Talk:Redshift/Archive 7

message: Note that those particular papers of the last dicussion belong in tired light and not here; but I got the impression that ScienceApologist in the last discussion rejected the opinions of three peer reviewed papers plus an apparently non peer-reviewed web article, based on the opinion of another apparently non peer-reviewed web article. IMO that's not in accord with Wikipedia rules. Harald88 08:34, 22 December 2005 (UTC)
replies: text: I am happy to continue the discussion at the other article. --ScienceApologist 15:43, 30 December 2005 (UTC)
thread_title:  peer reviewed papers contra non peer reviewed? 

message: I think more discretion is required about what's posted here. The topic "More hypocrisy from..." does not focus on improving the associated article. The topics "Raman redshift" and "Intrinsic redshift" pick out individual examples from a list previously submitted as an RfC that was discussed at length. Heavy usage of a talk page is OK, but not if it only consists of bringing up the same topics over and over in different groupings. Flying Jazz 04:12, 22 December 2005 (UTC)
replies: text: Leadership! My own introverted personality is better suited for quality control. Art LaPella 15:09, 22 December 2005 (UTC)
thread_title: Please reestablish the focus of this talk page

message: It's time to bow of the redshift article for several reasons. While scattering and redshift was certainly discussed in the RfC, "intrinsic redshift" appears to have been mentioned only in relation to Arp, I can find no further discussion. That it is further suggested that "intrinsic redshift" only applies to Arp, and I can demonstrate with references that that is not the case, and this evidence is consigned to an Archive within a few ours, bothers me.
But what quite disturbs me, is the Disneyesque presentaion of the redshift article. Even if it doesn't say so implicitly, the article presents itself as if 100% of scientists acknowledge that there are only three kinds of "true" redshift, and that it is fully understood and accepted 100%. It's not as if we are discussing a subject where one or two non-qualified individuals have some pet-theories. That there are other scientists who dare question redshift/cosmology , who actually produce peer-reviewed articles questioning redshift, and that they are labelled "woo woos", "pseudoscientists", and "pathological sceptics", and merely mentioning this is considered dissent by just one or two people, is disprectful at best, and not on the spirit of scientific endevour at worst.
Are there non-Doppler redshift? I have no idea. But the American Physics Society deems the subject worth of discussion ; that's not my theory, that's a reflection of what is going on in science on redshift. It's a shame that the editor(s) of the redshift article also can't reflect what's going on in the world.
I'm sorry if this sounds like sour grapes, but it's meant as a genuine criticism.
I'll be removing my Request for Arbitration, though I can't suport the support for Peer Review because I think the article also requires addition work (historic mention of Doppler, Ballot, Fizeau, Huggins, etc , and a note on how redshift is actually measured). And I believe that the article needs to be converted from what I think is a scientific article, to something more appealing to non-scientists (as an example, read out the first sentence to a non-scientist, and gague the expression).
Joshua, and all the other editors, I have enjoyed many of your contributions, even though some of them are quite exasperating. I apologise to all those that have been upset with my comments over the months. I hope you all have a very merry Christmas (I'm a Jewish atheist myself), but I digress.
--Iantresman 16:51, 22 December 2005 (UTC)
thread_title: Time to bow out

message: I have two main comments on the current edit, which I'll open for discussion here before editing the article itself. Firstly, Olbers' Paradox is very interesting and worth a mention, but it does not in itself require a Big Bang. A de Sitter universe (H=constant, e.g. a cosmological constant dominated universe) has no big bang, but has (1+z)^4 surface brightness dimming. 
::Excellent point. --ScienceApologist 14:06, 4 January 2006 (UTC)
replies: text: I also agree with this suggestion. --ScienceApologist 14:06, 4 January 2006 (UTC)
thread_title: Olbers' Paradox and 'Gravitational' redshift

message: Date: 12/03/06    From: Ian Tresman   To:   Emil Wolf
I wonder if you could clarify the following point:
Is the Wolf effect primarily a radiative effect, or is it really just a form of scattering that requires a scattering medium?
By itself, the Wolf effect can not produce spectral shifts greater than the line width? And if there is a shift greater than the line width, then scattering must be involved, which implies a distortion of the spectra?
Wolf replied (though I don't think he quite clarifies the question on scattering). I've added a link to the paper he refers to, which is on Daniel James' Web site:
Date: Mon, 13 Mar 2006 11:22:27 -0500  To:   Ian Tresman   From: Emil Wolf 
I am writing in response to our e-mail of March 12th, concerning the redshift and the Wolf effect.  It seems, that the term "the Wolf effect" has now been adopted for the phenomena of changes in the spectrum of either a radiated or a scattered field, caused either by source correlations, or by correlations in the physical properties (e.g. the refractive index) of a scattering medium.  
You are right in saying that under certain circumstances the Wolf effect cannot produce spectral shift shifts greater than the line width.  But this is only true for radiation from simple sources or from scattering on what is called static media i.e. media for which the physical properties do not change in time.  For scattering on media where the physical property do change in time (one then speaks of dynamic scattering), appreciable changes may be generated.  Some examples are given in a paper which I am attaching to this e-mail.  Please note that figure 2 in the paper provides an example where the shift is many times greater than the width of the spectrum.
You say that if there is a shift greater than the line width then scattering must be involved which implies a distortion of the spectra.  That is actually not necessary so.  In the figure I just mentioned there is some distortion but it is relatively small.  In this connection I should also mention that when astronomers talk about shift of a spectral line, they usually refer to the shift of the its peak.  The exact profiles of the lines can be very seldom be determined in astronomy.  
He does mention "... a radiated or a scattered field,...", which to me implies that radiation is not scattering, and the introduction to paper he mentions, also separates "radiation from primary sources .. secondary sources" and "scattering processes". --Iantresman 16:38, 13 March 2006 (UTC)
replies: text: This confirms what I have been saying (or at least meaning) all along, that there is a form of the Wolf effect that does not depend on scattering, but the size of this effect is so small (only comparable to the line width) that it is little more than a curiousity in any field, and even less than that in cosmology. It is in the category of the redshift in solar spectral lines at sunset due to the wavelength-dependence of Rayleigh scattering. --Art Carlson 17:41, 13 March 2006 (UTC)
replies: text: Indeed, the radiative Wolf effect produces a tiny shift, which by itself might be insignificant to cosmology. But this is an article primarily on redshift, rather than cosmology. Anyway, the scattering analogue of the radiative Wolf effect will produce large frequency-independent shifts that may not be disorted, and is directly relevant to cosmology, as discussed in the paper, and others. --Iantresman 18:10, 13 March 2006 (UTC)
replies: text: that there is a form of the Wolf effect that does not depend on scattering It looks to me like Wolf is saying that there are no forms of the Wolf Effect which do not depends on scattering. They instead correspond to scattering at the source rather than scattering through a medium. --ScienceApologist 18:32, 13 March 2006 (UTC)
replies: text: Sorry, where does Wolf say that? If you read the first paragraph of Wolf's email, he says it's a phenomenon in radiative OR scattering spectra, caused by source correlations OR by correlations in scattering medium. Nowhere does he imply that source correlations in radiative spectra is anything to do with scattering. --Iantresman 19:03, 13 March 2006 (UTC)
replies: text: When Wolf says "But this is only true for radiation from simple sources or from scattering on what is called static media i.e. media for which the physical properties do not change in time." he is positing an equivalence between radiation from simple sources and scattering on a static medium. This only makes sense if the radiation from the simple sources is affected by scattering at the sources. The only way to get a change in frequency is to transfer some photon energy to a medium, in the case of simple sources it is the medium at the source. --ScienceApologist 19:07, 13 March 2006 (UTC)
replies: text: If a radiative spectrum imparts some of its momemtum to the source, that's fine, it's still not scattering (even if there are similarities), it still produces a Doppler-like frequency-independent redshifts, and scattering analogues of the Wolf effect may still produce large distortion-free Doppler-like redshifts, which Wolf and other significant adherents discuss in a redshift/cosmology setting, AND IT'S ALL VERIFIABLE. --Iantresman 19:31, 13 March 2006 (UTC)
replies: text: Since the radiative spectrum only imparts its momentum onto other sources, it is scattering. --ScienceApologist 19:35, 13 March 2006 (UTC)
replies: text: So provide some sources containing "radiative" and "scattering" in the same sentence that makes this clear. --Iantresman 19:40, 13 March 2006 (UTC)
replies: text: Rybicki and Lightman treat scattering through the radiation and absorption of photons through a medium in the first look they do in their text. --ScienceApologist 19:42, 13 March 2006 (UTC)
replies: text: Title, page number, quote? --Iantresman 20:07, 13 March 2006 (UTC)
replies: text: Chapter and verse are irrelevant for the purposes of this argument. The citation is to the first few chapters of the book on radiative processes. Read the book and get back to me. I'm not going to spoon-feed you information -- especially considering that this reference has zero-chance of making it into the article. --ScienceApologist 21:21, 13 March 2006 (UTC)
replies: text: I would have put it this way: "Title, Radiative Processes in Astrophysics. Page number and quote, the first few chapters in general." Art LaPella 23:19, 13 March 2006 (UTC)
replies: text: Scattering is mentioned on pages 8, 11 and 14, but I can find no confirmation of your view. Scattering is then mentioned on page 33 in the section on scattering, so I can find not verification of your point of view. Wolf and James say that "The Wolf effect is the name given to several closely related phenomena in radiation physics [..] analogous effects may occur in the scattering of light". This is verifiable PDF. As a radiative process, this is different from scattering, it says so in black and white. --Iantresman 00:11, 14 March 2006 (UTC)

text: You're forgetting the undue weight section of NPOV. That's why it is excluded. We already mention effects that account for the optical phenomena that the Wolf Effect describes in the article. --ScienceApologist 21:21, 13 March 2006 (UTC)
replies: text: We're going around in circles. It has already been demonstrated that there are prominent adherers as defined in Wiki's section on Under Weight. Emil Wolf himself is listed as one of the Top 1000 Scientists of all time.  This has nothing to do with whether the Wolf Effect is considered important, or even merely considered, by astronomers. --Iantresman 21:41, 13 March 2006 (UTC)
thread_title: Clarification from Emil Wolf

message: *Direct quotations suporting that the Wolf effect produces a redshift
:*"Non-cosmological redshifts of spectral lines" 
:*"Here, we demonstrate that under certain circumstances the modification of the normalized spectrum of the emitted light caused by the correlations between the source fluctuations within the source region can produce redshifts of spectral lines in the emitted light". 
*Direct quotations suporting that the Wolf effect produces a frequency-independent Doppler-like redshift
:*"In 1986, Wolf introduced the scaling law, which is a condition upon the spatial coherence properties of a source under which the radiated field has the same normalized spectrum as the source; in other words, if the source obeys the scaling law, the radiation pattern is independent of wavelength." PDF
:*"A review is also presented of recent research, which has revealed that under certain circumstances the changes in the spectrum of light scattered on random media may imitate the Doppler effect, even though the source, the medium and the observer are all at rest with respect to one another. In the final section"   PDF
:*"Doppler-like Frequency Shifts Generated by Dynamic Scattering,”" 
*Direct quotations suporting that the Wolf effect produces large redshifts
:*We see that, just as in the case when the shift is due to the Doppler effect, the relative frequency shift z induced by this mechanism is independent of frequency and can take on any value in the range —1 < z< [infinity], even though the source, the medium and the observer are at rest with respect to each other.  
:*"Very recently it was predicted (Wolf 1989a, b) that the frequency shifts induced by scattering from time-dependent random media with suitable correlation properties may imitate a Doppler shift of any magnitude," PDF
*Direct quotations suporting that Wolf effect is due to a radiative process
:*"The Wolf effect is the name given to several closely related phenomena in radiation physics..."  PDF
:*"For radiation from primary sources, the spectral changes are induced by correlations" PDF
*Direct quotations suporting that radiative effects are analogous to (hence not the same as) scattering
:*"There is a well known analogy between the processes of radiation from primary sources and scattering of light by media of finite extent."  PDF
:*"Because of the well known analogy between radiation and scattering,.."  PDF
:*"For radiation from primary sources, the spectral changes are induced by correlations..." [..] "for radiation from secondary sources..." [..] "In scattering processes the changes in the spectrum are induced by correlations" PDF
*Direct quotations suporting that Wolf effect is significant in science
:*"more than 100 papers on this subject, both theoretical and experimental, have been published" PDF
:*"Since then over 100 papers have appeared on this and related topics..." PDF
*Direct quotations suporting that Wolf effect has relevence to cosmology
:*"Non-cosmological redshifts of spectral lines" 
:*"Some remarks about potential implications of correlation-induced spectral shifts for cosmology may perhaps be appropriate here."  PDF
:*"Spectral shifts and cosmology"    PDF
:*"It seems therefore possible, in principle, that this effect may contribute toward the redshifts observed in the spectra of some astronomical objects. PDF
:*" the ' evidence' for non-cosmological redshifts..." PDF
(Please don't break up to list) --Iantresman 01:15, 14 March 2006 (UTC)
replies: text: Please stop confounding the radiative Wolf effect (if I may use that terminology), that cannot produce large or frequency-independent redshifts, with the scattering Wolf effect, which does not occur in vacuum. There is not one Wolf effect. --Art Carlson 08:54, 14 March 2006 (UTC)
thread_title: Direct verifiable quotations supporting the Wolf effect

message: Emil Wolf has just replied to my last query as follows:
To: Emil Wolf
From: Ian Tresman
Date: 13 Mar 2006
Can you just comment on whether (a) a "radiated field" is considered a type of "scattering"? (b) Presumably the former may occur in a vacuum (free space), whereas scattering requires a medium?
And his response:
To: Ian Tresman
From: Emil Wolf
Date: 15 Mar 2006
Here is my response to your question contained in your e-mail of March 13th.  The processes of radiation and of scattering are rather similar, but they are distinct.  Radiation is generated by atoms and molecules in some region of space (the source).  The process may be "spontaneous" or "stimulated", depending on the nature of the source and on the environment in which it is located.  On the other hand scattering is always generated by an external field which interacts with the atoms in the medium and makes them radiate.  Mathematically the two processes are very similar but physically they are different.
--Iantresman 17:26, 15 March 2006 (UTC)
thread_title: Email Wolf Clarification II

message: ScienceApologist speculated: "there are some differences between the three types of redshifts currently listed on the page and the "redshift" assocaited with the Wolf Effect. In particular, the Wolf Effect is related to some rather specific radiative transfer points about coherent sources and resonance" 
James et al wrote: "We have shown that frequency shifts of spectral lines which mimic the Doppler effect can be generated by scattering from a random medium which has a physically plausible correlation function for the dielectric fluctuations. We emphasize that this mechanism cannot be explained either by naive considerations involving photon fluxes or by radiative transfer or coherent wave propagation." (my emphasis). Verifiable reference: "Shifts of Spectral Lines Caused by Scattering From Random Media"
* You also said that the Wolf effect does not produce a Doppler-like redshift. You were wrong as is clear from the literature, and is verifiable from the several citations that I have provided
* You said that the Wolf effect does not produce a frequency-independent redshift. You were wrong as is clear from the literature, and is verifiable from the several citations that I have provided.
* You said that the Wolf effect does not produce a redshift that is consistent with the definition on this page. You were wrong as is clear from the literature, and is verifiable from the several citations that I have provided.
* You said that the Wolf effect is a scattering mechanism, which effectively the same as a radiative one, but have been unable to prvoide a verifiable quote supporting this view, and Wolf says above that "they are distinct".
--Iantresman 22:11, 15 March 2006 (UTC)
thread_title: Radiative transfer

message: The text says "A single photon .. can redshift"; while a single photon can redshift, scattering can also redshift a single photon such that it would be indistinguishable from a single photon that has been redshifted in any other way? Perhaps that needs clarification, or written in a less ambiguous way?  --Iantresman 19:39, 17 March 2006 (UTC)
replies: text: Since this is a single photon in a vacuum, there can be no scattering. There is no ambiguity. --ScienceApologist 20:13, 17 March 2006 (UTC)
replies: text: The radiative Wolf effect (which is not scattering, and will take place in an idealistic vacuum), will redshift a single photon, and is INDISTINGUISHABLE from any other redshifted photon. --Iantresman 21:37, 17 March 2006 (UTC)
replies: text: No, the radiative Wolf effect is a coherence effect and needs to have more than one photon as per the very references you cite. --ScienceApologist 22:10, 17 March 2006 (UTC)
thread_title: Single photon redshift

message: I can't find any references to "Classical redshifts". This might be causing some confusion with "Classical physics", which is incompatible with Relativistic causes of redshift. A general ADS search 
found just 4 references, but I think it's in a slightly different context. It certainly doesn't appear to be a "standard" term. --Iantresman 14:06, 16 March 2006 (UTC)
replies: text: I never liked it anyway. Removed. --ScienceApologist 14:35, 16 March 2006 (UTC)
thread_title: "Classical redshift"

message: Would any of the other editors (in addition to ScienceApologist), please clarify what Wikipedia means as exceeding "Undue weight", and thus reach the criteria for including in this article. --Iantresman 20:16, 1 April 2006 (UTC)
thread_title: Undue weight

message: Well I have been assigned as your mediator. Let's start by trying to find places where we can agree. I would propose that:
:*we agree to have civil discourse on this page
:*we agree to avoid arguments about semantics
:*we agree to be responsive to each other
:*we agree that the purpose of the talk page is to work together to improve the article
:*we agree that the purpose of the article is to represent factually the state of science in this field
:*we agree that this is not the place to determine the correct theory
:*we agree that our personal viewpoint is irrelevant
:*we agree that not all theories are equally accepted
:*we agree that each theory should be represented proportionally to its prevalence and acceptance within the scientific community
:*we agree that any single citation is not definitive
:*we agree that there are some theories that are not sufficiently prevalent to warrant inclusion
:*we agree that there is room to present alternative theories of sufficeint merit (as alternative theories)
Let me see if we can agree on these principles before we proceed. I would very much appreciate your cooperation. I would hope that we would all end up satisfied with the eventual results. Let's start a new era of consensus building.
--Nick Y. 19:24, 13 April 2006 (UTC)
replies: text: I agree with every statement made above. --ScienceApologist 20:41, 13 April 2006 (UTC)
thread_title:  Cabal Mediation