Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!whuxl!houxm!ihnp4!qantel!hplabs!sri-unix.ARPA!DAM%MIT-OZ@MIT-MC.ARPA From: DAM%MIT-OZ@MIT-MC.ARPA Newsgroups: net.physics Subject: Quantum Field Theory Message-ID: <400@sri-arpa.ARPA> Date: Mon, 15-Jul-85 13:59:00 EDT Article-I.D.: sri-arpa.400 Posted: Mon Jul 15 13:59:00 1985 Date-Received: Wed, 17-Jul-85 20:57:07 EDT Lines: 31 It is interesting that you pointed out that the wave function is not distributed in space. I find this to be one of the most disturbing properties of quantum mechanics. The wave function is distributed in configuration space, i.e. the space of all possible CONFIGURATIONS of the system. For classical n-particaal systems this configuration space has 3n dimensions. (Footnote: Actually, as was pointed out, many representations of the wave function are possible. The wave function can be thought of as a point in a Hilbert space and the Hilbert space can have different spectral representations corrosponding to different sets of operators. But I like to think in terms of configuration space because it allows me to switch between classical and quantum-mechanical thinking.) What bothers me is that I don't fully understand the relationship between a wave function distributed over configuration space and real-live space-time. Given a wave function distributed over configuration space how can one talk about "events" which occur at particular points of "space-time"? It seems to me that the physical theory should account for events which accur in a SINGLE FOUR DIMENSIONAL SPACE-TIME MANIFOLD. But I don't see how to define such a manifold in terms of quantum field theory (but then again I don't really understand quantum field theory). As a somewhat sophisticated non-physicist it seems to me that this question would be important for understanding the relationship between quantum field theory and gravitation. If one could define a single four-dimensional "causal manifold" in terms of quantum field theory one might see why such a manifold is curved.