Remembering Professor Chen-Ning Yang: A life of profound brilliance and enduring dedication
Professor Chen-Ning Yang, world-renowned theoretical physicist, Nobel laureate, academician of the Chinese Academy of Sciences, and professor and honorary director of the Institute for Advanced Study, Tsinghua University, passed away in Beijing on October 18, 2025, at the age of 103.
Over the past century, nearly 200 laureates have received the Nobel Prize in Physics, yet even within that distinguished company, Yang occupies a singular place. In 1957, at only 35 years of age, he shared the Nobel Prize in Physics with Tsung-Dao Lee for proposing the revolutionary hypothesis of parity non-conservation, a discovery that transformed the very foundations of modern physics.
At the Nobel ceremony, the Chairman of the Nobel Physics Committee, Professor O.B. Klein, described their work with the deepest admiration: “Professor Lee and Professor Yang … through your consistent and unprejudiced thinking, you have been able to break a most puzzling deadlock in the field of elementary particle physics, where now experimental and theoretical work is pouring forth as the result of your brilliant achievement.”
The US Department of Energy would later summarize the magnitude of their discovery in simple but powerful terms: “Because of their work, all scientific theories based on parity had to be reexamined.”
Indeed, the discovery of parity violation is only one of Yang’s monumental contributions to physics. His Yang-Mills gauge field theory, developed with Robert Mills in 1954, has exerted an even deeper and broader influence by laying the conceptual foundation for much of modern particle physics.
The roots of this theory trace back to Albert Einstein’s general theory of relativity in 1916, which first introduced the profound notion that physical fields could be understood geometrically—that gravity was equivalent to the curvature of space-time itself. Since then, physicists sought to unify the various field theories under a single, coherent framework, yet progress stalled until 1954, when Yang and Mills published their celebrated paper, “Conservation of Isotopic Spin and Isotopic Gauge Invariance.” Their work extended the concept of gauge invariance to non-commuting variables, opening a new era in theoretical physics.
Yang’s doctoral mentor, the eminent physicist Edward Teller, would remark nearly three decades later, in 1982, “I cannot talk about the work of Frank (Yang’s English name) without reminding you unnecessarily of the famous paper of Yang and Mills … This, after all, has become the foundation of any further discussion.”
