Talk:Redshift

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[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)

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)

[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.

[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)