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Talk:Redshift

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Old talk: from Red Shift, up to April, 2004, up to August 2005, up to Novemeber 2005 ---

Redshift and the POV of nonscientist layman Iantresman

As things have settled down a bit, I popped over here to see a terrible change to this article. Ian, claiming that the nonstandard redshift explanations are "non-Doppler" and the others are "Doppler" is not only incorrect, it belies an inordinate ignorance of the physics involved. You need to cut out your POV-pushing. Redshift is well described as the article stands right now. All that really needs to be done is relegate the non-standard explanations to POV-related articles. Redshift is well-established in intro astronomy texts as the four causes listed up front. The remaining ideas are outside of the mainstream and do not belong in the article. --ScienceApologist 17:47, 1 December 2005 (UTC)

Science edit now complete. If anybody sees any errors or ambiguities, let me know. --ScienceApologist 18:03, 1 December 2005 (UTC)

By the way, no scattering processes are included anymore. They are not agreed upon in the scientific community to allow for full-band redshifts and therefore should not be included. --ScienceApologist 18:03, 1 December 2005 (UTC)


I've reverted your changes Joshua. I'm sorry you didn't like the changes to the article.
  • Your description of me as a "nonscientist layman" is childish.
  • I have not made any "claims" as you put it. Every statement I have included is taken from peer-reviewed articles as required by the scientific process, and as suggested by Misplaced Pages policy. I suggest that you read it more thoroughly.
  • Redshift, as described by this article, is far more inclusive than your narrow viewpoint.
  • "Redshift is well-established in intro astronomy texts"
I suggest that you get you head out of your as-tronomy text book, and read further afield.
--Iantresman 19:35, 1 December 2005 (UTC)
We need to write this article so that, say, a secondary school student wishing to learn about the subject will be properly informed about the consensus on the subject. As the article stands as you have it, it is full of errors, innuendo that are external to the subject, and general bad science. The article will be reverted.
I strongly suggest you read an introductory astronomy text currently in use at the secondary, college, or graduate level and see what it has to say about redshift. That is our bellweather and our standard.
I stand by my assertion that you are a non-scientist layman who is inappropriately editting the article. I do not mind comments or edits by you, but I will continue to make sure no errors or NPOV problems creep into the article.
Thanks,
--ScienceApologist 22:24, 1 December 2005 (UTC)


  • "I strongly suggest you read an introductory astronomy text"
Your astronomy point of view, Joshua, is indeed one POV, and as such is not a neutral point of view. I am delighted to include that point of view in the article.
  • "I will continue to make sure no errors..."
I note that you have not highlighted any errors to date, except to point out that certain redshifts mentioned are not Doppler-like redshifts. I am pleased that we agree, that the non-Doppler redshifts were excluded.


  • As evidence of the use of the term redshift elsewhere, and in peer-reviewed articles, I submit:
  • I think you need to provide some peer-reviewed articles to suggest that these 500-odd peer-reviwed articles are using the term redshift incorrectly in their fields.

--Iantresman 23:02, 1 December 2005 (UTC)

Ian, your POV pushing is out of control. Your refusal to read introductory astronomy texts means that you refuse to address the real concerns about the article representing consensus in the field. I encourage you to read the Italian article for an example of a good redshift article, for example. Your insertion of nonsense does not deserve inclusion in the article. --ScienceApologist 23:06, 1 December 2005 (UTC)


  • I have already said that I am quite happy with your astronomical definition and use of the word 'redshift'. I have read some text books, and I believe that your point of view is quite accurate.
  • "Your insertion of nonsense..."
500 peer-reviewed articles are nonsense? Surely I misunderstand you?
  • Thanks for the message on my talk page. You mention that I am "getting all information from very biased sources"
My source is the Astrophysics Data System. How is that biased?
--Iantresman 23:25, 1 December 2005 (UTC)
When you claim that you are getting your information from adsabs, I know this to be false because there is no way you read all the articles you purported to read. More than that, you have not demonstrated a cursory understanding of the subject and instead are content to naysay and bring in irrelevent material. You haven't made a thorough evaluation of the sources you wish to consider, nor have you taken the advice of myself and others to read the Italian page which is a featured article. Instead you are insisting that there are many points of view about redshifts, a claim that is not backed up even by the papers you cite and do not read. As such, I can only say that your sources are indeed the many "intrinsic redshift" "Arp" and nonstandard cosmology websites which make a big to-do about what is or isn't phenomenologically sound. Please, research standard definitions before you go charging on into redefining a page on a very standard subject. --ScienceApologist 16:45, 2 December 2005 (UTC)
If you click on any of the links to the references I gave above, you will find a list of search results, from the Astrophysics Data System. A very simple check:
  • Redshift as used in Brillouin scattering over 30 references (Click link)
  • The very first search result is "Structure-dependent electronic properties of nanocrystalline cerium oxide films" (Click for the Abstract)
  • An extract reads: We investigate the electronic properties of nanocrystalline cerium oxide The fundamental gap Eg of CeOx is due to the Brillouin zone explaining the redshift of Eg in nanostructured CeOx... (my emphasis)
Unless you are suggesting that cerium oxide films are subject to Doppler, Cosmological or Gravitational redshifts, then I would suggest that the author's use of redshift is not included in your exclusive astronomy-related definition.
There are lots of other examples from the search results, such as the explicit "The origin of the redshift in Brillouin spectra"
To summarise: I have provided 500 peer-reviewed references that seem to use redshift in a non-astronomy-related manner, and you have rubbished then all. You have balls. I'm still waiting for ONE peer-reviewed reference from yourself.
"Nonscientist layman" --Iantresman 17:46, 2 December 2005 (UTC)

All you need to do to show me your POV deserves inclusion is cite one example where someone applies any of the formulae in this article to a cause not cited in the article. Any of the five formulae will do. Until then, you haven't demonstrated that they are talking about the same thing. -ScienceApologist 21:51, 2 December 2005 (UTC)

Ian's demonstartion of understanding

Ian, please before you start inserting your POV into the article answer the following questions:

  1. If an object has an observed wavelength of 600 nm and an emission wavelength of 400 nm, what is the redshift?
  2. What recessional velocity does a redshift of z=1 correspond to? (HINT: it is not c).
  3. A spectroscopic binary shows a recessional velocity of 30 km/sec. What is its redshift?
  4. What is the Doppler broadening of a line refer to? Can Doppler broadening of a line be said to be due to redshift?

These will give us an indication of how familiar you are with the subject you wish to completely overhaul with your supposed "neutral" POV.

We need to have an article that will help students, for example, answer these questions with as little clutter as possible.

Thanks,

--ScienceApologist 23:14, 1 December 2005 (UTC)


I'm not jumping through any hoops for you Joshua. If I have made any errors in my additions, besides your non-acceptance of 500 peer-reviewed, non-Doppler-like redshifts, then I am happy to be corrected. --Iantresman 23:25, 1 December 2005 (UTC)
See the article, the corrections have been made. --ScienceApologist 23:28, 1 December 2005 (UTC)

Can't we just be friends?

Sarcastic title aside, sometimes I worry that people on Misplaced Pages like arguing more than improving articles. If we use Google scholar, and search for "redshift" we get 187,000 hits. If we exclude the litany of astrophysical words : "cosmology cosmological star stars stellar galaxy galaxies galactic extragalactic nebula quasar quasars QSO supernova supernovae forest CfA IRAS astrophysics astrophysical GRB" (forest is to exclude the Lyman-α forest without excluding other mentions of hydrogen) we get a little less than 6,000 hits, and probably about half of them are still astrophysical uses. This clearly indicates that the astrophysical usage predominates. So why not write, "redshift is primarily used by the astrophysical community to indicate a proportional increase in the wavelength of light across the spectrum ... the only known causes are relativistic effects such as the Doppler shift, Hubble redshift and gravitational redshift. Atomic, condensed matter and other physicists occasionaly use redshift to indicate a frequency dependent effect, in which the wavelength of a given spectral line is reduced. This is usually accompanied by other effects, such as the broadening or splitting of the spectral line, and can be caused by the Stark effect, Brillouin scattering, the Wolf effect, etc..." –Joke137 18:23, 2 December 2005 (UTC)

Yes, I agree that (a) something like this should be added to the list of causes (b) and also a note that redshift means "shift", as in spectral shift due to any of the numerous possible causes.
I do not contest that the astronomical use predominates, but that's arguably because there are more researchers. There's also 200 million Americans, but that's no reason to exclude eskimos from an Encyclopedia. --Iantresman 18:40, 2 December 2005 (UTC)
I have been in many discussions with atomic, condensed matter, and other physicists and have never seen them use "redshift" as it is used in this article to describe a frequency dependent shift. None of the resources Ian has pointed to do that either, instead there are some that make vague claims about polluting redshift in astrophysical conditions. Therefore, our disclaimer on the page is sufficient. --ScienceApologist 21:53, 2 December 2005 (UTC)

I don't know, how about or or or . These are all Greek to me, but they certainly don't seem to be talking about the redshifts I know and love. It seems to me that while the astrophysical usage overwhelmingly predominates, it is natural also to use it for a generic behavior in which some effect shifts to longer wavelengths. –Joke137 22:05, 2 December 2005 (UTC)

Your first citation is to a poorly written (from the English standpoint) paper on the Stark Effect. It seems the authors and the reviewers could have done with some vocabulary adjustment, but I understand the idea of the frequency shift due to Zeeman splitting can be locally viewed as analogous to the gravitational redshift for certain lines. Not a good choice of wording, if you ask me, but I cannot find reference to someone else using that wording that wasn't translating into English. Maybe it's an issue of translation? The second paper I cannot make heads-or-tails of. The last two papers appear to be about redshifts that are at least superficially due to the mechanisms we post above. To that end, I'm not sure we've demonstrated that there are people who use redshift to mean something other than the definition we have here. --ScienceApologist 22:17, 2 December 2005 (UTC)

Well done Joshua, "there are people who use redshift to mean something other than the definition we have here".
Nonscientist layman --Iantresman 22:40, 2 December 2005 (UTC)
Yes, Ian, there are people who use "Redshift" to refer to a computer program. That should also not be included on this page. -ScienceApologist 02:23, 3 December 2005 (UTC)

POV pushing section removed

===Frequency-dependent redshifts===

There are also a number of causes of frequency-dependent redshift of spectral lines. This use of the term 'redshift' is in less common usage, and will not be discussed further in this article. They include Brillouin scattering , Compton scattering , Raman scattering Wolf effect , and other theories such as tired light theories These redshift mechanisms are sometimes called non-Doppler redshifts , non-Cosmological redshifts , or intrinsic redshifts .

This section was removed as the statements made about the citations are not verified. --ScienceApologist 02:30, 3 December 2005 (UTC)


RfC: Request for Comments

Misplaced Pages Request_for_comments page

Myself, user:iantresman is having a content dispute with user:ScienceApologist (previously User: Joshuaschroeder ) over whether to mention that some scientists use the term 'redshift' in a wider context than is used by that in astronomy to mean just Doppler, Cosmological or Gravitational redshift. I do not contest that the astonomical use of the term dominates. Details of the dispute may be read above, and on previous archive pages.

I propose that the article includes something to the effect that (a) a 'redshift' means 'a shift in frequency' (ie regardless of the cause, such as in 'the spectral line is redshifted') (b) under the section "Causes of redshift": Some scientists recognsied a number of causes of frequency-dependent redshift of spectral lines. This use of the term 'redshift' is in less common usage, and will not be discussed further in this article. They include Brillouin scattering , Compton scattering , Raman scattering Wolf effect , Neutrino redshift , and other theories such as tired light theories These redshift mechanisms are sometimes called non-Doppler redshifts , non-Cosmological redshifts , or intrinsic redshifts .

Evidence in support of the proposal (user:iantresman)

  1. Over 500 peer-reviewed references (see list above) using the term 'redshift' in a non-Doppler-like manner.
  2. 5 votes out of 5 in the Discussion on the Bad Astronomy Universe Today Forum in the thread "Spectral line redshift versus Doppler redshift", including supporting comments from Jet Propulsion Laboratory physicist Tim Thompson
  3. Confirmation from three professors of physics that they use the term 'redshift' in a non-Doppler-like manner, including Prof. Daniel F.V. James , Prof. Emil Wolf , and Prof. Theoretical Physics, Indian Statistical Institute, Sisir Roy
  4. Contributing editors (a) User:Serjeant who writes regarding the Wolf effect "it certainly rates a mention" (b) Prof. Daniel F.V. James (mentioned above) who writes "The term "redshift" is not used just by astronomers. it refers to any process which increases the wavelength of light" (c) user:naasking who writes "the general "Redshift" phenomenon should in fact discuss all redshift (ie. all mechanisms of redshift,.." (d) User:Joke137 who also supported mentioning non-Doppler-like redshifts.
  5. The Misplaced Pages Neutral Point of View page requires articles to be "representing all majority and significant-minority views fairly and without bias."

Evidence opposing the proposal (user:ScienceApologist)

{to come}


Please Support or Oppose, together with a comment, and sign and date by either adding "--~~~~" (if you have an account), or your name and date if you don't.

Nominations

Support As proposed above, --Iantresman 12:20, 3 December 2005 (UTC)

Category: