Activities in 1998-1999

From the Report for Academic Year 1998-1999
of the Institute for Advanced Study

PIET HUT investigated the evolution of compact star clusters, using N-body simulations in which both stellar evolution and physical collisions between stars were taken into account. Observational consequences of the latter process are the presence of blue stragglers and, in the case of run-away mergers, possibly the presence of one or more black holes. These investigations were based on large-scale simulations, using the GRAPE-4, a special-purpose computer developed by a group of astrophysicists at Tokyo University. The simulations formed part of a collaborative project with Jun Makino and Simon Portegies Zwart, from Tokyo, and Steve McMillan, from Drexel.

Hut organized a conference at Tokyo University, `Astrophysics on the GRAPE Family of Special Purpose Computers', in January 1999, together with Makino. They also published an invited review under the same title in Science. Currently, Hut is involved in the ongoing project to develop the GRAPE-6, which at a speed of more than 100 Tflops is expected to become once again the world's fastest computer in the year 2000, regaining the title that it's predecessor, the GRAPE-4, had held in 1995 and 1996.

Together with co-author Douglas Heggie, from Edinburgh University, Hut finished the first draft of a monograph, titled `The Gravitational Million-Body Problem'. While aimed primarily at graduate students in astrophysics, this book is also meant to convey some of the salient points of stellar dynamics to colleagues working in quite different areas, such as plasma physics and computer science.

Hut organized a summer school, titled `Values in a World of Fact', in August 1998, together with cognitive psychologist Roger Shepard, from Stanford, philosopher of science Bas van Fraassen, from Princeton University, physicist Arthur Zajonc, from Amherst College, and writer Steven Tainer, from Berkeley. This was the first public offering of the Kira Institute (web site:, founded by them during the previous academic year.

Among several other interdisciplinary activities, Hut organized a session at the State of the World Forum, in San Francisco, in October 1988, titled `The Role of the Subject in Science'. He also organized a conference `Ambiguity brought into Focus', in March 1999, together with Hayao Kawai, at the International Research Center for Japanese Studies, Kyoto. Among some of the invited talks he gave were a lecture `Science, Phenomenology, and World Views', at a conference on Non-Duality in Asian and Western Philosophy and Science, at Columbia University, New York, in April 1999, and a lecture `Theory, Experiment, and Nature', at a Symposium on the Philosophy of Science at Leiden, Holland, in June 1999.