Talk:Redshift/Archive 6

Archive 1

←

Archive 4

Archive 5

Archive 6

Archive 7

Archive 8

→

Archive 10

Astronomical & laboratory observed redshift phenomenon

I see that someone has changed the disambiguation sentence to read that "This article is about the astronomical phenomenon." Flying Jazz is quite correct when he says that Redshift is an observation. This does not make redshift an "astronommical phenomonenon"; redshift is a phenomenon that is observed both in astronomy AND also the laboratory.

Strictly, only the Cosmological redshift is an astronomical redshift. Doppler and gravitational redshifts occur EVERYWHERE there is movement and mass. And laboratory demonstrated redshifts also occur everywhere.

Since redshift is observed both in astronomy and the laboratory, I proposed that:

• An article is created called "Astronomical redshift" (or similar) since this is a common subcategory of redshift
• The current article on redshift should explains:

• Where redshift is observed (eg astronomical and laboratory)
• Examples of redshift observed in each group (Astronomy: CMB, galaxies, stars, the Sun; Laboratory: Compton, Raman, Brillouin, Wolf)
• We should also mention HOW redshift is recorded and measured. How does an emission line let us do this? And we should answer a very good question from someone ealier (which has been removed!), in the case of astronomical redshifts, how do we "measure" source wavelengths since we can't do it directly.
• How do the characteristics of the observed redshift lets us distinguish between (a) Proportional-Z/Non-proportional-Z (b) Disortion free vs non-Distortion free (c) How do we distinguish between Doppler, Cosmological and Gravitational redshifts.

--Iantresman 12:43, 15 December 2005 (UTC)

There is a false distinction being made between astronomical observations and the "laboratory". Astronomical observations can be considered a type of laboratory. --ScienceApologist 15:57, 15 December 2005 (UTC)

Ian mentions only the redshifts he wants included but misses nearly 70% of the scattering processes that can also cause "redshifts". --ScienceApologist 15:57, 15 December 2005 (UTC)

Joshua, can you provide a couple of examples of such scattering mechanisms, together with peer-reviewed refernces in which their cause of redshift is mentioned? --Iantresman 00:11, 16 December 2005 (UTC)

"Redshift" is a term defined on this page. As such Mie scattering, for example, could cause a redshift if looked from the correct perspective. You are thinking way too narrowly, Ian. Scattering causes redshifts because it changes the observed frequencies of electromagnetic radiation that scatter. Your request for peer reviewed references is laughable. I suppose you want me to do a google scholar search with the terms "Mie scattering" and "redshift" in the same article (if we were to go by your criteria for what counts as a "reference"). --ScienceApologist

Quibble on rewrite

Transverse Doppler effect was not mentioned in the "Doppler-like redshift" section.

More hypocrisy from Joshua Shroeder

I see Joshua, that you are still not practicing what you preach:

• You have unilaterally deleted the Doppler redshift page, and redirect it to this Redshift article, despite your lecturing me on renaming the Non-standard cosmology page. That your edits require no consultation, and other people's edits require YOUR consultation, is hypocrisy.

The page contained no information not currently on this page. --ScienceApologist 16:43, 15 December 2005 (UTC)

• I see you decided not to delete the Gravitational redshift page. Could it be because I had a hand in the Doppler redshift page? Hypocrisy.

The fact is, Ian, that page you wrote had no new information except for a few choice words that were inaccurate. We might at some point create a "Doppler redshift page", but it will look much different than that. --ScienceApologist 16:01, 15 December 2005 (UTC)

• That you were quite happy to LOOSE the information on the History of Redshift in Astronomy, in which there were citations to every comment.

Good team work Joshua. --Iantresman 15:28, 15 December 2005 (UTC)

I am somewhat amused by the contention of Iantresman that he has accurately portrayed the history of redshift, even though when I pointed out that he was incorrect in his reference to this above, he didn't respond. The section was inaccurate and basically original research in all of its novel points. For example, Slipher's observations were later discovered to be a mixture of Hubble Flow and Doppler shifts. --ScienceApologist 16:01, 15 December 2005 (UTC)#

So Joshua, I must have missed this. Where did you point this out?

Example of the inaccuracies?

Slipher's thought he had measured a Doppler redshift? Do galaxies exhibit no Doppler redshift?

--Iantresman 19:04, 15 December 2005 (UTC)

Joshua, just a polite reminder to answer these points? --Iantresman 00:11, 16 December 2005 (UTC)

• Your scholarship with regards to the history of redshift seems to be wanting. You have refered to your knowledge of the subject before and when I expressed incredulity there was no response. In particular, there is inaccuracy in your advocacy of scattering theories being "important" in the history of redshift.
• We already include Slipher appropriately in the article. This question is immaterial.

--ScienceApologist 01:28, 16 December 2005 (UTC)

Close RfC?

Is it possible to close the RfC now? Any objections? --ScienceApologist 16:41, 15 December 2005 (UTC)

Sure, if you abide by the results. I've not made one edit to the article while the discussion have been going on. Since the RfC was begun, the article now proclaims that this is an article on "Astronomical redshift" (and that wasn't discussed). I proposed that the article include non-Doppler-like redshifts. I note from the feedback that:

RfC Support New requests for clarification have been made of the supporters in red. Beyond their initial comments, they have not clarified their positions. Myself Harald88 Eric Lerner (who corrected you on non-Doppler mechanisms and the Wolf Effect) Flying Jazz The table takes a multitude of opinions expressed about a variety of topics and oversimplifies that discourse into two columns without identifying what exactly in the RfC we supported or opposed. So I made myself green on both sides to mock it. register a discontentment with oversimplifications. DavidRussell Jerry Jensen Art Carlson (who does not object to a list) Note: rewrote the article in its current form	RfC Oppose Salsb Joshua Shroeder Flying Jazz When you add votes, please add an i when counting mine. After all...it's a complex issue... *Serjeant
Alternative suggestions Dragons flight (to make a page on "Astronomical redshift") DV8 2XL who concurs with Dragons flight Art LaPella (I think concurs with Dragons flight)	Unclear suggestions Joke Jon (Jonathanischoice)
Additional support (on the Wolf effect) Prof. Daniel James	Evidence against Joshua Shroeder
Additional evidence Compliance with Wikipedia policy: Extensive citations NPOV policy to include significant minority views Verifiability	Additional evidence against Non-compliance with Wikipedia policy: NPOV policy on undue weight Verifiability Ian Tresman's inability to understand points about the scientific use of redshift.

I'm happy with both my original proposal, or the suggestion to have a page on "Astronomical redshift". Apologies if I have misrepresented anyone, it is not intentional. I think it is interesting that conspicuous by their absence, are any number of astronomers fighting against the proposal.

I welcome others to interpret the results themselves.

--Iantresman 19:04, 15 December 2005 (UTC)

I submit that the results were in accord with the current edits to the article. We have a consensus version unless there is anybody who claims otherwise. Ian's table doesn't seem to do anything but make his RfC case again and list names. --ScienceApologist 19:26, 15 December 2005 (UTC)

Raman redshifts

Just to continue my evidence that redshift is used in Raman scatting (see my extracts regarding Compton scattering and Brillouin scatting above), here are some specific extracts (my emphasis):

• "A resonant Raman line is shown to cause a redshift of the pulse spectrum" [1]
• "The effect of Raman self-scattering leads to redshifting of the pulse spectrum" [2]
• "An equally self-consistent interpretation is that the intervening gassy material PARTIALLY CAUSES the Large Quasar Redshifts via a Non-Doppler (or Non-Space Expansion) Redshift mechanism such as Raman, CREIL, Compton, Plasma or Wolf effects." [3]*

And yet another paper supporting frequency independent Wolf Effect

• Lab Experiments Revealing Non-Doppler Redshifts with Possible Cosmological Applications [4]*

"Laboratory experiments reveal redshifts and broadening of the spectral lines emanating from a mercury discharge [..] The source, the intervening medium, and the detector are stationary [..] [..] The observed relative wavelength shift of the spectral lines (Z) is independent of wavelength similar to the Doppler effect. [..] Possible theoretical interpretations are suggested including "correlation induced wavelength shifts" caused by scattering of the electromagnetic radiation by the medium (Wolf Effects)." (Those marked * are not peer-reviewed, but conference abstracts) --Iantresman 21:19, 15 December 2005 (UTC)

Once again this evidence only seems to prove that User:Iantresman is going to blissfully ignore the discussions we had about how to handle scattering in this article and refuses to accept the consensus that is now dealt with in the article. --ScienceApologist 23:02, 15 December 2005 (UTC)

I haven't been on much after my initial edit and suggestions , but I think the resolution of the scattering problem was done nicely, with the paragraph explaining the different usage and referring the reader elsewhere. Salsb 13:34, 19 December 2005 (UTC)

Request for Arbitration

Joshua, I've put in a request for arbitration on your conduct in this article, and others. I feel that your ignoring the contributions by many of those who took time to contibute to the Request for comments, and many of your other actions, are not compatible with Wikipedia policies and styles --Iantresman 15:45, 17 December 2005 (UTC)

Ian, a request for arbitrartion is the last resort in the dispute resolution process. You have evidence that RfC or mediation won't work? --ScienceApologist 16:00, 17 December 2005 (UTC)

NPOV

I've put back the Neutral Point of View tag on the grounds that:

• The Request for Comments was closed prematurely and unilaterally
• This is now subject to a Request for Arbitration
• I for one haven't edited the article since the RfC was started, since the object was to consider changes based on consensus
• I've just noticed that someone in the Featured article candidates page has thought that "scattering redshifts" might include something like Rayleigh scattering which is responsible for making the sun redden at sunset; as far as I know, this is NOT a redshift and does not produce a spectral shift. However, other scattering phenomenon, such as Brillouin scattering, Compton scattering, and the Wolf Effect, do produce a spectral shift and hence a redshift as a result of scattering. --Iantresman 09:49, 20 December 2005 (UTC)

I suspect the confusion above may have resulted from my mention of "solar redshift" (excluded from the article), where a genuine redshift is measured from the sun [5]. [6] [7]

First of all, I know very well what Rayleigh scattering is all about. My point was that, if you take everything at face value and interpret the words naively, then the Sun is "redshifted" at sunset: the peak of the spectrum you see moves to longer wavelengths. I was simply trying to illustrate why geometrical and kinematic frequency shifts should be discussed separately from those caused by interactions. (Rayleigh, Compton—just a question of names. It's all photons hitting electrons, when you get down to it.) I find your interpretation of "spectral shift" confusing.

Second, in my judgment the RfC was closed at an appropriate time. (I had no part in it and had never edited this article before the FAC.)

Third, I find myself forced to conclude that the NPOV tag was added in bad faith. Your conduct puzzles me: you say that the RfC was closed "prematurely and unilaterally", which is presumably a bad thing, yet you unilaterally instigated an RfArb and are unilaterally trying to sway the course of the FAC process. To this latter end, you have been systematically misinterpreting my comments to favor your position, to such an extent that I find it difficult to maintain good faith and blame it upon miscommunication. Anville 10:20, 20 December 2005 (UTC)

Thanks for the clarifiation on scattering. If people do indeed naively suggest that the sun's light is "redshifted" during sunset, then I would suggest that there is no harm in explaining this in the article. Of course the Wolf effect does not produce a redshift like this, but an actual spectral redshift, but the effect is excluded from the article.

Already explained in the article. See the scattering section. --ScienceApologist 14:20, 20 December 2005 (UTC)

I added the NPOV tag for three reasons:

• Comments in Featured Article status were suggesting that the article is stable [8]. I disagree. Part of the reason for this is that I have not been editing the main redshift article, since I felt that you can't make edits until you have heard all comments.

An interesting opinion. When do you propose that "all comments" will be made? --ScienceApologist 14:20, 20 December 2005 (UTC)

• I believe that my Request for Comments was closed early because it was not resolved; By this I mean that a proportion of people who took the time to comment were ignored. For example, if you look at the summary table I made in the Close RfC section above, ScienceApologist claims that he has made a "strikethrough those who did not respond"[9], when if you check my RfC, there are clearly messages of support for my proposals from Harald88 [10], Eric Lerner [11], DavidRussell [12] and Jerry Jensen [13].

You will also notice that there are requests for clarification made for each of these people, none of which responded. Perhaps you can get them to clarify their positions, but as they wouldn't respond after the initial points, why are they being paraded as standards? --ScienceApologist 14:20, 20 December 2005 (UTC)

Note that Joshua has just amended [[14]] his statement in the RfC Summary table above suggesting that he requested further clarification for each person. The "clarification" to harald88 is a dismissal [15], to DavidRussell is on a side issue on Halton Arp [16], to Eric Lerner is an unsubstantiated disagreement [17] and I can't find any response to Jerry Jensen at all. --Iantresman 14:44, 20 December 2005 (UTC)

I requested a clarification from Harald88 on this talkpage at the time and again today. Eric Lerner didn't state that he supported your RfC. Jerry Jensen is a regular at Bad Astronomy who didn't even bother to make an account and can't be counted on to make another appearance unless you get in touch with him over there. And David Russel similarly doesn't have substantial contributions. I have placed noticed on each of their talkpages. Maybe we'll get a response. --ScienceApologist 14:57, 20 December 2005 (UTC)

• So please show your history/diffs were you queried Harald88 on his original comment (at the time)
• Are you serious? (a) Being a regular at Bad Astronomy (b) not creating an account (c) doesn't have substantial contributions.
• There is no requirement for these people to have to repeat themselves. Their contributions are clear, and your clarifications have yet to be clarified. --Iantresman 15:25, 20 December 2005 (UTC)

The people who contribute creating accounts expressly to respond to your RfC or not even bothering to create an account and then vanish do not seem to be as important perspectives as those editors who have helped with this dispute. Right now you have lined up a list of editors who hasn't been involved in any of our discussions. As they haven't, there isn't any indication at the present time that they know what the new situation is or whether their perspective is being rightly considered or promoted (namely by you, Ian). I have placed notices on their talkpages and we will see if they respond. If they do not, we can only assume they have opted out of the discussion. As it is we have a consensus version made by many different editors, and I have yet to see you acknowledge this. --ScienceApologist 16:35, 20 December 2005 (UTC)

• The RfC was started on 3 Dec 2005 [18]
• harald88 has had an account since 10 Oct 2005 [19]
• DavidRussell had an account since 25 Nov 2005 [20]
• Eric Lerner has had an account since 9 Nov 2005 [21]
• Jerry Jensen (who came in under an IP address) has been contributing since 6 Jan 2005 [22]
• I declare that the suggestion that people are "creating accounts expressly to respond to [my] RfC" is FALSE (not to mention irrelevent)
• All of these people were involved in discussions. They made their comments, period.
• And I assume that you can't find mention of where you asked harald88 for clarificatin on his talk page?--Iantresman 18:05, 20 December 2005 (UTC)

If these four people had made their comments yesterday, then I'm sure there would be a differntly outlook on the content of the article. But do we ignore them just because they resonded before more recent contributors?

The issue is that there has been progress made in editting the article since they responded and they've been requested to respond to the article. I am going to make requests on their talkpages to respond again and we'll see if they give us some ideas. --ScienceApologist

What's the beef? I thought the RfC was about whether the page should include scattering or be a pure astronomical/Doppler redshift article. Everyone agreed long ago to include a section on scattering. What do you want, Ian? Is it just a question of whether a list is appropriate or not? --Art Carlson 15:28, 20 December 2005 (UTC)

• Correct. This whole discussion is about adding one sentence along the lines of "Examples of scattering phenomenon that produce such redshift include Brillouin scattering, Compton scattering, Raman scattering, and the Wolf effect".
• Why? (a) Examples are informative and qualifying. Look at the Wikipedia page on planets; there is a whole section giving a list of not only the planets, but even a "laundry list" of non-planets (candidates) (b) A link provides a quick way for people to go and find out more information.

A list of scattering mechanisms is not informative because just reading the name does not tell a reader anything about the process. A list is not qualifying because every scattering mechanism can in one form or another produce a redshift. If someone wants to know more about scattering, the first thing they should do is read the scattering article. If someone wants to know more about candidate planets, there is no single article they can turn to, so a list in the planets article is necessary. I think this article is marginally better without a list. Is there any editor other than Ian who thinks that the current discussion of scattering is inadequate, specifically that a list of scattering mechansims would be an improvement? --Art Carlson 09:30, 21 December 2005 (UTC)

Not me, for one.--Serjeant 11:45, 21 December 2005 (UTC)

I think a list here would be a mistake, but I hope a table comparing/contrasting all the named scattering mechanisms in physics is added to the scattering article. Flying Jazz 13:19, 21 December 2005 (UTC)

I agree 100% with this suggestion. --ScienceApologist 13:31, 21 December 2005 (UTC)

I'm not sure that is the case, and haven't been able to get confirmation from anyone. For example, Rayleigh scattering which is responsible for the sun reddening at sunset, seems to change the wavelength of the peak of the visible spectrum, but there are NO shifts of any spectral lines. I do not consider this a redshift, and have not seen it described as such.

Don't look into the sun! You'll go blind. Look at the blue sky instead. The red light at sunset is the photons which have not been scattered. The scattered photons have changed their direction, they have gained transverse momentum. Since momentum is conserved, the molecule doing the scattering must have gained momentum in the opposite direction. If it gained momentum, then it also gained energy, which means the photon lost energy, it was redshifted. This is a general property of any form of scattering from individual particles. (Collective scattering works in a similar way but is more complicated.) --Art Carlson 12:32, 21 December 2005 (UTC)

• So if I record a spectrum of sunlight at sunset, I'll see that spectral lines have shifted compared to a spectrum recorded at noon? --Iantresman 13:47, 21 December 2005 (UTC)

Minimally, yes, you will. The reddening will be more dramatic than the shift in spectral lines, but a scattering medium will distort the spectral lines and since higher frequency light is more prone to scattering than lower frequency light, you will see an associated redshift. In fact, you quoted the first step in calculating this redshift when you quoted the Compton redshift calculation. You will see a slight shift in the spectral lines. --ScienceApologist 14:08, 21 December 2005 (UTC)

• That's good enough for me. --Iantresman 15:57, 21 December 2005 (UTC)

Brillouin scattering etc, produce an actual spectral shift of emission/absorption lines, and I am aware of only a handful of scattering processes that do this.

Finally, while scattering may fasciliate the Wolf effect, the cause is actually due to the interaction of two photons. But I'm still trying to confirm this too.--Iantresman 11:12, 21 December 2005 (UTC)

Classical electrodynamics in a vacuum is linear. There is no interaction between two photons. --Art Carlson 12:35, 21 December 2005 (UTC)

It's actually photon-phonon interactions that cause the Wolf Effect. --ScienceApologist 14:10, 21 December 2005 (UTC)

• That's a type of scattering? --Iantresman 16:56, 21 December 2005 (UTC)

Depends on how you define scattering. Microphysically, it's very similar. --ScienceApologist 17:10, 21 December 2005 (UTC)

• Unless the sentence is inaccurate, I don't consider that unreasonable. And I can't think of any reasons not to include it.
• And if it makes Joshua happy, I won't even mention the possibility that any of these can produce Doppler-like redshifts, as longs as Joshua doesn't stick in one of his "qualifying comments". --Iantresman 18:20, 20 December 2005 (UTC)

What's wrong with including the "laundry list" on the scattering page? --ScienceApologist 14:10, 21 December 2005 (UTC)

• The article is undergoing a Request for Arbitration

So is my NPOV tag really a lack of good faith? --Iantresman 12:17, 20 December 2005 (UTC)

I would say your tag is a lack of good faith. The RfArb was started by you. --ScienceApologist 14:20, 20 December 2005 (UTC)

RfC closed or not?

Ian you stated when I asked if we could close the RfC: Sure, if you abide by the results. When I stated that the results were the current consensus version you did not respond. Now you are stating that you think the RfC was closed prematurely. So I need to ask a clarification: what do you think the results of the RfC were (not in table form but in point-by-point content inclusion/exclusion form)? --ScienceApologist 15:18, 20 December 2005 (UTC)

Let me take a taste of my own medicine and say what I think the results of the RfC were:

• There are many ways scientists talk about redshift. This article is on the usages from mostly an astrophysical standpoint, though laboratory based observations are included. Bathochromic shifts are linked to in a disambig sense since there is evidence from the literature and from photochemists that they are referred to in such a way.
• Photochemists use redshift in a different way from physicists. They, in particular, believe that any frequency shift toward the red no matter how it is described is a "redshift". This may be more of an informal rather than a formal definition.
• There are three common causes cited for redshift in astrophysics texts. Sometimes "tired light" is mentioned in a historical context, but it is not taken seriously as a viable alternative since the expansion of space is accepted.
• Scattering can cause a frequency shift. This can sometimes be described as a "redshift", even to the point of applying the mathematical definition of redshift (${\frac {\Delta \lambda }{\lambda }}$ for example) in order to obtain theoretical descriptions of observations. There is no known scattering form that is completely frequency independent across the spectrum the way the definition of z demands. Nevertheless, it is appropriate to mention scattering in this article as it can cause shifts in frequency. Art Carlson wrote the scattering section to deal with this issue.
• Individual types of scattering are omitted because they are a level of abstraction removed from the discussion of redshifts. An interested reader can go to the scattering page and read about them.
• The Wolf Effect is related to Raman scattering (though it relies on a resonant rather than scattering medium -- effectively phonon rather than photon interactions) and as such is minimally frequency dependent over the largest parts of the electromagnetic spectrum (for example, comparing gamma ray emission to radio emission). There may be regimes where it is frequency-independent (for example, over a spectroscope's range of sensitivity), but this is hardly relevent to the redshift article. The Wolf Effect was proposed as a mechanism to explain quasar redshifts and since host galaxies have been found around quasars, this effect has been discounted as a mechanism by all but a vanishingly small minority of astronomers. Therefore the Wolf Effect is rightly excluded from this article.
• Halton Arp proposes that there are such things as intrinsic redshifts in quasars. He supports "variable mass" as a cause for this. This advocacy is rightly catagorized as well-beyond the mainstream and isn't taken seriously by the vast majority of astronomers. It is excluded from the article because of this.
• Redshift quantization has been suggested by various astronomers from time to time. Redshift surveys do not exhibit any trace of redshift quantization beyond clustering of galaxies. (2dF was tested for such a thing) It is excluded from the article because of this.

• So wouldn't it be better that a redshift article discusses the "many ways scientists talk about redshift"? And then a Redshift (Astronomy) pages can go into as much detail as you want. Otherwise we (a) marginalise the non-astronomical scientists (b) Make it look like there are only three types of redshift worth discussing.

It was decided that the major use for redshift was astronomical. This isn't to say that others don't use the term, only that the redshift page should remain here and should deal mainly with the places is it used. Marginalization isn't always a bad thing, especially because what is being marginalized are perspectives which we include well in the article (in the scattering section, for example). --ScienceApologist 13:16, 21 December 2005 (UTC)

• If Doppler, Gravitational, Cosmological, and optical scattering produce redshifts, why is writing several paragraphs about gravitional redshift not an abstraction, but merely mentioning by way of example a handful of scattering mechanims, is? We're talking about added one sentence to the article, and to consider that "an abstraction" or "a laundry list" still surprises me. See my additional comments to Art Carlson above.

Because scattering isn't ever used as a redshift diagnostic while the other kinds are. --ScienceApologist 13:16, 21 December 2005 (UTC)

• That (a) the Wolf effect can produce redshifts, and (b) that the Wolf effect has been proposed for galactic redshift are two totally different theories. I've never suggested mentioning the latter in the redshift article, even though you've provided no peer-reviwed articles arguing against it. With all due respect Joshua, you are not the arbitor of peer-reviwed citations, and nor are you the "voice if the mainstream".

? The Wolf Effect hasn't been shown to be a diagnostic tool beyond the quasar controversies where it has been falsified as a major candidate. --ScienceApologist 13:16, 21 December 2005 (UTC)

• Peer-reviewed citation? --Iantresman 13:43, 21 December 2005 (UTC)

See the citations to host galaxy observations made on the RfC page. --ScienceApologist 13:46, 21 December 2005 (UTC)

• That's called "my theory is better than your theory". It's like saying that the "standard theory" has been falsified because it is not consistent with the "Wolf Effect". Until you can provide a peer-reviewed citation that shows a problem with the Wolf effect regarding galaxies, then all you have is an opinion (or a Point of View). --Iantresman 15:13, 21 December 2005 (UTC)

You were the one who said the Wolf Effect applied to quasars, not I. We pointed out that quasar redshifts were shown to be consistent with the host galaxies which contained them showing that the redshifts assoicated with galaxies (well-known from Hubble Law and peculiar velocities) were the same as those associated with quasars. The Wolf Effect is not used as a diagnostic tool by any of the cites to it you have mentioned. Therefore, we have provided the evidence required to show that the Wolf Effect does not belong as a source of redshift for galaxies or quasars. --ScienceApologist 16:17, 21 December 2005 (UTC)

• Intrinsic redshifts have been discussed by not only Arp, but in almost 50 other papers [23]. This not about promoting who is right or wrong. It's about discussing a recognise phrase that is to do with redshift. As an unbiased article, we have a duty to explain (a) What is meant by "intrinsic redshift" (b) Why various scientists have suggested it (c) Why other scientists have argued against it. Arp's explanation of intrinsic redshift is but ONE theory, but whether it is right or wrong, doesn't dismiss the whole field of "intrinisc redshifts", whatever they may or may not turn out to be.

We have no duty to include a neologism that isn't accepted by the majority of the astronomical community any more than we have to explain tired light on this page. --ScienceApologist 13:16, 21 December 2005 (UTC)

• Likewise redshift quantization, why don't we say what this means, why evidence originally suggested it, and then tell people what recent surveys have found?

See above. --ScienceApologist 13:16, 21 December 2005 (UTC)

--Iantresman 19:24, 20 December 2005 (UTC)

Those topics seem to have been addressed and discussed at length during the RfC.Flying Jazz 20:56, 20 December 2005 (UTC)

analogous but not equivalent

Why not simply "similar? (If the article wasn't now in discussion, I'd have substituted it already). Harald88 23:05, 20 December 2005 (UTC)

Seems fine to me. --ScienceApologist 13:48, 21 December 2005 (UTC)

Criteria for a redshifting, Doppler like effect

To be able to be confused with a Doppler effect, a non-Doppler redshifting process by interaction with matter must obey the following conditions:

1) It must not blur the images. Therefore, it must not modify the wave surfaces, that is it must be a space-coherent effect. The simplest example of coherent processes is the refraction by which a lot of molecules interact with a light beam of any intensity (down to nearly zero !). Evidently, refraction does not shift the frequencies, it is only an example of a coherent process. Many other coherent interactions are studied using lasers.

2) It must not blur the spectra The result of an exchange of energy of a monochromatic beam with matter must be a single-frequency beam. Therefore, if the origin of the process is a scattering, it is necessary that the scattered wave interferes with the exciting wave into a single frequency wave. The coherence of the scattering is necessary but not sufficient.

3) The relative frequency shift must be, at least approximately, constant in the usual range of observations. By a Doppler effect, the relative frequency shift is strictly constant, but in some observations, it is not; a small variation of the relative frequency shift can only be observed on the lines of a multiplet to be sure that the origin of the lines is the same; when it is observed, it is considered usually as a consequence of a variation of the fine structure constant.

4) The effect must obey both principles of thermodynamics. The energy lost in a redshift must be transferred to some matter or electromagnetic beam, and increase the entropy of the system. A parametric effect which is a coherent effect in which light beams exchange energy while the matter return to its initial state after an interaction works well; an example of parametric effect is frequency doubling of a laser beam in a crystal.

5) The theory of the effect must fail with time-coherent light. Else it is a genuine Doppler effect.

Demonstration:

Suppose that the light of a continuous wave laser L is received, redshifted, by a receiver R. While L sends m cycles, R receives n; the number of cycles along the path LR (supposed stable) is increased of m-n, that is the number of wavelengths is increased of m-n: therefore it is a relative movement of L and R, it is a Doppler effect.

Consequently, a parameter evaluatig the coherence of the light (length of light pulses for instance) must appear in the theory, so that the theory fails using time-coherent light.

Few proposed redshifting effects obey all these conditions. The effects which obey it differ by the type of interaction with matter : it may be an interaction with a plasma (with a transfer of energy to acoustic waves, for instance), or a spectroscopic interaction (resonant, therefore strong in the CREIL effect).

--83.177.198.81 08:09, 21 December 2005 (UTC)JMB

Can you help indicate how this might help us categorise Brillouin, Compton, Raman and Rayleigh scattering, the Wolf Effect? I believe that some of these are not a redshift at all (Rayleigh), some shift, but are not Doppler-like (Brillouin, Compton, Raman), and the Wolf effect is usually not Doppler-like, but may be --Iantresman 08:31, 21 December 2005 (UTC)

What is your evidence that Rayleigh scattering cannot redshift light? --ScienceApologist 13:49, 21 December 2005 (UTC)

• Some guy called Joshua Schroeder has been telling me for the last 6 months that the ONLY true redshifts are Doppler, Cosmological and Gravitational, and all others are second-class causes that are "inferior to astronomy" that no-one would be interested in. And why would they be looking for them on a page called 'redshift'.
• I have one reference that says quite clearly "One demonstration involves novel materials to display Rayleigh scattering (blue skies, red sunsets and interstellar reddening - NOT redshift!) -" [24], but perhaps this shows only that the phrase "Rayleigh scattering" just happens to occur on the same sentence as the word "redshift", or perhaps I just don't understand what I think it means.
• I can find not peer-reviewed references from anybody who says anything resembling "Rayleigh scattering may cause redshift", unlike Brillouin, Compton, Raman scattering, and the Wolf Effect, where I have numerous peer-reviewed citations like:

• "Compton Scattering Can Explain Redshifting"[25], but I realise this is my misunderstanding of the words "can explain", "redshift" and "Compton scatterin".
• "The origin of the redshift in Brillouin spectra..."[26], must clearly be authored by a pseudoscientific, pathological pseudoskeptic
• And regarding the Wolf effect "under certain circumstances the changes in the spectrum of light scattered on random media may imitate the Doppler effect" [27], must be wrong because the Gravitational redshift also imitates the Doppler-redshift... oops, sorry, my logic is failing me.

• But I'm quite happy Joshua, to take your word for it, unless you do citations now?
• --Iantresman 15:54, 21 December 2005 (UTC)

• Ian, your refusal to understand points is amazing. Scattering shifts light as described in the article. No one has ever said "inferior to astronomy".
• Indeed, scattering is not considered to be a redshift. That is the gist of your citation. It would include other scattering effects as well such as CREIL, Wolf Effect, etc. So thanks for your reference showing that your advocacy is so problematic.
• Your inability to understand the difference between describing a frequency shift as a redshift and using a scattering mechanism as a redshift diagnostic is the major source of contention on this article. In particular, your misuse of references, your continued inability to understand the points made about the article, and your insistence on misrepresentating the quotes of other users and references makes it clear that your ideas should be rejected. --ScienceApologist 16:23, 21 December 2005 (UTC)

• Joshua, I would welcome your explanation of the first citation that I give above "Compton Scattering Can Explain Redshifting" [28] in which the abstract says "This paper introduces a hypothesis that multiple collisions with minute particles such as neutrinos can cause redshifting in the manner of Compton's paper .. Redshift then becomes a measure of distance but not of recession." Is he not implying that observed astronomical redshifts are due to Compton scattering rather than the expansion of space? --Iantresman 18:11, 21 December 2005 (UTC)

This paper is wrong. --ScienceApologist 20:24, 21 December 2005 (UTC)

What! I don't understand what you mean? You mean the paper was accidentally printed? Shouldn't have been printed? What do you mean wrong? --Iantresman 20:58, 21 December 2005 (UTC)

The major claim of the paper is incorrect. This is covered by Wright [29]. --ScienceApologist 21:00, 21 December 2005 (UTC)

• And presumably any paper, peer-reviewed or not, that suggests Brillouin, Compton, Raman scattering, or the Wolf effect have anything to do with explaining "intrinsic" redshifts are intrinsically incorrect? --Iantresman 22:30, 21 December 2005 (UTC)

Frankly, the ability of the paper to explain itself is the criteria by which it is judged. Wright thoroughly trounces the Compton Effect as a source for redshift. --ScienceApologist 22:36, 21 December 2005 (UTC)

• And presumably any paper, peer-reviewed or not, that suggests Brillouin, Compton, Raman scattering, or the Wolf effect have anything to do with explaining "intrinsic" redshifts are intrinsically incorrect? --Iantresman 22:30, 21 December 2005 (UTC)

No, the gist of my commentary was that Ned Wright's page explains why the Compton Effect cannot explain the Hubble Flow. "Intrinsic redshifting" is a neologism invented by some quasar and Big Bang naysayers. --ScienceApologist

Interesting! Do those objections also apply to the following?

P.Marmet, A New Non-Doppler Redshift, Physics Essays, Vol. 1, No: 1, p. 24-32 (1988). For an online view: [[30]] ;

And in support, R.L.Carezani, The Compton Effect and Autodynamics , Physics Essays vol.6 p.384 (1993). Online at [[31]]

Cheers, Harald88 22:08, 21 December 2005 (UTC)

Marmet and Carezani are well-known woo-woos... not even worthy of debunking in my book. --ScienceApologist 22:36, 21 December 2005 (UTC)

I don't have your book; what counts in science is the contents of papers that made it through review. Authors who often write good papers sometimes write bad papers, and authors who rarely write good papers sometimes manage to output a few anyway. In science we primarily look at the contents. I see no error in conservation of energy and momentum; also I know of no peer reviewed paper that finds fault in it. I like to read it, if you know of such a paper. Do you?

Apart of that, for inclusion in the article: IMO the weak point is that Physics Essays is not at high standing; OTOH here we have two independent papers that come out at the same, so that handwaving isn't sufficient. It's not comparable with the just removed self advertisement of self published web pages. Harald88 22:56, 21 December 2005 (UTC)

I'm sorry, Harald88, I cannot make heads or tails of what you are trying to say here. Yes, indeed, peer review is fundamental to creation of scientific consensus. Yes, Marmet and Carezani have had tremendous problems trying to get through peer review. (Is that what you meant by "high standing"?) Perhaps you could clarify your points on the "conservation of energy and momentum" as I see no one here who "finds fault in it". I think you are saying that these papers represent some sort of criticism, but as to what that criticism is I cannot say. Are you trying to make an "Einstein was wrong" case here or are you trying to say something else? Because you'll have to be a lot more clear with what you are advocating. --ScienceApologist 23:06, 21 December 2005 (UTC)

By the way, yes, Marmet's explanation for redshift can be criticized on the same grounds. --ScienceApologist 23:10, 21 December 2005 (UTC)

Improving a criterium of selection of the proposals for Doppler-like redshifts

I have given here 5 criteria allowing to select a reliable Doppler-like redshift. It is necessary to look at these very simple criteria (which are not new) before a study of a proposed effect.

Here, I answer a question: Can you help indicate how this might help us categorise Brillouin, Compton, Raman and Rayleigh scattering, the Wolf Effect? I believe that some of these are not a redshift at all (Rayleigh), some shift, but are not Doppler-like (Brillouin, Compton, Raman), and the Wolf effect is usually not Doppler-like, but may be --Iantresman 08:31, 21 December 2005 (UTC)

By definition, the Rayleigh scattering does not change the frequencies.

The Rayleigh space-coherent scattering explains the refraction.

A large part of the blue of the sky is produced by a Rayleigh space-incoherent scattering of the light of the Sun. The sky is blue because the scattering increases with the frequency, but there is no change of frequency. The complementary effect makes the Sun more red, this is well seen when the path through the atmosphere is large, the Sun being at the horizon.

The remainder of the blue of the sky is produced by a Raman space-incoherent scattering, the usual Raman scattering. The frequency of a fraction of the intensity is shifted of a quantified energy, so that satellite lines appear in the spectrum: An exciting line produces a lot of lines, it cannot be confused with a Doppler effect.

It is not easy to observe the Raman space-coherent scattering because it is difficult to keep a space-coherence between beams having different frequencies. Therefore it is only observed in refined laboratory laser experiments.

The Compton scattering corresponds to the exchange of energy of the light with the translational energy of a particle. It is space-incoherent and cannot be confused with a Doppler redshift. The wolf effect corresponds to a lot of Compton scatterings, the lines become wide, it always remain some intensity at the exciting frequency.

These effects do not verify all conditions I indicate for a Doppler-like scattering. In particular, the verification of the last condition is extremely simple (does the effect work using a CW laser ? ) and shows that many proposed effects are not Doppler-like. It seems to me that only the CREIL and a similar effect using a Brillouin scattering in a plasma verify the criteria, therefore may be confused with a Doppler effect. --JMO 08:55, 24 December 2005 (UTC)