Talk:Redshift

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This article has had a scientific peer review which has now been archived. It may contain ideas that you can use to improve this article.

Archives
1, 2, 3, 4, 5, 6, 7, 8, 9 Debate about "See Also" policy and relationship to "What links here" - /See Also Dispute June 2006 Policy debate about an edit that moved content from another article to Redshift - /Content Moved From Redshift Quantization Dispute June 2006

Contents 1 Congratulations 2 Using the Wolf Effect as an example in physical opitcs/radiative transfer 3 Congratulations 4 Congratulations 5 Photograph 6 Plasma Redshift and Tired Light 7 Mechanism text 8 majorish edit 9 List or separate article for unconventional theories? 10 Red shift in one direction = blue shift in opposite direction and vice versa? 11 Relative Doppler Effect question 12 Junk Science? 13 Title and spinoff problems 14 Energy considerations 15 Additional Mechanism 16 blue shift 17 clarification of shifts 18 Different kinds of redshift 19 Halton Arp 20 See also 21 Including some implausible hypotheses in the main article 22 The current sentence looks good to me 22.1 7 extra words & Theories can be important even if almost everyone agrees they are wrong 23 Summary of Viewpoints about the prominence of Halton Arp, Intrinsic redshift, and Tired light and how to proceed from here 24 Tired light

[edit] Congratulations

Well done folks on a very clear, comprehensive and well-referenced article! Work pressures mean I've not contributed for some time, but I'm very happy to see the article in such a healthy state.

I won't wade in straight away with new edits; I'd first like to discuss with you two areas that I wonder if the article should cover, or cover differently.

Firstly, the article gives metrics for each of the redshift mechanisms. In fact, these are only examples; the Kerr metric also has gravitational redshift, for example. I like it that the article mentions coordinate transformations, which are a natural way of explaining the Doppler effect (SR or otherwise), but they are less natural for the other redshift mechanisms. Perhaps this could be expanded or rejigged somehow? The physical distinction between redshift from expansion of space and gravitational redshift is the non-constancy of spatial metric elements and temporal metric elements. I wonder if the article should note this distinction, and note in the table that the metrics are examples. Can we simultaneously satisfy both the expert reader and the novice?

Secondly, there are plans to measure the expansion of the Universe in real time, for example with CODEX on the European Extremely Large Telescope. The effect is tiny (dz/dt is about 10^{-10} per year) but if the systematics aren't a killer it could be a very interesting experiment. Perhaps this rates a mention.

Serjeant 12:40, 25 November 2006 (UTC)

We might resolve your first issue by putting a (for example) disclaimer in the table. You might also head on over to metric expansion of space where I had to explain the difference between the equivalence principle and the expansion of space.

The second issue also might be better discussed at the metric expansion of space page. Though it may deserve at least passing mention here.

--ScienceApologist 13:48, 4 December 2006 (UTC)

"The physical distinction between redshift from expansion of space and gravitational redshift is the non-constancy of spatial metric elements and temporal metric elements." This is very true -- Schwartzschild has a timelike Killing vector, so light bouncing back and forth in a station-keeping box won't redshift, while this is not true for the FRW (actually there are some incredibly subtle issues there that confuse my colleagues! -- although about half of those colleagues think I'm the one who's confused.) In any case, Serjeant, I think that this is a really subtle issue that is best not covered by the article -- it really would take a detailed discussion I think that would better belong in a textbook. Sdedeo (tips) 03:48, 29 December 2006 (UTC)

[edit] Using the Wolf Effect as an example in physical opitcs/radiative transfer

Since there are other ways to get frequency shifts in physical optics and radiative transfer, it is inappropriate to unduly weight the Wolf Effect. There is no chance that we will link to every alternative redshift mechanism in this section due to WP:NPOV#Undue weight, so I submit that we remove the reference to this singular effect. --ScienceApologist 13:20, 7 December 2006 (UTC)

[edit] Congratulations

I pretty much understood it - I think. I've actually seen red and green falling stars about 10 ten years ago. Did I get it? I hope so, because it was written in such clear, plain, language. Once again, thanks so much to all who worked on it (The picture is extra-pretty:) )NinaEliza 00:54, 29 December 2006 (UTC)

Unfortunately, the color of falling stars is likely due to the chemical composition and temperature of the meteor rather than this effect, but I'm glad you liked the article. --ScienceApologist 02:23, 29 December 2006 (UTC)

[edit] Congratulations

I'm mostly out of the wikiproject these days, but I'm a professional astronomer (a postdoc right now), and read through the article pretty carefully. It is very well done, and I doubt that Britannica could cover the subject a fraction as well as it is covered here. Not only are some of the usual fallacies avoided, but some important and clever editorial decisions are made (unifying the discussion under reference frame transformations) that really enlighten the subject. I would be more than happy to recommend this article to a student.

Congratulations to everyone who has worked on this article.

Sdedeo (tips) 03:42, 29 December 2006 (UTC)

[edit] Photograph

I plead complete and utter ignorance on this subject - but can redshift be photographed, and if so is it possible to incorporate an image of redshift actually occurring into the article? I suspect not as it already looks thorough but I thought it was worth asking. Thanks Yeanold Viskersenn 03:47, 29 December 2006 (UTC)

To "see" a redshift, the object would have to be traveling faster than any macroscopic object that exists here on Earth has ever traveled with respect to any other object. --ScienceApologist 04:11, 29 December 2006 (UTC)

Would it be possible to find two galaxies, matched for their physical parameters (number of stars, age, ellipticity, what-the-heck-do-I-know) and viewing angle, but one at low redshift and one at high redshift? Once the images are adjusted for size and brightness, it should be possible to see the difference in color in a true color image (I think). --Art Carlson 10:51, 29 December 2006 (UTC)

The best we can probably hope for is looking at HUDF objects. Those things look like red dots and the galaxies in their own frames are probably very blue starburst galaxies. --ScienceApologist 12:46, 29 December 2006 (UTC)

Interesting idea, and a question to embaress astronomers like me who can't tell you off the top of their heads if galaxy properties vary so much that redshift comparisons that are visually obvious are possible! Sdedeo (tips) 11:09, 29 December 2006 (UTC)

[edit] Plasma Redshift and Tired Light

I think this page would be more complete if it mentioned some theories which challenge the conventional explanation for the observed cosmological redshift - and therefore which challenge the Big Bang Theory. The most prominent one is Ari Brynjolffson's January 2004 "Redshift of photons penetrating a hot plasma" (http://arxiv.org/abs/astro-ph/0401420). I have a partially developed theory, and a long discussion of the implications of any such plasma redshift mechanism (http://astroneu.com). For instance, a theory such as this might explain the heating and acceleration of the solar corona, which is not explained by the best conventional theories, which are based on magnetic waves, rather than the interaction of sunlight on sparse plasmas (http://astroneu.com/plasma-redshift-1/#Cranmer). Other theories include Paul Marmet's neutral hydrogen (and therefore not plasma-based) theory (http://www.newtonphysics.on.ca/HUBBLE/Hubble.html), Lyndon Ashmore's Tired Light theory (http://www.lyndonashmore.com) and Thomas Smid's theory (http://www.plasmaphysics.org.uk/research/redshift.htm) of light pulses being stretched by the electric fields between particles in low density plasmas. I don't understand Ari Brynjolfsson's theory enough to criticise it, and I don't support the other theories, but I think they are worth mentioning.

Alternatively these theories might be mentioned on the Tired Light page, with a more prominent link to that page from the Redshift page. Currently Tired Light is only mentioned via a footnote to the statement: "the consensus among astronomers is that the redshifts they observe are due to some combination of the three established forms of Doppler-like redshifts. Alternative hypotheses are not generally considered plausible." I am not sure if all the other theories would be classed as "tired light" by their authors, but my theory certainly is.

There have been long discussions about tired light in the past, such as in archive 7 of this page.

I think the current page is good in many ways. However, I think the term "cosmological redshift" should be applied to an observed relationship between redshift and apparent distance, rather than to a specific purported mechanism by which the redshift occurs: the theorised expansion of the Universe. This concern could be resolved by replacing "Cosmological redshift" with "Expansion of space" in the table, which would bring the left column into line with the headings which follow. The current redirection of "Cosmological_redshift" to "Hubble's Law" makes me think that the term does refer to an observational concept, rather than a specific mechanism.

I do not accept as a factual statement: "The difference between physical velocity and space expansion is clearly illustrated by the Expanding Rubber Sheet Universe,". Its not at all clear to me what the expansion of space is, if it is not simply things being blown apart - which means "physical velocity" to me. An encyclopedia article shouldn't assume that everyone understands or accepts as an absolute fact that the Universe is expanding or that electromagnetic radiation is quantized and so can be reliably treated as individual "photons". Robin Whittle 04:17, 29 December 2006 (UTC)

• Not a chance in hell. I have spent the last year trying to add information on alternative redshift theories, even generic descriptions such as "intrinsic redshift", "Non-cosmological redshift", and more specifically the "Wolf effect", "Tired light" and others.
• One individual, ScienceApologist has taken it upon himself to ASSUME that the only description of redshift, is that used by cosmologists.
• Despite Wiki policy allowing us to describe all significant views, these alternatives have been systematically removed for all manner of reasons, from absolute denial, to claiming little or no support.
• Worse, there is little will from editors to change this situation, where the mainstream view is ipso facto taken to be both the neutral point of view and the truth. --Iantresman 10:15, 29 December 2006 (UTC)

Just to be clear, I can not think of a single professional astronomer I have met working in the field (and I have met about a thousand) who thinks that the description of redshift as appears in this article is incorrect. Alternative explainations for redshift died out many years ago (the 1960s?) under the mountains of evidence accumulating from vastly different subfields of the science. We cover fringe theories in the relevant articles and speaking as someone in the field it seems that the "alternative" theories are given the proper weight -- i.e., referenced in passing but not treated as in any sense mainstream. Sdedeo (tips) 11:13, 29 December 2006 (UTC)

• You (Robin) will have a hard time establishing notability of a scientific theory that has not been published in a peer-reviewed journal (and even then it is not automatic).
• I agree that the Expanding Rubber Sheet Universe does not "clearly" illustrate anything. (See, however, the recent comment by Sdedeo.)
• In my opinion, the quantization of light is one of those things, like the roundness of the Earth, that is so well supported and so widely accepted, that it is editorially appropriate to refer to it as though it were a fact. In contexts where it might not be understood, of course, there should be a link, probably to Photon.

--Art Carlson 13:03, 29 December 2006 (UTC)

There is a difference, of course, between the quantization of light and the quantization of redshift. --ScienceApologist 13:06, 29 December 2006 (UTC)

In this article I feel it could be better explained that there are other 'fringe theories' out there. Either in the article or more clearly stated in Note 33 (or in the area where Note 33 is referenced). I don't know much about the subject matter but I think the 'fringe theories' are hidden a bit too much in the article. Strawberry Island 16:09, 29 December 2006 (UTC)

The 'fringe theories' are not notable enough for further inclusion in this article as reported by Sdedeo. --ScienceApologist 16:14, 29 December 2006 (UTC)

• Sdedeo, no-one is saying that the description of redshift in this article is incorrect. And no-one is saying that alternative redshift theories are correct either. You are wrong about the alternative redshift theories, as is evidence from the peer reviewed papers that continue to appear on the subject. How many peer reviewed papers do you want? Five? Ten? {http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?db_key=AST&db_key=PHY&db_key=PRE&qform=AST&sim_query=YES&ned_query=YES&aut_logic=OR&obj_logic=OR&author=&object=&start_mon=&start_year=&end_mon=&end_year=&ttl_logic=OR&title=&txt_logic=OR&text=%22intrinsic+redshift%22&nr_to_return=100&start_nr=1&jou_pick=NO&ref_stems=&data_and=ALL&group_and=ALL&start_entry_day=&start_entry_mon=&start_entry_year=&end_entry_day=&end_entry_mon=&end_entry_year=&min_score=&sort=SCORE&data_type=SHORT&aut_syn=YES&ttl_syn=YES&txt_syn=YES&aut_wt=1.0&obj_wt=1.0&ttl_wt=0.3&txt_wt=3.0&aut_wgt=YES&obj_wgt=YES&ttl_wgt=YES&txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1}
• That you consider "astronomers" to be the sole arbiters of redshift is highly selective and biased.
• For example, the Wolf effect is described as a redshift in the literature (peer reviewed), by the experts in the field, and textbooks on the subject. I am not aware of any reliable sources that dispute this. --Iantresman 18:31, 29 December 2006 (UTC)

Sorry, I should be clear. The vast, utterly overwhelming consensus on cosmological redshifts is what is currently described in the article. Astronomers, being the professional group that studies these cosmological redshifts, are surely the arbiters of this question and the relevant community to define what is and is not fringe. Meanwhile, the existence of peer-reviewed papers disputing this is really insufficient to challenge that. The Wolf effect is, by vast community consensus in place for many decades, not the cause of cosmological redshifts. You will not find any recent textbook on cosmology or astrophysics from a reputable publishing house that disputes this. Sdedeo (tips) 18:41, 29 December 2006 (UTC)

• Absolutely. But this is not an article solely about "cosmological redshifts". It's an article about "redshift" in general, as indicated by the title, and the introductory paragraph. I have no problem with a separate article called "Cosmological redshift", and even Doppler redshift, just as there is already an article called Gravitational redshift.
• But to suggest that there are only three types of redshift, and no other alternative theories, is demonstrably and verifiably false.
• No-one is suggesting that the Wolf effect is a cause of Cosmological redshift. Reliable sources, the experts, and textbooks describe it as a "redshift" (or new redshift mechanism). A small number of people have also suggested it as a contributing non-cosmological redshift, but not as an alternative to the cosmological redshift. --Iantresman 19:19, 29 December 2006 (UTC)

I see what you are saying. My feeling is that this article should not become a grab bag for every single mechanism that changes the frequency of a photon, and I've added a paragraph to the introduction that I think solves the problem you describe. Sdedeo (tips) 19:55, 29 December 2006 (UTC)

• That's perfect, it makes the acknowledgment, is verifiable, accurate and allows the reader to find out more. --Iantresman 20:38, 29 December 2006 (UTC)
• Is it worth mentioning "Intrinsic redshift" an article which describes some of these theories in more detail? --Iantresman 20:41, 29 December 2006 (UTC)

I see that the mention of the Wolf effect lasted less than 24 hours, being excised by ScienceApologist claiming "more general" usage, when it does no such thing. The text now implies some other mechanisms which may only be described as a redshift, whereas the Wolf effect actually produces a redshift, and other theories might too. Nothing like giving the reader misleading information. Once again, ScienceApologist is the only person on the planet that disputes the Wolf effect as a new redshift mechanism. --Iantresman 16:58, 30 December 2006 (UTC)

I find it hard to see the changes, amidst all the vandalism reversion, which I guess results from the article being featured on Wikipedia's main page for a day.

The theories I mentioned do not pass the notability test, but does that guideline apply to what can be mentioned in an article? My impression of the http://en.wikipedia.org/wiki/WP:NOTE guideline is that it controls whether there should be an article on a topic, with the notability test being applied to the topic.

I am not suggesting that alternative theories be accorded any greater status than that they are not accepted as valid by the mainstream cosmologists. I just think that it would be good to have a list of them at the bottom of the article. While I do not support Halton Arp's theories at all, I think the list should link to Intrinsic Redshift and Redshift Quantization.

The entire edifice of the Big Bang Theory, which is the most prominent alternative to multiple religiously based views of creation, rests on the mechanisms responsible for the observed cosmological redshift. Religion/cosmology is probably the oldest and most over-arching human activity. I think the redshift debate is really important - though most people think everything has been settled.

The fact that mainstream researchers don't recognise problems in the current paradigm does not guarantee that the paradigm will survive. For instance: http://en.wikipedia.org/wiki/Continental_drift#Debate .

Is this Redshift article about the conventional understanding of redshift mechanisms or about the current state of scientific debate about redshift mechanisms? I don't think the matter is settled enough to forget that this is a debate.

A reader wanting conventional 'facts' to solve a problem - such as their homework assignment - wouldn't be interested in unconventional theories, but adding a short section on unconventional theories at the bottom of the page wouldn't cause them any bother.

Maybe the main redshift article should contain a link to a second article "Redshift Debate", where non-conventional theories and the history of the debate are covered. In such a page, the fact that theories are non-conventional and perhaps not written up in peer-reviewed journals would not be a problem. Non-standard Cosmologies is a relevant article, but I think there are enough non-conventional redshift theories to make a good article.

Regarding 'photon' and quantization of electromagnetic radiation: I assume both mean that emr is ejected as a discrete packet from one piece of matter and that this entire packet is absorbed by another piece of matter. The idea that two photons can interfere is not compatible with my understanding of the emr itself being quantized.

The Photon article currently mentions nothing about interference between two different photons. My impression is that the original Dirac theory has been modified to account for interference, such as between two lasers or radio transmitters - but I don't see how that is compatible with quantization of emr itself, which to me is different from quantization of emr's interaction with matter. I can't explain why the apparently diffuse field results in what we observe as discrete, intense, energy deposition - but lack of a full explanation doesn't mean that I think interference between two separate sources disproves the hypothesis of actual quantization of emr.

Thanks ScienceApologist for changing "a photon" to "electromagnetic radiation". Robin Whittle 05:21, 30 December 2006 (UTC)

I don't wish to start a debate on quantization of emr here - I just wanted to explain why I don't accept it. The Photon article lists some references (note 28) for experiments which supposedly demonstrate that it is quantized. I am reading the Thorn et al. paper http://people.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf which seems to contain a good review of this field and some other papers on interference between two photons. These include papers citing Phleegor and Mandel 1967. I can send these to anyone who is interested. Robin Whittle 10:18, 30 December 2006 (UTC)

Of course less notability is required to mention something in a minor article than to mention it in a major article or to give it its own article. In this case, we could consider mentioning the alternative theories in a footnote. I'm thinking of the case that I come here with the idea of taking a look at all the far-fetched redshift theories, just in case there is some gold among the dross. Or maybe I'm only interested in the sociology of fringe theories and want to look into what kind of people so enjoy swimming against the tide. On the other hand, including a link to an external site, even in a footnote, suggests that that site has some educational value. We have not yet established that for these sites, and doing so is probably beyond our mandate. If no one has published their opinion of the theory, not even the anonymous referee of a journal, then we can only report our own opinion, but that is indistinguishable from original research. If we include a list of theories without evaluating them, then we have no rationale not to include a link to every crackpot theory an individual puts on his web site. On the whole, I think it is a better decision to stick to half-way notable theories, even within a footnote.

The fundamental problem is that I see no evidence that the "scientific debate" you talk about actually exists. If the debate takes place completely outside of professional journals, then it is not a scientific debate. I can not see any significant debate in politics or the popular press either.

P.S. It seems to me that your skepticism of the quantization of radiation results from a misunderstanding. Two photons cannot interfere with each other unless they are coherent, but then they are (in some sense at least) one and the same photon. But you are right, this is not the place to debate it, and that fact that you have some questions does not change the fact that photons are so widely accepted that Wikipedia should talk about them in the indicative mood.

--Art Carlson 17:15, 30 December 2006 (UTC)

Please see new section below: "List or separate article for unconventional theories?". I am discussing about emr quantization on the photon talk page. Robin Whittle 12:38, 1 January 2007 (UTC)

[edit] Mechanism text

The following text was added well-intentioned, but awkwardly:

A redshift can be measured by looking at the spectrum of light that comes from a single source (be the analyzed, unknown source called _X) (see idealized spectrum illustration top-right). If there are features in this spectrum such as absorption lines, emission lines, or other variations in light intensity, then a redshift can in principle be calculated. This requires comparing the observed spectrum of _X to a known spectrum (be the known source called _A) with similar features. For example, the atomic element hydrogen, when exposed to light, has a definite signature spectrum that shows features at regular intervals. If the same pattern of features (imagine a chart on which the wavelength is represented on the horizontal axis, and on which the intensities of light at different wavelengths are represented vertically. The curves, lines, spikes etc. formed on this chart would be unique and probably distinguishable for each element) as on spectrum of _A (in this example, hydrogen) is observed in another spectrum - the spectrum of _X - with the only noticeable difference being that of a shift in wavelength, then _X could be identified as _A, and a redshift could be determined for the object _X.

Aside from the _A and _X awkwardness, there seems, to me, to be a problem with describing an image that we don't have. This would be a good image to produce and include in the text, and I encourage a motivated editor to make such an image. However, I don't think that making a textual abstaction as such is helpful for the reader, and giving these abstractions arbitrary lables _X and _A is doubly confusing.

--ScienceApologist 12:56, 29 December 2006 (UTC)

I agree on the awkwardness of the paragraph. We do have an image that precisely shows what's going on -- at the head of the article. It might be nice to go into more detail on how redshifts are measured using lines, but I think this is confusing. Sdedeo (tips) 18:14, 29 December 2006 (UTC)

It's a bit confusing for some people who may think that it is just the lines themselves that are shifting and not the entire spectrum (continuum and all). It might be a good idea to get the plots of the spectra of two different galaxies at different redshifts to show the shift of the continuum and the lines. --ScienceApologist 01:08, 2 January 2007 (UTC)

Ordinary exponential decay of waves is found in almost all cyclic phenomenon on Earth. It is extremely well known in water waves, the vibration of springs, and other kinds of oscillatory phenomena. Reasonable grounds exist for the idea that the difference between adjacent manifolds cannot be made absolute in general relativity, because of uncertainty between them. It is displayed in macroscopic form in the Klein Bottle, which illustrates that the difference between the interior and exterior of any closed domain is not absolute. In this way, the energy and time domains within the photon's quantum are not absolutely distinct. The high energy of a freshly emitted photon gradually flows, through the not-quite-absolute manifold separating it from the time domain within the same photon, and that is a sufficient basis for exponential decay sufficient to explain the Hubble Red Shift. Even the magnitude of the uncertainty between the two domains is already known. It is the Planck action quantum. A document describing that is on the internet. SyntheticET (talk) 18:34, 4 May 2009 (UTC)

[edit] majorish edit

I just made a somewhat large edit to the breakdown of linearity in the Hubble Law. The previous version we had was a little unfocused and a bit confusing, and I think what I put in is a better direction to take (i.e., focusing on the breakdown of the Hubble law). But people like dark energy, so like the last version I snuck it in anyway. The material about quantum cosmology is not relevant to the discussion, and I took that out as well. Sdedeo (tips) 18:32, 29 December 2006 (UTC)

[edit] List or separate article for unconventional theories?

(Continuing from "Plasma Redshift and Tired Light".) Art, I don't think it is fair to characterise all proponents of non-conventional redshift theories as "people who enjoy swimming against the tide". You are entitled to think such people are misguided, but some such folk are genuinely trying to explain something which they think is wrongly understood at present.

I think I understand the concern about slippery slopes and science articles being loaded down with references to theories which are so vague or ridiculous that they are never going to advance scientific understanding. Likewise I think I understand the desire to only mention scientific work which has appeared in peer reviewed journals.

Here are some concerns I have with the peer review system and some arguments about why at least some unconventional theories should be listed, either in a section at the end, or in a separate page such as "Redshift_ unconventional_theories" which is not so restricted by the goal of protecting the reader from the work of people who choose to communicate directly, rather than via peer-reviewed journals.

I think incomplete theories can make an important contribution to science - as a stepping stone to something better, once some other people work with the good bits and add their own improvements. It is my impression that such theories are unlikely to pass peer review and be published.

Suppose for a moment that the Universe is not expanding and that most of the cosmological redshift is due to interaction with the intergalactic medium, by a mechanism which is currently not recognised - due to the mechanism being inconceivable (that is, it looks impossible and therefore unscientific) within the photon paradigm of electromagnetic radiation. If so, it is vital that new theories, including incomplete ones, be discussed. I think that a WP article can safely point to non-conventional theories, and so enable the reader to look at the scientific process, with all its messiness, in progress. The current narrow focus of this and other articles where extensive deletions have been challenged by people such as Iantresman seems to result from the view that the current paradigm is beyond question, and that the interests of readers could not possibly be served by mentioning theories which are outside this paradigm. (The trouble with paradigms is no-one can see what their own paradigm really is. Only someone with very different ideas can see the limitations of someone else's paradigm.)

I think a paper which suggests this - challenging the current paradigm of cosmology and probably quantum mechanics - is going to have a much harder passage through peer review than a conventional paper devoted to a smaller and more conventional topic.

I understand that Ari Brynjolfsson's paper http://arxiv.org/abs/astro-ph/0401420 languished in peer review for an unreasonably long time before being rejected without satisfactory explanation. Although I don't understand the math sufficiently to evaluate this paper, it seems to be a theory which is perfectly amenable to scientific discussion. It is carefully written, coherent, not too vague, makes definite predictions, and is - as far as I know - based on conventional mathematics and established principles. It may turn out to be completely wrong, but it is not the purpose of peer review to prevent publication of theories which the reviewer considers merely wrong. I think that Ari Brynjolfsson's theory is scientifically testable, and that if the peer review system was working properly, his paper would have appeared in a peer reviewed journal well before 2004.

I don't have enough faith in peer review to feel that we are doing readers a service by excluding mention of every single non-peer reviewed theory. Having a set of links to unconventional theories shouldn't detract from the value of the article, or give the impression those theories are as accepted as the mainstream theories. However, if the list became very long, it could be a drag and cause for the creation of a separate page.

By ignoring the unconventional, textbooks and encyclopedias (which are relied upon by most non-specialists and establish new entrants' conceptual framework) lock in the prevailing paradigm and make most people think that the field is settled and beyond question. This stifles the critical and imaginative thinking which is required for further scientific progress. Of course, not all textbooks and encyclopedias do this, but there is a tendency towards brevity at the expense of a richer exposition of doubts and controversies.

The question of redshift mechanisms in plasma is absolutely crucial to astronomy, cosmology and therefore a great deal of science and philosophy. Since there is no satisfactory conventional explanation (http://astroneu.com/plasma-redshift-1/#Cranmer) for how the sun deposits 1/10000 of its output in the the corona and solar wind, I don't think that conventional theories regarding light and plasma should be regarded as being beyond question.

To not mention any scientific theory which is outside the peer review system tends to restrict WP to portraying the prevailing paradigm - and tending to imply, without formally acknowledging so, that the current paradigm is not worth questioning, and that no-one is questioning it.

Such an approach tends to present WP's science content as "reliable facts, or the best conventional theories can get to them". This ignores the fact that science is an imperfect, human, activity. Anyone interested in how scientists actually work - including wannabe scientists and scientists who have chosen to publish directly in arxiv.org, rather than via peer reviewed journals - would be badly served by such an approach.

An external site doesn't have to contain only peer-reviewed work to be of "educational value". I think that at least some work outside peer-reviewed journals has educational value to at least some readers. Firstly it is of interest to anyone studying the broader topic of people struggling to contribute to science. Secondly there may well be some lasting scientific gold amongst the half-baked or seemingly crazy theories. Thirdly, it enables people to compare sites which they may well decide are loony and genuinely unscientific with sites and papers they (and the prevailing editors) think are of high scientific value.

Broadly speaking, in a user-maintained encyclopedia which involves no physical cost constrains (except due to printer ink and paper to those who chose to print the entire article), I think we can be more helpful to readers by at least including links to theories which are clearly challenging the mainstream paradigms, as long as we indicate this is their status, and don't try to pretend they are any more widely than they are.

So, prevailing editors (ScienceApologist et al.), if you can't handle the idea of a list of links to non-conventional theories on this page, then would you please accept a link at the bottom to a page such as "Redshift_ unconventional_theories" AND not interfere with that page? I am sure Iantresman and like-minded individuals would start such a page with a link to the conventional page with a note that the new page discusses and links to theories which fall outside the framework adopted by editors of the conventional page. Robin Whittle 12:38, 1 January 2007 (UTC)

All editors are welcome to edit all articles of Wikipedia. No article can ever be declared off-limits (see WP:OWN). An article with such a title and suggested content would be deleted per Wikipedia's original research policy and it is also a POV fork which is an editting tactic that is specifically forbidden. So, unfortunately you're stuck editting here, at redshift quantization or at intrinsic redshift. And no, I will not restrict my editting. --ScienceApologist 13:56, 1 January 2007 (UTC)

Dear Robin, I appreciate the care you are taking to explain your point of view (and especially the civil tone), but I think you are missing the kernel of my reservations. How are we, as encyclopedia editors, to decide which theories are worth linking to and which are such garbage that it would be a disservice to our readers to give them any free press? The bar of peer review is really quite low, and any scientist can tell you that a lot of garbage gets past it. All you have to do is find one referee of one journal that is willing to say that your ideas are not obviously flawed and might be interesting to other scientists in one way or another. If a theory has not passed this minimal test, how are we as editors to decide it merits exposure without doing any original research? We have no basis within the policies of Wikipedia to decide that the peer review process for Ari Brynjolfsson's paper was "unreasonably" long, or that the reasons for rejection (which are not a matter of public record anyway) were not "satisfactory". Such objections to including non-notable theories remain regardless of the form in which we present them. I don't think the peer review system is as bad as you do, but it doesn't really matter. We are not here to right the wrongs of the world, just to present the current state of collective knowledge. --Art Carlson 20:50, 1 January 2007 (UTC)

I apologise for suggesting something which violates http://en.wikipedia.org/wiki/WP:OWN. I suggested it because I think it makes sense in the context of a discussion list where it is desired to let two or more individuals or groups discuss something in their own way, without interference from people who have contrary purposes or fundamental beliefs.

Persistent problems can arise from Wikipedia's attempt to get a loose and changing group of self-selected individuals to create and maintain a single article which aims to resembles that which might be created by a single, paid, carefully chosen, leading authority. One approach is to create another system with different policies, such as Wikinfo.org - which "provides a seamless platform for the meshing of encyclopaedic material, original work, creative work and public domain material to further both education and information."

I think the central issues on this Redshift page - and on potentially tens or hundreds of thousands of other pages - are:

1 - WP insistence on peer-reviewed material as the only criteria for notability in science articles.

2 - Whether this notability requirement must be applied to everything which is mentioned in the article, including non-peer-reviewed critiques or alternative perspectives - and if so, whether such mentions should be in the main body of the article, or only in footnotes.

Thanks ScienceApologist for pointing out your view that my suggestion runs foul of http://en.wikipedia.org/wiki/WP:POVFORK - although you state your view as if it was a fact.

However it could be argued that what I am suggesting is an article not so much on "redshift" (according to the limits imposed by WP guidelines), but on redshift theories which are outside the mainstream and due to their lack of publication within the peer review system are not considered as worthy of mention as "science" within WP.

I know this sounds dodgy, but your response raises some important questions about the scope of "science" as you see it, and the scope of articles and elements of articles which you believe you can, and should, delete or edit in ways which are contrary to the wishes of those whose material you alter. For instance, is an article on philosophy of science a "scientific" article for the purpose of applying WP guidelines? I don't think of philosophy as science.

I consider the WP policies on "science" and the way you and others interpret them to be important matters of philosophy of science. If I were to write a philosophical essay on this subject, would there be any objection to it being linked to from a "philosophy of science" WP article?

Writing essays on your own personal opinions are not allowed in Wikipedia per original research limitations. --ScienceApologist 00:43, 2 January 2007 (UTC)

Similarly, discussions on these talk pages can mention all sorts of things which are not peer-reviewed. WP presents the "Discussion" tab ready for anyone to click, but would you consider it to be against WP guidelines to include, within the body of an article (perhaps within a footnote) a specific reference to the talk page (and perhaps a particular date or link to a relevant discussion) for the benefit of readers who are interested in disputes about what theories are excluded from being even mentioned the main article?

Readers may be interested in a lot of things. However, it is not our job as editors to provide them with their hearts' desires, it is our job to write a verifiable and reliable encyclopedia. --ScienceApologist 00:43, 2 January 2007 (UTC)

If a "non-scientific" article discusses or links to a theory, essay, external resource etc. which is somehow deemed to be "scientific" for the purposes of applying WP guidelines, would you argue that all such discussions or links be deleted if the material it refers to has not been peer-reviewed?

Talk pages have considerably more leeway for discussing articles. Articles themselves need to contain information that conforms to verifiability and reliability. --ScienceApologist 00:43, 2 January 2007 (UTC)

Regarding creating two articles to cope with differing points of view, WP:POVFORK states, in part:

There is no consensus whether a "Criticism of .... " article is always a POV fork. At least the "Criticism of ... " article should contain rebuttals if available, and the original article should contain a summary of the "Criticism of ... " article.

If I amended my proposal to include the following, would you consider that it might be admissible under http://en.wikipedia.org/wiki/WP:POVFORK?

1 - The new article be titled "Criticism of conventional Redshift theories". (Though I think "Redshift_ unconventional_theories" is preferable, the longer title would be better if it clearly identifies the new article within WP as a particular form of article.)

2 - The new article should contain rebuttals, or links to rebuttals within WP and without, including to peer-reviewed and non-peer-reviewed sources and to WP articles which do not necessarily concern "science").

3 - That the original "Redshift" article should contain a summary of the new page, in a separately titled section before the references and footnotes, such as "Some of the theories mentioned in this article have been the subject of criticism from sources which fall outside WP guidelines for inclusion in scientific articles such as these. These are discussed in "Criticism of conventional Redshift theories". (I think that is enough of a summary of the new article. It would be impractical to summarise the criticisms themselves.)

I would still object on the grounds I outlined above. --ScienceApologist 00:43, 2 January 2007 (UTC)

Thanks, Art, for your constructive response. The current state of collective knowledge includes some material which exists outside (non-self-published) books and peer-reviewed journals. For instance some people choose to use arxiv.org, to use websites (which can be instantly updated, contain hyperlinks and have many pages) and to contribute via conference proceedings.

For instance a Zero Point Energy FAQ http://van.physics.uiuc.edu/qa/listing.php?id=1256 is currently an external link from http://en.wikipedia.org/wiki/Zero-point_energy . Ned Wright's web pages are cited in footnotes and links in various WP pages, including Tired_light.

I can imagine that a researcher who believes their research was delayed from being made public for a long time, after submitting it to the peer review system, only to have it rejected, would not want to try putting that paper or probably others through another such attempt.

I am well aware that a lot of important scientific communication occurs before the stage of peer-reviewed articles, starting with shooting the breeze at the Monday afternoon tea in the physics department. This does not change the fact that professional scientists publish peer-reviewed articles as soon as an idea has been sufficiently developed to make that possible. Before that, the chatter and fermentation is not notable in the sense of an encyclopedia. -- You have written a lot in this discussion, but you still haven't said what criteria you propose as an alternative to the imperfect tool of peer-review in order to separate the grain from the chaff. --Art Carlson 11:09, 2 January 2007 (UTC)

Perhaps the best place to continue this discussion is http://en.wikipedia.org/wiki/Wikipedia_talk:Fringe_theories, http://en.wikipedia.org/wiki/WP:SCIENCE, http://en.wikipedia.org/wiki/Wikipedia_talk:Notability_(science) where potential guidelines are currently being formulated by some participants in this discussion. Robin Whittle 00:34, 2 January 2007 (UTC)

Yes, WP:SCI and WP:FRINGE are good places to discuss what kinds of sources and material should be in Wikipedia. --ScienceApologist 00:43, 2 January 2007 (UTC)

Oops - I see Ned Wright's pages may be acceptable in http://en.wikipedia.org/wiki/WP:RS because he is writing in a field where his work has been published in peer-reviewed journals. Still, it would have been more professional if he http://www.astro.ucla.edu/~wright/lerner_errors.html and Eric Lerner http://www.bigbangneverhappened.org/wrightreply.html linked to each other's sites.Robin Whittle 00:59, 2 January 2007 (UTC)

ScienceApologist, I wasn't suggesting placing my own essay on WP. I will rephrase my question: In a philosophy of science article, would you delete a discussion of, or a link to, something which you thought was not scientifically notable, due to your view that either the article itself was "scientific" or that the section of the article which linked to or discussed the external resource was "scientific"?

Opinions on reliability of an encyclopedia vary, but I would consider an article which gave even a brief mention of critiques of itself, or of the policies and paradigms within which it was created, to be more reliable. This is a broad principle which applies to science and other fields. A reliable source shouldn't be so short of space or written with an overly obsessive aim of saving readers the bother of reading even a few lines regarding alternative perspectives.

Would you delete a reference at the end of main article to its talk page regarding disputes over the contents of the article ? This is a simple and commonplace mechanism to alert interested readers to the complexities and compromises which were involved in creating the article they are reading. I have placed a 3 line test case in the article:

Non-conventional theories - Some theories which challenge the mainstream understanding and which do not meet Wikipedia scientific notability are mentioned in this article's Discussion page. (See link at top of page.)

You indicate you would object to, or delete, an article of the form "Criticism of . . ." despite it sometimes being acceptable under WP guidelines. You give no reason why this approach is allowable in some cased, but not to science articles. I suggest that this and the question of links to the discussion page regarding non-conventional theories be discussed at: WP:SCIENCE and WP:FRINGE.

—Preceding unsigned comment added by Robin Whittle (talk • contribs) 02:20, 2 January 2007

Talk page link inappropriate and already removed (before I got to it). Vsmith 02:50, 2 January 2007 (UTC)

I often see links to the talk page when there is a Disputed_statement banner at the start of the article. I have been unable to find rules or guidelines governing link from the main article to its talk page or to any other talk page. Can someone point me to them? Robin Whittle 03:44, 3 January 2007 (UTC)

Wikipedia:Avoid self-references#Examples of self-references states that a possible exception to the rule against self-reference is "Use of templates in the article namespace that self-reference because they link to articles in the user, talk, or Wikipedia namespace or that are special articles", which presumably covers the banner Robin Whittle refers to. Notice the quote implies that "link to articles in the ... talk ... namespace" would otherwise be a prohibited self-reference. Also, the rest of that article opposes self-reference regardless of whether a wikilink is involved. In addition to this legalism, I'm unaware of any page that links or mentions its talk page, except through a template. Art LaPella 04:19, 3 January 2007 (UTC)

Thank, Art. I apologise for making this self-reference to the talk page. Robin Whittle 02:17, 6 January 2007 (UTC)

Hello everyone. I'm dipping back into this article talk page for a bit. I would like to congratulate the very vigilant professional scientists who have had a hand in the editing of this article, which is super. The following comment from a non-scientist drew my attention:

To not mention any scientific theory which is outside the peer review system tends to restrict WP to portraying the prevailing paradigm - and tending to imply, without formally acknowledging so, that the current paradigm is not worth questioning, and that no-one is questioning it.

This seems to be the nub of the discussion above, and it's the view of a reasonable and open-minded lay person. However, to me this seems to mis-understand what science is. Scientists (and I speak as one) are whores for ideas. If a new idea is supported by evidence, professionals leap over themselves to claim to have been among the first to appreciate this (witness the cosmological constant bandwagon, which I'm also on). There are a few examples of new great ideas in science being slow to catch on, but there are many, many more examples that don't catch on because they're not very good. Because of this, it's important for encyclopaedia articles on scientific topics to accurately and honestly represent the consensus view. Inevitably there is the risk that good ideas are not presented, but the place for presenting such ideas is in the scientific literature, whether their merits can be tested, not in a public encyclopaedia in which the general reader expects reliable, well-tested information. Software companies don't willingly release buggy software, and encyclopaedias shouldn't release ill-tested information. ScienceApologist, and others, are quite correct in taking every step to do this. Incidentally, there has already been extensive debate on the archived talk pages about various non-consensus, fringe positions. Best wishes,Serjeant 22:23, 19 March 2007 (UTC)

[edit] Red shift in one direction = blue shift in opposite direction and vice versa?

If there's a red shift in one direction, does this mean that there will ALWAYS be a blue shift in the opposite direction, and vice versa? JustN5:12 22:13, 23 March 2007 (UTC)

Poorly phrased question. If there is a redshift for an object and it is moving 90 degrees to the line of sight, there will also be a redshift for an object if it is moving 270 degrees to the line of sight (opposite direction). If there is a redshift for an object that is moving 0 degrees to the line of sight, there will be a blueshift for an object moving 180 degrees to the line of sight. --ScienceApologist 23:57, 23 March 2007 (UTC)

[edit] Relative Doppler Effect question

Why doesn't the relativistic doppler effect say that, while we see many galaxies moving at high C-ratio speeds relative to us, we do not know what direction they are moving in? That is, if a galaxy is moving at .7C relative to ours, it will show Lorentz contraction, time dilation, and a redshift no matter what the direction. What convinced us that everything moving fast relative to us is moving away? Thanks.

Bruce Wallman Brucewallman 18:13, 1 October 2007 (UTC)

The Hubble law is works out to very far distances and is not due to the doppler effect, per se. The evidence is tied together with our current understanding of physical cosmology. ScienceApologist 18:30, 2 October 2007 (UTC)

[edit] Junk Science?

My youth preacher was telling me that this, along with evolution and all the science of origins and what not is junk science. I can go to the evolution page and at least see some mention of this controversy (though it's hardly a fair representation of both sides) but there's not even a mention of the possibility that this isn't true. Why aren't both sides presented? —Preceding unsigned comment added by 74.227.196.57 (talk) 21:47, 22 October 2007 (UTC)

Just calling the consensus view of redshift "junk science" doesn't give me a lot to go on. Did your preacher have any concrete criticisms of the view presented in the article? I think you should keep in mind that this view was developed over decades by hundreds of people devoting their careers to it, and based on a lot of very sophisticated measurements. It is not easy for an outsider to even understand the state of the art, much less debunk it. How many years has your preacher spent studying physics and astronomy? But getting back to the article, even if the view of redshift presented there really is "junk science", we can only put things into the article that are based on reliable sources, and the weight given to any point of view must be in proportion to the prominence of that point of view. Can you give us a source calling the consensus view of redshift "junk science" or challenging it with scientific arguments? Is this source reliable for the information it provides, and does it represent a significant viewpoint within the scientific community or society at large? These are the ground rules we have tried to follow in writing this article. You are welcome to contribute and correct us where we may be wrong, but be aware that you will have to follow the same rules. --Art Carlson 07:53, 23 October 2007 (UTC) (P.S. I am willing to get into the details of the science with you, if you are interested, but this page is is not really the right place to do that. It would be better if you emailed me using this link.)

Dude quit wasting your time on wikipedia. You can't even tell when people are being facetious anymore. —Preceding unsigned comment added by 74.227.196.57 (talk) 16:53, 24 October 2007 (UTC)

[edit] Title and spinoff problems

Obviously the concept of redshift really can't be discussed without including blueshift, which this article does in everything except title - instead giving a separate stub to Blue shift (note the inconsistency of style between redshift and blue shift). To fix this I propose renaming/moving this page to something like redshift/blueshift, red/blueshift, etc. and redirect any old pages like blue shift. Anynobody 04:54, 26 May 2008 (UTC)

Or alternatively we could merge and redirect blue shift here. The general wave phenomenon is covered at Doppler effect. Using the Redshift title has the advantage of simplicity and, at least in my limited experience, covers most instances of Doppler-shifted light. If I recall correctly, we should avoid using the solidus in article titles since that denotes subpage.

It is not true that for every red shift there is a blue shift. They cannot all be merged; the discussion becomes chaos.

Perhaps three different redshift pages should exist, named, say,

1. Hubble Red Shift

2. Radar and Lidar Red and Blue Shift

3. Gravitational Red and Blue Shift.

That way, persons wanting to add material on blue shift could do that on pages discussing phenomena that actually do manifest blue shift. They would not have to add blue shift comments to pages where blue shift is not a subject. SyntheticET (talk) 20:54, 23 October 2008 (UTC)

[edit] Energy considerations

Since the expansion of the universe leads to a red shift, it also indicate a loss of energy. Photons from the recombination and mater/antimater annihilation in the early universe must at one time have made up a great part of its energy. Now, through cosmological redshift, most of that energy appear to be gone. How is that possible? —Preceding unsigned comment added by 83.254.79.14 (talk) 22:19, 29 May 2008 (UTC)

General relativity. Energy conservation in GR. ScienceApologist (talk) 23:17, 29 May 2008 (UTC)

[edit] Additional Mechanism

Now is an appropriate time to include in the MECHANISMS section, mention of Wave Decay theory. Wave decay had been proposed by Edwin Hubble and his co-workers around 1900 A.D. soon after discovery of the spectroscopic shift toward longer wavelengths that was named after him. The controversy was obviously political to astronomers. Hubble withdrew from wave decay and assumed the position demanded: the cause was at that time unknown. If it had been sought after the discovery of the quantum by Max Planck, a wave decay equation would probably have been written in the 1920's. As it was, the world was just out of one war and facing another.

In 1957 Expanding Universe and Big Bang theory became politically important and then urgent. Once dismissed as "tired light", wave decay was taken out of circulation after In high school physics it had been stated in 1958 that as for tired light, "no mechanism has been found." That does not preclude the determination of such a mechanism now, in the new millennium.

It is sensible by now, over half a century later, to consider wave decay theory a serious contender. This is not a contest for the throne. At least one mechanism already exists in the form of an equation that appears to describe the Hubble Red shift accurately. SyntheticET (talk) 20:01, 23 October 2008 (UTC)

[edit] blue shift

Why is blue shift redirected here? There is no mention of it here. 70.51.9.237 (talk) 11:34, 9 July 2008 (UTC)

It's mentioned 26 times, for instance at the end of the first paragraph. A blue shift is about the same as a redshift, but in reverse, so the same explanation applies. The article is called "redshift" not "redshifts and blue shifts" because cosmic expansion causes a redshift, not a blue shift. Art LaPella (talk) 23:08, 9 July 2008 (UTC)

[edit] clarification of shifts

It is very important in this discussion to keep the different kinds of spectral shift distinct. More than one kind of spectrographic wavelength shift exists in nature. They are all fundamentally different in one or more of the important fundamental dimensions of physics.

1. Velocity or Doppler Shift can be a shift toward longer or shorter wavelength depending on the direction of motion relatively toward or away from an observer. Doppler Shift is widely used in radar for determining vehicle speeds, as at traffic control cameras.

2. Gravitational frequency shift is also a shift toward longer or shorter wavelength depending on the direction of motion, whether rising or falling from the gravitationally massive object. Gravitational red shift is observed in the Sun's spectrum and in spectra of other, massive stars.

3. Hubble Red Shift always appears as a shift toward longer wavelengths. This is observed only in light from extremely distant objects, mostly galaxies beyond 50 million light years distant.

4. Others, such as the refractive dispersion with prisms, might be called 'shifts' though they add a lateral spatial dimension.

Spectral wavelength shift is often popularly called red or blue because red is the longer-wave end, and blue is the shorter end of the visible spectrum.

Red shift is therefore a shift toward longer wavelengths. When extreme, red shift can drive wavelengths well past the visible, into the infrared, millimeter, meter or longer wavelengths. Red shift occurs in all three mentioned above - Doppler, Gravitational, and Hubble Red. (Might be a good name for beer.)

Blue shift is a shift toward shorter wavelengths such as, when seen from visible light, the blue end of the rainbow spectrum. Blue shift occurs in velocity and gravitational shift only. Blue shift cannot be observed in Hubble Red Shift, because Hubble Red Shift depends on distance in space-time, and negative distances in the cosmological sense do not exist.

Generally, Hubble Red Shift is observed reaching much greater magnitude than either of velocity or gravitational shift. SyntheticET (talk) 20:41, 23 October 2008 (UTC)

Your 1, 2, and 3 are different aspects of the same thing, and we ought to explain that as much as we keep them distinct. 4 is different, but is never called redshift to my knowledge. -- BenRG (talk) 16:49, 28 February 2009 (UTC)

[edit] Different kinds of redshift

There's only one kind of redshift in general relativity. Cosmological redshift, gravitational redshift and special relativistic redshift are approximate formulas that work in certain spacetime geometries with high degrees of symmetry. They're very useful approximations, but their ontological status is the same as that of linearized gravity. Saying that there are two kinds of redshift, Doppler and cosmological, is the same as saying that there are two kinds of gravity, linear gravity and the nonlinear corrections. I'm mentioning this partly in reference to the image recently created and added by Brews ohare, which I copied on the right. I hate deleting images that people obviously spent time on, but I really think the article is better without this one. -- BenRG (talk) 16:40, 28 February 2009 (UTC)

Point well taken. It's one that's difficult to accept because so many people are convinced that the Doppler effect is responsible for the cosmological redshift when, in fact, it is strictly not a Doppler effect at all. Disambiguation can be taken too far, and I think that you rightly point out that this image may go a bit overboard. ScienceApologist (talk) 01:51, 1 March 2009 (UTC)

In response: (i) the image does not say there are two kinds of redshift, but that it illustrates two sources of redshift. (Gravitational redshift would make three sources). (ii) as indicated in the caption, this figure is very similar to one in a textbook; how misleading can it be?? (iii) in very many sources the distinction between Doppler and cosmological origins is made with exactly this example: the point is that in the cosmological case the stretch of wavelength occurs after the light leaves the source and so is obviously independent of the relative motion of the emitter and receiver. I believe these remarks strongly support retaining the figure. Brews ohare (talk) 22:58, 1 March 2009 (UTC)

On light-like spacetime intervals there is no "after the light leaves the source". There is only emission and observation. ScienceApologist (talk) 23:10, 1 March 2009 (UTC)

And in terms of the figure that means … ? See Harrison, a reputed figure in the field with many oft-cited publications. To quote: "Light leaves a galaxy, which is stationary in its local region of space, and is eventually received by observers who are stationary in their own local region of space. Between the galaxy and the observer, light travels through vast regions of expanding space. As a result, all wavelengths of the light are stretched by the expansion of space (see Figure 15.1). It is as simple as that." And here is a figure with a similar idea from a source different than that in the caption Jones et al. Brews ohare (talk) 23:44, 1 March 2009 (UTC)

This explanation is not quite right. The verbalization misses the point that integrating along a light-like geodesic does not only require the movement through vast amounts of space but also vast amounts of time. If light just traveled on space-like geodesics there would be possible observations that would have no redshift whatsoever. ScienceApologist (talk) 00:24, 2 March 2009 (UTC)

Normal thought process would expect that to travel from point A to point B would take time. Do you think all three figures are misleading? This one, Jones', and Theo Koupelis, Karl F. Kuhn (2007). In Quest of the Universe (5 ed.). Jones & Bartlett Publishers. p. 557. ISBN 0763743879. http://books.google.com/books?id=6rTttN4ZdyoC&pg=PA557. ? Brews ohare (talk) 00:57, 2 March 2009 (UTC)

What I pointed out, however, is that the "normal thought processes" are misleading since it doesn't take any "time" at all since ds^2=0. It is a light-like geodesic, is all. That's neither "time" nor "space", in some sense. The three figures are perhaps needlessly complicated and are not equipped to handle some of the subtleties of these ideas. ScienceApologist (talk) 01:00, 2 March 2009 (UTC)

The Doppler shift diagram is beyond dispute, I'd guess? Every EM book in existence uses it. Brews ohare (talk) 01:06, 2 March 2009 (UTC)

We actually already have an image which illustrates this. The approaching/receding ball. ScienceApologist (talk) 01:08, 2 March 2009 (UTC)

Do you take issue with Harrison's description? Do you think the diagram is at variance with his description? Do you think that some comments about light-like space-time intervals or the ontological status of linearized gravity will make things clearer? Can you explain simply some unified viewpoint that makes Doppler shift, gravitational shift and cosmological shift all approximations of some universal formula expressing the same single physical fact? And would anyone care? Or, would they continue to use the simpler formulation as more in keeping with normal intuition? Brews ohare (talk) 00:11, 2 March 2009 (UTC)

I don't have easy answers to most of your questions. The figure itself seems to not do a very good job of explaining the situation, in my opinion, but I really don't care that much. The bigger problem is when people confuse explanations. Anything that gets people to understand better is great. Perhaps we should ask for a third opinion. ScienceApologist (talk) 00:24, 2 March 2009 (UTC)

The questions vary in complexity. For example, yes or no will do for the first two:

• Do you take issue with Harrison's description?
• Do you think the diagram is at variance with his description?

And, I expect the answer to this one is "no"?

• Can you explain simply some unified viewpoint that makes Doppler shift, gravitational shift and cosmological shift all approximations of some universal formula expressing the same single physical fact? Brews ohare (talk) 01:03, 2 March 2009 (UTC)

• • Yes.
  • Not sure. The diagram has a weird "green shift" which I don't understand.
  • To get a redshift, simply use the tt component of the metric at point A and divide it into the tt component of the metric at point B. The square root of this value is 1 + z. That's true no matter what the shift is. ScienceApologist (talk) 01:06, 2 March 2009 (UTC)

Hmmm.-I am not aware that the Doppler shift works this way as a metric related matter. Brews ohare (talk) 01:09, 2 March 2009 (UTC)

Yes, it works. It requires a transformation of coordinates from t to t', but it works. ScienceApologist (talk) 01:11, 2 March 2009 (UTC)

Can you provide a description available on-line? I'd like to learn a bit more. As for my "green shift", the idea was that the blue light stretching longer would become green before it became red. Brews ohare (talk) 01:15, 2 March 2009 (UTC)

Well, that's green shift is sorely confusing... I still am not sure I understand it since the blue waves appear to overlap with the green waves which overlap with the red waves. In any case, the derivation you request is essentially here with the full GR-metric notation left out because the only terms of relevance are the tt terms. ScienceApologist (talk) 01:25, 2 March 2009 (UTC)

This derivation assumes an emitter moving with velocity v and simply does a little coordinate algebra to find the wavelength change. That doesn't seem to me to be related to a model of cosmological expansion. Brews ohare (talk) 01:42, 2 March 2009 (UTC)

The coordinate algebra also is what is done to derive the cosmological redshift. It's the same derivation, just different assumptions about the metric. That's why 1+z=(1+z_pec)(1+z_H) since the components simply multiply when you tack on the additional assumptions. If you need more, I suggest looking at MTW. ScienceApologist (talk) 02:02, 2 March 2009 (UTC)

I assume this reference is to isbn 9780716703440? Is there no reference available on-line? Brews ohare (talk) 02:19, 2 March 2009 (UTC)

I revised the figure to take your overlap comments into account somewhat. Continuous gradation of color is a bit beyond me. Brews ohare (talk) 02:06, 2 March 2009 (UTC)

Brews ohare, you recently added to another article an excellent paper by Bunn and Hogg which explains this in detail, and a short diatribe by John Peacock which says the same thing. Harrison mentions curvature and expansion in the same breath as properties of spacetime but fails to notice the difference, which is that there's a curvature tensor but no expansion tensor. Expansion isn't a definable property of spacetime in general relativity. If I give you a region of spacetime with galaxy worldlines in it, there's no way to tell how much of their relative motion is due to Hubble expansion and how much is peculiar motion—and it doesn't matter, since you can treat it all as peculiar or all as Hubble and you'll get the same value for the redshift (and all other measurable quantities) either way. Harrison and the textbooks are wrong. It happens all the time in cosmology. Think of this as another equal-transit-time fallacy or taste map of the tongue. -- BenRG (talk) 02:28, 2 March 2009 (UTC)

Hi BenRG: Well have you the confidence and the energy to write an appropriate well-documented discussion? I've looked at a ton of texts on this subject and find them all over the map. Personally, your view that all velocities are velocities makes more sense to me than the expanding balloon idea where space expands between galaxies but not inside them. Brews ohare (talk) 02:54, 2 March 2009 (UTC)

In other news, I now understand what your image is going for and have to say that BenRG is right on the money with his critique. It falls into the traps warned about by Bunn & Hogg and Peacocke. The idea that the "stretching" of space is what somehow allows for the "stretching" of the wavelength of light is only true in a proximate sense. In the sense in which your drawing is made, it is actually incorrect: mixing two different perspectives -- one that relies on contiguous Minkowski arrangements and one that treats the scale factor multiplied by the radial coordinate as the difference between two reference frames. This is, in my mind, more misleading than it is informative, I'm sorry to say. ScienceApologist (talk) 14:24, 2 March 2009 (UTC)

I hear you. Here's my take on this - let me know your reaction. The various authors mentioned (Harrison, Jones et al., Kopellis & Kuhn) all use figures and a matching discussion that agrees with the figure we're discussing. That is, this figure is not worse than these sources, but you think these sources have prostituted the analysis to get an easy presentation.

There are dissenting voices outside this mainstream, for example, Whiting, Bunn&Hogg, Baryshev, and Peacock. I take it that you would agree with them?

So (i) are you and the dissenters right? See Francis et al. (ii) if you are, can the diagram be fixed to suit you? and (iii) if it can or if it cannot, can a suitable presentation be made? It would require more than a figure: it would require a convincing and documented exposition. It also would be necessary to point out the flaws in the very widely disseminated but unsatisfactory argument associated with the diagram.

In addition, the very widely used expanding balloon argument (also in the present Wiki article) in which space expands between galaxies but does not expand inside galaxies would have to be dissed. Brews ohare (talk) 17:37, 2 March 2009 (UTC)

Here is a discussion that might be a starting point: Hobson et al. Brews ohare (talk) 19:20, 2 March 2009 (UTC)

I'm not sure we actually need a diagram for this, but I'll mull these ideas over for a bit. In any case, this is good food for thought. ScienceApologist (talk) 19:23, 2 March 2009 (UTC)

Thanks for that link. It is a cautionary example of the kind of mess we can get into here. It appears that the right analogy to the math is not available right now. So maybe it's best to leave things in their present widely disseminated but misleading form until something better comes along? It's hard to believe that we are going to come up with a great analogy when many skilled and thoughtful types well versed in the theory cannot. Brews ohare (talk) 19:52, 2 March 2009 (UTC)

Here's a proposal: Leave the present discussion as it is, but add a "Mathematical analysis" section following Hobson et al. with the preamble that analogy is imperfect and subject to debate (see so-and-so) so next is a mathematical derivation of red shift that stems from GR and does not invoke any analogy. Brews ohare (talk) 20:03, 2 March 2009 (UTC)

[edit] Halton Arp

Why would this article benefit from a see also link to this one fringe astronomer? The other links are to related theories, which seems much more appropriate. If he has made some significant contribution to the field, let us just write about it like we do Doppler and Hubble. - 2/0 (formerly Eldereft) (cont.) 03:52, 3 May 2009 (UTC)

If it wasn't for the link I wouldn't have known about intrinsic redshift but now I do. Just giving other readers the same opportunity to learn.Landed little marsdon (talk) 13:00, 3 May 2009 (UTC)

[edit] See also

WP:SEE ALSO says that links already in the article probably don't belong in the see also. This article does not need a see also section. Also: Talk:Redshift/See Also Dispute June 2006

Works for me - this is a featured article, and does a pretty good job at presenting the topic and explaining how it relates to other topics without recourse to a simple list. Let us just integrate into the article anything else that comes up. - 2/0 (cont.) 00:46, 18 May 2009 (UTC)

I don't see intrinsic redshift in the article and per npov it should probably get a brief mention. Until then a see also reference will have to do. As for the previous discussion, that seems to be mainly two banned editors arguing childishly. I think both their views can be safely ignored.Landed little marsdon (talk) 17:45, 18 May 2009 (UTC)

I only have one cosmology text on hand so perhaps my sourcing is biased, but it does not mention intrinsic redshift, tired light, red shift quantization, MOND, plasma cosmology, or any such similar discarded theories or universally ignored ideas. Following treatments by sources reliable to the subject at hand, this article should also not confer upon them any relevancy. - 2/0 (cont.) 20:13, 18 May 2009 (UTC)

See ref 41 in the article for the sources you seek. I still think a brief paragraph in the article is the appropriate way to cover these other views but a see also will do for the mo. Landed little marsdon (talk) 20:38, 18 May 2009 (UTC)

The merits of a See Also section and several other matters were discussed at length by multiple editors a few years ago. Despite the fact (as Landed little marsdon correctly states) that two of the editors who dominated the discussion behaved childishly, many other editors contributed to the discussion who did not behave childishly, consensus was reached, and featured article status was attained. Over the next couple hours, I will be examining recent changes made to this article and reverting changes that go against this strong prior consensus. Flying Jazz (talk) 02:33, 20 May 2009 (UTC)

It looks like the "See Also" list was the only significant point of contention related to the discussion a few years ago. For portions of the discussion in addition to Talk:Redshift/See Also Dispute June 2006, see Wikipedia:Mediation_Cabal/Cases/2006-03-19_Talk_at_Redshift and the talk page archives. I would ask any editor who wishes to include a "See Also" list to first justify here on the talk page what is included and what is not included in their list. Brews's original list was:

• Hubble constant
• Physical cosmology
• 2dF Galaxy Redshift Survey
• Lambda-CDM model
• Cosmic distance ladder

Brews's edit summary stated: "it is a convenience to have such list so one needn't read whole article to find possible links." I would not object to a "See Also" list containing these 5 items if I understood why they were more likely to serve the reader's convenience than any other set of listed links. Unless there's an understandable reason for a particular set of "See Also" links, I think it makes sense to have none. Flying Jazz (talk) 04:09, 20 May 2009 (UTC)

[edit] Including some implausible hypotheses in the main article

A long-standing version of this article contained the statement "Alternative hypotheses are not generally considered plausible." with a footnote mentioning tired light and intrinsic redshift. A recent edit changed this sentence to "Alternative hypotheses and explanations for redshift such as tired light or intrinsic redshift are not generally considered plausible." I am reverting this sentence for two reasons. First, it provides undue weight to the implausible in an article that should remain focused on an observable phenomenon and what actually causes it. Second, it provides undue weight to two possible implausibilities when countless other incorrect hypotheses could be mentioned. A consensus among editors determined that the original method best served the reader. Flying Jazz (talk) 01:21, 22 May 2009 (UTC)

You have misunderstood undue weight. That these alternatives exist is not a minority view. It is a simple fact that is very reliably sourced. With their inclusion the article is far more informative than without.Landed little marsdon (talk) 07:31, 22 May 2009 (UTC)

Obviously, we disagree about applying undue weight in this particular instance. I would never claim that you misunderstand the entire concept. That would be uncivil. I would like to understand your logic about information. You claim that moving information from a footnote to the main article creates a "far more informative" article. If you move a couple pieces of fruit from the fridge to a fruit bowl, do you also claim to have far more fruit? Flying Jazz (talk) 13:19, 22 May 2009 (UTC)

Your own claims succumb to this argument far more than mine. That is, "informative" has an accessibility dimension to it that can be altered by rearrangement far more easily than the almost totally quantitative notion of weight. Thus, how does merely moving fruit out of the fridge increase its weight to an undue level. Re your point about civility, you seem to have had no qualms below about launching into a personal attack. Landed little marsdon (talk) 17:11, 22 May 2009 (UTC)

Could you list a few of those countless other hypotheses, especially ones with their own Wikipedia article? --Art Carlson (talk) 09:24, 22 May 2009 (UTC)

See one list of possible lists at Talk:Redshift/Archive 7#Attempting (again) to focus the discussion and bring sanity to the talk page and the ensuing discussion. In every complex area of science, there is a verifiable history of a large number of rejected hypotheses, so my view a few years ago was that neither tired light nor intrinsic redshift should be mentioned in this article--not even in a footnote. But the consensus was against me, and I'm neither an astronomer nor an edit warrior, so I believe tired light and intrinsic redshift were both mentioned in a footnote when the article became featured. What's changed since this article became featured? Is there any new importance that's been attributed to tired light and intrinsic redshift that justifies moving them from a footnote to the main article? To my (very limited) knowledge, there has been none. The only recent change is internal to Wikipedia: ScienceApologist has been banned. Does this mean that redshift mechanisms related to non-standard cosmologies may now be safely moved out of the featured-article-consensus footnote and into the main article? Well, without ScienceApologist here, my opinion is that there seems to be a POV-pushing edit warrior on one side of the issue but not the other. What do you think will happen to the article? Flying Jazz (talk) 13:19, 22 May 2009 (UTC)

It is not that easy to extract actual candidates from the discussion you linked. CREIL is mentioned several times, but CREIL redirects to Raman scattering, which does not even mention redshift. Also CREIL has had much less significance in the astronomical community than even tired light and intrinsic redshifts, so I think that would be in a different category. The Wolf effect at least has its own article, which is strongly oriented to astronomy, so that might fit better, although it is less significant historically. Ian Tresman notwithstanding, I don't know what else could be included in the list. ... But I didn't realize before that there was also a lengthy footnote. I think at least the footnote should stay (but tired light and intrinsic redshift should be wikilinked there). Given the footnote, I would have a weak preference for streamlining the text, i.e. not mentioning the specifics there. --Art Carlson (talk) 14:56, 22 May 2009 (UTC)

I prefer the mention in the article proper and a reduction of the footnote. That being said, I am not convinced by the current placement, and think that given the additional stuff mentioned by Jazz we should ago for a brief paragraph in the history section which lists but in no way advocates some of the alternative views. This way, the reader gets a much more comprehensive and accurate picture of the topic, as opposed to one which focuses on the currently accepted view alone. I guess this is the difference between a general encyclopedia entry and a scientific text book description.Landed little marsdon (talk) 17:22, 22 May 2009 (UTC)

[edit] The current sentence looks good to me

FWIW, I think it is a good idea to mention the two most important classes of alternative redshift theory in the main article, as is done now, with a sentence which leads to an informative footnote with links to "nonstandard cosmologies" article: "Alternative hypotheses and explanations for redshift such as tired light or intrinsic redshift are not generally considered plausible." I think this is a factual statement - these are not generally considered plausible.

I think a "See-also" section mentioning these would be good, but I don't feel like arguing strongly for it. "Tired light", "Intrinsic redshift" and "non-standard cosmologies" all have their own articles and are clearly important to the redshift question. This longer form of the sentence is a very minor burden in this suitably longish article, so I don't support reducing it to a shorter version which does not mention tired light and intrinsic redshift.

In the absence of an article on "alternative redshift theories", I guess the "non-standard cosmologies" is a good place to mention any such theories which are sufficiently notable. Redshift is absolutely central to cosmology, and since no-one has got out a tape measure and directly observed the distant objects receding, the current Doppler-based accepted theory should be regarded as a theory whose validity is not beyond question.

I feel that anyone who argues strongly against including mention of, and links to articles about "tired light" or "intrinsic redshift" is probably trying to protect readers from theories which this person is sure are untrue. Without reading the formal WP definition of neutral POV, I think that such an attitude and exclusion of mention is not a neutral POV. I am sure "intrinsic redshift" is untrue, but I think it is important that these theories be in WP articles and linked to from the main redshift article. There are multiple potential tired light theories, so just because the well known ones are easily falsified doesn't mean new ones won't be. (I don't accept that Sn1A observations or others absolutely prove expansion. There are prominent astrophycists who question the BBT, so any theory which is contrary to the BBT should not necessarily be excluded as lacking notability or as unworthy of mention in a science article.)

Science is a debate. To present it as a series of established facts is to completely misrepresent it - and also to strip away a lot of the excitement and interest which properly belongs with a question as momentous as the nature of the redshift of distant astonomical objects. I think WP should support readers who view science as a debate. So the article should make it easy for them to find information about parts of the debate which may be poorly regarded now, but nonetheless formed part of the history of the debate - and might perhaps be further developed and better regarded in the future. A few extra words, an extensive footnote, and two in-article links to other articles seems like a good way of doing this.

I don't support the view, as I understand it, that because there are apparently lots of non-Doppler redshift theories, and because we don't want to mention all of them (perhaps some are not considered "notable") that we should not mention any of them. (Ari Brynjolfsson's http://arxiv.org/abs/astro-ph/0401420 is apparently still considered not notable enough to include in WP. It is a tired light theory, which could, if notable enough, have its own section in the tired light article.) Mentioning the two most prominent classes of theories seems fine, and the current sentence uses "such as", so it is not an attempt at a complete list. (Mr) Robin Whittle (talk) 12:04, 23 May 2009 (UTC)

Thank you, Robin, for posting your views on the talk page rather than altering the article first without consensus as others have done. To learn more about your opinions, I hope you don't mind if I refer other editors to your web pages at http://astroneu.com/ and http://astroneu.com/plasma-redshift-1/ . If you'd prefer I not do this then feel free to remove this sentence and the previous one from my comments. Nobody to date has argued strongly for removing links to Tired Light and Intrinsic Redshift from the article footnote. Flying Jazz (talk) 12:53, 23 May 2009 (UTC)

That's fine to point people to my site, but it is rather long and I don't yet have an alternative theory redshift theory to present. To save folks time: I point out, with references to a paper by Steven Cranmer, that conventional magnetic explanations of the heating and acceleration of the solar corona and wind are inadequate - therefore we shouldn't rule out some as yet not recognised interaction between electromagnetic radiation and sparse plasma is causing this heating and acceleration. In that context, I argue we shouldn't rule out some as-yet unrecognised tired light redshift affect in the sparse plasma or the IGM and at a greater rate per Mpc in the more concentrated IGM which no-doubt is falling into black holes (including, most likely "quasars"). I feel confident I can explain the heating, but I have a long way to go before I can explain it in a form ready for publication. This heating theory is not on my site. I would expect the same process to work in the IGM, heating it probably to hundreds of millions of degrees. If that theory works out OK in the years to come, maybe it might be found that the same or a similar process redshifts the light.

You wrote: "Nobody to date has argued strongly for removing links to Tired Light and Intrinsic Redshift from the article footnote." There are no such links in the footnote - that is http://en.wikipedia.org/wiki/Redshift#cite_note-reboul-40 . "Tired light" and "intrinsic redshift" are mentioned, but there is no link to articles from those words.

I understand you or someone else suggested that the mention of "tired light" and "intrinsic redshift" with their links be removed from the sentence at the end of para 1 under the heading "Observations in astronomy".

I am disagreeing with that suggestion. I would be happy if the current sentence and the footnote it references remained as is. Robin Whittle (talk) 13:09, 23 May 2009 (UTC)

If the sentence were removed from the main article, the links would certainly be replaced in the footnote. The link to nonstandard cosmologies would remain in the footnote. Flying Jazz (talk) 13:41, 23 May 2009 (UTC)

[edit] 7 extra words & Theories can be important even if almost everyone agrees they are wrong

I am posting this above Flying Jazz's summary to keep it prominent in the discussion.

Thanks Flying Jazz for this summary. You have correctly represented my position. I was not aware that the proposed changes would involve the links to the "tired light" and "intrinsic redshift" articles being moved to the footnote, which is sensible.

It seems we have a big discussion here about the inclusion of 7 words in an article which is at least 5,000 words already. So this can't be a discussion about conciseness, length, etc. My guess is that the motivation to exclude these words must be based on a notion that the theories they identify are so unimportant or at odds with "science" as to not be worthy of mention in this Wikipedia article, except in a footnote.

I guess that a position such as this would arise from a view of science which is entirely, or at least inordinately, focused on the supposed facts which science embodies in its theories: celebrating what is believed to be successful science, and actively shunning or deriding that which is believed to be either unsuccessful science, or pseudoscience - to the point where mention of such things in this article is either not allowed, or is at least relegated to a footnote.

If the only thing which mattered in science was the factual accuracy of the theories, and if in fact tired light and intrinsic redshift are truly wrong, then perhaps this position of working so hard to exclude them from the main body of an encyclopaedic article would be justified.

There are two problems with this. Firstly, we don't really know if they are wrong. Strictly speaking, "intrinsic redshift" hasn't been ruled out, since no-one has travelled to a redshifted galaxy and measured its light at close quarters with a spectrograph. I am sure the theory is incorrect, because I find it much easier to imagine some shift in wavelength due to Doppler or some new process in the IGM than whole galaxies of matter emitting at a different wavelength. The cosmologies based on intrinsic redshift (such as Halton Arp's) are arguably unscientific, since in explaining the light from AGNs and QSOs, AFAIK, they ignore the evidence that it results from black holes. (I read "Seeing Red".)

While tired light theories to date are not generally regarded as passing muster, it can't be ruled out that one may in the future. Since we can't explain the heating of the solar corona, we shouldn't rule out the possibility that there is something we don't yet understand about the interaction of light and sparse plasmas - and maybe that involves redshift. The coherence length of most or all of the signals we observe from distant galaxies is shorter than the likely interparticle spacing of the IGM. So as the wavefront couples to the particles, being slowed down by each one (a particle is like a cloud of gas with a refractive index above 1.0, but just a rather small cloud) it can be seen the IGM is an inhomogeneous medium for the signals we observe. So it would be unscientific to rule out the possibility of redshift due to interactions such as this, where the wavefronts of light are continually being slowed down by particles, speeding up again in the vacuum etc, coupling some of their momentum to and from the particles etc. Tired light theories would not be needed if the observed redshift matched exactly that from measured movement of the sources. However, so far, no-one has "proved" (a dangerous word in science) the universe is expanding - since no-one has physically measured the distant galaxies moving away.

But even if, in truth (which none of us can know for sure) both classes of redshift theory, and all others other than the conventional Doppler-based theory, are in fact completely wrong, that does not mean that mention of them should be excluded from - or unreasonably relegated to footnotes within - an encyclopaedic article.

Science is a process - a debate. People who want to know the accepted theories really should be interested in the tests they have been put to. Some of those tests include competition with other theories. The "tired light" and "intrinsic redshift" classes of theories are vitally important in the current standing of the Doppler-based theory of the cosmological redshift. I think all readers should be interested in the alternatives to the conventional theory. Even if many are not - being uninterested in the processes of science and only interested in its currently accepted explanations - I believe an encyclopaedic article should be written in a manner which illuminates the development of the currently accepted theory. This involves mention of the alternatives.

In other words, the scientific standing of the conventional Doppler-based theory of cosmological redshift depends in part on the existence of alternative theories, the fact that they are not widely accepted, and most importantly in the arguments about their validity which lead to most people rejecting them and supporting the Doppler-based theory.

I am arguing that 7 words: "such as tired light or intrinsic redshift" be devoted to mentioning the two most prominent classes of alternative theories, with links to their WP articles. These classes of theories are clearly notable, otherwise they wouldn't have articles. Robin Whittle (talk) 16:31, 23 May 2009 (UTC)

That, particularly the second part, pretty much sums up my take on things, and there is very little I would want to add. Perhaps this: we are writing an encyclopedia here and not a science textbook. As such we need to cover historical and other details not necessarily supportive or even that related to current scientific thinking in a way that a textbook would not. Think of this as the difference between an article called 'Redshift' and an article called 'Current scientific thinking on redshift'. The former will, if it is a good article, include the latter, but it will also contain other things besides. It is these other things that make the article comprehensive and it is these other things that I am concerned with here. Landed little marsdon (talk) 17:07, 23 May 2009 (UTC)

Thanks Landed little marsdon. A science textbook which failed to mention the development of theories, including alternative theories and why they were rejected, would be a very poor text indeed. By discussing the currently accepted results of the scientific process without their historical context, such a textbook would not assist people in thinking scientifically. By portraying science *as* these results, with the implication that these results are better than those obtained by other means (divinatation, faith, rolling dice etc.), and celebrating the triumph of science by way of the apparent superiority of these results, such a textbook would be promoting science without helping readers understand the scientific process.

Strictly speaking, nothing is ever proven in science. Observations are made, questions are asked and experiments are conducted. Theories are proposed, debated, modified, discarded and revived. Maybe one theory survives (in the minds of most who are debating it) all challenges. But you don't know what you don't know, and theories may have to be altered or abandoned. Light shows no evidence of travelling in an ether - oops, there goes Newtonian mechanics. DNA methylation changes as cells develop in the body and is handed on to future generations - oops . . . complete rewrite of genetics to include epigenetics. Many auto-immune diseases turn out to be due to humans evolving a naturally over-responding immune response due to everpresent parasitic infections, especially by helminthic worms . . . major revisions required to immunology. Continental drift . . .

I think there are scientific theories which have now been so thoroughly tested, and for which no-one is proposing alternatives, that we can pretty safely regard them as "fact". For instance the motion of the planets around the Sun and the existence of galaxies. However, since we can't explain the heating of the solar corona and since there are many difficulties with the Big Bang Theory, I think the Doppler interpretation of the cosmological redshift is best thought of as a scientific work in progress. Robin Whittle (talk) 02:12, 24 May 2009 (UTC)

Has anything in the astronomical or physics community/literature changed to justify a more prominent position for tired light and intrinsic redshift in this article? Robin, after scrolling up through the talk page, I believe you are simply repeating and rephrasing arguments you've made since your arrival on this talk page in late 2006. From Dec 29, 2006: "I think this page would be more complete if it mentioned some theories which challenge the conventional explanation." From Dec 30, 2006: "I don't think the matter is settled enough to forget that this is a debate." From Jan 1, 2007: "By ignoring the unconventional, textbooks and encyclopedias (which are relied upon by most non-specialists and establish new entrants' conceptual framework) lock in the prevailing paradigm and make most people think that the field is settled and beyond question." And most recently from May 23, 2009: "the article should make it easy for them to find information about parts of the debate." My view of the talk page archives is that in late 2006/early 2007, your opinions about what should be done with the article were expressed, duly considered by a significant number of editors here, and, ultimately, rejected by consensus. Please understand from my summary below that I am considering two ways to proceed: seeking more editors from the community would definitely be the way to go if there were something new to discuss with them and if there were focused, non-repetitive people involved in the discussion. Otherwise, I think bringing more editors here would just be wasting their time and protecting the consensus featured article would definitely be the way for me to go along with seeking help from some admin or whatever they're called if it continues to be reverted. Flying Jazz (talk) 16:30, 24 May 2009 (UTC)

Landed little marsdon, is that really your take on things? That only 7 words should be moved from the footnote to the article? If so, then why did you argue for adding "a brief paragraph in the history section"? Are you writing the paragraph that you would like to see added or have you decided on path 2a below? You have until tomorrow to decide what you actually want. Are you able to focus on anything and discuss that particular thing with other editors at Wikipedia? Or will you decide tomorrow to argue for something entirely different in order to continue to disrupt the article and disrupt Wikipedia again and again? Flying Jazz (talk) 16:41, 24 May 2009 (UTC)

Hi Flying Jazz, Please ignore whatever I wrote before yesterday. My preference is for the sentence to remain as it is, for at least the reason that "tired light" and "intrinsic redshift" are significant parts of the debate which resulted in the Doppler-based interpretation being widely accepted. These are notable theories about the topic, with their own articles. Devoting a few words in the body of the article to these classes of theory, with links to their article, seems a bare minimum an encyclopedic article should do in terms of enabling readers to understand the scientific debate. Those theories are scientific theories - they are not pseudoscience. They can and have been scientifically tested - and they have been rejected.

I will be interested to see if anyone takes up my challenge and argues why 7 words in a 5000+ word article is too much to devote to these rejected theories. However, I won't write any more. Robin Whittle (talk) 03:33, 25 May 2009 (UTC)

I think it is essential for anyone who would accept the footnote but reject the in-article links to address this point. I cannot even begin to understand how the footnote can be perfectly ok while the other is completely unacceptable.Landed little marsdon (talk) 14:44, 25 May 2009 (UTC)

Of course. I will address this point and Robin's post head-on. It has to do with ways of thought. Most people believe that their ways of thought are awfully good, that others think like they do, and that those who do not think like they do should change their mind. Robin has often stated that science is a debate. However, this is only half the story. This is the half of the story that advocates of fringe theories mention. Here is the other half. Science is a debate with consequences. The consequences are that the accepted ideas become prominent and the rejected ideas lose prominence. The rejected ideas never disappear entirely. They remain in the old literature for anyone to view and discuss. My way of thought is that one of the consequences when a hypothesis is rejected by the scientific community is that the idea should be mentioned less prominently in an encyclopedia article, if it is mentioned at all. I believe that's an awfully good way of thought. I believe most editors, admins, advocates, arbitrators, and others at Wikipedia would agree with me, but maybe I'm wrong. My only question at this point is who to disturb first if Landed little marsden reverts me again? Should I bother the people at Project: Astronomy for something that seems so obvious or should I go directly to the bureaucratic types? I suppose both would be best. Flying Jazz (talk) 15:55, 25 May 2009 (UTC)

[edit] Summary of Viewpoints about the prominence of Halton Arp, Intrinsic redshift, and Tired light and how to proceed from here

Please note that I have begun to refactor the talk page to place this summary and plan at the bottom. I will continue to do so until Monday May 25. My goal is to clarify the discourse to date for the benefit of new editors who arrive. If any editor does not want this to happen, feel free to remove this paragraph and return this section to its original chronological position.

Please let me know if I've misrepresented your recent opinions:

• Art: has a weak preference for the long-standing, consensus featured article version where links to Halton Arp, Intrinsic Redshift, Tired Light were in a long footnote.
• Flying Jazz: I have a weak preference for none of these topics being mentioned at all, but mentioning them in the long footnote is a close second and I concede to the long-standing, consensus featured article version.
• Robin Whittle: prefers the new version where links to Intrinsic Redshift and Tired Light have been moved from the footnote to a sentence in the article itself. Would prefer a See Also list but does not feel like arguing strongly for it.
• Landed little marsdon: Maybe wants Halton Arp in a See Also list (diff). Or perhaps wants Intrinsic Redshift along with several other items in a See Also list (diff). Maybe wants Intrinsic redshift in a See Also list with nothing else there (diff). Seems to want the links to Intrinsic redshift and Tired light in the main body of the text instead of in the footnote (diff). But most recently, in the talk page above, wants "The additional stuff mentioned by Jazz" here in a paragraph in the History section.

Here is my suggestion for how to proceed.

• 1) Please spend the next two days correcting any misinterpretations I may may have made in the above list.
• 2) Landed little marsdon, please spend the next two days deciding precisely what you would like to include in the article so we know your single, specific, exact, and focused proposal.

• 2a) If your proposal is only to maintain your most recent edit (diff) then write that down in the talk page and that is what we will discuss.
• 2b) If your proposal is to include an entire paragraph in the history section based on my comments here, please use the next two days to create that paragraph, place it here on the talk page, and we will also discuss that paragraph in addition to 2a.

• 3) Beginning on Monday, I will do one of the following:

• 3a) If Landed little marsdon is able to decide exactly what he/she wants by choosing path 2a or 2b, then something may occur that resembles an actual, focused disagreement among adults about a specific matter. In that case, I will post a notice at Wikipedia_talk:WikiProject_Astronomy asking for a larger community of editors to help us with the editing impasse.
• 3b) If Landed little marsdon is unable to decide exactly what he/she wants by choosing path 2a or 2b or if he/she pretends to choose a specific path and then avoids focusing on it later in the discourse, then I don't think a focused discussion among adults will be possible with this editor. I will simply stop engaging him or her, revert, and if my revert is reverted, I'll go and whine to some admin or arbitrator or whatever they're called. I've been on Wikipedia for four years and never done that before, but there's a first time for everything. Based on this user's recent history, if 3b occurs, I think the situation will be clear to any reasonable person who takes the time to investigate it. Flying Jazz (talk) 13:46, 23 May 2009 (UTC)

My view, which appears to be in line with the majority of editors who commented some years ago, is that that the article would be better if it contained a brief reference to tired light and intrinsic redshift. The exact wording is not something I feel needs to be decided on until the general point is agreed.Landed little marsdon (talk) 23:52, 24 May 2009 (UTC)

And to back up the idea that there was broad support in previous discussions for what I am saying, I would put forward this acknowledgement from scienceapologist (one of the main disputants from years ago) that tired light is highly notable, and this acknowledgement from flying jazz that his/her arguments against inclusion (the same arguments he/she is using again now) are not the best.[1] I quote:

'Well....OK. That's enough people who want it kept in for different reasons to convince me that maybe I was being too pedantic.'

Note also the admission that many people support inclusion. Landed little marsdon (talk) 10:57, 25 May 2009 (UTC)

Finally, perhaps you may be beginning to understand, Landed little marsdon! You are absolutely correct! That was the moment years ago that I recognized that a consensus of editors was for inclusion of a link to Tired Light, and yes, eventually, in the consensus featured article version, there it was, in a footnote, against what I thought was best. Thank you for tracking down that exact moment when, as a fair-minded editor in the Wikipedia community, I stopped arguing and stopped editing to remove it altogether because to do that would have been to disrupt the encyclopedia just as you have been doing. I am glad that you recognize a moment when I separated myself from the behavior of people like Iantresman, ScienceApologist, and yourself. I would never argue today for complete removal after that consensus had been reached. Flying Jazz (talk) 13:58, 25 May 2009 (UTC)

The type of mention of tired light being discussed in the above link, and being agreed upon by many editors then, and being objected to by you (then and now) using, as you admit, mere pedantry; was not a footnote reference as you are now falsely suggesting, but was in fact almost identical to the text I recently added. This can be seen clearly from this edit, made only a few days after the discussion from which the above quote was drawn. [2]. It is unclear why you are now resorting to the same discredited arguments in favour of exactly the same point when you have already conceded the point and the poor quality of your arguments many years ago.Landed little marsdon (talk) 14:35, 25 May 2009 (UTC)

There were many arguments about many topics during those months that led up to the article being featured. Most editors acting in good faith on a complex article will change their minds about the prominence of multiple things on multiple occasions. Eventually, after I was less active in developing the article, the consensus favored including a mention in a footnote. Please try to understand that when editors are actually collaborating to improve an article and bring it up to featured status, the Talk pages at Wikipedia become working social spaces rather than battlegrounds. It makes me giggle today that my statement from January 2006: "That's enough people who want it kept in for different reasons to convince me that maybe I was being too pedantic." is being used to discredit consensus opinions that were reached in my absence. Flying Jazz (talk) 16:27, 25 May 2009 (UTC)

Yeah, and it makes of giggle to see your idea of "adult discussion" is to completely ignore the statements you made above about the way forward, launch into a stream of personal attacks at every opportunity, and then just go ahead and implement your version even though the majority now, and previously,has always been against you. Landed little marsdon (talk) 16:36, 25 May 2009 (UTC)

If you would like to file a complaint about my behavior in recent days, there are administrators here who will read what you have to say and take both our words into account. If you believe the consensus would be with you, nothing is preventing you from posting a notice at Wikipedia_talk:WikiProject_Astronomy yourself to bring more knowledgeable editors here. Flying Jazz (talk) 17:08, 25 May 2009 (UTC)

[edit] Tired light

Tired light seems to me an obvious and undisputed part of the history of redshift. To exclude this topic from the history section leaves that section incomplete at best and revisionist at worst. Landed little marsdon (talk) 20:37, 25 May 2009 (UTC)

That's odd. Just yesterday you were arguing for something else. Hello to anyone joining us from the Astronomy Project. For any of you who have contributed to this article in the past, bringing it to featured status, thank you. I'd like to ask that you read the last couple sections of this talkpage before engaging in this discussion. Flying Jazz (talk) 20:56, 25 May 2009 (UTC)

The most recent edits placing mention of tired light and no other disregarded mechanisms into the main article are acceptable to me and resolve the edit warring and talk page conflict as far as I'm concerned. I am replacing the link to intrinsic redshift in the footnote, as promised to Robin above. Flying Jazz (talk) 10:10, 27 May 2009 (UTC)

What on Terra? Honestly I think that moving this interesting and historically relevant information into the footnote like that is unbecoming of a paperless encyclopedia, I think the information regarding these topics should remain visible to the reader. Unomi (talk) 10:32, 30 May 2009 (UTC)

Thanks Flying Jazz and Little landed marsdon. Robin Whittle (talk) 00:35, 20 June 2009 (UTC)