Chen Ning Yang

Chen Ning Yang, the theoretical physicist whose insights into nature's symmetries helped redefine particle physics and paved the way for the Standard Model, died October 18, 2025, in Beijing. He was 103. Tsinghua University announced that he died after an illness.

Born in Hefei, Anhui province, China, Yang was raised on the campus of Tsinghua University, where his father taught mathematics. He earned a B.Sc. at National Southwest Associated University in Kunming, China 1942 and an M.Sc. at Tsinghua in 1944 before traveling to the University of Chicago, completing his Ph.D. in 1948. He worked under the influence of Enrico Fermi; his doctoral thesis was supervised by Edward Teller.

In 1956, Yang and Tsung Dao Lee challenged a bedrock assumption of physics: that the weak nuclear interaction preserves mirror symmetry, or parity. Chien-Shiung Wu soon led the landmark experiment that confirmed parity violation. Yang and Lee received the 1957 Nobel Prize in Physics for "penetrating investigation of the so-called parity laws," a result that shook the field.

Yang's 1954 paper with Robert L. Mills introduced non-abelian gauge theory, now known as Yang–Mills theory. It became foundational to modern particle physics, underlying the unification of the strong and electroweak forces.

After an early appointment at the Institute for Advanced Study in Princeton beginning in 1949, Yang became Albert Einstein Professor of Physics at the State University of New York at Stony Brook in 1966, serving there until 1999. He was the founding director of the university's Institute for Theoretical Physics. Later, he rejoined Tsinghua University in Beijing and remained a revered figure in Chinese and international science communities.

Yang became a U.S. citizen in 1964 and renounced that citizenship in 2015. He described the United States as a "beautiful country" that offered him opportunity, even as he reaffirmed his connections to China. He later donated many honors and memorabilia, including his Nobel medal, to academic institutions.

He is survived by his wife, Weng Fan, and three children. Earlier, he was married to Tu Chih-li (d. 2003).

By Legacy News Staff

(Image: Felix Wong/South China Morning Post via Getty Images)