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Help Understanding MME

  1. Nov 26, 2005 #1
    I think I understand what the Michelson Morley expiroment proved, but I was wondering if we were ever able explained the small fringe differance that still exist?
     
  2. jcsd
  3. Nov 26, 2005 #2

    ahrkron

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    I think the remaining displacement was just consistent with zero, given the experimental errors.

    AFAIK, the experiment has been repeated several times, most probably with improved accuracies. If the displacement is ever found to be significantly different from zero (i.e., if the expected experimental error is small compared to the measured displacement) everybody will be quite excited.
     
  4. Dec 3, 2005 #3
    please have a look at a paper of mine om arxiv phyhsics education devoted to
    the Michelson-Morley experiment.
    brothenstein@gmail.com
     
  5. Dec 3, 2005 #4

    Aether

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    M-M experiments probe the rotational invariance component of local Lorentz symmetry. Modern M-M experiments in which the light beams travel through vaccum all have vanishingly small residual fringe shifts. Some people have noted that there seems to be a connection between the refractivity of the media through which the light beams travel and the residual fringe shifts as a function of absolute motion: http://www.scieng.flinders.edu.au/cpes/people/cahill_r/processphysics.html, but such claims aren't really supported by any new and conclusive experiments...at least not yet.
     
    Last edited: Dec 3, 2005
  6. Dec 3, 2005 #5

    jtbell

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    Those claims are apparently not even supported by Michelson and Morley's data, based on modern error-analysis techniques:

    http://groups.google.com/group/sci.physics.relativity/msg/7df6f9e77e4ee6c8
     
  7. Dec 3, 2005 #6

    Aether

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    "For the case of the original Michelson Morley experiment"...Cahill claims that there is much more evidence than just the original M-M experiment, especially the results of Dayton Miller, and including all other published results for M-M experiments conducted in gaseous media. At least AFAIK, there are no published results for a M-M experiment which are inconsistent with Cahill's claim. What seems strange to me is that there aren't any published results from an experiment that clearly and directly refutes Cahill's claim.
     
    Last edited: Dec 3, 2005
  8. Dec 3, 2005 #7

    selfAdjoint

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    Are people still citing Dayton Miller? I thought his results had been found to be due to systematic movement of his apparatus. Recall that he had situated it on a mountain top to get it out of any condensed ether associated with the earth, and as a result it was subject to micoroscopic oscillations drivien by the wind there.
     
  9. Dec 3, 2005 #8

    Aether

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    I don't recall hearing anything about these microscopic oscillations before; I did read something about Einstein speculating openly that Miller's result was probably due to temperature gradients in the room where Miller's apparatus was operated, and Miller was insulted by that. Nevertheless, all published results for M-M experiments conducted in gaseous media seem to be consistent with the same locally preferred frame (except that several different investigators, all referring to more-or-less the same set of experimental data, have come up with different estimates for the direction and magnitude of the Earth's motion wrt that frame).

    Try it, take the published results from any M-M experiment, and see if there aren't residual fringe shifts reported that are roughly proportional to the refractivity of the media and also consistent with Miller's/Cahill's locally preferred frame. I'm not saying that this is proof for a locally preferred frame, but it is interesting.
     
    Last edited: Dec 3, 2005
  10. Dec 3, 2005 #9

    jtbell

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  11. Dec 3, 2005 #10

    Aether

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    "I can show all this unambiguously using modern DSP and data analysis techniques. Note his systematic error can be cleanly and unambiguously separated from any possible real signal."

    That would be interesting to see if/when he actually comes through with a paper that demonstrates this.
     
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