Talk:Wolf effect

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Expert opinion[edit]

Copy of email sent out to experts in optics:

http://en.wikipedia.org/wiki/Wolf_effect

I am trying to improve the article on the Wolf effect on Wikipedia above. I was wondering whether you could clarify:

  1. Can the Wolf effect be considered to be a redshift, or a new redshift mechanism?
  2. Is this generally accepted, or only by a small number of researchers in optics?

Regards,

Ian Tresman


Reply from Mark Bocko who demonstrated the Wolf effect in the laboratory [1]:

From: Mark Bocko Subject: Re: Wolf effect and redshift

Ian - answers below ....

  1. It is a non-kinematic spectral shift mechanism, i.e., the source can be stationary and still exhibit the spectral shift, which can be red or blue by the way. The basic mechanism is mutual interference of the light coming from different parts of an extended body. So I would say that you can consider it to be a new red-shift mechanism.
  2. The physics is completely accepted and believed, and several people have constructed sources in the laboratory that exhibit the Wolf effect. The question is however if sources with just the right properties that would lead to a red-shift exist in nature. So I do not think that anyone who worked in this area would actually suggest that the cosmological redshifts that we observe are due to the Wolf-effect and not due to an expanding universe.

I hope this clarifies matters for you. Thank you for your interest,

Best regards, Mark


Reply from Robert S Knox (co-worker of Mark Bocko). In their paper, Bob Knox is affiliated with the Department of Physics and Astronomy, University of Rochester.

From: Robert S Knox Subject: Re: Wolf effect and redshift

Ian, You wrote

  1. this depends on the context. I would lean toward "mechanism." I've heard the phrase "Wolf shift" but not frequently. And of course the shift can be either red or blue.
  2. I think the Wolf effect is generally accepted, because it has a mathematically sound basis and has been demonstrated (your refs. 5 and 6). However, because there are such stringent requirements placed on the source correlations that produce the effect optically, it has (thus far) limited applicability except to the demonstrations of its principle. "Acceptance" is a relative term. The number of researchers interested will be proportional to the need to apply it.

Best wishes, Bob Knox

i.e. The Wolf effect is a redshift mechanism. It's application to "nature" (or astronomy) is "cautious" (as the existing article indicates). --Iantresman 17:48, 15 December 2006 (UTC)

Nope, Ian, none of the experts answered in the affirmative or described it as a "redshift mechanism". Therefore, I say we are in good standing not calling it that. Thanks for doing the legwork and quoting the responses exactly. They illustrate my ideas beautifully. --ScienceApologist 20:14, 15 December 2006 (UTC)

  • So when Mark Bocko writes: "you can consider it to be a new red-shift mechanism", how is that not in the affirmative? --Iantresman 20:25, 15 December 2006 (UTC)
  • When Bob Knox writes: "I would lean toward "mechanism." how is that not an affirmation towards "redshift mechanism" --Iantresman 20:28, 15 December 2006 (UTC)
Non-committal and not indicating that this is necessarily the standard consensus. Without an unequivocal verification of your position, I'm pretty confident we are fine with the way it is. I'm not going to entertain your POV-pushing any longer. This conversation is over as far as I'm concerned. --ScienceApologist 21:04, 15 December 2006 (UTC)
  • "you can consider it to be a new red-shift mechanism" is unequivocal. That's not my point of view, that's the point of view of an expert in the field. --Iantresman 21:32, 15 December 2006 (UTC)
But they didn't jump out and say it was one, only that one could consider it to be so. Since we have to consider whether readers will be confused by such terminology (and I venture to say that they will be), then it is best that we stick to our present description. --ScienceApologist 22:26, 15 December 2006 (UTC)
  • So "you can consider it to be a new red-shift mechanism" is not good enough, and they have to jump through hoops too. Your description does not represent the world view. --Iantresman 22:42, 15 December 2006 (UTC)
Just because one can do something doesn't mean one should do it. There is an encyclopedia to consider. --ScienceApologist 04:48, 16 December 2006 (UTC)
  • OK, so what we have here are credible experts (albeit private communications so not formally citable) saying precisely what I've said above: the Wolf effect is a frequency shift (can be red or blue) and is not widely considered as an explanation for cosmological redshift, which means the form of words describing it as a frequency shift which will be seen as red from our perspective and which may explain some discordant redshifts, would appear to be entirely accurate. Indeed, based on the above commentary, I would be very wary of including any reference to the plasma crowd here, because it's evident that these experts dismiss the possibility that Wolf effect might be a generic redshift mechanism and both point out that the shift can be red or blue, meaning it should be described as a frequency shift. and yet, Ian, you choose to interpret that as saying the exact opposite of my reading. If anything, these two comments seem to em to amke your case even weaker, and it was not strong to begin with. Guy (Help!) 12:09, 16 December 2006 (UTC)
  • How many times do I have to say it? I have NEVER considered the Wolf effect as widely held view as an explanation for cosmological redshift, and I have NEVER described it as such.
  • What is important, is that the Wolf effect is described as a new redshift mechanism (Doppler-like to be precise). This view is mainstream among those in optics, and is described as such in the literature, and in textbooks.
  • And yes, the Wolf effect can be both a redshift and blueshift, but there is also a "no blueshift" condition that produces just redshifts. --Iantresman 15:49, 16 December 2006 (UTC)
No, what is important is that it is a frequency shift, which is what the article says. You have not provided any compelling reason why the present text should be changed, or any credible argument why the present wording is worse than your preferred version, which several editors find problematic for various reasons. Guy (Help!) 23:17, 16 December 2006 (UTC)
  • Yes, the Wolf effect is a frequency shift, (similar to that which could be produced by Brillouin scattering), and is described as such, and should be described as such first.
  • But the compelling reason to additionally characterize the Wolf effect as a redshift is (a) It is verifiably accurate (b) It distinguishes it from the likes of Brillouin scattering (c) It notes the similarity to the Doppler-like redshift (d) Experts in the field also characterise it as a redshift (e) Peer reviewed sources described it as a redshift (f) Textbooks describe it as a redshift.
  • Some of your criticisms are demonstrably incorrect:
  • You wrote: "these experts dismiss the possibility that Wolf effect might be a generic redshift mechanism"
  • ScienceApologist wrote: "none of the experts answered in the affirmative or described it as a "redshift mechanism"."
  • Yet Emil Wolf wrote: "In 1986 I predicted the existence of a new mechanism for producing redshifts .. "[2]
  • Marco Marnane Capria wrote: "A New Optical Redshift Mechanism.."[3]
  • Sisir Roy and S. Datta wrote: ".. this new mechanism for redshift .."[4]
  • Mark Bocko (above) wrote: "I would say that you can consider it to be a new red-shift mechanism."
  • I have provided compelling reasons. I have also shown that the experts do indeed describe the Wolf effect a redshift mechanism. --Iantresman 23:52, 16 December 2006 (UTC)
Your reasons may seem compelling from your point of view as one who has already made up their mind that it should be so, but you don't seem to have made any converts. Rather than repeating the arguments we've already heard and rejected, what say you bring better arguments? Or better still, suggest an alternate form of words that others can get behind? Your repeated insistence on a rejected form of words is disruptive. Guy (Help!) 19:10, 17 December 2006 (UTC)

Your desire for a change to the text has been rejected, Ian. Move on. --ScienceApologist 18:36, 16 December 2006 (UTC)


So you're basically saying that without presenting ANY verifiable evidence whatsoever, not from ANY kind of source, not ANY critical texts, that you personally merely "reject" the description, despite it being overwhelmingly verifiable from expert sources, peer reviewed sources, primary sources, and textbooks. --Iantresman 00:48, 18 December 2006 (UTC)

Nope, we aren't saying that. --ScienceApologist 01:37, 18 December 2006 (UTC)
  • Just remind me of your source, which mentions the Wolf effect, on which you are basing your views? --Iantresman 11:14, 18 December 2006 (UTC)
Same ones you're using, Ian. --ScienceApologist 13:36, 18 December 2006 (UTC)
  • They characterise the Wolf effect as a redshift. How many quotes do I have to extract? --Iantresman 14:03, 18 December 2006 (UTC)
  • They also characterize it as a frequency shift. And quite frankly, extracting quotes NEVER works. The issue is that the Wolf Effect is verifiably both a frequency shift and a redshift. Since redshift carries unfortunate connotations in this line, we call it a frequency shift to help the reader. --ScienceApologist 14:13, 18 December 2006 (UTC)
  • Yes, it is a frequency shift, no dispute. It is ALSO a redshift. That's not a connotation. It is a redshift. No one else on the planet suggests this is an "unfortunate connotations", and it is not verifiable. You don't help the reader by removing information that correctly characterizes the Wolf effect. --Iantresman 14:24, 18 December 2006 (UTC)
Saying that something is a redshift connotes a relationship with astrophysics: "The question is however if sources with just the right properties that would lead to a red-shift exist in nature. So I do not think that anyone who worked in this area would actually suggest that the cosmological redshifts that we observe are due to the Wolf-effect and not due to an expanding universe." --ScienceApologist 14:36, 18 December 2006 (UTC)
  • Rubbish. There may be a connotation in the minds of astronomers and scientists, but not in the minds of those working in optics, and the rest of the planet. Here are some definitions of redshift, or which 60% of the extracts do not mention an astronomical context at all. Only one out of 10 gives an astronomy-only definition, and even your Wikipedia entry for Redshift does not mention an astronomical context until the middle of the third paragraph.
  • Now, what? Are you going to claim unreliable sources, or cherry pick some astronomy books to make your point? --Iantresman 15:08, 18 December 2006 (UTC)

Nope, I'm going to declare this conversation over. Your point is not taken by anyone but yourself. Don't like it, start an RfC. --ScienceApologist 15:35, 18 December 2006 (UTC)

  • I have demonstrated that your suggestion of confusion with astronomical redshift is not supported by the sources. Any where there is a connection with astronomy, no confusion is implied. And even if there was perceived confusion, it's nothing which any editor could easily clarify.
  • I have demonstrated that the view I wish to described is supported by the experts, reliable sources, and textbooks.
  • I am still waiting for you to provide ONE source that suggests any kind of issue regarding the Wolf effect as a redshift. --Iantresman 16:19, 18 December 2006 (UTC)

Ian, all you've demonstrated is that you don't know the difference between an editorial argument and a fact. --ScienceApologist 19:14, 18 December 2006 (UTC)

  • My editorial argument is based on all the evidence I've presented. I'm still waiting for some substance that supports yours. --Iantresman 19:56, 18 December 2006 (UTC)
  • I can bring a horse to water, but I can't make him drink. --ScienceApologist 03:34, 19 December 2006 (UTC)
  • Not especially helpful. Can you think of a form of words that Ian might be able to accept? Try to be a little accommodating, yes? Guy (Help!) 12:10, 19 December 2006 (UTC)
I think your summary below does it brilliantly. Thanks, JzG. --ScienceApologist 13:04, 19 December 2006 (UTC)
  • Ian, repeatedly re-stating your opinion is simply not helping. To baldly call it a "new redshift mechanism" is to risk misleading; the best you have from your experts is that it could be described as such, but one of them suggests that we don't do that and supports what we actually do in the article whihc is to describe it as a frequency shift mechanism - this is more specific and thus less likely to mislead. We've also noted how it could be applied to observed discordant redshifts, which addresses anything that might be left unanswered in the frequency shift description. You are arguing for a less specific definition which has been seen by others as promoting a fringe agenda, and is also arguably factually incorrect (Wolf shift can be blue or red), and it simply isn't going to fly. So I offer you one last time: come up with an alternate form of words which is acceptable to other editors, or at least forms the basis for a debate, or please just drop it. If you can't come up with something new I'm going to archive this entire discussion out before it degenerates into yet another slugfest. Guy (Help!) 12:10, 19 December 2006 (UTC)
  • Repeatedly stating your opinion is no different to mine, with the difference that mine is supported by peer reviewed sources and expert opinion.
  • I am NOT asking for a less specific definition.
  • I agree that primarily, the Wolf effect should be described as a frequency shift, as it is now. This is accurate because the Wolf effect does not always produce a redshift.
  • But I am saying that in additional to this description, we reflect the view of the experts and sources, and say that the Wolf effect has also been described as a redshift, or new redshift mechanism.
  • Mark Bocko said that he "would say that you can consider it to be a new red-shift mechanism."
  • Robert Knox said that he "would lean toward [redshift] "mechanism.""
  • Emil Wolf said that "I predicted the existing of a new mechanism for producing redshifts"[5]
  • And many others.
  • There is no confusion. They call it a redshift mechanism because it is considered to be a redshift mechanism. That is unambiguous and factually accurate.
  • Even IF there was some confusion, again that sources clarify the issue and tell us that the Wolf effect is not being offered as an alternative to the Cosmological redshift.
  • I find no sources that even hint at any confusion or dispute. --Iantresman 13:48, 19 December 2006 (UTC)
  • Summary: you absolutely refuse to countenance compromise. Fine, your loss, the article stays as it is. I'll archive this discussion shortly as it's evidently futile. Still, I tried. Guy (Help!) 19:52, 19 December 2006 (UTC)
  • For the record, neither you, nor ScienceApologist have compromised either, and have refused to describe the Wolf Effect as it is described in numerous sources. Two editors have decided that they known better than all the experts, and all the peer reviewed sources. I tried too. --Iantresman 20:23, 19 December 2006 (UTC)
  • Ian, I have offered to compromise numerous times - pretty much every comment, I think. See the number of times I've invited you to suggest a form of words which SA might be prepared to accept? SA doesn't want your text in, so it's not a surprise that he doesn't feel a need to suggest a compromise. Why should he care? Me, I am not going to start suggesting compromise forms of words because (a) I don't claim to be an expert and (b) without evidence of willingness to compromise on your part it would be a waste of time. So. You are the one who cares, how about you take the first step? I don't see it as a problem for Wikipedia not to have this statement in the article, it's satisfactory to me as it stands and there is no doubt that SA is perfectly content with the current article, so the ball really is in your court here, and demanding capitulation instead of proposing compromise does not really help your case. Guy (Help!) 14:53, 20 December 2006 (UTC)
  • The point is that ScienceApologist is demanding complete capitulation from me. That begs the question why.
  • It's like suggesting that we don't call the sky "blue"; we don't have to call it blue, and we could compromise the wording. But when all the source say it's blue, WHY should we compromise. It is blue.
  • The compromise is HOW we describe the Wolf effect as a "redshift".
  • Another example. I could quibble over the Big Bang being called a "theory". I can present a fair argument that it has reached only the status of a "model", and describing it as a theory could be "confusing". If I can present NO evidence supporting that view, then why should there be a compromise on the word "theory", just because one editor thinks it might be confusing?
  • As it is I can provide verifiable sources characterising the Big Bang as a model, [6] [7] [8], so at least I can provide some verifiable substance to my view.
  • So I would be more than happy to make suggestions on HOW we describe the Wolf effect as a "redshift", but not using the word "redshift" is misleading, and does not represent the world view. --Iantresman 22:51, 20 December 2006 (UTC)
  • We already do describe it as a frequency shift mechanism (can be red or blue, remember?) and as an explanation for some discordant redshifts. I don't see SA as demanding capitulation, simply as uninterested in your point of view. I am interested, so I'd like to see you propose a form of words which SA might find acceptable. Guy (Help!) 15:19, 21 December 2006 (UTC)
  • Note that a blueshift is a negative redshift,[9] so "redshift" does not exclude blueshifts.
  • All redshifts are frequency shifts. Not all frequency shifts are redshifts (or blueshifts).
  • Note also that describing the Wolf effect additionally as a redshift, is not my point of view. It is a verifiable point of view of the experts in the field, and numerous verifiable sources.
  • ScienceApologist will not entertain any description of the Wolf effect being described as a "redshift", or a "redshift mechanism". That is not only complete capitulation, it is not verifiably supported. --Iantresman 16:16, 21 December 2006 (UTC)
  • So you say, but I see no evidence that you've actually tried. How about trying? Guy (Help!) 17:28, 21 December 2006 (UTC)

Just thought now might be the time for another voice! Let me please start by saying that I support the wiki and no individual, as such I respect all of you and only ask that you all do the same :)

The idea of a "negative redshift" being a blueshift, while literally true, I think is a strech. A blueshift is a blueshift, a redshift is a redshift. You don't claim that a ray of light is bent -300 degrees from normal, you say it's bent 60 degrees. To play on the doppler analogy, you have positive and negative frequency shifts, and as such I feel that the term frequency shift is best suited to define it. I do feel that if the shift is generally red that should be mentioned as well, which is what is observed in the cosmos. So perhaps we could all be happy with something like "The Wolf Effect (sometimes Wolf shift) is a frequency shift in the electromagnetic spectrum.[1] The most commonly observed shift is red, thought it is theoritically possible for the shift to gravitaty towards the blue end of the spectrum." Of course we should spell everything properly :)

Hopefully that'll help everyone reach consensus. I'm open to debate of course! --Robert Stone, Jr. 04:03, 5 January 2007 (UTC)

  • Does that make it clearer? I don't know. Ian seems unwilling to even document what compromises he would accept. Guy (Help!) 17:22, 8 January 2007 (UTC)


Due to conservation of energy, frequency shifts over the entire 4 pi steradians will be redshifted and blueshifted in equal proportions. --ScienceApologist 22:42, 8 January 2007 (UTC)

Wolf effect and redshift attribution[edit]

  • The new combined policy of WP:A on Attribution, I believe has a bearing on the discussion here. I have provided several attributed statements above, in which several scientists have described the Wolf effect as a new redshift mechanism, including peer reviewed papers and books.
  • Can someone provide an attributed source which questions the Wolf effect as a redshift in any way? --Iantresman 16:28, 6 March 2007 (UTC)
  • All you have to do is provide attribution supporting your position on the Wolf effect and redshift. It's that simple. --Iantresman 19:49, 6 March 2007 (UTC)
  • Remind me, which of your citations mentions the Wolf effect and redshift? --Iantresman 19:56, 6 March 2007 (UTC)

Detailed not technical[edit]

18-Oct-2007: I have been editing several technical articles (such as "Discrete Fourier transform") to add simplified wording, but this article "Wolf Effect" is not too technical, just detailed in content. The article doesn't even mention "interference" (or "astrophysics"). Actual overly technical articles typically have more than 3 rare terms in a sentence (such as aquifer, aquitard & aquiclude) or contain several mathematical formulas; however, this article doesn't involve any of those technical issues. I have removed tag "{{technical}}" and suggested writing a more detailed analysis as to why the article is troublesome. Please don't tag an article as "technical" just because it contains detailed information. -Wikid77 07:26, 18 October 2007 (UTC)

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:06, 10 November 2007 (UTC)