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December 17-20, 2004

A workshop organized by the
Pacific Institute for Theoretical Physics

This is one of a series of conferences organised by PITP in conjunction with the 7 Pines institute. This conference was held at the 7 Pines institute, 7 Pines, Minnesota.

A. J. Leggett (Urbana)
P. C. E. Stamp (PITP, UBC)
R. Wald (Chicago)
W. G. Unruh (UBC)
The problem of the apparent ‘flow of time’, and the asymmetry of physical processes in Nature despite the symmetry embodied in physical laws, is an old one, whose interest extends well beyond physics and philosophy. Physicists nowadays distinguish several ‘Arrows of Time’, the 2 most important being the ‘cosmological arrow’, and the ‘thermodynamic arrow’. The presence of these arrows is behind diverse physical phenomena ranging from the Big Bang, and the irreversible phenomena we see in systems from nuclei to stars and galaxies, to the variety of biological organisms living on Earth (and presumably elsewhere), including ourselves.

The purpose of this workshop is twofold. The first is synthetic- we wish to bring together scientists from various disciplines and philosophers, so that a proper exposition of the different points of view on this topic may be given. Most discussions of the Arrows of Time have concentrated on features arising from a particular field of physics, but some of the essential problems arise precisely because the phenomenon of time direction is so universal. We are therefore bringing together not just physicists- in fields ranging from gravity and cosmology to condensed matter physics and statistical mechanics- but also researchers working in biology and on other complex systems. The aim is to compare the different views of the arrows of time that have arisen in these fields, and to arrive at some sort of synthesis which takes account of important scientific developments in recent years. These developments include a deeper understanding of complexity, and also of the role of information in physical processes, particularly information in biological and other complex systems, and quantum information.

This synthetic role would not be complete without at the same time an examination of the philosophical problems associated with a direction of time- these are some of the most difficult problems in the philosophy of science. The workshop will include a variety of philosophical experts in this area, who have studied questions ranging from time travel, thermodynamic irreversibility, and causality, to biological evolution and the ‘psychological’ arrow of time.

The proceedings of this workshop are online, and we hope that some of the ideas and discussions will be published as a book.

Co-sponsored by and the 7 Pines Institute.