I think it's better to say that most physicists view the Copenhagen interpretation as convenient for calculation --- we don't believe the collapse is a physical event. A "measurement" is just an interaction, like any other physical interaction. When a small system interacts with a larger one, the two systems become entangled and have a joint wave function. This is true whether the larger system is the brain of an experimenter, a photographic plate, or any other macroscopic system. In theory, if we could account for all the interactions we could reverse them, and disentangle the two systems. The smaller system would then be "unmeasured". But this is rather like unscrambling an egg. If the interactions are difficult to control or reverse --- which is generally true when the larger system has a huge number of particles --- then the system's wave function effectively collapses. - Cris On Jun 30, 2014, at 6:31 PM, Mike Stay <metaweta@gmail.com> wrote:
On Mon, Jun 30, 2014 at 5:24 PM, Eugene Salamin via math-fun <math-fun@mailman.xmission.com> wrote:
Most physicists go with the Copenhagen interpretation since it appears to be the least problematical. This is the interpretation which posits that the wave function is a probability amplitude, possessing the same kind of reality as classical probability.
All of the interpretations say that, as far as I'm aware. Copenhagen says that the wave function "collapses" randomly when it's observed. The collapse postulate, in my opinion, is clearly wrong. If it actually behaved that way, it would be
- The only non-linear evolution in all of quantum mechanics. - The only non-unitary evolution in all of quantum mechanics. - The only non-differentiable (in fact, discontinuous) phenomenon in all of quantum mechanics. - The only phenomenon in all of quantum mechanics that is non-local in the configuration space. - The only phenomenon in all of physics that violates CPT symmetry. - The only phenomenon in all of physics that violates Liouville's Theorem (has a many-to-one mapping from initial conditions to outcomes). - The only phenomenon in all of physics that is acausal / non-deterministic / inherently random. - The only phenomenon in all of physics that is non-local in spacetime and propagates an influence faster than light.
(http://lesswrong.com/lw/q6/collapse_postulates/)
-- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun