Is this paper correct?

[aristo dorticos]

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]]

[aristo dorticos]

Post by aristo dorticos
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]]

[Richard Livingston]

Post by aristo dorticos

Post by aristo dorticos
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.

[aristo dorticos]

Post by Richard Livingston

Post by aristo dorticos

Post by aristo dorticos
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
-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.