George Smoot

George Smoot
Smoot at Ithaka Science Center in 2009
George Smoot
Born	George Fitzgerald Smoot III 20 2, 1945
Birthplace	Yukon, Florida, U.S.
Died	Template:Death date and age Paris, France
Nationality	American
Occupation	Astrophysicist, cosmologist
Known for	Discovery of anisotropy in the cosmic microwave background radiation
Education	Ph.D. in Physics, Massachusetts Institute of Technology (1970)
Awards	Nobel Prize in Physics (2006), NASA Exceptional Scientific Achievement Medal (1991), Ernest Orlando Lawrence Award (1995)
Website	[aether.lbl.gov Official site]

George Fitzgerald Smoot III (February 20, 1945 – September 18, 2025) was an American astrophysicist and cosmologist who shared the 2006 Nobel Prize in Physics with John C. Mather for their discovery of the blackbody form and anisotropy of the cosmic microwave background (CMB) radiation. Their work, carried out through NASA's Cosmic Background Explorer (COBE) satellite, provided some of the most compelling observational evidence supporting the Big Bang theory of the origin of the universe. Smoot's team detected tiny temperature fluctuations—anisotropies—in the CMB, revealing the primordial seeds from which galaxies and large-scale cosmic structures eventually formed. The Nobel Prize committee described the COBE project as "the starting point for cosmology as a precision science." Smoot spent the majority of his career at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, where he worked from 1970 until his retirement as professor emeritus. He died on September 18, 2025, in Paris, France, at the age of 80.

Early Life

George Fitzgerald Smoot III was born on February 20, 1945, in Yukon, Florida, a small community in the United States. Details about his parents and early family life are limited in publicly available records, though his upbringing took place in the postwar United States during a period of growing national investment in science and technology. Smoot demonstrated an early aptitude for mathematics and the physical sciences, interests that would guide his academic trajectory from an early age.

His intellectual curiosity led him to pursue higher education at one of the nation's premier research institutions, the Massachusetts Institute of Technology (MIT), where he would ultimately complete both his undergraduate and graduate studies. Growing up in the era of the Space Race, Smoot was part of a generation of American scientists inspired by the nation's expanding frontiers in space exploration and fundamental physics research.

Education

Smoot attended the Massachusetts Institute of Technology, where he earned dual bachelor's degrees in mathematics and physics in 1966. He remained at MIT for his graduate studies, completing his Ph.D. in physics in 1970. His doctoral thesis, titled "Charge Exchange of Positive Kaon on Platinum at Three GeV/C," was supervised by physicist David H. Frisch and dealt with particle physics rather than the cosmological research for which he would later become known. The rigorous training in experimental physics that Smoot received at MIT would prove invaluable in his later career designing and operating sensitive instruments to measure faint signals from the early universe.

Career

Early Research at Berkeley and Lawrence Berkeley National Laboratory

After completing his Ph.D. at MIT in 1970, Smoot joined the University of California, Berkeley, and the Lawrence Berkeley National Laboratory (LBNL), where he would remain for the rest of his career. His early research interests at Berkeley shifted from particle physics to cosmology, as he became increasingly drawn to fundamental questions about the origin and structure of the universe.

One of Smoot's initial projects at Berkeley involved studying the cosmic microwave background radiation—the faint thermal glow left over from the Big Bang—using high-altitude balloon experiments and other ground-based and airborne instruments. These early experiments helped him develop expertise in the design of sensitive radiometric instruments, which would prove essential in his later satellite-based work.

Smoot and his collaborators conducted experiments to test the isotropy of the CMB—whether the radiation appeared the same in every direction—and to search for a dipole anisotropy that would indicate the motion of the Earth and the Milky Way relative to the rest frame of the CMB. These measurements, conducted through a series of increasingly sophisticated experiments during the 1970s and early 1980s, successfully detected the dipole anisotropy caused by the motion of our galaxy through space.

The COBE Satellite and the Discovery of CMB Anisotropy

The defining achievement of Smoot's career came through his involvement with NASA's Cosmic Background Explorer (COBE) satellite, launched on November 18, 1989. Smoot served as the principal investigator of one of COBE's three instruments, the Differential Microwave Radiometer (DMR), which was designed to map small temperature variations across the cosmic microwave background sky.

The CMB had been discovered in 1965 by Arno Penzias and Robert Wilson, who received the 1978 Nobel Prize in Physics for their finding. While the existence of the CMB confirmed a key prediction of the Big Bang theory, cosmologists recognized that tiny fluctuations in its temperature—predicted by theories of structure formation—must exist but had not yet been detected. These fluctuations, or anisotropies, would represent the seeds of all the structures observed in the present-day universe: galaxies, galaxy clusters, and the vast cosmic web.

In April 1992, the COBE team, with Smoot as a lead spokesperson, announced that the DMR instrument had detected intrinsic anisotropies in the CMB at a level of approximately one part in 100,000. This discovery was met with enormous excitement in the scientific community and in the broader public. The finding confirmed that the early universe was not perfectly smooth but contained slight density variations that, through gravitational instability over billions of years, grew into the large-scale structures observed today.

Meanwhile, COBE's other main instrument, the Far Infrared Absolute Spectrophotometer (FIRAS), operated by John C. Mather, demonstrated that the CMB spectrum was an almost perfect blackbody—the most precise blackbody spectrum ever measured—confirming another fundamental prediction of the Big Bang theory. Together, the two measurements made by COBE established a new era of precision observational cosmology.

The Nobel Prize committee, in awarding the 2006 Nobel Prize in Physics jointly to Smoot and Mather, stated that "the COBE project can also be regarded as the starting point for cosmology as a precision science." The COBE results paved the way for subsequent CMB experiments, including the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck satellite, which mapped the CMB with ever-greater precision and resolution.

Post-COBE Research

Following the success of COBE, Smoot continued his research into cosmology and astrophysics at Berkeley and LBNL. He was involved in a range of projects aimed at extending the precision measurements of the CMB and studying the large-scale structure and expansion history of the universe.

Smoot was associated with the SuperNova/Acceleration Probe (SNAP), a proposed space telescope designed to study dark energy through observations of distant Type Ia supernovae. Dark energy—the mysterious force driving the accelerating expansion of the universe—had been discovered in 1998 and represented one of the most profound open questions in physics. Smoot's engagement with projects like SNAP reflected his continued interest in using cutting-edge observational techniques to address foundational cosmological questions.

He also maintained an active research group at Berkeley, mentoring graduate students and postdoctoral researchers. His group's research encompassed a variety of topics in observational and theoretical cosmology.

International Academic Roles

In addition to his long-standing position at UC Berkeley, Smoot held academic appointments and affiliations at institutions around the world. He served as Chair of the Endowment Fund "Physics of the Universe" of the Paris Center for Cosmological Physics. He spent considerable time in Paris in his later years and ultimately died there on September 18, 2025.

Smoot was honored by several universities worldwide with honorary doctorates and visiting professorships, reflecting the international significance of his contributions to cosmology.

Science Advocacy

Smoot was an advocate for increased federal funding for basic science research. In May 2008, he was one of 20 American Nobel laureates in physics who signed a letter addressed to President George W. Bush urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy's Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.

Popular Culture Appearances

Smoot made several appearances in popular media. He appeared as himself on the television game show Are You Smarter than a 5th Grader? in 2009. He also made a guest appearance as himself on the CBS television series The Big Bang Theory, a show centered on physicists and their social lives.

Personal Life

Smoot was known among colleagues for his dedication to research and his engaging personality in scientific discussions. In 2007, following his Nobel Prize award, Smoot donated $500,000 to establish the Berkeley Center for Cosmological Physics at UC Berkeley. He additionally donated a portion of his Nobel Prize money, less travel costs, to the East Bay Community Foundation, a charitable organization serving the San Francisco Bay Area.

Smoot spent his final years dividing his time between Berkeley and Paris, where he held academic affiliations with the Paris Center for Cosmological Physics. He died on September 18, 2025, in Paris, France, at the age of 80.

Recognition

Smoot received numerous awards and honors over the course of his career, reflecting the significance of his contributions to cosmology and astrophysics.

His most prominent honor was the 2006 Nobel Prize in Physics, shared with John C. Mather, "for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The award recognized the transformative impact of the COBE satellite measurements on the understanding of the early universe.

Prior to the Nobel Prize, Smoot had received several other major distinctions:

• NASA Exceptional Scientific Achievement Medal (1991) — awarded in recognition of his work on the COBE satellite and the detection of CMB anisotropy.
• Ernest Orlando Lawrence Award (1995) — presented by the U.S. Department of Energy for outstanding contributions in the field of physics.
• Einstein Medal (2003) — awarded by the Albert Einstein Society in Bern, Switzerland.
• Daniel Chalonge Medal (2006) — presented by the International School of Astrophysics "Daniel Chalonge."
• Gruber Prize in Cosmology (2006) — a major international prize recognizing fundamental advances in the field of cosmology.

Smoot was elected a member of the National Academy of Sciences of the United States and a Fellow of the American Physical Society, both among the highest professional honors for an American scientist. He was also awarded honorary doctorates and professorships by several universities around the world.

He served as a member of the advisory board of the scientific journal Universe.

Legacy

George Smoot's contributions to cosmology fundamentally altered the scientific understanding of the origin and evolution of the universe. The detection of anisotropies in the cosmic microwave background by the COBE DMR instrument, led by Smoot's team, provided the first observational evidence of the primordial density fluctuations from which all cosmic structure formed. This measurement confirmed a key prediction of inflationary cosmology and the Big Bang model, and it opened a new era in which the parameters of the universe could be determined with high precision.

The COBE results inspired a succession of increasingly precise CMB experiments. The Wilkinson Microwave Anisotropy Probe (WMAP), launched in 2001, and the European Space Agency's Planck satellite, launched in 2009, built directly on the foundation laid by COBE. These missions mapped the CMB with far greater angular resolution and sensitivity, enabling the determination of the age, geometry, composition, and expansion rate of the universe to unprecedented accuracy. The field of precision cosmology that emerged from these efforts traces its origins to the COBE measurements for which Smoot and Mather received the Nobel Prize.

Smoot's philanthropic contributions also left a mark on the scientific community. His donation of $500,000 in Nobel Prize funds to establish the Berkeley Center for Cosmological Physics helped create an institutional framework for continued research in the field he helped define.

At the time of his death, tributes from the scientific community emphasized both his scientific achievements and his role in bringing cosmology to a broader public audience. UC Berkeley, the Lawrence Berkeley National Laboratory, and institutions around the world recognized him as a central figure in twentieth- and twenty-first-century cosmology.