Bulletin Spring‧Summer 1998

arguments lasting well beyond 'lights out' in their small room at the middle school. Once, they settled an argument by means of a candle-lit reading of key paragraphs from Heisenberg's The Physical Principle of the Quantum Theory. While they were arguing about a science that would change human warfare and history forever, soldiers were marching past with prisoners soon to be shot. China was being torn apart by Japanese invaders and civil strife. Yang, however, was groomed by the best Chinese scientists, thrown together by the exigencies of war, and with the aid of the Tsing Hua Foundation, he obtained within another six years his Ph.D. from the University of Chicago. His taste and style in physics, though, had already been shaped with his friends back in the tea houses in Kunming. So, too, had his command of English, aided by reading and discussion of authors such as Conrad, Kipling and Galsworthy. A year after the Ph.D. he moved in 1949 to the Institute for Advanced Studies at Princeton, where he became a professor in 1955. In 1957 he won the Nobel Prize for Physics with Ms co- researcher, Prof. T.D. Lee. Predictably, academic honours rapidly came his way: Princeton's honorary doctorate was followed by a swarm of others from as far away as England, Poland, Russia and Taiwan. Yang and Lee's Nobel Prize discovery in 1956 was parity non-conservation for the weak inter-actions, the notion that left-handed and right-handed particles do not behave perfectly symmetrically as mirror images of each other. This insight demolished an unwa r r an t ed assumption held by previous physicists. Earlier, in 1954, with Robert Mills, Yang Chen Ning had also formulated the theory of non-Abelian gauge fields, an enquiry later recognized to be of even more fundamental importance than the Nobel Prize work, for it has led to a unified theory by which to understand the nature of matter itself, the forces that act upon it, and the 'fearful symmetries', to use the poet William Blake's phrase, that operate to hold the formalism together. This general field-theory synthesizes at least three and possibly four of what were once thought of as four basic forces of nature. It provides a theoretical framework within which it was later shown that the seemingly separate forces are differing aspects of one force. This 'conceptual masterpiece' as it has been called, explains many features of the interaction of subatomic particles, and has redirected developments in physics especially in the last 25 years, as well as building bridges from theoretical physics to advanced mathematics, achievements admired by such brilliant mathematicians as Prof. S.S. Chern, S.T. Yau and Sir Michael Atiyah, all of them honorary graduates of our university. Those who can follow Yang's wo rk in physics through his many publications and papers testify to its precise elegance, distinguished by a feeling for beauty and symmetry. To quote from his Nobel lecture, 'The Law of Parity Conservation and Other Symmetry Laws of Physics' is to hear Yang's feeling for the beauty of mathematical reasoning coming through: When one pauses to consider the elegance and the beautiful perfection,' he says, 'of the mathematical reasoning involved and contrast it w i th the complex and far reaching physical consequences, a deep sense of respect for the power of the symmetry laws never fails to develop,' Prof. Yang's interest in Chinese and Western art suggests that he possesses an aesthetic sensibility also at work in the deepest levels of his scientific thinking. This is what the poet Wordsworth called 'the finer spirit' of humanity. Since his Nobel Prize, Prof. Yang's work has richly merited an array of honours and awards: the Rumford Premium (1980), the US National Medal of Science (1986), the Benjamin Franklin Medal (1993), the Bower Award (1994) and the N. Bogoliubov Prize (1996). His services to physics have led him to a host of distinguished lectureships at many prestigious universities world-wide from Zurich to Stockholm, from Harvard to Fudan. His service to the international community includes not only contributions to the Academy of Sciences in his native China and to that of his second country, the United States of America, but to the Royal Society in Britain, the Academia Sinica in Taiwan, and other academies in Latin America and Europe, including the Pontifical Academy of Science at the request of the Pope in 1997. His generosity as an academic may be traced throughout his career but most vividly for us through his long relationship w i th this university and Hong Kong. In 1964 he made a sensation with his lecture to overflow audiences in the then newly opened City Hall. In 1983 Yang Chinese University Bulletin Spring • S u m m er 1998 14