Bruce Winstein, an experimental physicist who studied the afterglow of the universe’s birth, died Feb. 28 after a four-year battle with cancer. He was 67.
Winstein, the Samuel K. Allison Distinguished Service Professor in Physics, the Enrico Fermi Institute and the College, was known as a punctilious leader of experiments measuring the aftermath of the big bang in two fundamental fields of physics — particle physics and cosmology.
A strong advocate of “blinded” measurements, in which scientists intentionally conceal the final answer while analyzing data to prevent their preconceptions from influencing the result, he imported many practices of particle physics after his mid-career switch into cosmology, the study of the early universe,. “Psychologically, it’s better,” Winstein told an interviewer in 2000. “There’s no concern about, ‘Do we agree with our old experiment?’”
In 1999, after 25 years of increasingly precise measurements at the Fermi National Accelerator Laboratory, Winstein and colleagues produced the first definitive evidence of “direct” CP violation — proof that matter and anti-matter, once thought to be mirror opposites, are not perfect twins. The result showed that the direction time flows, from past to future, is part of the fundamental laws of the universe. The size of the finding produced an “audible gasp” from the Fermilab audience, reports said. In accordance with the “blinded” technique, Winstein had not known the results until the days before the announcement.
“Bruce had the skill and the passion to measure that quantity to whatever precision necessary,” said James Cronin, the University Professor Emeritus in Physics, who won the Nobel Prize in 1980 for the discovery of CP violation. “The experiments took extraordinary sensitivity and attention to detail.”
"Bruce was an extraordinary experimentalist who applied what he learned from particle physics directly to the field of cosmology,” said Stephan Meyer, Associate Director of the Kavli Institute for Cosmological Physics. “The result was a new experiment using a different approach and different instrumentation — a great thing for difficult and subtle measurements."
At a daylong “Brucefest” retirement party hosted by UChicago last month, former students recalled Winstein as an intense experimenter. “I remember, with surprising fondness, your regular 11 p.m. call asking what I’d learned since dinner,” said Ritchie Patterson, the Department Chair of Physics at Cornell University and a doctoral student of Winstein’s in the 1980s.
Outside the lab, Winstein was a mischievous presence. He arranged increasingly elaborate and red-herring-filled surprise birthday parties for his wife, Joan, through 32 years of marriage, and loved hiking with his family each year in the Rocky Mountains. Winstein was an avid audiophile, hosting “blinded” comparisons in the 1980s between vinyl records and then-new compact discs.
Winstein had a deep interest in film, took silent movies with a hand-cranked, 16-millimeter camera, and founded a film series at the California Institute of Technology while a graduate student. He was proud of having met both Stan Laurel – of Laurel and Hardy, whose films he collected – and Michelangelo Antonioni, the Italian modernist director whom Winstein studied intensely.
He later taught two courses on Antonioni at UChicago’s undergraduate College, and he lectured on the director’s work at Middlebury College this past fall. “He really appreciated Antonioni’s creativity and his use of the medium,” said Ted Perry, a Middlebury film scholar and Antonioni specialist, and a friend of Winstein’s.
In 1999, Winstein won a Guggenheim Fellowship to collaborate with researchers in cosmology at Princeton University. He began to study the cosmic microwave background radiation — the first flash of light produced after the big bang, now an extraordinarily dim afterglow whose patterns show the footprints of events in the early universe.
Back at Chicago, Winstein helped found the Kavli Institute, where he served as the first director and brought together an interdisciplinary group of physicists and astronomers. He led the QUIET experiment, an international collaboration in Chile’s Atacama Desert to measure the polarization, or twists, in the background radiation, to learn the effects of gravity waves believed to have rippled through the fabric of space-time almost 14 billion years ago.
“He had an uncanny ability to motivate people working with him to get more out of them than anyone expected,” said Edward Blucher, UChicago’s chairman of the Department of Physics.
Bruce Darrell Winstein was born in Los Angeles on Sept. 25, 1943. He attended UCLA before earning his doctorate in physics at California Institute of Technology in 1970.
Winstein was elected to the National Academy of Sciences in 1995 and to the American Academy of Arts & Sciences in 2007. The American Physical Society awarded Winstein and two others the 2007 Panofsky Prize for outstanding achievements in experimental particle physics. In 1976, he gave the inaugural Arthur Holly Compton Lectures, a public lecture series at UChicago. He served on the faculty at Stanford University in 1986.
Winstein is survived by wife Joan, his children Keith and Allison, and his sister Carolee.
A memorial service is planned for the spring. In lieu of flowers, the family requests donations be sent to the Bruce Winstein Fund for Graduate Students, c/o Department of Physics, KPTC 201, University of Chicago, 5720 South Ellis Ave., Chicago, IL 60637.
—Prof. Jacqueline Stewart
