Yang Chen-Ning or Chen-Ning Yang (; born 1 October 1922), also known as C. N. Yang or by the English name Frank Yang, is a Chinese theoretical physicist who made significant contributions to statistical mechanics, integrable systems, gauge theory, and both particle physics and condensed matter physics. He and Tsung-Dao Lee received the 1957 Nobel Prize in Physics for their work on parity non-conservation of weak interaction. The two proposed that one of the basic quantum-mechanics laws, the conservation of parity, is violated in the so-called weak nuclear reactions, those nuclear processes that result in the emission of beta or alpha particles. Yang is also well known for his collaboration with Robert Mills in developing non-abelian gauge theory, widely known as the Yang–Mills theory. Early life and education Yang was born in Hefei, Anhui, China. His father, (; 1896–1973), was a mathematician, and his mother, Meng Hwa Loh Yang (), was a housewife. Yang attended elementary school and high school in Beijing, and in the autumn of 1937 his family moved to Hefei after the Japanese invaded China. In 1938 they moved to Kunming, Yunnan, where National Southwestern Associated University was located. In the same year, as a second year student, Yang passed the entrance examination and studied at National Southwestern Associated University. He received a Bachelor of Science in 1942, with his thesis on the application of group theory to molecular spectra, under the supervision of Ta-You Wu. Yang continued to study graduate courses there for two years under the supervision of Wang Zhuxi, working on statistical mechanics. In 1944 he received a Master of Science from Tsinghua University, which had moved to Kunming during the Sino-Japanese War (1937–1945). Yang was then awarded a scholarship from the Boxer Indemnity Scholarship Program, set up by the United States government using part of the money China had been forced to pay following the Boxer Rebellion. His departure for the United States was delayed for one year, during which time he taught in a middle school as a teacher and studied field theory. Yang entered the University of Chicago in January 1946 and studied with Edward Teller (1908–2003). He received a Doctor of Philosophy in 1948. Career Yang remained at the University of Chicago for a year as an assistant to Enrico Fermi. In 1949 he was invited to do his research at the Institute for Advanced Study in Princeton, New Jersey,