Chen-Ning Yang, the Chinese American theoretical physicist, who has died aged 103, won the Nobel prize in physics in 1957.
It was during a period at the Institute for Advanced Study at Princeton, New Jersey, in 1950 that Yang (also known as CN Yang, or Frank Yang) befriended another young Chinese émigré, Tsung-Dao Lee. They shared the Nobel prize for work that overthrew the widely accepted “parity laws” – that the forces acting on fundamental subatomic particles are symmetric between left and right. In the popular description, they overthrew the concept of “mirror symmetry”. Although the Nobel was for this work, performed in 1956, the most far-reaching of Yang’s many contributions to theoretical physics had come earlier.
