When Japanese planes bombed Pearl Harbor, Roger Hildebrand was studying chemistry at the University of California at Berkeley.
Days later, a professor — Nobel Prize-winning physicist Ernest Lawrence — “tapped me on the shoulder and said, ‘Well, you want to help the war effort, don’t you?’ And there was only one answer to that,” Mr. Hildebrand recalled in an oral history.
Lawrence also told him, ” ‘You’re going to have to learn physics in a hurry,’ ” Mr. Hildebrand said in the interview with the Atomic Heritage Foundation. “I did, and I liked it.”
Mr. Hildebrand, then 19, got a quick lesson on how to operate a cyclotron — a particle accelerator. He started twiddling dials and watched the needles on the meters.
Nobody would talk about what the work was. But he deduced that he was refining radioactive material, including plutonium and uranium. It was transported to the University of Chicago, where scientists were helping to develop the atomic bomb in the top-secret effort known as the Manhattan Project.
Later, he worked in the “secret city” of Oak Ridge, Tennessee, another research center for the bomb.
According to the University of Chicago, where he was a professor for nearly 70 years, Mr. Hildebrand was the school’s last living scientist to have worked on the Manhattan Project. He died in January at 98 at a senior care facility in Massachusetts, where he’d moved to be near family, according to his son Peter.
Born in Berkeley, he was the son of Joel Hildebrand, who, besides being a renowned chemist at UC Berkeley, was president of the Sierra Club and manager of the 1936 U.S. Olympic ski team.
“Dad and his brothers climbed most of the peaks in the Sierras in high school or college and were on the ski team at Berkeley,” Peter Hildebrand said.
In 1944, Mr. Hildebrand married his high school sweetheart Jane Beedle. They were married for nearly 73 years, till her death in 2017.
After he earned a master’s in physics from Berkeley, the University of Chicago recruited him in 1952. Mr. Hildebrand was thrilled. He said it was widely accepted the school had the world’s top physics department — and, in Enrico Fermi, the best physicist.
“Besides being the brightest physicist in the world, he was a superb teacher,” he told the Atomic Heritage Foundation.
Remembering how intimidated he felt when Fermi told him he was going out of town and asked him to teach a class, Mr. Hildebrand said: “I sort of gulped because I knew that I’d be compared to what I think was the best physics teacher in the world.”
When he asked Fermi for a quick review of the material for the lesson, he said in the interview, “He began asking me questions about [a particle called] the deuteron, easy questions, and it made me think sort of with one side of my brain, ‘Gee, I’m pretty smart.’ The other side, I said, ‘Oh, no, it’s Fermi that’s making this seem simple.’ I taught his class and somehow survived.”
Fermi “seemed to be able to do anything better than anybody else,” he said. “If we had a baseball game, he grabbed the bat and hit home runs.”
In a separate interview by Henry Frisch, a fellow U. of C. physics professor, Mr. Hildebrand said “Fermi just helped anybody that was around.”
After serving as associate director of high-energy physics at Argonne National Laboratory, where he helped develop a particle accelerator, and as dean of the university’s undergraduate college, Mr. Hildebrand wanted a change.
“He looked around for a field he felt was ripe for an experienced newcomer” and settled on astrophysics, his son said.
Stars are formed from dust and gas pulled together by gravity.
“It was Roger who realized you could learn a lot from looking at the dust — but how to see the dust?” said John E. Carlstrom, a U. of C. astrophysicist.
To do that, Mr. Hildebrand did pioneering work designing instruments to detect infrared radiation.
He traveled to Mauna Kea, Hawaii, to use a California Institute of Technology telescope and to Chile to use telescopes at the Cerro Tololo Inter-American Observatory. He also used an airborne telescope on a retrofitted 747: the SOFIA, for Stratospheric Observatory for Infrared Astronomy.
Well into his later years, he displayed a youthful athleticism, camping with his family at the Boundary Waters Canoe Area Wilderness in northern Minnesota and Yellowstone National Park and canoeing the Wabash, Des Plaines and Fox rivers. In Hyde Park, he liked taking long walks and running.
A celebration of his life will be held at a later date.
He is also survived by his daughters Alice H. Klein and Kathryn J. Hildebrand, son Daniel M. Hildebrand, eight grandchildren and nine great-grandchildren.