Talk:Lorentz ether theory

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I just read this article to see what needed to be corrected, and to my surprise I saw little to correct, and it's mostly well phrased and presented. All that without any discussions! Congratulations for such an accurate and balanced presentation. Harald88 21:59, 5 January 2006 (UTC)


I agree. Martin Hogbin 12:20, 15 May 2006 (UTC)

But now not anymore, the intro has become inaccurate. I partly revert. Harald88 11:18, 7 August 2007 (UTC)

Contents

[edit] Expansion

Well, I've expanded the article in accordance to the German article.--D.H 17:21, 6 August 2007 (UTC)

[edit] strange sentence, please clarify

At the bottom of the article I came across the following sentence:

"Modern measurements empirically discredit ether theories in the massless (electromagnetic) sector."


It's not clear to me what is meant with that. In any case, Lorentz's version of SRT as well as Einstein's version of GRT (which includes SRT) imply according to them some kind of ether; and in harmony with those facts, the article states that it's a matter of taste. Thus something is obviously wrong with that sentence. Please correct it. Harald88 14:20, 27 September 2007 (UTC)

The edits where made by User:68.5.189.152. It think it's about Lorentz violation models, such as the testheories of Sexl/Mansouri etc. There is some similarity to Lorentz's theory, although they are not the same. So I tried to correct the sentence. --D.H 07:25, 28 September 2007 (UTC)

[edit] Irrelevant and misleading sentence

The article had:

"Although Einstein in 1921 used the term „gravitational ether“ in connection of general relativity, he clearly pointed out that this was no ether in the mechanical sense. [1]"

In fact, in the above paper, even Einstein recognized that also the ether of Lorentz was not mechanical - the suggestion above was therefore misleading to the readers. - http://www.mountainman.com.au/aether_0.html (better add an English reference like this one)

It may be useful however to refer to that paper, since it clarifes that with GRT Einstein came back to some kind of ether.

Harald88 (talk) 15:53, 18 November 2007 (UTC)

Well, I included the following passage in the article:
"In 1920 Einstein said that immobility is the only mechanical property of which the ether has not been deprived by Lorentz. He went on to introduce the term "gravitational ether", but contrary to Lorentz's ether the ether has no mechanical property, not even immobility:"
“ Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only wonld be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it. ”

--D.H (talk) 10:04, 19 November 2007 (UTC)

[edit] Paragraph with suspect suggestions

One paragraph suggests that Lorentz betrayed Poincare after his death as follows:

"However, 1916 in his main work „The theory of electrons“ Lorentz only mentioned Einstein and Minkowski in connection with the equality of the systems, but not Poincaré. [63] [15] And in 1927 Michelson suggested that Lorentz is the discoverer of the theory of relativity, but Lorentz replied:“ I considered my time transformation only as a heuristic working hypothesis. So the theory of relativity is really solely Einstein's work. And there can be no doubt that he would have conceived it even if the work of all his predecessors in the theory of this field had not been done at all. His work is in this respect independent of the previous theories.[64]"

- Wasn't his main work „The theory of electrons“ published in 1906? In that case, there is no contradiction: Lorentz had received letters by Poincare about the equality of the systems, but he could hardly make mention of private letters and there is no reason to believe that he knew of Poincare's 1905 paper.

- He may have completely forgotten about Poincare by 1928 (the year he died!), as he had worked intensely with Einstein while Poincare was long dead. However, after 1920 the "theory of relativity" usually meant the full theory (that is, general relativity) and it looks suspect that Lorentz replied to a personal remark in a 1928 post-mortem(?) publication -> so, which one?

Harald88 (talk) 21:32, 20 November 2007 (UTC)

It think you are aware of the dissertation "Lorentz's ether theory" by the Lorentz/Einstein expert Michel Jannsen. Well, the "suspect suggestion" was made by Jannsen, who is a reputable and well known historian of science an co-editor of Einstein's collected papers. It's true that Lorentz's book was based on lectures given in 1906, but there were two editions of Lorentz's book. The first, published in 1909 (three years after the lectures), the second with some corrections published in 1916. So Lorentz had enough time to make corrections and to give credit to Poincare, but he didn't. Jannsen wrote in Chapter 3, p. 91.

Poincaré had given his physical interpretation of the x dependence of local time in, of all places, his contribution to the Lorentz Festschrift of 1900 (Poincaré 1900b, p. 483), and again in a lecture in St. Louis in 1904 that was published in 1905 in his book La valeur de la science (Poincaré 1904, pp. 99–100 108 ). Yet, Lorentz was won over for the idea only by Einstein. Moreover, he did not even mention Poincaré in this context, whereas Lorentz is normally very careful to give credit wherever credit is due. In the second edition of The theory of electrons of 1916, Lorentz gives credit only to Einstein in the following footnote that is otherwise characteristic for Lorentz’s intellectual generosity: [...] It is totally unclear to me why Lorentz did not mention Poincaré at this juncture.
[And on p. 102 Jannsen wrote:]
In his paper “On the dynamics of the electron,” Poincaré, working independently of Einstein, gave an impeccable derivation of the relativistic transformation law for charge density (Poincaré 1906, pp. 151–152; quoted and discussed in Miller 1973, pp. 251–252). Lorentz does not refer to this important contribution of Poincaré in this passage in The theory of electrons. In the footnote he appended to this passage in the second edition of 1916, Lorentz gives a derivation of the relation between ρ′ and ρ which is mathematically equivalent to Poincaré’s 1906 derivation, again without citing Poincaré.

On the other hand, in 1921 Lorentz published a paper, in which he gave full credit to Poincare. So Lorentz's behaviour in connection with Poincare after 1905 was very strange ;-) --D.H (talk) 10:27, 21 November 2007 (UTC)
That topic is debated between historians of science; Janssen's is just one opinion among many, and everyone can only speculate. The date of a reprint should not be put in order to suggest that it was the time of writing, that would simply be fooling the readers. In fact we don't know how long before the second edition the additional footnotes were written (don't forget WW-I!).
It's of course OK to accredit debatable opinions to the persons who make them - the main rule is that Wikipedia is neutral, see WP:NPOV and WP:V. But Janssen did not insinuate that Lorentz betrayed Poincare in the above passages; instead he admitted that it was "totally unclear" to him. And "references such as "Lorentz 1928" are quite useless", since we can't verify them. Harald88 (talk) 06:43, 23 November 2007 (UTC)

It don't think that anyone says that Lorentz "betrayed" Poincare. The article only states that in 1921 Lorentz gave credit to Poincare, and in 1916 and 1928 Lorentz only gave credit to Einstein. That's all. --D.H (talk) 07:39, 23 November 2007 (UTC)

PS: Why do you say that "references such as Lorentz 1928 are quite useless". Of course you can verify them. Look into the section Lorentz ether theory#Bibliography, there you find this online available reference:

--D.H (talk) 09:15, 23 November 2007 (UTC)

The section indeed makes such unfounded claims and it certainly is very suggestive. Again:
- It's essential to distinguish between facts and opinions about facts.
- It's necessary to distinguish between publication dates of opinions from dates that those opinions were spoken or written down.
Note also that none of these papers and books were self-published.
We should try to improve that section in a Wikipedia way, and anyway the required changes are mostly small and/or subtle.
Thanks for explaining that although the reference is not in the Reference section, it can be found in "Bibliography". However, I think that that is far from optimal...
I now read Lorentz's comment of 1927, and unmistakenly there he meant special relativity. Apparently he had completely forgotten about Poincare, or perhaps he had never understood what Poincare told him. Here's where it may be useful to cite Janssen, according to whom "Lorentz was won over for the idea only by Einstein".
Harald88 (talk) 10:24, 24 November 2007 (UTC)
PS: The bibliography is excellent, (almost?) everything is freely accessible from internet. :-)
Harald88 (talk) 11:21, 24 November 2007 (UTC)

Thanks, it took me very long to find every paper of Lorentz/Poincare which are freely accessible, and I included them in the German and the English version of this Wiki-Article. --D.H (talk) 12:38, 24 November 2007 (UTC)

NO thank you - accessible original references is the kind of thing that really enhances the value of Wikipedia! :-)
I will now add Janssen's partial explanation that you gave here above. Harald88 (talk) 14:32, 24 November 2007 (UTC)

I've replace the Jannsen comment with another one, which suits better, I think. I also expanded the citations of Lorentz. --D.H (talk) 16:18, 27 November 2007 (UTC)

[edit] The Lead Paragraph and Some General Comments

The opening sentence gives several alternative names for the subject of the article, but I think it's slightly misleading, because each of those names refers to different things. For example, Lorentz's electron theory refers exclusively to electrodynamics, whereas what is today called Lorentz Ether Theory is more general and essentially includes all of physics, making it an alternative interpretation of special relativity. So I would suggest omitting the alternative names in the opening sentence, and in the body of the article I would try to clearly distinguish between Lorentz's electrodynamics and the neo-Lorentzian interpretation of special relativity called Lorentz Ether Theory. It would also be worth mentioning that it's unclear whether Lorentz himself ever fully embraced what we today call Lorentz Ether theory.

Another incidental comment - the article notes that Lorentz's ether was perfectly stationary, but then talks about "vibrations" of the ether. Those two concepts are mutually exclusive. Lorentz addressed this specifically, and said his preferred conception was that the ether really is perfectly immobile, and the "oscillations" of the electric and magnetic fields are just changes in state, not spatial vibrations.

I think there may be quite a bit of overlap between the "Priority" section of this article and certain other articles in Wikipedia (for example, on Priority Issues in Relativity). Since this article is about Lorentz Ether Theory, the priority it should be discussing is related to that theory, not special relativity. The article seems somewhat confused as to its actual subject, which I supposed is understandable considering the close relationship between LET and SR.

I'd also mention that there is a vast literature on this subject, in which all the available material is examined and evaluated by recognized scholars. Almost none of that material is mentioned in this article. See for example Miller, Torreti, Zahar, Earman, etc. Citing those reputable sources would avoid turning this article into a "novel narrative". SJC1 (talk) 17:52, 24 November 2007 (UTC)

I just read here above or directly in Janssen (I forgot) that Ehrenfest had used the term "Lorentz ether theory", in contrast with "Einstein's non-ether theory" or something along those lines. Probably such an early use of the term should be cited.
I agree that a distinction must be made between Lorentz's Electrodynamics theory (until 1904) and the New Mechanics from 1904.
Concerning the opinions of the authors, they are themselves the most reliable source for their own opinions. Secondary sources are required for answering ambiguities as well as for backing up the "narrative" as you put it - and the narrative is indeed that as found in such secondary sources. Thus I added one useful assertion by Janssen who BTW also discusses Miller etc.
More comments may be useful, but then, I had a similar thought about the priority section: much of that seems to more belong in Priority Issues in Relativity, while about the theoretical development of Lorentz and Poincare for what here is called "LET" there doesn't seem to be any issue at all. The only issue is the misrepresentation of Poincare as being subject to a "LET" interpretation, but I think that the article is sufficiently clear about it. Harald88 (talk) 10:41, 25 November 2007 (UTC)
Thanks for your comments. I personally prefer the interpretation of Darrigol, Galison, Jannsen etc.. But if you want to introduce some stuff of Zahar or Miller, it would be good for the balance of the article. Fell free to make some changes by yourself.
I'd also mention Holton and Stachel.SJC1 (talk) 09:50, 25 November 2007 (UTC)
I'm not sure if Lorentz's theory refers exclusively to electrodynamics. Ok, this was true in the beginning, but it was pointed out by Abraham in 1904 that Lorentz's electron model is not compatible with the electromagnetic worldview. Therefore Poincare was forced to introduce his non-electrical aether-stresses. Poincare also clearly pointed out that the relativity principle is valid for all forces, not only the electromagnetic ones.
That's my point, i.e., it eventually had to be expanded to include non-electrical effects, and ultimately ALL forces, including gravity, by which time the name "Lorentz Electrodynamics" and "Lorentz Electron Theory" are not really very appropriate any more. That's why I suggest not listing all those names as if they were synonymous. And note that even as late as 1909 Lorentz acknowledges that
I have not been able to obtain for the equations referred to moving axes EXACTLY the same form as for those which apply to a stationary system, Einstein has accomplished this by means of new variables slightly different from those which I have introduced. I have not availed myself of his substitutions, only because the formula are rather complicated and look somewhat artificial unless one deduces them from the principle of relativity itself.
So, historically, Lorentz reach a fully relativistic theory only after recognizing how Einstein did it with the principle of relativity, which he then outlined in Note 72 in the later edition. (Granted, Poincare did much the same thing, but only formally, and without fully recognizing the consequences.) Also, many of Lorentz's later writings make it clear that he never really bought into the fully relativistic model, even though he understood it and appreciated it.SJC1 (talk) 09:50, 25 November 2007 (UTC)
You are making debatable and in fact debated arguments here (by chance, I also disagree with some of your claims). The only option is to cite opinions and to discuss what citation to include where. Harald88 (talk) 10:41, 25 November 2007 (UTC)
It is a well-established fact, acknowledged by all the individuals themselves (Poincare, Lorentz, Einstein) as well as by all scholars, that Lorentz's 1904 was not fully relativistic (see his charge current expression). This is what Lorentz was referring to in the quotation from his 1909 book which you read above, where he specifically says this. It was corrected by both Poincare and Einstein, but only by invoking the principle of relativity itself. As Lorentz said, the formula look rather artificial unless one deduces them from the principle of relativity itself, which is precisely what both Einstein and Poincare did. And as late as 1909 Lorentz still had not assimilated this into his theory - although Bucherer's results disproving Kaufmann's claims went a long way toward getting Lorentz to adopt the fully relativistic (or else "artificial looking") version of the theory. It's certainly true that people debate things like this... but no knowledgeable and qualified people debate things like this. The non-fully-relativistic aspects of Lorentz's 1904 are not opinion, they are as objectively factual as any fact can be. Hopefully this article can be based on facts as well as the informed opinions of scholars (identified as such). SJC1 (talk) 18:54, 26 November 2007 (UTC)
It's true, the priority section is problematic, but it's hard to write a passage named "LET and SR" without mentioning the prioritiy issue between Lorentz, Poincare and Einstein. --D.H (talk) 07:41, 25 November 2007 (UTC)
It seems the several Wikipedia articles contain sections named "LET and SR" or some variation of that, each presenting another opportunity for someone else to give their preferred interpretation. I guess that's okay, it just results in a lot of overlap and redundancy. SJC1 (talk) 09:50, 25 November 2007 (UTC)
Indeed, as the differences concern approach and metaphysics, overlap and imprecisions are almost unavoidable.
I now modified the intro; I left the term New Mechanics (which encompasses the different approaches and interpretations) out of the intro since it is not neccessary there and it is self-evident where it is quoted. Harald88 (talk) 10:55, 25 November 2007 (UTC)

I have access to two early reviews of Lorentz's 1904 paper, which can be used to sketch in a ñut shell how the new theory was understood upon reception. Perhaps the lead section is a good place to add one or two key phrases from these sources (Comptes Rendus and Annalen der Physik, both 1905). Harald88 (talk) 11:25, 25 November 2007 (UTC)

Both Poincare and Einstein showed in June 1905 that the statement which you attribute to Langegin in May 1905 was in error. Of course, it's possible that Langevin meant only OPTICAL experiments, but the statement as you reported it is simply wrong, as detailed later in the article, so the statement certainly doesn't belong as the ultimate statement at the end of the article lead paragraph. If you want to document each mis-statement made by Langevin (and/or each misinterpretation of your own), that should be done elsewhere. SJC1 (talk) 15:27, 29 November 2007 (UTC)
I don't "attribute" a statement to Langevin: instread I cited it. Please don't misstate matters. And if you want to cite arguments that Poincaré and Einstein "showed that Langevin's statement" was in error, please do so. In fact, Janssen explains that Poincaré was even mistaken when he thought to "correct" a few small errors of Lorentz; thus in the end, Langevin was spot-on wit his analysis. I have not seen "detailed elsewhere in the article" that Langevin was wrong, nor have I seen such an admission by Lorentz himself. To the contrary,the article points out that also Poincaré explained that "Lorentz tried to complete and modify his hypothesis in order to harmonize it with the postulate of the complete impossibility of the determination of an absolute movement".

Thus I reinsert his assessment and include a remark of the general purpose of Lorentz, as explained by Lorentz and also attested by Langevin and Poincaré. Harald88 (talk) 22:36, 29 November 2007 (UTC)

The leading paragraph only mentions "length contraction" and the MM-experiment. But I think mentioning the Lorentz transformation (which includes both "length contration" and "local time") is more important for that theory, and therefore I replaced the section

According to Lorentz ether theory, light is transmitted through a light medium in which the motion of objects do not cause dragging effects, but do cause objects to contract in their direction of motion (Fitzgerald-Lorentz contraction). This was used as an explanation of why the Michelson-Morley experiment failed to detect an aether drag effect.

and inserted that one

According to Lorentz ether theory, light is transmitted through a light medium in which the motion of objects do not cause dragging effects, because inertial reference frames are connected by the Lorentz transformation. This was used as an explanation of why all experiments failed to detect an aether drag effect.

--D.H (talk) 16:10, 29 November 2007 (UTC)

PS:I agree that the Langevin citation does no belong in the leading section. The "assessment" section might be a better place, if one insists in including that assessment. --D.H (talk) 16:16, 29 November 2007 (UTC)

OK I put it there. He was one of the few people who was up-to-date with the theory almost from the start, and he was probably the first "notable" person to write a review about the theory.
But I have a problem with your new addition in the lead section: it sounds as if it confuses the Lorentz ether with a Stokes aether! In the Lorentz aether there can be no drag by objects but there is a sort of drag of light by matter, the Fizeau drag effect. The Lorentz transformation (mathematics) did not explain the absence of drag (physics); instead, in his theory the stationary aether explained the existence of inertial frames as well as the Lorentz transformation.
Regards, Harald88 (talk) 23:29, 29 November 2007 (UTC)

OK, I changed the lead again ;-).
BTW: Lorentz himself admitted, that he wasn't able to reach complete invariance of the equations in 1904. And Poincare only said, that "Lorentz tried to complete and modify his hypothesis". But it was actually done by Poincare and Einstein in 1905. --D.H (talk) 07:54, 30 November 2007 (UTC)

Yes, sure. As I hinted at here below, Janssen and others have explained that that did not mean that Lorentz made some kind of mistake - he simply did not write down the invariant forms that Poincare wrote down, and which demonstrate that the theory perfectly fulfills the PoR. THat was not clear to me in the past, and it obviously was not clear to SJC1 when he claimed that Langevin had it wrong! Harald88 01:43, 1 December 2007 (UTC)

[edit] Assessments: for balance, also negative assessments

I have the impression that especially in later times, the assessments about "LET" turned more negative and certainly nowadays many people think that it is outdated or so. For proper balance in views, it would be great if someone could find and cite one or two of such negative views. Harald88 (talk) 23:26, 29 November 2007 (UTC)

A first suggestion by myself: cite Janssen's opinion that SRT is preferable.
On a side note: it will certainly be useful to explain in a separate section the concept of corresponding states, and the misunderstandigs about it that started with Poincaré. This is well explained in Janssen chapter 3 "common misconceptions" (near the end).
In fact, an article of this length should not miss such an essential point.
Harald88 (talk) 07:30, 30 November 2007 (UTC)

Maybe too much of Jannsen is not good for the article, but I will try to insert some other assessments. --D.H 15:58, 30 November 2007 (UTC)

Yes, that thought also came up in my mind. However, Janssen is probably the most notable modern day "LET" expert and a respected source at that; moreover, he gives an overview of commentaries of others. :-)

Harald88 13:27, 1 December 2007 (UTC) (I had forgotten to sign that)

[edit] Comments on the Latest Edits to Lead Paragraph

The latest edits to the lead paragraph, consisting of:

The purpose of his theory was to explain why no experiments had been able to detect any motion relative to the aether. According to Lorentz ether theory, light is transmitted through a light medium in which the motion of objects do not cause dragging effects, because inertial reference frames are connected by the Lorentz transformation. This was used as an explanation of why all experiments failed to detect an aether drag effect.

need improvement in my opinion. For example, the sentence

"The purpose of Lorentz Ether Theory was to explain why no experiments had been able to detect any motion relative to the ether."

is messed up in two ways. First, Lorentz's purpose was to give a satisfactory account of electrodynamics, which includes but is not limited to just the one specific fact mentioned. So it's silly to list this as "the" purpose of the theory. In fact, Lorentz began working on the theory before that fact was known or even suspected. Also, the sentence once again confuses the subject of the article. You need to decide if the article is about Lorentz's theory in the historical sense, or about the modern neo-Lorentzian theory. The above sentence is presented right after following the development through Einstein and Minkowski, so at this point is "the theory" really Lorentz Ether Theory or is it special relativity? The article concludes by saying the two are empirically indistinguishable, so why isn't this stated in the lead paragraph? The modern Lorentz theory consists of special relativity with the added metaphysical assertion that one of the reference frames is "true"? On the other hand, if the article is about the historical Lorentz theory (at various times) this is not true.

This leads to another big problem with the latest edits. The discussion of inertial reference frames being connected by Lorentz transformations leads to confusions, again because this depends on whether you are talking about Lorentz's interpretation of his theory, or subsequent modern re-interpretations of his theory. Remember, according to Lorentz, inertial reference frames are related by Galilean transformations, and we can speak of absolute simultaneity without further specification, etc., whereas the "effective" coordinates referred to in the theory of corresponding states are related by Lorentz transformations. He later understood (from Einstein) that it's possible to regard the effective coordinates as actual inertial coordinates, but he never fully embraced this view. Poincare came closer, but he never really fully adopted this view either. On the other hand, it's possible for a modern neo-Lorentzian to adopt this view... although this is perilously close to special relativity. So again it all depends on precisely what you are trying to describe in this article. It seems to jump all over the place.

I'm tempted to suggest that the article should be called something like "The Origins of Special Relativity", or maybe "An Essay on the Historical Development of the theories of electrodynamics, from the late 19th century to today". But that isn't very encyclopedic. Maybe it should be "A Survey of the Literature commenting on the development of Special Relativity and Related Theories". I don't know. The article is problematic. I also suggest you guard against just making it a Survey of Jansenn's views. He should only be about 5% of the views expressed. You should refer to at least 20 equally or more distinguished scholars on this subject (unless you want to entitle the article "Janssen's Views of History").SJC1 (talk) 07:55, 30 November 2007 (UTC)

The problem is indeed in the term "Lorentz ether theory"; it was perhaps only once used (by Ehrenfest) to indicate the difference between Lorentz's ether relativity and Einstein's non-ether relativity (I adviced and still advice to include that citation, as found in Janssen). I any case, that is also what is usually meant in modern discusions - it does not just stand for an ether idea, and it should not be confused with his older, more limited theory of electrons. Both "LET" and "SRT" mean different things for different people, and "LET" is probably the least well defined.
Also, your assertion that "if the article is about the historical Lorentz theory (at various times) this is not true", is erroneous - as Janssen and others explained. Your reaction on those explantions was that Langevin (and, consequently, also Janssen) was wrong, but that doesn't do. The only thing you can do is propose a citation of that point of view, which then must be accompanied by the counter opinion with its explanation. That is what I brought here above, about the "confusions" related to the corresponding states.
Apart of that, your assessment that there are 20 equally or more distinguished experts about Lorentz's theory is big news to me! Please give references to some others. Harald88 02:08, 1 December 2007 (UTC)
Thanks for the analysis. It's true that the historical theory of Lorentz and Poincare must be distingueshed from modern neo-lorentzian theory (although the difference is not very great). Therefore I splitted the article in an historical section, and a recent activity section, and I plan to introduce the testtheory of Mansouri/Sexl in some detail.
However, it must be said that the difference in the historical theory of Lorentz and modern derivates of LET is not as great as you suggest. For example, look what Lorentz said in 1913: In all frames of reference this one has to be preferred, in which the ether is at rest. Clocks in this frame are showing the „real“ time and simultaneity is not relative. However, if the correctness of the relativity principle is accepted, it is impossible to find this system by experiment. He went on by saying, that there is little difference between the negation of a preferred reference frame, as in the theory of Einstein and Minkowski, to his own model. So it is a matter of taste which theory one prefers.
Well that's a very good definition of a modern, neo-lorentzian interpretation of SR. For example, Mansouri/Sexl wrote (General Relativity and Gravitation, Vol. 8, No. 7 (1977), pp. 497-513):

p.500: In this theory measuring rods show the standard Fitzgerald-Lorentz contraction and clocks the standard time dilatation when moving relative to the ether. Such a theory would have been the logical consequence of the development along the lines of Lorentz-Larmor-Poincaré. That the actual development went along different lines was due to the fact that "local time" was introduced at the early stage in considering the covariance of the Maxwell equations.
p. 512: Thus the much debated question [29, 30] concerning the empirical equivalence of special relativity and an ether theory taking into account time dilatation and length contraction but maintaining absolute simultaneity can be answered affirmatively.

Of course, Mansouri/Sexl preferred SRT over LET, but the interpretation of the ether is nearly exactly the same as Lorentz's. --D.H (talk) 09:01, 30 November 2007 (UTC)
I changed the introduction to emphasize the difference between the historical theories and modern neo-lorentzian models. And a description of the test theory of Mansouri/Sexl in the "Recent activity" section is also created. --D.H 16:01, 30 November 2007 (UTC)
Two points:
1. Why did you put "neo-Lorentzian" instead of "Lorentzian"? In his textbook, Lorentz himself presented his theory as an interpretation of special relativity; should Lorentz be called "neo-Lorentzian"? :-))
2. You now brought up another discussion item in the lead: "seems to be only coincidental". Logically that should be developed in the article. If you indeed intend to include the discussion about that assessment, I can provide a citation of Ives who showed that the PoR necessarily follows from the postulate of a stationary ether together with the conservation laws.
Regards, Harald88 02:24, 1 December 2007 (UTC)

As I said, the difference between the historical and modern versions of LET is not so great. However, Lorentz and Poincare developed the theory by trying to combine the Maxwell-equations with the relativity principle (without further explanation), but in modern versions (Grünbaum, Mansouri/Sexl etc.), a stationary ether (and absolute simultaneiity) is combined with the effects of length contraction and time dilation (also without explanation). Therefore, Minkowski called length contraction within Lorentz's model ironically as a "gift from heaven", and also Einstein critisized the ad-hoc character of Lorentz's hypothesis.
PS: Mayby you can insert some information on Ives in the "Recent activity /Neo-lorentzian interpretations" section. As far as I know, Ives defined velocity dependent mass, length contraction and time dilation as absolute effects in a stationary ether - no great difference to the Mansouri/Sexl. His neo-lorentzian interpretation is also based on energy and momentum conservation. --D.H 07:56, 1 December 2007 (UTC)

Fine, but it is definitely misleading and confusing to call Lorentz's opinion "neo-Lorentzian".
I'll try to add something to "neo(?) Lorentzian interpretations" later, when I have more time.
Regards, Harald88 13:25, 1 December 2007 (UTC)

I haven't invented the term "neo-lorentzian" ;-). But it's commonly used by many people - for example look at this article: Presentism and Relativity. Well, some people called themselves "Lorentzians", and others "Neo-lorentzians". But those are only words, which isn't very important, I think. --D.H 14:48, 1 December 2007 (UTC)

[edit] Langevin again

The statement of Langevin in his 1905-paper, that Lorentz arrived at "the physical impossibility to demonstrate the translational motion of the earth", is not correct, as pointed out by Poincare and Lorentz himself. However, I put the citation into the Lorentztransformation paragraph and wrote:

One of the first assessments of Lorentz's paper was by Paul Langevin in May 1905. According to him, this extension of the electron theories of Lorentz and Larmor led to "the physical impossibility to demonstrate the translational motion of the earth". [23] However, as shown by Poincaré on 5 June 1905, Lorentz didn't succeeded completely to show that the laws of electrodynamics were form-invariant.

I don't know if his 1911 paper should be mentioned in the article, although it's interesting, because it contains the first formulation of the twin paradox. --D.H 07:32, 4 December 2007 (UTC)

NO, it is wrong to state that Langevin's assessment was not correct, as both Lorentz himself stated and Janssen and others that he referred to explained that Lorentz's theory did arrive at that - and as pointed out here above by me in my comments of last week! Please study the last part of Janssen and don't put words in Lorentz's mouth that he didn't say. According to them, Lorentz simply did not succeed in showing that the laws of electrodynamics were form-invariant - and in fact, it wasn't even clear to himself at that time. THus your rephrasing is correct but the emphasis is wrong, as well as the removal from assessments.
Langevin's paper was a strong support for LET (IMHO, one of the strongest arguments in its favour ever written) - that it also contained what would become the "Twin paradox" for those who rejected LET is of secondary importance for this article.

Harald88 (talk) 23:16, 9 December 2007 (UTC)

Not every scholar has the same opinoun as Jannsen. Lorentz clearly wrote in 1921:

I was not able to achieve total invariance of the equations; my formulae remained cluttered up with excess terms, that should have vanished. These terms were too small to influence phenomena noticeably, and by this fact I could explain their independence of the Earth’s motion, revealed by observations, but I did not establish the relativity principle as a rigorous and universal truth. On the contrary, Poincaté achieved total invariance of the equations of electrodynamics and formulated the relativity postulate — a term first introduced by him . . . I may add that, while thus correcting the defects of my work, he never reproached me for them.

Lorentz used the words "defects of my work". And BTW: I think that Jannsen was unaware of the 1921-paper of Lorentz.--D.H (talk) 07:46, 10 December 2007 (UTC)

Unpublished personal material is not allowable for Wikipedia, and "to have cluttered formula's isn't an error. However, I find the admission by Lorentz of "excess terms, that should have vanished" and "too small to influence phenomena noticeably" rather convincing evidence that he indeed agreed with Poincare.
Still, one or two errors don't make a theory wrong; while if it would be so, then Einstein's 1905 paper should be similarly rejected since that one contains big errors such as for relativistic mass. Similarly, Poincaré himself stated in the same paper in which he perfected Lorentz's paper:
"The essential point, established by Lorentz, is that the electromagnetic field equations are not altered by a certain transformation, which I will call by the name of Lorentz".
Thus it remains a judgment call, and a matter of weighing with the same measures (=NPOV).
As Lorentz and Poincare are cited, adding the assessment of Langevin in its proper place will help the readers to understand that "LET" vintage 1904 already contained the basic elements of relativity theory and that this had been mentioned in the French (CR) and German (Beiblätter) literature before Poincare and Einstein came with improvements.
In addition, it should also be made clear that already Poincare 1904 refers to Lorentz 1904, eventhough it wasn't a review of Lorentz's paper but some strong and inspiring preliminary comments based on it.
Harald88 (talk) 23:53, 10 December 2007 (UTC)

[edit] another suspect uncited statement

"So Einstein thought it was necessary to replace Lorentz's theory by another one".

I think that that is wrong and claimed by nobody, so I added a tag. As far as I know, Einstein always claimed innocence of knowledge of Lorentz's 1904 paper at the time of his 1905 paper and he also suggested not to know of Poincaré's 1904 and 1905 papers. Moreover, in 1907 he even referred to both his paper of 1905 and that of Lorentz of 1904 as describing the basics of the new theory.

Note also that it's biased to present negative opinions about the length contraction hypothesis ("ad hoc") and not the positive counter opinion of Lorentz ("not ad hoc").

Harald88 (talk) 23:02, 9 December 2007 (UTC)

It's not uncited. Einstein himself said this, look at Ref. 66 (1907), where he wrote: "Es hatte daher den Anschein, als ob die Lorentzschen Theorie wieder verlassen und durch eine Theorie ersetzt werden müsse, deren Grundlagen dem Relativitätsprinzip entsprechen".
Unfortunately, in the next weeks I have not time to make edits on this page. Merry Christmas to you --D.H (talk) 07:39, 10 December 2007 (UTC)
1. It was uncited in the article. And if you add that citation, it is misleading: "die Lorentzschen Theorie" points in that article to Lorentzian Electrodynamics ("H. A. Lorentzsche Elektrodynamik") and not to Relativity. Both Lorentz and Einstein agreed that Lorentzian Electrodynamics needed to be replaced by a new theory. Thus that sentence must be rephrased accordingly.
Note: I now notice that Einstein did not emphasize the difference between Lorentz 1904 ("LET") and Lorentz 1895 ("Lorentzian Electrodynamics"). It's however clear when taking into acount that he discusses Kaufmann's paper which also cites both Lorentz 1904 and Einstein 1905, and by adding emphasis:
"Im folgenden ist nun der Versuch gemacht, die Arbeiten zu ein em Ganzen zusammen zu fassen, welche bisher aus der Vereinigung von H. A. Lorentzscher Theorie und Relativitätsprinzip hervorgegangen sind. In den ersten beiden Teilen der Arbeit sind die kinematische Grundlagen sowie deren Anwendung auf die Grundgleichungen der Maxwell-Lorentzschen Theorie behandelt; dabei hielt ich mich an Arbeiten von Lorentz (1904) und Einstein (1905)."
That example by Einstein was followed in the first publication of the collection of papers "Lorentz et al, The Principle of Relativity".
2. The "ad hoc" in that article similarly referrs to length contraction in Lorentzian Electrodynamics (1895); apparently Einstein cites there the argument that Poincare made against that older theory, and to which the New Mechanics / Special Relativity was an an answer.
4. For neutrality Lorentz's opinion of the non-ad-hoc nature of length contraction must be cited as well.
3. Have a nice vacation!
Harald88 (talk) 23:06, 10 December 2007 (UTC)

[edit] Admitted bias by commentators

It will be useful to express the admitted or obvious bias of the cited secondary sources. For example Darigol, despite the fact that he may well be one of the least biased commentators, admits to have an "Einsteinian" philosophical bias which indeed affects some of his commentaries in an obvious manner. Harald88 (talk) 23:24, 9 December 2007 (UTC)

[edit] Editorial: Shift to SRT, Assessments and Priority

- It appeared as if Assessments of LET was instead about assessment of the shift to SRT. What matters most for an article on a topic (LET) is assessment about that topic and not about the shift to a variant of it. Thus I made the assessment independent of the Shift to SRT topic.

- As discussed before, priority issues are discussed elsewhere. Worse, by splitting assessments up into assessments and a sub topic about priority issues, much that also belongs in the assessments main is now under priority. Thus it will be better to move everything that belongs under assessments out of priority, and to keep priority as short as possible and with a link to the corresponding article.

- Assessments that arguably are not about LET don't belong there, in particular not if no secondary source makes that claim.

83.76.119.112 (talk) 07:49, 11 December 2007 (UTC)


[edit] Ives's Misunderstanding

Harald says "To highlight the value of the LET interpretation [Ives] published a paper that describes how the Lorentz transformations necessarily follow from classical space and time concepts in combination with the laws of Maxwell and the conservation laws." This is simply wrong, and it is well known to be wrong, and the wrongness of it can be verified in innumerable reputable sources. Only anti-relativity cranks fail to understand Ives's mistake, which isn't surprising, since it's the same mistake they themselves have based their lives upon. The mistake (for the benefit of any non-crank who may read this) is that the Lorentz transformations of space and time do NOT follow from the laws of electromagnetism, because there are other forces of nature (gravity and the strong and weak nuclear forces) that do not satisfy the laws of electromagnetism, and yet are Lorentz covariant. Obviously the Lorentz covariance of non-electromagnetic forces does not "necessarily follow" from the laws of electromagnetism. Furthermore, even electromagnetism is now known not to be governed by Maxwell's equations, a fact which was already apparent in 1900 with Plank and the ultra-violet catastrophe, and even more clear in 1905 with Einstein's quantum photon, and utterly clear today (in 2007) with the well established quantum electrodynamics. Hence, the premise of Maxwell's equations was incorrect, and even if it had been correct, it was clearly insufficient to serve as the basis for space and time transformations. For Lorentz the transformed t and x were derived only for Maxwell's equations. For everything else (e.g., mechanical inertia) Lorentz and Poincare simple and explicitly ASSUMED Lorentz covariance. They finally realized that this assumption (relativity) was necessary and unavoidable to fully account for the inability to detect absolute motion. But, having labored for decades only to arrive at the necessity of this assumption, they were surprised to learn that it was also fully sufficient. All the other deductive labor prior to the assumption of relativity was superfluous, because once you assume relativity, all the rest follows. In other words, the idea espoused by Ives's and his ilk is totally false, and is well-known to be false. It would be helpful if editors of this article at least educate themselves to the point where they understand this. SJC1 (talk) 22:45, 11 December 2007 (UTC)

There are many assertions in the above emotional discourse, even the suggestion that a famous scientist and the reviewers of the journal in which he published were "cranks". In any case, the above claim that my abovementioned paraphrase about Ives is "simply wrong" was not supported by any reference, and the arguments dealt with a truncated version of that sentence: nowhere was it claimed that the "Lorentz transformations follow from the laws of electromagnetism". And perhaps SJC1 meant that I should have written "according to Ives"? That is easily fixed! :)
Imperfections are no excuse for the deletion of a reference. Thus I reinsert that paragraph. Harald88 (talk) 17:53, 29 March 2008 (UTC)

[edit] Expansion -2

I've expanded the sections "Principles and conventions", "The shift to relativity" and the "Bibliography". Some of the assessments of Poincaré and Lorentz were moved into the sections "Principles and conventions" and "The shift to relativity". Also the section "mass-energy-equivalence" is moved into the relativity section. Some corrections in the sections Lorentz-transformation (charge density, four-dimensional space) and some minor corrections (style, references) in other sections were made.--D.H (talk) 15:49, 29 December 2007 (UTC)

[edit] Relativity priority dispute

I moved the priority section into the article Relativity priority dispute. There seems to be the correct place. --D.H (talk) 17:33, 15 March 2008 (UTC)

[edit] original research deleted

I made the description of Ives' neo-Lorentzian theory more to-the-point by removing irrelevant (and rather misleading) comments about his opinion on other interpetations - that section is about neo-Lorentzian interpretations and not about other ideas or claims by Ives or about Einstein's interpretation. I also deleted new original research that was phrased as follows:

He published a paper in which he asserted (erroneously[2]) .

Clearly the reviewers of Ives' paper disagreed with the abovementioned claim; and certainly Lorentz did not comment in 1909 on Ives' paper! I have read Ives' paper and I disagree with calling it a "derivation": I would call it a deduction. However, I found no errors and I know of no exisiting paper that makes such a claim - to the contrary! Other scientists such as Emmy Noether have also emphasized that everything follows from the conservation laws - and to make that clear we could add a reference to such a paper, but then again, it's not really to the point. I now found http://www.eftaylor.com/pub/symmetry.html but I haven't read it. Harald88 (talk) 17:54, 19 April 2008 (UTC)

Note: it was only after the inception of relativity theory that the inertia of energy became well understood. That knowledge was used in Ives' derivation. Harald88 (talk) 19:18, 19 April 2008 (UTC)

[edit] Problems with "Later Activity" Section

The section entitled "Later Activity" at the end of the article seems mis-labeled and out of place. It consists of just three topics, a summary of Herbert Ives' ideas, a mention of a parameterization for characterizing Non-Lorentzian theories, and a discussion of breaking Lorentz symmetry. The latter two are explicitly NOT taking about Lorentz ether theory, so they don't really belong in the article. The first, discussing Herbert Ives, is not really notable as "activity" on Lorentz ether theory, but only as opposition to special relativity. Ives was not a significant scientific figure, nothing he wrote was new, and articles published in the Journal of Optics do not constitute scholarly research papers in fundamental physics. In summary, I would say the entire last section should be deleted, until someone can provide some actual content pertaining to actual recent activity on Lorentz ether theory.Denveron (talk) 04:41, 4 May 2008 (UTC)

As Robertson said, Ives theory (which included a preferred reference frame) is only a complicated form of SR and therefore it seems to be a good example of a lorentzian interpretation of SR. So why not mention it? And Mansouri/Sexl themselves say that their test theory is "along the lines of Lorentz-Larmor-Poincaré". However, I agree that the last section on symmetry is unnecessary, therefore I deleted it. --D.H (talk) 08:46, 4 May 2008 (UTC)