Physicist George Smoot, known for his work that confirmed the Big Bang theory, died on September 18 in Paris at age 80. Smoot was a professor emeritus of physics at the University of California, Berkeley, and held positions at Lawrence Berkeley National Laboratory and Université Paris-Cité.
Smoot’s research with John Mather using NASA’s Cosmic Background Explorer (COBE) satellite led to the first detection of minute temperature fluctuations in the cosmic microwave background (CMB), which provided strong evidence for the Big Bang theory. Their work earned them the 2006 Nobel Prize in Physics.
At a 1992 press conference, Smoot described the significance of their discovery: “If you’re religious, it’s like seeing God.” The CMB measurements allowed scientists to explore how the universe evolved from its infancy nearly 14 billion years ago. According to an obituary posted by Laboratoire Astroparticule et Cosmologie (APC), “Today cosmology is at the center stage of physics, due in no small part to this [Smoot’s] and subsequent measurements of the CMB. This discovery prompted many researchers to switch to cosmology. A host of experiments, from the ground, from stratospheric balloons and from space have now followed the pioneering COBE measurements.”
The COBE satellite was launched in 1989 after a long development process involving many collaborators. Mather’s instrument showed that microwave background radiation matched predictions if the universe formed in a fireball. Smoot’s instruments detected tiny fluctuations—one part in 100,000—in temperature and density that later developed into galaxies.
Stephen Hawking called Smoot’s detection “the greatest scientific discovery of the century.” Reflecting on these findings at the time, Smoot said: “Those measurements really confirmed our picture of the Big Bang. By studying the fluctuations in the microwave background, we found a tool that allowed us to explore the early universe, to see how it evolved and what it’s made of.”
Smoot joined UC Berkeley’s faculty in 1994 after working at Berkeley Lab since 1971. The Nobel committee cited him and Mather for “the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation.” In 2007 he used part of his Nobel Prize winnings to help endow UC Berkeley’s Center for Cosmological Physics.
Outside research and teaching, Smoot appeared as himself on television shows such as “The Big Bang Theory” and won $1 million on “Are You Smarter Than a Fifth Grader?” Colleague Saul Perlmutter described him as someone who enjoyed anticipating future developments: “He was somebody who always enjoyed looking ahead to what was happening in the world and what was coming next… Almost always, I had that feeling that he was right.”
APC remembered him as someone who “revolutionized our understanding of the cosmos and placed cosmology on a firm experimental footing.” In recent years he focused on applying physics discoveries to air quality and medicine while inspiring young people toward scientific careers.
Born February 20, 1945 in Yukon, Florida, Smoot spent parts of his childhood in Alaska before earning degrees from MIT. He moved into cosmology after initial work failed to detect antimatter with high-altitude balloons but succeeded later with instruments detecting differences in CMB temperature using aircraft.
Smoot submitted one of several proposals for a satellite mission measuring CMB anisotropies; these efforts merged into COBE under project director John Mather at NASA Goddard Space Flight Center. After announcing COBE results in 1992—which refined knowledge about universal expansion—he continued contributing through projects like ESA’s Planck satellite.
He also helped establish research centers internationally—including France’s Paris Center for Cosmological Physics—and supported education through programs like “Teaching the Universe” for teachers as well as online courses such as “Gravity!” with Pierre Binétruy.
His awards included Switzerland’s Einstein Medal (2003), DOE’s Lawrence Award (1995), NASA Medal for Exceptional Scientific Achievement (1991), among others. He was also elected to membership in the National Academy of Sciences.
Smoot is survived by his sister Sharon Smoot Bowie; two nieces; and partner Nóra Csiszár.
