Chen Ning Yang Portrait of Chen Ning Yang (born 1922), Chinese-American physicist and Nobel Laureate. Yang gained his degree at Kunming, China, and his Doctorate under Teller at Chicago. Yang and Tsung Dao Lee proved in 1956 that parity conservation (mirror-image symmetry) is violated in interactions involving the weak nuclear force. This work won the pair the 1957 Nobel Prize for Physics. Yang and Lee went on to make many predictions in weak force theory, many of which are confirmed by experiment. Yang also worked with R.L. Mills on a non-Abelian gauge theory (the Yang-Mills theory) used extensively in quantum field studies. Photographed in the 1980s.