Bulletin Spring‧Summer 1999

his Humboldt Senior Scientist Award, the Broid a Prize for Laser Spectroscopy, the K i ng Faisal International Prize for Science, the Arthur Schawlow Prize for Laser Science of the American Physical Society, the Optical Society o f America's William F. Megger s Award for Spectroscopy ， his various fellowships, and hi s membership of not only the US National Academy of Sciences, but of the Academica Sinica in Taipei and, as a Foreign Academician of the Chinese Academy of Sciences. Such achievements testify to his outstanding work in physics and to the crucial role he plays in the promotion of scientific research in China . Ill 1997, he shared the Nobel Prize with William Phillips and Claude Cohen-Tannoudji. Prof. Chu showed that the random motion of atoms at high speeds in different directions can be controlled, ordered, and slowed down b y strategically positioned lasers. This results in the cooling of the atoms. The laser cooling and trapping of atoms by means of what has bee n called optical 'molasses' is a breakthrough for theoretical physics as well as for experimental techniques and procedures: to bring atoms almost to a standstill facilitates more precise study of them, has led to deeper understanding of the interaction betwee n light and matter, and has enlarged the arena in which theoretical ideas can be tested. Prof. Chu's methods have stimulated intense activity among physicists worldwide. The study of the quantum behaviour of dilute atomic vapours at very low temperatures has applications in, for example, the refinement of atomic clocks , developments in atomic lithography, and the development of the first atom laser. The exacting precision of Prof. Chu's work is matched by the imaginative inventiveness that distinguishes his experiments and innovative techniques. Prof. Arthur Schawlow, the inventor of lasers and a Nobel laureate for 1981, points to the wide range of interests in different problems that marks Steven Chu's thinking and to his grasp of theoretical speculation, enabling him to devise the kind of searching experiments that display great virtuosity. The virtuosity is what we migh t call his style in experimental physics, a style distinguished b y a willingness to address a crucial but intransigent problem in a fashion that operates at the edge of what is technologically possible and yet succeeds. Thus he proceeds in those extraordinarily difficult investigations that have made such important contributions to atomic and condensed matter physics, biology, and polymer science. He was the first to obtain high resolution spectra of positronium and muonium. Furthermore, he confirmed De Gennes’ model of reptation— the way polymer strands 'relax'. Yet the man capable of such advanced experimental physics is not too lofty to help a student sweep up the laboratory in order to keep it tidy! Those who attended Prof. Chu's Wei Lun Distinguished Lecture here at The Chinese University of Hong Kong in March 1998 on 'Laser Cooling and Trapping of Atoms and Particles' can agree that it was extremely well received , creating a high level of intellectual excitement. His lectures are acclaimed for the wit and clarity he brings to his exposition of creative scientific ideas. He focuses on what turns out to b e the centrally important factor. He influences advanced students and co-workers in ways that earn their sincere gratitude. We are indeed fortunate that he has been able to advise u s and to inspire young scientists everywhere with his views on scientific and technological development. Mr. Chancellor, for his services to the scientific community worldwide, his enthusiastic inspiration of Chinese scientists in particular, and his fruitful liaison with our university, I present Steven Chu, Nobel laureate, for the award of the degree of Doctor of Science, honoris causa. • The 54th Congregation