James Bardeen, expert in unraveling Einstein’s equations, dies at 83

James Bardeen, who helped elucidate the properties and behavior of black holes, setting the stage for what has been called the golden age of black hole astrophysics, died June 20 in Seattle. He was 83 years old.

His son William said the cause was cancer. Dr. Bardeen, professor emeritus of physics at the University of Washington, lived in a nursing home in Seattle.

Dr. Bardeen was a scion of a family of renowned physicists. His father, John, twice won the Nobel Prize in Physics, for the invention of the transistor and the theory of superconductivity; his brother, William, is a quantum theory expert at the Fermi National Accelerator Laboratory in Illinois.

Dr. Bardeen was an expert at unraveling the equations of Einstein’s general theory of relativity. This theory attributes what we call gravity to the curvature of spacetime by matter and energy. Its most mysterious and disturbing consequence was the possibility of black holes, places so dense that they became bottomless one-way exit ramps out of the universe, swallowing even light and time.

Dr. Bardeen would find his life’s work investigating these mysteries, as well as the mysteries related to the evolution of the universe.

“Jim was part of the generation where the best and the brightest went to work on general relativity,” said Michael Turner, cosmologist and professor emeritus at the University of Chicago, who described Dr Bardeen as “a gentle giant “.

James Maxwell Bardeen was born in Minneapolis on May 9, 1939. His mother, Jane Maxwell Bardeen, was a zoologist and high school teacher. Following her father’s work, the family moved to Washington, D.C.; in Summit, NJ; then to Champaign-Urbana, Illinois, where he graduated from University of Illinois Laboratory High School.

He attended Harvard and graduated with a physics degree in 1960, despite his father’s advice that biology was the wave of the future. “Everyone knew who my father was,” he said in a 2020 oral history interview taped by the Federal University of Paraguay, adding that he didn’t feel the need to compete with him. . “It was impossible, anyway,” he said.

Working under physicist Richard Feynman and astrophysicist William A. Fowler (both of whom would become Nobel laureates), Dr. Bardeen earned his Ph.D. from the California Institute of Technology in 1965. His thesis was on the structure of supermassive stars millions of times the mass of the Sun; astronomers were beginning to suspect that they were the source of the prodigious energies of quasars discovered in the nuclei of distant galaxies.

After holding postdoctoral positions at Caltech and the University of California, Berkeley, he joined the University of Washington’s astronomy department in 1967. An avid hiker and mountaineer, he was drawn to the school by its easy access to the outside.

By then, what Nobel laureate Kip Thorne, a professor at the California Institute of Technology, calls the golden age of black hole research was well underway, and Dr Bardeen was involved in international meetings. At one o’clock in Paris in 1967, he met Nancy Thomas, a middle school teacher from Connecticut who was trying to brush up on her French. They married in 1968.

In addition to his son William, senior vice president and chief strategy officer of The New York Times Company, and his brother, William, Dr. Bardeen’s wife survives him, as well as another son, David, and two small children. -children. A sister, Elizabeth Greytak, died in 2000.

Credit…Edouard Braniff

Dr. Bardeen was a member of the National Academy of Sciences, as were his brother and father.

Although he was quick at math, Dr. Bardeen didn’t write any faster than he spoke. William Press, a former student of Dr. Thorne now at the University of Texas, remembers being sent to Seattle to complete a paper he and Dr. Bardeen were supposed to write. Nothing had been written. Dr. Bardeen’s wife then ordered the two to sit on opposite ends of a couch with a pad of paper. Dr. Bardeen would write a sentence and pass the pad to Dr. Press, who would reject or approve it, then return the pad. Each sentence, Dr. Press said, took minutes. It took them three days, but the paper was written.

One of the highlights of those years was a month-long “summer school” in Les Houches, France, in 1972, with all the leading black hole specialists. Dr. Bardeen was one of six guest speakers. It was during this meeting that he, Stephen Hawking of Cambridge University and Brandon Carter, now of the Paris Observatory, wrote a landmark paper titled “The Four Laws of Black Hole Mechanics”, which became a springboard for future work, including that of Dr. Hawking. surprise calculation that black holes could leak and possibly explode.

In another famous calculation from the same year, Dr. Bardeen deduced the shape and size of a black hole’s “shadow” as seen against a distant star field – a donut of light surrounding the dark space.

This shape was made famous, Dr. Thorne said, by Event Horizon Telescope observations of black holes in the M87 galaxy and at the center of the Milky Way, and by visualizations in the movie “Interstellar.”

Another of Dr. Bardeen’s passions was cosmology. In a 1982 paper, he, Dr Turner and Paul Steinhardt of Princeton described how submicroscopic fluctuations in matter and energy density in the early universe would increase and give rise to the pattern of galaxies we see in the sky. today.

“Jim was delighted that we used his formalism,” Dr. Turner said, “and was sure we had it right.”

Dr. Bardeen moved to Yale in 1972. Four years later, unhappy with the academic bureaucracy in the East and longing for the outdoors again, he returned to the University of Washington. He retired in 2006.

But he never stopped working. Dr Thorne recounted a recent phone conversation in which they recalled hiking and camping trips they used to take with their families. In the same conversation, Dr. Bardeen described recent ideas he had about what happens when a black hole evaporates, suggesting that it might turn into a white hole.

“It was an aspect of Jim in a nutshell,” Dr. Thorne wrote in an email, “thinking deeply about physics creatively until the end of his life.”

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