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SR predictions on an recent microwave experiement

  1. Aug 26, 2007 #1
    I quickly read the followoing IEEE paper:

    Absence of the Relativistic Transverse Doppler Shift at Microwave Frequencies

    The author claims he proved that he invalidated experimentally the SR prediction of a transverse Doppler effect for microwaves.
    Its experimental setup is shown in figure 1.

    Basically, an homodyne frequency-shift detection is used.
    It involves a fixed source and a fixed detector.
    The setup involves two paths: a "reference path" and an "active path".
    In the active path, the microwave beam passes trough a rotating emission-reception system.
    Because of the rotation of the beam within the "active path", the author claims a transverse Doppler effect should be observed.
    The author did not detect any shift and concluded this invalidates SR.

    I think this paper is totally wrong in its analysis and its conclusion. Experimental results are right but useless.
    The source and the detector have no relative motion and therefore I would not expect ant Doppler shift.
    In addition, if one considers a even simpler version of this experiment, the conclusion of "no Doppler shift expected" is even more obvious to me. This simplified version would be based on a cylindrical cavity in the "active path" whose walls would be rotating. It is clear that rotating walls would make any difference compared with fixed wall: reflexion on perfect conducting walls does not depend on the transverse motion.

    I would like to elaborate on my first impression.
    I am interrested by your own ideas and comments on this experiement as well as in the basic theory to analyse such experiments in general.

    Thanks
     
    Last edited: Aug 26, 2007
  2. jcsd
  3. Aug 26, 2007 #2

    Ich

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    Science Advisor

    Hi,

    I did a quick analysis of this experiment one year ago, showing that SR predicts a null result, as measured. Sorry it's in German; in English: your first impression is right, emitter and source are at rest, that's it. What's happening between: the wavefront is blueshifted and tilted as seen by the rotating disk, and will be re-emitted blueshifted and tilted. No change happens.

    I had a rather lengthy discussion with Prof. Thim via e-mail concerning another paper where he thought to show an inconsistency in the Lorentz Transforms. He emerged as a full scale crank, beyond any reasoning. Hard to believe that he was (is?) still teaching students at the University of Linz.
     
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