NOBEL LAUREATE: James Peebles, Princeton University Albert Einstein Professor of Science, emeritus, and professor of physics, emeritus, has been awarded the 2019 Nobel Prize in Physics “for theoretical discoveries in physical cosmology.”  (Photo courtesy of Princeton University Office of Communications)

By Anne Levin

James Peebles, Princeton University professor emeritus and a graduate of the Class of 1962, has been awarded the 2019 Nobel Prize in Physics “for theoretical discoveries in physical cosmology.”

Peebles was one of three to be recognized with the honor on Tuesday, October 8. He receives half of the approximately $908,000 cash award. The other half is shared by Michel Mayor and Didier Queloz of the University of Geneva, Switzlerland, and the University of Cambridge, “for the discovery of an exoplanet orbiting a solar-type star.”

At a press conference held Tuesday afternoon at Richardson Auditorium, University President Christopher L. Eisgruber, who as a physics major was a student of Peebles, said, “While searching the cosmos, he never lost focus on what was right in front of him: his students.”

Eisgruber recalled Peebles as “a popular teacher and a fixture in the undergraduate program.” Peebles was famous for his ice cream breaks, when halfway through the class, he and his students would buy ice cream from the vending machines in Jadwin’s basement. “If I remember correctly, he would continue the lecture with ice cream in one hand and chalk in the other,” Eisgruber said.

The University’s Physics Department Chair, Professor Herman L. Verlinde, said of Peebles, “He is one of the true pioneers, one of the founding fathers of a whole branch of physics now called theoretical cosmology.”

According to the Royal Swedish Academy of Sciences, “James Peebles took on the cosmos, with its billions of galaxies and galaxy clusters. His theoretical framework, developed over two decades, is the foundation of our modern understanding of the universe’s history, from the Big Bang to the present day.”

Peebles is the Albert Einstein Professor of Science, emeritus, and professor of physics, emeritus. During the Nobel news conference by phone, he said, “When I started working in this subject — I can tell you the date, 1964 — at the invitation of my mentor, Professor Robert Henry Dicke, I was very uneasy about going into this subject because the experimental observational basis was so
modest…. I just kept going. Which particular step did I take? I would be very hard-pressed to say. It’s a life’s work.”

Born just outside Manitoba, Canada, on April 25, 1935, Peebles received his B.S. from University of Manitoba in 1958
and earned his Ph.D. in physics from Princeton in 1962. He taught at the University for his entire career. He was an instructor and researcher in the early 1960s, became an assistant professor in 1965, associate professor in 1968, and full professor in 1972. He transferred to emeritus status in 2000.

Colleagues praised and congratulated Peebles on the University website. The honor “is so appropriate,” said Lyman Page, the James S. McDonnell Distinguished University Professor in Physics. “No one else has advanced our fundamental understanding of the universe more. Multiple of his predictions were shown to be correct through measurements. On top of it, he is uncommonly thoughtful, gracious, and kind.”

“It is difficult to overstate Jim’s contributions to humanity’s understanding of our place in the universe,” said Bill Jones, associate professor of physics. “In addition to laying a great deal of the theoretical groundwork for modern cosmology, Jim pioneered many of the methods that have made cosmology a predictive science and one that allows us to test our theories with observational data. Generous to his students and colleagues, I doubt a kinder soul has ever been so recognized. Congratulations, Jim!”

Among his many honors, Peebles received the 2005 Crafoord Prize with fellow Princeton astrophysicist James Gunn, also from the Royal Swedish Academy of Sciences, according to the website. In 2004 he received the Shaw Prize, and gave this account: “When I started work on cosmology, in the early 1960s, I felt uneasy as well as excited, because the long extrapolation from well-established laboratory results to the physics of our expanding universe was supported by exceedingly limited empirical evidence. I remember thinking I might complete two or three projects in this subject and then move on to something less speculative. That never happened because each project led to ideas for others, in a flow that was too interesting to resist.”

Peebles has published several books on cosmology that are considered classics in the field, and his upcoming book, Cosmology’s Century, An Inside History of Our Modern Understanding of the Universe, will come out in June 2020 from Princeton University Press.

At the press conference, Peebles said he was “proud and delighted at the friendly reception I have received here. It’s such a joy to see the recognition of work that so many have done.” He expressed thanks to the University of Manitoba for showing him that he loved physics. He urged students in the audience to continue the work. “I hope you guys hurry up to make those discoveries so I can enjoy them,” he said.