• Is this paper correct?

    From aristo dorticos@21:1/5 to All on Sat Oct 29 13:53:59 2022
    https://arxiv.org/abs/1904.13252

    Seems to revolutionize the thinking about the Mossbauer rotor effect.

    [[Mod. note -- The same author also has a newer paper,
    https://arxiv.org/abs/2203.02282
    on similar topics.
    -- jt]]

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  • From aristo dorticos@21:1/5 to aristo dorticos on Sun Oct 30 18:05:42 2022
    On Saturday, October 29, 2022 at 1:54:03 PM UTC-7, aristo dorticos wrote:
    https://arxiv.org/abs/1904.13252

    Seems to revolutionize the thinking about the Mossbauer rotor effect.

    [[Mod. note -- The same author also has a newer paper, https://arxiv.org/abs/2203.02282
    on similar topics.
    -- jt]]
    To me both papers seem correct (and supported by experimental data).
    What is your opinion?

    [[Mod. note -- At a quick look I don't see any problems. -- jt]]

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  • From Richard Livingston@21:1/5 to eggy20...@gmail.com on Mon Oct 31 18:02:31 2022
    On Sunday, October 30, 2022 at 8:05:47 PM UTC-5, eggy20...@gmail.com wrote:
    On Saturday, October 29, 2022 at 1:54:03 PM UTC-7, aristo dorticos wrote:
    https://arxiv.org/abs/1904.13252

    Seems to revolutionize the thinking about the Mossbauer rotor effect.

    [[Mod. note -- The same author also has a newer paper, https://arxiv.org/abs/2203.02282
    on similar topics.
    -- jt]]
    To me both papers seem correct (and supported by experimental data).
    What is your opinion?

    [[Mod. note -- At a quick look I don't see any problems. -- jt]]

    I looked at those papers yesterday and while I don't feel I studied them enough to offer a firm and authoritative opinion, I do have some concerns:

    -It appears that the source is also rotating. The rotation speeds are quite high,
    and it only takes a fraction of a mm/sec to shift the Mossbauer peak significantly.
    (see figure 2a in second cited paper) I wonder if the deviations from k=0.5 is an experimental artifact due to small effective velocity of the source?
    -If I was setting up this experiment I would have the source stationary. To eliminate this issue.
    -It is pretty well accepted that there should be a shift due to the relativistic
    Doppler shift due to the lateral speed of the rotating absorber. The
    question is, is there another shift due to the radial acceleration? I might be
    wrong, but I don't believe the "metric" used in the second paper makes
    sense in this experiment, particularly the g_00 which would contribute
    to a red or blue shift. I just don't think that is applicable here.
    -If the source and absorber were both accelerating, or were in a
    gravitational field, THEN a red/blue shift due to the acceleration would
    be applicable, but in this rotating frame, not.
    -The one effect of the radial acceleration I do wonder about has to do
    with the extended duration of the Mossbauer interaction. The reason
    the line width is so narrow is that the emission has a long decay time,
    and as a result the recoil is taken up by many atoms in the lattice. If
    during this time the absorber has an effective velocity wrt the source,
    then there might be a shift in resonance. I'm skeptical of this mechanism however because it would work both ways and broaden the resonance
    rather than shift it. I'm also a bit skeptical that this mechanism would
    apply at all.

    My suspicion is that the measured deviation from k=0.5 is an experimental artifact and not real.

    Rich L.

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  • From aristo dorticos@21:1/5 to richali...@gmail.com on Tue Nov 1 00:44:27 2022
    On Monday, October 31, 2022 at 6:02:36 PM UTC-7, richali...@gmail.com wrote:
    On Sunday, October 30, 2022 at 8:05:47 PM UTC-5, eggy20...@gmail.com wrote:
    On Saturday, October 29, 2022 at 1:54:03 PM UTC-7, aristo dorticos wrote:
    https://arxiv.org/abs/1904.13252

    Seems to revolutionize the thinking about the Mossbauer rotor effect.

    [[Mod. note -- The same author also has a newer paper, https://arxiv.org/abs/2203.02282
    on similar topics.
    -- jt]]
    To me both papers seem correct (and supported by experimental data).
    What is your opinion?

    [[Mod. note -- At a quick look I don't see any problems. -- jt]]
    I looked at those papers yesterday and while I don't feel I studied them enough
    to offer a firm and authoritative opinion, I do have some concerns:

    -It appears that the source is also rotating. The rotation speeds are quite high,
    and it only takes a fraction of a mm/sec to shift the Mossbauer peak significantly.
    (see figure 2a in second cited paper) I wonder if the deviations from k=0.5 is
    an experimental artifact due to small effective velocity of the source?
    -If I was setting up this experiment I would have the source stationary. To eliminate this issue.
    -It is pretty well accepted that there should be a shift due to the relativistic
    Doppler shift due to the lateral speed of the rotating absorber. The
    question is, is there another shift due to the radial acceleration? I might be
    wrong, but I don't believe the "metric" used in the second paper makes
    sense in this experiment, particularly the g_00 which would contribute
    to a red or blue shift. I just don't think that is applicable here.
    -If the source and absorber were both accelerating, or were in a gravitational field, THEN a red/blue shift due to the acceleration would
    be applicable, but in this rotating frame, not.
    -The one effect of the radial acceleration I do wonder about has to do
    with the extended duration of the Mossbauer interaction. The reason
    the line width is so narrow is that the emission has a long decay time,
    and as a result the recoil is taken up by many atoms in the lattice. If during this time the absorber has an effective velocity wrt the source,
    then there might be a shift in resonance. I'm skeptical of this mechanism however because it would work both ways and broaden the resonance
    rather than shift it. I'm also a bit skeptical that this mechanism would apply at all.

    My suspicion is that the measured deviation from k=0.5 is an experimental artifact and not real.

    Rich L.


    Thank you

    The absorber (detector) is stationary, only the source is rotating.
    As such, the metric used by Corda is the correct one.

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