again disrupted by a further Japanese invasion, Lee continued at the National Southwestern Associated University in Kunming the next year in 1945, where he studied with Professor Wu Ta-You. Life and research in US Professor Wu nominated Lee for a Chinese government fellowship for graduate study in the US. In 1946, Lee went to the University of Chicago and was selected by Professor Enrico Fermi to become his PhD student. Lee received his Ph.D. under Fermi in 1950 for his research work Hydrogen Content of White Dwarf Stars. Lee served as research associate and lecturer in physics at the University of California at Berkeley from 1950 to 1951. In 1953, Lee joined Columbia University, where he remained until retirement. His first work at Columbia was on a solvable model of quantum field theory better known as the Lee model. Soon, his focus turned to particle physics and the developing puzzle of K meson decays. Lee realized in early 1956 that the key to the puzzle was parity non-conservation. At Lee's suggestion, the first experimental test was on hyperion decay by the Steinberger group. At that time, the experimental result gave only an indication of a 2 standard deviation effect of possible parity violation. Encouraged by this feasibility study, Lee made a systematic study of possible Time reversal (T), Parity (P), Charge Conjugation (C), and CP violations in weak interactions with collaborators, including C. N. Yang. After the definitive experimental confirmation by Chien-Shiung Wu and her assistants that showed that parity was not conserved, Lee and Yang were awarded the 1957 Nobel Prize in Physics. Unfortunately Wu was not awarded the Nobel prize, which is considered one of the largest controversies in Nobel committee history. In the early 1960s, Lee and collaborators initiated the important field of high energy neutrino physics. In 1964, Lee, with M. Nauenberg, analyzed the divergences connected with particles of zero rest mass, and described a general method known as the KLN theorem for dealing with these divergences, which still plays an important role in contemporary work in QCD, with its massless, self-interacting gluons. In 1974–75, Lee published several papers on "A New Form of Matter in High Density", which led to the modern field of RHIC physics, now dominating the entire high energy nuclear physics field. Besides particle physics, Lee has been active in statistical mechanics, astrophysics, hydrodynamics, many body system, solid state, lattice QCD. In