WILLIAM BARDEEN

BARDEEN--William Allan. William Allan Bardeen, husband, father and physicist, passed away November 18, 2025, in Warrenville, IL his home for over 30 years. Bill was born September 15, 1941, in Washington PA and grew up in Summit, NJ and Champaign-Urbana, IL where he attended University High School. He received his B.A. in physics from Cornell University in 1962 and his PhD from the University of Minnesota in 1968. He was awarded an Honorary Doctorate from Minnesota in 2002. After postdoctoral appointments at the C.N. Yang Institute for Theoretical Physics, Stony Brook and the Institute for Advanced Studies, Princeton, he was an Associate Professor at Stanford University. Shortly after a permanent theory group was formed in 1975, Bill joined Fermi National Accelerator Laboratory as a theoretical physicist where he remained as a scientist emeritus until his death, a period of 50 years. He liked to say he studied the smallest things in the Universe, and his brother Jim, an astrophysicist, the largest. Bill, one the leading authorities on quantum field theory, made fundamental contributions to many aspects of gauge theories and the fundamental interactions. His long career benefited from engaging with the global physics community, supported by local hosts and fellowships. He commented that having that kind of support and collaboration was important, especially for somebody who stayed active in research as he did. Bill was an avid athlete playing baseball, basketball and volleyball throughout his life. Later, he took up bicycling and could be seen riding around Warrenville and to Wheaton, Naperville or Batavia. Bill enjoyed the Colorado mountains. A longtime friend of the Aspen Center for Physics and a trustee for five years, he could be found with his family on weekend hikes or on the ski slopes at Christmas. Bill was his family's genealogist and published "The Barden/Bardeen Genealogy." Bill's graduate work was supported by a NASA Traineeship, and later he received fellowships from the Alfred P Sloan Foundation, the Alexander von Humboldt Foundation, and the Guggenheim Foundation. Bill was awarded J.J. Sakurai Prize from the American Physical Society in 1996. He became a Fellow of the American Physical Society in 1984, a Fellow of the American Academy of Arts and Sciences in 1998, a Member of the National Academy of Sciences in 1999, and a Fellow of the American Association for the Advancement of Science in 2009. Bill was a son of John Bardeen, two-time Nobel Laureate in physics and professor of physics at the University of Illinois, Urbana-Champaign. His mother, Jane Maxwell Bardeen, was a zoologist and active in school and community affairs. His brother James Maxwell Bardeen was a theoretical astrophysicist at the University of Washington and his sister Elizabeth Bardeen Greytak a systems analyst at A.D. Little. He was preceded in death by his parents, brother, and sister. He is survived by his high school sweetheart and beloved wife of 64 years, Marjorie Gaylord Bardeen, son Charles Gaylord Bardeen Boulder, CO, daughter Karen Gail Bardeen Oak Park, IL, sister-in-law Nancy Bardeen, brother-in-law Thomas Greytak and four nephews William and David Bardeen and Andrew and Matthew Greytak. A memorial service will be held after the holidays.