Thread on Lorentz Invariance Violation

[Russell E]

Yesterday there was a thread here on a claimed violation of Lorentz invariance, but I can't locate it today. Was the thread moved? Can someone point me to its new location? (I don't remember the exact title of the thread, but the posts referred to a letter in the Sep 2010 issue of European Journal of Physics C.)

 

[bcrowell]

It does seem to have been removed. I think that may have happened because there was a long thread with a bunch of kook material in it, and the deletion of that was not done with surgical precision. The paper you're referring to was, after all, published in a peer-reviewed journal.

Here's a recap of what I know about this. Santosh Devasia is a professor of mechanical engineering at UW. He claims that various experiments show Lorentz violation, when the authors of the papers interpret their own experiments as supporting Lorentz invariance.

http://arxiv.org/abs/1003.2970

http://arxiv.org/abs/0808.3798

http://resources.metapress.com/pdf-preview.axd?code=b55166258582206j&size=largest

G. Saathoff et al., Phys. Rev. Lett. 91, 190403 (2003)

http://prl.aps.org/abstract/PRL/v91/i19/e190403

confirms gamma to 1 part in 10^7, at 6.4% of c

description by Baez: http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html

I think the long and the short of it is that Devasia is wrong, but incorrect papers do get published sometimes in peer-reviewed journals.

Note that this is not a claim of a new experimental detection of Lorentz-invariance violation. It's a reinterpretation of previous experiments that *verified* Lorentz invariance.

 

[yuiop]

Thanks for posting the links again Ben. Very public spirited of you! I have saved a copy to my desktop because more than likely this thread will be deleted soon too. While the papers may have been published in peer reviewed journals, they point to potential problems with relativity theory and as such are obviously not welcome here.

 

[Tantalos]

The author of this paper does not deny SR, but he asks a question on the results of some experiment. In his paper he asks why should we neglect the transverse Doppler effect. It was deleted shortly after I posted what the transverse Doppler effect is. I don't know why it deserved to be deleted.

 

[bcrowell]

While the papers may have been published in peer reviewed journals, they point to potential problems with relativity theory and as such are obviously not welcome here.

I have never detected any such bias here. The thing is that of the posts that claim to point out problems with relativity, 99% are by people who are completely ignorant of the experimental basis of relativity, aren't aware of their own ignorance, aren't willing to learn, and aren't able to back up their claims with references to peer-reviewed papers. The fact that those 99% get deleted or locked does not imply that there is a bias on the part of the PF admins in terms of substance. It just shows that there is a statistical bias among such posters -- they are almost all trolls, fools, kooks, and/or uninformed loudmouths.

 

[bcrowell]

The author of this paper does not deny SR, but he asks a question on the results of some experiment. In his paper he asks why should we neglect the transverse Doppler effect.

Devasia *claims* that the authors of the original papers neglected the transverse Doppler effect. I don't think that the original authors would agree with that statement.

It was deleted shortly after I posted what the transverse Doppler effect is. I don't know why it deserved to be deleted.

The transverse Doppler effect is defined as the part of the relativistic Doppler effect that occurs because of the motion of the source and/or observer in the direction perpendicular to the line connecting them. In Newtonian mechanics, there is no transverse Doppler effect. There is one in relativity, and it can be interpreted as the effect of time dilation due to the relative motion of the source and the observer.

 

[Tantalos]

Devasia *claims* that the authors of the original papers neglected the transverse Doppler effect. I don't think that the original authors would agree with that statement.

It would be nice to read some article about that.

 

[Weber2]

The author of this paper does not deny SR, but he asks a question on the results of some experiment. In his paper he asks why should we neglect the transverse Doppler effect. It was deleted shortly after I posted what the transverse Doppler effect is. I don't know why it deserved to be deleted.

The article does not deny SR --- it showed that based on SR, transverse effects should not be neglected. And if included, there seems to be a difference between SR --- especially in high-speed ions. Although at lower speeds the experiments would match SR predictions.

 

[Weber2]

Yesterday there was a thread here on a claimed violation of Lorentz invariance, but I can't locate it today. Was the thread moved? Can someone point me to its new location? (I don't remember the exact title of the thread, but the posts referred to a letter in the Sep 2010 issue of European Journal of Physics C.)

The journal article appeared in the European Physical Journal C --- the paper can be downloaded for free at http://www.springerlink.com/content/b55166258582206j/fulltext.pdf

 

[yuiop]

It just shows that there is a statistical bias among such posters -- they are almost all trolls, fools, kooks, and/or uninformed loudmouths.

That does not explain why a thread about a paper that was published in a peer reviewed journal was deleted, unless you are claiming that the author Devasia, his peer reviewers and the editors of the European Physical Journal C are "trolls, fools, kooks, and/or uninformed loudmouths".

 

[Dale]

I also posted in that thread and, as of my last post, I didn't see anything objectionable in that thread. That in itself was a surprise to me since bcrowell's experience is similar to mine and I would have expected hijacking almost immediately. Perhaps that happened sometime after I last saw it.

 

[Russell E]

It would be nice to read some article about that.

A (not very complimentary) review of that paper can be found here:

http://www.mathpages.com/home/kmath090/kmath090.htm

 

[bcrowell]

It just shows that there is a statistical bias among such posters -- they are almost all trolls, fools, kooks, and/or uninformed loudmouths.

That does not explain why a thread about a paper that was published in a peer reviewed journal was deleted, unless you are claiming that the author Devasia, his peer reviewers and the editors of the European Physical Journal C are "trolls, fools, kooks, and/or uninformed loudmouths".

I didn't claim that it explained why the thread was deleted. I do claim that Devasia is a kook. As I stated before, peer review is not perfect, and it's not surprising that bad papers sometimes make it through peer review.

 

[Weber2]

A (not very complimentary) review of that paper can be found here:
http://www.mathpages.com/home/kmath090/kmath090.htm

The review is quite good --- nevertheless it does not address the doppler effect in emissions (based on SR).

The main issue raised in the article is that condition of "excitation of the resonance in the moving ions" is being identified by observations centered at \eta_0 in the laboratory frame. This is a critical point in the analysis --- if photons observed through interference filters (centered at \eta_0, i.e., the transition frequency of the stationary ions in the laboratory frame) are being observed at \eta_0 in the laboratory frame, then they could not have been emitted at \eta_0 from the ions as well (in the moving frame linked to the ions). There should be a transverse doppler shift between the two -- the frequency of emission and the frequency of observation --- according to SR.

By using interference filters (centered at \eta_0 in the laboratory frame) when measuring the photons (in the laboratory frame), the experiment is biased to measure ions that were emitting photons at a specific frequency (in the moving ion frame) --- which is different from \eta_0 in the moving ion frame.

 

[bcrowell]

One thing I hadn't realized until today was that Devasia seems to belong to the same tribe of anti-relativity kooks as A.K.T. Assis and Marcelo de Almeida Bueno. You can recognize these people because they all believe that Weber's electrodynamics overthrows relativity. (See Devasia's "Relative-Velocity-Dependent Weber-type Models in Electromagnetism," http://arxiv.org/abs/0808.3798 .)

 

[bcrowell]

The review is quite good --- nevertheless it does not address the doppler effect in emissions (based on SR).

The main issue raised in the article is that condition of "excitation of the resonance in the moving ions" is being identified by observations centered at \eta_0 in the laboratory frame. This is a critical point in the analysis --- if photons observed through interference filters (centered at \eta_0, i.e., the transition frequency of the stationary ions in the laboratory frame) are being observed at \eta_0 in the laboratory frame, then they could not have been emitted at \eta_0 from the ions as well (in the moving frame linked to the ions). There should be a transverse doppler shift between the two -- the frequency of emission and the frequency of observation --- according to SR.

By using interference filters (centered at \eta_0 in the laboratory frame) when measuring the photons (in the laboratory frame), the experiment is biased to measure ions that were emitting photons at a specific frequency (in the moving ion frame) --- which is different from \eta_0 in the moving ion frame.

The mathpages analysis does address all of these points.

 

[Russell E]

The review is quite good --- nevertheless it does not address the doppler effect in emissions (based on SR).

Not true. That web page explicitly describes the Doppler effect between emission and reception. In fact, it describes it both for classical Doppler and for relativistic Doppler. The conclusion is that the letter published in the EJPC is mistaken.

The main issue raised in the article is that condition of "excitation of the resonance in the moving ions" is being identified by observations centered at \eta_0 in the laboratory frame.

Well, yes and no. As explained on that web page, the EJPC letter first argues that the emitter frequency could differ from the reference frequency due to the Stark and/or Zeeman effects, but then it completely ignores those effects, and pretends to compute a shift from the Doppler effect, based on the (completely baseless) premise that the observed frequency in the lab frame equals the reference frequency for the ion at rest. That is simply nonsense.

 

[Weber2]

As explained on that web page, the EJPC letter first argues that the emitter frequency could differ from the reference frequency due to the Stark and/or Zeeman effects, but then it completely ignores those effects, and pretends to compute a shift from the Doppler effect, based on the (completely baseless) premise that the observed frequency in the lab frame equals the reference frequency for the ion at rest. That is simply nonsense.

It would seem that the ions are probably emitting photons at frequencies distributed about the reference frequency \eta_o in the moving ion frame --- all photons are probably not exactly at \eta_o due to, e.g., Stark and/or Zeeman effects.

However, the measurements --- to detect when the lasers excite the resonance --- is done in the laboratory frame at frequency \eta_o (use of narrow prefilters centered at \eta_o, e.g., as described in detail in Ref [14] of the article).

Therefore, the experiments appear to measure the lamb dip in specific set of photons at \eta_o with respect to the laboratory frame, which could bias the results... since these would not correspond to \eta_o with respect to the moving ion frame due to Doppler shifts.

 

[bcrowell]

It would seem that the ions are probably emitting photons at frequencies distributed about the reference frequency \eta_o in the moving ion frame --- all photons are probably not exactly at \eta_o due to, e.g., Stark and/or Zeeman effects.

The mathpages critique points out that the discussion of Stark and Zeeman effects in the Devasia paper doesn't make sense.

 

[Russell E]

It would seem that the ions are probably emitting photons at frequencies distributed about the reference frequency \eta_o in the moving ion frame --- all photons are probably not exactly at \eta_o due to, e.g., Stark and/or Zeeman effects.

However, the measurements --- to detect when the lasers excite the resonance --- is done in the laboratory frame at frequency \eta_o (use of narrow prefilters centered at \eta_o, e.g., as described in detail in Ref [14] of the article).

Therefore, the experiments appear to measure the lamb dip in specific set of photons at \eta_o with respect to the laboratory frame, which could bias the results... since these would not correspond to \eta_o with respect to the moving ion frame due to Doppler shifts.

You misunderstand. It doesn't matter which photons are used to detect the dip. All that matters is that the distinctive dip occurs when the lasers are correctly tuned to the ions. If you detect this dip by monitoring "incidental" photons of a frequency that differs slightly from the actual primary resonant frequency, it doesn't matter - unless you wish to argue (speculate/fantasize) that the precise dip in these incidental photons occurs at a condition significantly different than the condition where the dip in the primary photons occurs. But (first) this is not actually the case, and (second) the magnitude of this effect, if it existed, would obviously have *nothing* at all to do with the magnitude of the transverse Doppler shift between the ion frame and the lab frame. The EJPC letter preposterously claims that the hypothetical shift in the dip of the incidental photons relative to the primary photons is equal to the transverse Doppler shift between ion and lab frames. These two things have nothing to do with each other. It is totally absurd.

 

[Weber2]

This is probably the key issue to the argument

It doesn't matter which photons are used to detect the dip. All that matters is that the distinctive dip occurs when the lasers are correctly tuned to the ions. If you detect this dip by monitoring "incidental" photons of a frequency that differs slightly from the actual primary resonant frequency, it doesn't matter.

The difference in frequency of the photons (between the laboratory and moving-ion frames) is not slight --- it is similar to the doppler shift in the lasers. If the dip is for photons at \eta_o in the laboratory frame then I am not clear why this would correspond to photons (the same photons) at frequency \eta_o in the moving-ion frame as well.

I am not sure why this would not matter --- the experimental conditions are measuring a dip in photons at frequency \gamma\eta_o in the moving-ion frame ...

 

[bcrowell]

Weber2, you haven't addressed what are in my opinion the two most devastating aspects of the mathpages critique: (1) The Devasia paper speculates that the experimenters in question made a blunder by filtering for a specific frequency -- and apparently *all* the experimenters in question, in five experiments by different groups over a period of 35 years, would have to have made exactly the same mistake. (2) The Devasia paper speculates about Stark and Zeeman effects without quantifying them, without suggesting what external fields might have produced them, and without suggesting how such effects could have been present in *all* the relevant experiments, by different groups, over a period of 35 years.

 

[Weber2]

(1) ... speculates that the experimenters in question made a blunder by filtering for a specific frequency ..

There is nothing wrong with the experiments at all. The reason (pre)filters are used before the PMTs is to probably reduce background noise ... (at low speeds it would make sense to only extract photons near the main \eta_o frequency in the laboratory frame).
The question is how to intepret the results using SR predictions.

(2) The Devasia paper speculates about Stark and Zeeman effects without quantifying them...

The use of the prefilter implies that the photons being measured at \eta_o in the laboratory frame was emitted at a different frequency \gamma\eta_o in the moving-ion frame. Photons of this frequency \gamma\eta_o (in the moving-ion frame) could be emitted because the emitted photons probably cover a distribution of frequencies in the ion frame and not a single frequency. (Effects such as Stark and Zeeman effects can account for such distributions.)

 

[Russell E]

There is nothing wrong with the experiments at all. The reason (pre)filters are used before the PMTs is to probably reduce background noise ... (at low speeds it would make sense to only extract photons near the main \eta_o frequency in the laboratory frame).
The question is how to intepret the results using SR predictions.

No, according to your account, all the experiments have been totally botched, by inserting filters that block out the very signal that the experimenters are trying to observe. Frankly, I suspect you've simply mis-interpreted some sloppy wording in reference 14. When they say they apply a filter to select photons near the resonant frequency of the ions, they presumably expect the reader to realize that this refers to the resonant frequency as observed in the frame of the filter. It would make no sense to filter out the very frequency that they are trying to observe. That's what you're claiming they did.

You're saying the experimenters have committed a very blatent experimental error, one that is even more implausible when you remember that, with the filtering you described, they ought to observe nothing at all, because the magnitude of the shifts produced by the Stark and Zeeman effects (caused by unspecified external fields that you are hypothesizing) are obviously not the same as the magnitude of the transverse Doppler shift between the lab and ion frames. That's why your account of the experiment doesn't make any sense.

I suggest you contact the authors of reference 14, and ask them to explain their filtering to you in more detail. In particular, ask if they really filtered out the very frequency of the "flouresence" that they were trying to observe, by failing to account for the time dilation factor in the transverse Doppler shift of the ion emissions (which is, after all, the very subject of the experiment!).

 

[Tantalos]

This means that the transverse Doppler effect does not exists, does it?

 

[bcrowell]

This means that the transverse Doppler effect does not exists, does it?

It does exist. Please see the sticky titled "FAQ: Experimental Basis of Special Relativity" at the top of this forum. Devasia is simply confused about the role of the transverse Doppler effect in the experiments he claims are wrong.

 

[Tantalos]

The anti-paper states that in those experiments the transverse Doppler effect gets canceled by time dilatation and length contraction in the ion's RF. Where can it be observed and why it is not canceled in those cases?

 

[Weber2]

simply mis-interpreted some sloppy wording in reference 14. When they say they apply a filter to select photons near the resonant frequency of the ions, they presumably expect the reader to realize that this refers to the resonant frequency as observed in the frame of the filter. It would make no sense to filter out the very frequency that they are trying to observe.

The frequency of the interference filter is specified very clearly in Ref [14], which is available at http://archiv.ub.uni-heidelberg.de/...xte/2005/5934/pdf/doktorarbeit_sreinhardt.pdf . In particular, the caption of Figure 6.7 of Ref [14] states “… and an interference filter (transmission 548 nm, half-width 10 nm (s.[Mer00])) are placed”. This is the transition frequency \eta_o in the laboratory frame as seen in Figure 3.1 of Ref [14].

I do not think that there is an error in the experiments. For example, if the photons emitted at \eta_o (in the moving ion-frame) were to be measured then the interference filter would have to be at \eta_o/\gamma in the laboratory frame. However, this would require a-priori knowledge of the time-dilation factor \gamma, which is what the experiments are trying to evaluate (at high speeds).

Therefore, placing the interference filters at \eta_o (in the laboratory frame) is quite reasonable in the experiments and not an error. However, the time-dilation effect between the emitted and observed photons needs to be included in the SR calculations with the use of the pre-filter --- since the observed lamb-dip is for photons at a specific frequency\eta_o in the laboratory frame.

 

[Weber2]

This means that the transverse Doppler effect does not exists, does it?

The EPJ C paper only claims deviations in the experiments at higher speeds --- low speed transverse Doppler should still remain the same according to the EPJ C paper.

 

[Dale]

I just went through the math on my own. R=1 according to SR, the previous papers are correct and the EPJ C paper is in error.