physicist and writer Freeman J. Dyson, who for more than six decades made Princeton’s Institute for Advanced Study (IAS) his academic home, died February 28 at Penn Medicine Princeton Medical Center in Plainsboro. He was 96.

In a statement announcing Dyson’s death last week, the IAS said he “embraced the stunning diversity of the universe with unique spirit.”  Dyson “generated revolutionary scientific insights, including calculations bridging the quantum and human worlds,” the IAS statement read. “His contributions stem from his work in numerous areas, including nuclear engineering, solild state physics, ferronmagnetism, astrophysics, biology, and applied mathematics.”

Commenting on Dyson’s passing, IAS Director and Leon Levy Professor Robbert Dijkgraaf said, ““No life is more entangled with the Institute and impossible to capture — architect of modern particle physics, free-range mathematician, advocate of space travel, astrobiology and disarmament, futurist, eternal graduate student, rebel to many preconceived ideas including his own, thoughtful essayist, all the time a wise observer of the human scene. His secret was simply saying ‘yes’ to everything in life, till the very end. We are blessed and honored that Freeman, Imme, and their family made the Institute their home. It will be so forever.”

With all of his academic accomplishments, Dyson was also a loving father who took great joy in his six children. “It was just his interest in whatever it was we were thinking about, and what we spent our time doing, and what interested us,” said Mia Dyson, the second youngest of the siblings. “I did a lot of theater, and he was passionate about that.”

Mia Dyson remembers sitting on her father’s lap as he read the book Le Petit Prince to her. “I was very little. I was tucked into his lap, and I could hear his voice rumbling into my bones as he read,” she recalled. “All of a sudden there was this enormous quaking and I turned around to look. He blew his nose into his handkerchief because he was weeping at the beauty of it. He wept at beautiful stories and poetry. He had an enormously warm heart, and I appreciated that so much.”

Edward Witten, the IAS’ Charles Simonyi Professor in the School of Natural Sciences, said Dyson made fundamental contributions in an incredibly wide variety of fields in physics and mathematics. “His contributions were so wide-ranging that it is virtually impossible for any one person to summarize them adequately,” Witten said. “Quantum electrodynamics, quantum statistical mechanics, Diophantine approximation of numbers, and random matrix ensembles are just a few of the fields to which Freeman contributed at the highest level. But really, he left his mark almost everywhere.”

Simonyi, who is IAS board chair, said, ““Freeman Dyson was truly a ‘free thinker’ — there were absolutely no bounds to what he was willing to imagine, no bounds of complexity, of conventional wisdom, of scope and time. His thoughts, just as the universe he was exploring, and expressed in the title of one of his many books, were truly ‘Infinite in All Directions.’”

Among his numerous books, Dyson wrote Disturbing the Universe, a portrait-gallery of people he had known during his career as a scientist; Weapons and Hope (1984), which won the National Book Critics Circle Award for Nonfiction in 1984; and Infinite in All Directions (1988) a philosophical meditation based on his Gifford Lectures on Natural Theology given at the University of Aberdeen in Scotland. His most recent work, Maker of Patterns (2018), is an autobiographical account of his life through letters written to his parents.

The British-born Dyson was honored with more than 20 honorary degrees and was elected to numerous learned societies. He joined the IAS as a member in 1948 at the invitation of J. Robert Oppenheimer, and became a permanent member of the faculty in 1953. He also studied at Cornell University, doing graduate work with Hans Bethe and Richard Feynman.

“The Institute provided Dyson the freedom and flexibility to follow his curiosity to new areas and fields that interested him,” reads the Institute’s statement. “In 1956, Dyson began a three-year association with General Atomic, where he worked to design a nuclear reactor that would be inherently safe, or, as colleague Edward Teller put it, “‘not only idiot-proof, but PhD proof.’” The TRIGA reactor is still in production today and used mostly by hospitals.

But it is Dyson’s warmth and encouragement as a parent that his children remember most. “One time my little sister was playing oboe in a concert at school,” said Mia Dyson. “My parents were in the audience. When it was over and the orchestra stood up to bow, my father was so thrilled at my sister’s playing that he leapt out of his seat and ran down the aisle, jumped onto the stage, and embraced her. Of course, she was mortified. But that was him. He would get lost in his enthusiasms.”