Talk:False Doppler

A Suggestion for Resolving this Disputed Article
If anyone can cite a single reputable source for the term "false Doppler", then that source should be listed in the article, and the article content should be based on that source. Wikipedia has rules against original works and essays. If no one can cite such a source, then this article is clearly in violation of the "original research" prohibition, and does not belong in Wikipedia. &mdash;The preceding unsigned comment was added by 63.24.109.103 (talk &bull; contribs) 17:52, 19 November 2005.

Any References for "False Doppler"?
The second AfD vote was predicated on statements that can very easily be verified to be false. For example, the original AfD pointed out that the term "false Doppler" was fabircated by Mr. Baird, and that a Google search turns up ZERO relevant hits, provided you don't count the hundreds of mirrors of this Wikipedia article itself, and provided you don't count things like "an airplane reported a false doppler indication of a storm", which obviously is not relevant.

Now, in the recent AfD, a Bairdian says "Fact: There are 314 hits on Google for "False Doppler". Well, if you take 10 seconds to check (which apparently none of the voters took the trouble to do), you will find that the original statements about this were correct... there are ZERO relevant hits. The Bairdian is just counting mirrors of this Wikipedia page itself, plus the weather related hits, all of which he have nothing to do with this subject. Moreover, the Bairdian KNOWS that these hits are not relevant, and yet he made the claim anyway. It's really too bad that Wikipedia has no effective mechanisms for dealing with cranks like Baird.

AfD result
This article was the subject of a second AfD in November, 2005. The result was strong consensus keep after rewrite and nom. withdrawl. Xoloz 17:25, 12 November 2005 (UTC)
 * I'm glad to see this article has returned to normal. Keep up the good work! Durova 04:46, 15 November 2005 (UTC)

Deletion discussion
Article kept after previous AfD. See: Articles for deletion/False Doppler --HappyCamper 21:01, 2 October 2005 (UTC)


 * I don't agree with removing Eric Baird's name from this article. This article was created by Eric to express his particular point of view of the Doppler effect, and he created the term "false Doppler" to suggest that the scientific community doesn't understand or is confused about the Doppler effect. It is not a historical term. It is misleading to present the term without stating up front where it came from. Of course, as soon as we state where it came from, it raises the question of why there is a Wikipedia article about it. Good question.

A review of Erk's contributions to Wikipedia shows that he has created a whole batch of articles all trying to smuggle in his own "theory" of the Doppler effect, under various names. All of them are patently POV. None of them contain suitable content for Wikipedia articles. Needless the say, the sensible thing is to simply delete this article, since there is no such thing as "false doppler", but since the motion to delete the article failed, we ought to at least be honest and present it for what it is: an essay by Eric Baird on his own particular POV of science (a POV which happens to be misguided and erroneous according to consensus scientific opinion). Same goes for the Erk articles "Accoustic Doppler", "Doppler Equations", "Spatial Doppler Effect", "Lorentz Term", "Classical Theories and Relativity", and probably others that I haven't noticed.


 * The current version of this article is not bad, but only because it has been completely re-written from the original "Erk" version. The only problem with the current article is that it essentially consists of an explanation of why there is no such thing as "false Doppler". So it's like having an article on "blidgetous moons" and then explaining in the article that there's really no such thing, and we just made up that expression.130.76.32.16 14:22, 6 October 2005 (UTC)
 * Wow thats a good idea for an article! --The Minister of War 22:03, 6 October 2005 (UTC)

If you are serious that this article does not represent normal scientific values, then perhaps it and other articles need to be categorised as Pseudoscience ?? Ian Cairns 17:31, 7 October 2005 (UTC)

Why Eric Baird's Articles Violate Wikipedia Policy
I don't think it rises to the level of pseudoscience. All these articles by Eric Baird are just surreptitious attempts to smuggle some of his misunderstandings into Wikipedia. I just think it's a shame that crackpots like Erk are slowly but surely taking over Wikipedia. You have only to look at the volumes of crackpot nonsense he has just written (see below) in "defense" of his articles, to see how pointless it is to try to "reason" with such people.

The only viable way of dealing with physics cranks is by strictly enforcing the Wikipedia policy. Here it is again:

Quote of Official Wikipedia Policy:

Wikipedia's founder, Jimbo Wales, has described original research as follows: The phrase "original research" originated primarily as a practical means to deal with physics cranks, of which of course there are a number on the Web. The basic concept is as follows: It can be quite difficult for us to make any valid judgment as to whether a particular thing is true or not. It isn't appropriate for us to try to determine whether someone's novel theory of physics is valid; we aren't really equipped to do that. But what we can do is check whether or not it actually has been published in reputable journals or by reputable publishers. So it's quite convenient to avoid judging the credibility of things by simply sticking to things that have been judged credible by people much better equipped to decide. The exact same principle will hold true for history" (WikiEN-l, December 3, 2004).

'''The phrase "original research" in this context refers to ... any new interpretation, analysis, or synthesis of published data, statements, concepts or ideas that, in the words of Wikipedia's founder Jimbo Wales, would amount to a "novel narrative or historical interpretation".'''

'''If a viewpoint is held by an extremely small (or vastly limited) minority, it doesn't belong in Wikipedia ... regardless of whether it's true or not; and regardless of whether you can prove it or not.'''

What counts as a reputable publication?

Reputable publications include peer-reviewed journals, books published by a known academic publishing house or university press, and divisions of a general publisher which have a good reputation for scholarly publications.

End quote

response to call for deletion
Well, while I'm touched that some people here seem to want to attribute this effect to me, it was actually mentioned by Oliver Lodge around the turn or the 19/20th Century, where he referred to the shift effect that should be expected from a transverse-aimed detector as " ... a spurious or apparent Doppler effect." (1909)..
 * Oliver Lodge, “Aberration Problems,” Philosophical Transactions of the Royal Society (1893) sections 56-57
 * Oliver Lodge, The Ether of Space (Harper & Brothers, London, 1909) chapter X


 * All you have done here is to confirm that you, in fact, made up the term "false Doppler". By the way, no one has attributed "this effect" to you. "This effect" is nothing but the classical Doppler Effect, taking the classical aberration correctly into account. The Doppler effect is attributed to Doppler; aberration was discovered by Bradley. The only thing attributed to Eric Baird is the fictitious name and a muddled pseudo-explanation for these things. 63.24.47.44 16:05, 8 October 2005 (UTC)

Once you investigate this subject, its actually fairly straightforward:


 * Wikipedia is not the place for Eric Baird's "investigations" .63.24.47.44 16:05, 8 October 2005 (UTC)


 * For emission theory, or for an aether moving with the signal source, the expected redshift is f'/f = 1- v^2/c^2 … in other words, it’s what we would now consider to be a "Lorentz-squared" redshift, stronger than the effect that we predict using special relativity.


 * For a stationary absolute undragged aether, there's no effect.
 * For an absolute aether moving at an intermediate speed between that of the observer and emitter, the redshift should be somewhere between zero and Lorentz-squared.
 * For a fully- or partially-dragged aether, again, the redshift calculation should give an outcome somewhere in this range, between zero and Lorentz-squared.

Hence, according to almost any model that was considered half-credible in the C19th, modern experimental equipment designed to identify the SR transverse redshift effect should indeed report a redshift, but not because of any SR-specific time dilation effects.


 * You seem to completely misunderstand the whole subject, and all the terms involved. For example, the term "transverse Doppler effect" is just the traditional name for the time-dilation component of the Doppler formula. It happens to come from the "transverse" condition when classical theory predicts no frequency shift and special relativity predicts some, but it is understood that "transverseness" is relative, so this condition is not transverse with respect to all frames of reference, and there are other conditions that are transverse with respect to other frames of reference. Regardless of the angle, the relativistic Doppler formula in general differs from the classical formula in the second order of v/c, and this difference can be observed in suitable conditions at any angle, including purely longitudinal arrangements. In fact, one of the most important tests of "transverse Doppler" was purely longitudinal (Ives-Stillwell). Please note that these tests are not just Yes/No tests (frequency shift or no frequency shift), it is understood that in general there is a frequency shift for both classical and relativistic theories (aside from special cases). These predictions differ in the second order, and it is this small difference that is checked to test for the relativistic "transverse Doppler". This is all perfectly trivial to anyone who understands it. Since you clearly don't understand it, maybe you are not the ideal person to be writing encyclopedia articles about it. Just a thought.

All of this is deterministic mathematics: there's no obvious POV aspect to the math that I can see, these are simply the predictions that these sorts of theories will make in these circumstances. Historically, this seems to have been recognised at the time, by Lodge, and hopefully also by any other physicists at the time working with light-propagation problems – as the worked example shows, it's really only introductory-level physics. I might even be giving Lodge unfair credit here because I was only looking for texts in English, and much of the serious work on light-propagation models around this time had been done on the continent and published in French or German.

Too trivial? Yes, the effect is trivial, in the sense that it doesn't require any new physics or ideas, and the math is straightforward. The working was meant to demonstrate that. However, it only appears to be trivial to some physics people after it's been carefully explained to them. If the argument now looks obvious to you, ask yourself how some of those supplied quotes got into print, and whether they might have seemed reasonable to you before reading this article. Hindsight is a wonderful thing.

Importance: Overlooking this effect has had unfortunate consequences for some experimental tests of SR, it means that some experiments that probably could have produced convincing evidence for or against SR didn't end up telling us very much about whether SR really was more accurate in this respect than a broad range of older theories. There was a string of announcements from experimenters that the "transverse redshift" effect was real ... of course it was real, the question should have been not so much, "is it there", but "which one is it"? Is it a single Lorentz redshift, or a Lorentz-squared redshift, or something else?


 * Eric, this demonstrates (once again) that you have absolutely no idea what you're talking about. All the tests of the so-called "transverse Doppler effect" predicted by special relativity have specifically been checking the magnitude of the frequency shift, not just the presence or absence of a shift. It is well known (and totally obvious) that some amount of frequency shift is predicted by both the classical and the relativistic theories. Needless to say, both theories have a "null" condition where the shift changes from red to blue, but this occurs at different conditions for the two theories. In general, the predictions of classical theory and special relativity differ only in the second order in v/c, i.e., the difference between "gamma" and "gamma squared". Even for purely longitudinal condition the classical and relativistic predictions differ in the second order. It is this second order difference that represents the "transverse Doppler effect", and it has been shown with very good precision that the classical prediction is wrong and the relativistic prediction is correct.
 * Eric, if you really fail to understand this, you are not qualified to be authoring encyclopedia articles on the subject. 130.76.32.16 14:56, 21 October 2005 (UTC)

So: a lot of these experiments generally considered to be supporting SR are almost useless as they are now, and can't safely be reanalysed retrospectively for a wider range of possible outcomes, because of the limitations of the test theory that they were performed under, and at some point they are probably going to have to be done again. That's frustrating.

Article name: No, I wasn't really happy with the name "false Doppler" either, but I thought that that's what Lodge had called it and I was trying to stay close to the contemporary usage. I'm guessing that he chose to present it as a "spurious" Doppler effect to avoid kneejerk objections that a transverse-moving object couldn’t possibly show a conventional Doppler redshift, by definition. So the "false Doppler" name was NOT me trying to be "nasty" to physics people or score points, it was me trying to be tactful, following Lodge's example.


 * You are operating under numerous profound misunderstandings, which you are trying to smuggle into Wikipedia under the guise of "tactful" articles presenting your misguided view of the ordinary Doppler and aberration effects. 63.24.47.44 16:05, 8 October 2005 (UTC)

Myself, I much prefer the term "aberration redshift" as a casual descriptive phrase – it seems to be self-explanatory, but, again, some people would probably see it as an attempt to invent a new technical term, so I stuck with the clumsier "false Doppler". If at some point all those old C19th textbooks end up scanned and OCRed and Googled, perhaps we can sift through them online and find another (better) historic name. But that might be some years off. 'Til then, Googleability isn’t (yet) an ironclad test for historical usage.

We could call it "Redshift effects under pre-SR theory, due to aberration, that are difficult to distinguish from SR's transverse Doppler effect", but that's too long. It could be shortened to "pseudo-transverse Doppler effect", but then someone's probably going to complain that "pseudo-transverse" isn't a generally accepted term, either. Any ideas, anyone?


 * This is one of your misunderstandings. These effects are not difficult to distinguish from the special relativistic effect. If your physics education was so poor that you find these effects surprising, then you should work to improve your physics education. You should not create Wikipedia articles implying that everyone else's physics education is as poor as yours. Wikipedia is not the place for personal essays on physics (yours our anyone else's). 63.24.47.44 16:05, 8 October 2005 (UTC)

Original research?: No, not unless going to a good physics library and looking up old reference material (or bothering to actually try the calculations instead of taking them on trust) counts as original research. I don't think it does.


 * That's not the kind of "original research" that is at issue here. This article qualifies as original research because it is your own POV on the history of physics and what you believe to be confusion on the part of real scientists. You are free to write essays about this, but you should not post them as Wikipedia articles. 63.24.47.44 16:05, 8 October 2005 (UTC)

What useful purpose does this article serve? Well, if some fairly recent teaching on a subject has been wrong, then that deserves an article setting things right and explaining. An encyclopedia should try to correct mistakes rather then perpetuate them.

I think that that "normal scientific values" should dictate that when a fairly simple issue turns out to have been misunderstood and misrepresented to the extent that a lot of serious experimental work on the subject gets damaged, one is obliged to mention the issue for the benefit of the next generation of researchers and experimenters so that they don’t go out and make the same mistakes as the last. ErkDemon 07:54, 8 October 2005 (UTC)

overlap with SR
rewritten by someone else: "'This should not be confused with the transverse Doppler effect in special relativity, which occurs when the distance between the emitter and receiver is actually not changing, i.e., it is a truly transverse effect, due to time dilation. This is a uniquely relativistic effect, which has nothing to do with combined effects of classical Doppler and aberration discussed in this article.'"

No, that might be an understandable assumption to someone brought up with a standard SR syllabus, but its not really true when you look at the math.

Special relativity lets us obtain the same final physical predictions regardless of which frame we treat lightspeed as being constant in, yes?

So, if we assume that lightspeed is fixed in the observer's frame, we say that there's no propagation redshift effect, and the visible trnasverse redshift is 100% due to the time dilation of the moving source.

But it's also legitimate to assume that the speed of light is fixed in the emitter's frame. This gives us a stronger calculated aberration redshift effect of f'/f = 1 - vv/cc We then say that since the observer is now described as "moving", their clocks are time-dilated, and as a result they see everything to be blueshifted due to their relative motion and their reference clocks being slow. Multiplying the two effects togrether then gives a final visible shift of

(1 - vv/cc) * 1/SQRT[1- vv/cc] = SQRT[1 - vv/cc]

, in other words, a single Lorentz redshift, as before.

Under SR these two descriptions are indistinguishable and interchangeable, so, the same redshift that you normally calculate as being due to time dilation in one exercise is actually a stronger redshift due to aberration in the other (partly cancelled by a Lorentz blueshift). With a suitable backward use of a velocity-addition formula, you can even claim that lightspeed is fixed in an intemediate frame, and that the entire effect is a simple propagation effect due to aberration, with time dilation playing no part at all (observer and emitter both nominally moving at the same speeds, and nominally time-dilated by the same amount) - the SR magic still works.

But in order to understand how these different explanations can coexist under SR, one really has to understand the aberration redshift effect, SR's ability to use multiple descriptions in different reference frames and obtain the same physical outcome with each description doesn't work without it.

So, a statement that the two calculations should not be confused, and that one has nothing to do with the other, is not borne out by the structure of special relativity. It's a brave bluff, but under SR, the two effects are deeply intertwined. ErkDemon 08:24, 8 October 2005 (UTC)

Why Eric Baird's Articles on Doppler are Incorrect
For an emitter moving with velocity u and receiver moving with velocity v relative to a system of reference in terms of which the signal velocity C has the same magnitude in all directions (which implies u=0 for an emission theory), the full Doppler effect is

f'/f =  {[1 - C*v/|C|^2]/[1 - C*u/|C|^2]} sqrt([1-u^2]/[1-v^2])

where * denotes the dot product and units are chosen so that the speed of light in vacuum is 1. The part in curly brackets is the classical Doppler effect (including all the things that seem so mysterious to Eric Baird), and the square root factor is the relativistic contribution. This is the difference between classical Doppler and relativistic Doppler. It is clear and simple, and if Eric Baird is confused about it, he should not take it as an ocassion to write a flurry of Wikipedia articles to advertise and perpetuate his confusion.63.24.47.44 16:21, 8 October 2005 (UTC)


 * You continue to miss the point, Eric. Wikipedia is not a forum for you to discuss your own personal ideas on physics. The Wikipedia policy recognizes that people who are inclined to post POV articles need to be kept out of Wikipedia (as much as possible), and that this cannot be done by arguing, because crackpots LIVE to argue endlessly, and very few Wikipedia editors are qualified to distinguish sense from nonsense in areas of physics and mathematics. So, the Wikipedia policy is simply to reject articles that amount to personal essays - regardless of whether they are correct (because crackpots with argue endlessly that they are correct). This article on "False Doppler" (a term which you made up) is just one of your own personal essays, trying to insinuate that special relativity is wrong and/or is just a misunderstanding of classical emission theory, and you try to disguise these insinuations to an extent that the average Wikipedia editor won't immediately recognize them. The same is true of all the other "Doppler" articles you have originated (proliferated).


 * The content of your essays that is factual is already covered in other, more appropriate, articles. All the content that is just your "investigations" and re-interpretations of history is inappropriate for Wikipedia.63.24.119.167 06:31, 10 October 2005 (UTC)


 * No, when you say "The content of your essays that is factual is already covered in other, more appropriate, articles." that might look as if you are talking confidently from a position of personal knowledge ... but a scan of Wikipedia.EN suggests otherwise.


 * Since the "transverse Doppler" page has been mentioned, I did a Wikipedia search this morning for all the other articles containing the term "transverse Doppler" and the total number of pages ... was three. Take away this article, and the "transverse Doppler" and "Doppler equations" articles, and the hit count on Wikipedia for "transverse Doppler" drops to zero. Not only does the term not seem to have been discussed in existing articles before I got to work, it doesn't seem to have existed on Wikipedia at all. So if someone wanted to look up "transverse Doppler" on Wiki, and typed it into a search box, without these pages: zero hits. ErkDemon 08:40, 18 October 2005 (UTC)

Defining New Terms - e.g., "False Doppler"
There is an explicit Wikipedia policy against defining new terms. This entire article is nothing but an attempt to define a new term, namely "false Doppler", which Mr. Baird admits he simply made up. In fact, he even goes on to say that he doesn't really like the expression, and would prefer to define yet another new term ("aberration redshift", or something like that). Clearly this article is not consistent with Wikipedia policy, and clearly Mr. Baird does not understand that policy.

There is already a Wikipedia article on the Doppler Effect, and that's the right place for information on the Doppler effect, if anyone wants to contribute. The entire Doppler effect, including the effects of aberration and special relativistic time dilation can be expressed in a single equation, which is quite well understood, but Mr. Baird has created a whole series of alternate narratives in separate articles, all expressing his own personal point of view, including


 * Doppler Equations
 * Spatial Doppler Effect
 * Accoustic Doppler
 * Lorentz Term
 * Classical Theories and Relativity
 * Transverse Doppler

The article on "Lorentz Term" is a good example of the problem posed by Mr. Baird. There was already an article on the "Lorentz Factor", and Mr. Baird created an alternate article called "Lorentz Term". The only apparent purpose for creating these alternate articles is to provide a venue for Mr. Baird's own personal essays on these subjects. The article on "Spatial Doppler Effect" is another example of Mr. Baird making up new terms. He cites as the source of this term a statement that someone once made that certain optical effects are the spatial analog of the Doppler effect. This isn't sufficient to justify making up a new term and creating a Wikipedia article about it. The essay on "Classical Theories and Relativity" is quite clearly POV. And so it goes. The only one of the bunch that could be acceptable is "Transverse Doppler", but even that would be better covered by the existing article on the Doppler Effect. All the rest should either be merged into a single article on the Doppler Effect (to the extent that the material is factual and verifiable) or deleted.

To merge or not to merge, that is the question== ==

Merge to "Doppler effect"? Nooooo! At least, not yet.
I would suggest that if anyone is thinking of merging all the existing Doppler articles together that they hold off on making that decision until all of the articles in question are mature and thorough and have had all their NPOV disputes thrashed out. Otherwise, imagine what a nightmare of disagreements and edit wars we might get in the merged article! Once all the individual articles have been expanded and polished, you might still want to consider merging them, but if the individual articles have been expanded sufficiently by then, and have lots of references each, then perhaps a merged article would be too big and clumsy, and perhaps at that point, the "Doppler effects" category might do a better job of letting people find the specific information that they want more easily. Part of the joy of hypertext is the ability to cut through rigid hierarchical structures and instead have a series of multipurpose articles that can be organised and arranged according to multiple schemes simultaneously (a single article can be in several overlapping categories at once). That way, someone working on medical Doppler applications and reading a piece on Doppler bloodflow measurement can follow a link to the appropriate equations or principles without finding themselves looking at a page that contains masses of information about special relativity and cosmology: Likewise, with separate articles organised via categories, a special relativity student can look at the "special relativity" category and pick out articles on relativistic Doppler and transverse Doppler without wading through a monster article full of material about acoustics and the precise sound-reflecting properties of red blood cells, when all they want to do is look up a couple of SR equations.

If one is a specialist, it is tempting to decide that a large subject ought to be ordered in a particular way, according to the priorities in one's own research field: A cosmologist might want a merged Doppler page to stress Hubble shift, while a medical technician might consider cosmology to be a useless subject and cite statistics to show that most recent research papers on Doppler effects have been about bloodflow, which actually saves lives (unlike cosmology), another physicist might think that its obvious that transverse Doppler effects and the relativistic Doppler equation ought to be given pride of place, and so on. Smaller specialist articles branching off from one central article makes things more flexible, avoids POV ordering disputes, and also encourages people to add more detail and references to the individual specialist pages.

Merge to "Transverse Doppler"?
Having said all that, with this article, I agree that there's a definite "issue" about what on earth to refer to the effect as, and since it seems that significant numbers of people have missed the original article's point, perhaps some sort of detailed discussion about the different meanings of "transverse" used in comparative theory is in order to make it intelligible to a larger number of people. And a discussion of "transverseness under SR" probably belongs on the "transverse Doppler" page, along with the quotes about transverse effects that have already been deleted by someone from this article.

So I tell you what I'll do: Instead of rewriting this page and repairing all the dodgy edits (and there have been some real clunkers!), and renaming it, I'll merge the core of these arguments into the "transverse Doppler" page.  But not yet: The transverse Doppler page needs enlarging first, otherwise these arguments will take up a disproportionate amount of that article, and I'd be accused of "hijacking" the transverse Doppler page for my own supposedly-evil ends and turning into a "vehicle" for something. :( When people are determined to see ulterior motives and bad intent, they tend to do so no matter what one does. :(

And it seems that not everyone here is yet satisfied that the pre-SR lab-transverse redshift result is correct, so perhaps I should wait until we've at least thrashed out a consensus on the mathematical validity of the thing here, before moving the argument to the Transverse Doppler page. Hopefully that won't take long. We don't have to agree about the significance of the result, just that it's right. Then we'll have a nice clean TD discussion page, with a link back to here for the pre-SR theory discusions.

For anyone wondering why I didn’t just append these arguments to the "transverse Doppler" page to begin with, well, there wasn't one, and if I'd written a transverse Doppler article that was just about this pre-SR effect, then I think people would have been justified in being upset. If I'd added information that some would see as not supporting SR to an existing "Doppler effect" page which didn’t yet even mention any SR effects, that could have been argued as making the Doppler article unbalanced. So after writing this page, I wrote a small "transverse Doppler" stub, then waited for someone else to come along and enlarge it, so that the piece on this side of mainstream theory wouldn’t be written by just me. But it didn't grow much. So I guess I'll have to grudgingly enlarge it myself, and then merge the core of this article into it, as some sort of postscript about the comparable physical predictions of pre-SR theories.

So, at this current time, I guess that's the plan. To leave this badly-mangled page "parked" here, uncorrected, until the "transverse Doppler" page has grown large enough to accept it as a small add-on rather than as a dominant section. ErkDemon 06:37, 17 October 2005 (UTC)

terminology
Shouldn't the term "special relativity" be instead 'spatial relativity'? A Doppler Effect as compared to a False Doppler Effect involves the effects of space placement upon light emisions as measured. [As somewhat of a down-to-earth analogy, there are roasted fowl and then there is the alarming 'spatch-cocked' contrivance] 11/25/2005  19:16, 25 November 2005 (UTC)  beadtot