Wednesday, December 23, 2009

Measurement in QM

A conference was held at Boston University in 1996, the proceedings of which are in "Conceptual Foundations of Quantum Mechanics", edited by Tian Yu Cao (amazon.com link). The conference included philosophers and physicists. Quantum Field Theorists included Steven Weinberg, David Gross, Bryce DeWitt, Arthur Wightman, Sidney Coleman.

Excerpt from one of the discussions:
Saunders: .....in measurement processes we have what appears to be a violation of unitary dynamics. It seems we cannot implement measurement processes unitarily....
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Colseman: There is a position on measurement theory which grossomodo is shared by at least Bryce and me and probably other people, which eventually goes back to Hugh Everett and which denies the existence of non-unitary process of measurement, and says that it is just a process that can be eliminated. That's easy to prove but hard to believe. And I don't want to go into it now, although I would be happy to go into it privately. And during your stay at Harvard I gave a public lecture on this topic....
I want the transcript of that public lecture. I haven't been able to locate it yet.

In the excerpt above, Saunders might be Simon Saunders, in which case he was at Harvard during these relevant time periods:
1995-96: Associate professor, Department of Philosophy, Harvard University.
1990-95: Assistant professor, Department of Philosophy, Harvard University.

This is a rather long period over which to search :(.

PS: As per Wolfgang's comment, it is "Quantum Mechanics in Your Face (streaming video)" (A lecture given by Sidney Coleman at the New England sectional meeting of the American Physical Society (Apr. 9, 1994).)