Talk:Redshift

Skip to table of contents

This is the talk page for discussing improvements to the Redshift article.
This is not a forum for general discussion of the subject of the article.

Put new text under old text. Click here to start a new topic.
New to Wikipedia? Welcome! Learn to edit; get help.

Article policies

Find sources: Google (books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL

Archives (index): 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11: 3 months

Redshift is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.

This article appeared on Wikipedia's Main Page as Today's featured article on December 29, 2006, and on October 23, 2025.

Article milestones
Date	Process	Result
December 17, 2005	Peer review	Reviewed
December 23, 2005	Featured article candidate	Not promoted
January 17, 2006	Good article nominee	Listed
August 30, 2006	Featured article candidate	Not promoted
October 15, 2006	Featured article candidate	Promoted
October 18, 2006	Peer review	Reviewed
December 29, 2006	Today's featured article	Main Page
August 2, 2025	Featured article review	Kept
Current status: Featured article

Astronomy: Cosmology Top‑importance

	Astronomy portal This article is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.AstronomyWikipedia:WikiProject AstronomyTemplate:WikiProject AstronomyAstronomy
Top	This article has been rated as Top-importance on the project's importance scale.
	This article is supported by Cosmology task force.

Physics High‑importance

	Physics portal This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics
High	This article has been rated as High-importance on the project's importance scale.

Color Mid‑importance

	This article is supported by WikiProject Color, a project that provides a central approach to color-related subjects on Wikipedia. Help us improve articles to good and 1.0 standards; visit the wikiproject page for more details.ColorWikipedia:WikiProject ColorTemplate:WikiProject Colorcolor
Mid	This article has been rated as Mid-importance on the project's importance scale.

Measurement (defunct)

This article is within the scope of WikiProject Measurement, a project which is currently considered to be defunct.MeasurementWikipedia:WikiProject MeasurementTemplate:WikiProject MeasurementMeasurement

Archives

Index 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
11

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

This page has archives. Topics inactive for 90 days are automatically archived by if there are more than 3.

ENGVAR

This article made TFA with a mixture of spelling variants in it (which shouldn't be possible but oh well). I thought to standardise on US English per this old revision which seems to be predominantly American ("analyzing"; "quantized"); SchroCat has changed it to British English. Per MOS:RETAIN we are supposed to keep the spelling variant of the original author, and per WP:ENGVAR the article should all be in the same variant. Personally I don't care which one this article uses, but promoting something on the main page which was in such a state is less than ideal. TFA is not supposed to be article rescue. John (talk) 14:24, 23 October 2025 (UTC)[reply]

According to [1] and [2], some calculations, and wordcounter.net:

19 out of 5529 words in the current revision are British English(0.34%)

14 out of 5529 words in the current revision are American English(0.25%)

4 out of 1340 words in the revision you gave are British English(0.37%)

3 out of 1340 words in the revision you gave are American English(0.22%)

(Rounded to 2 decimal figures)

This means that in around 20 years, The use of British English dropped by 0.03%, and the use of American English increased by 0.03%. These numbers are not very high, so they are probably not significant. However, this means that the paper was actually leaning toward British English by 1 word above American English in the revision you gave, but the use of American English in this paper has increased since then, even though British English is still used slightly more.

It looks to me like this article should actually use British English. Any thoughts? Tactical Falcon (talk) 01:01, 24 October 2025 (UTC)[reply]

I just checked @SchroCat's edit, and apparently 18 words were changed from American to British English. The fixed calculations are:

1 out of 5529 words in the current revision are British English(0.02%)

32 out of 5529 words in the current revision are American English(0.58%)

In 20 years, the use of British English dropped by 0.36%, and the use of American English increased by 0.33%. These numbers are probably significant. The revision you gave was still leaning slightly toward British English, but before SchroCat's edit, this article was definitely in American English. I'm fine with this article being changed to American English with this new information in mind. Tactical Falcon (talk) 01:10, 24 October 2025 (UTC)[reply]

Blue

The lead states:" The terms derive from the colours red and blue which form the extremes of the visible light spectrum." Blue is NOT at the extreme of the visible light spectrum! I'm 99.9% sure most readers KNOW better. Blue is what is OFTEN seen in natural displays of the spectrum (rainbows and ice halos) at the edges opposite that of the red edge, but violet is the extreme of visible light (high frequency, short wavelength). (ignoring that some people can see a bit into the UV) The lead needs to be reworded, imho. (I've no idea why blue was selected rather than violet for the term blueshift, I suspect it was to keep the word to two simple syllables, but that's a wild guess.75.90.13.139 (talk) 21:10, 23 October 2025 (UTC)[reply]

Split blueshift?

Shouldn't blueshift have its own article? I'm curious about why it was lumped in with redshift. Tactical Falcon (talk) 01:15, 24 October 2025 (UTC)[reply]

No, the phenomenon is called redshift. Blueshift is not a distinct phenomenon, just a shift in the opposite direction. The section of this article on blueshift just amounts to examples with opposite sign. Johnjbarton (talk) 01:28, 24 October 2025 (UTC)[reply]

Agree that splitting the pages doesn't make sense. But "redshift" is not any broader of a term than "blueshift" is, and I could see potentially naming the the page "redshift and blueshift". (I can't think of a widespread term that encompasses both, except potentially "Doppler shift" but that's not how gravitational shifts are usually framed even though they are equivalent.) Aseyhe (talk) 01:55, 24 October 2025 (UTC)[reply]

Given Hubble's law, I'd expect that "redshift" would win the WP:COMMONNAME battle. I don't see a need for a rename. Praemonitus (talk) 05:02, 24 October 2025 (UTC)[reply]

Redshift might be more significant than blueshift, but blueshift is still something separate. So I think this would be better renamed. Does anyone else have an opinion on this? Tactical Falcon (talk) 22:38, 24 October 2025 (UTC)[reply]

As stated by others above, blueshift isn't "something separate", it's just a different sign. The number of blueshifted astronomical objects is tiny in comparison, and the term is not used very often. I don't see a need for a rename either. - Parejkoj (talk) 17:33, 25 October 2025 (UTC)[reply]

Given that redshift and blueshift are different phenomena, WP:AND seems appropriate. (Sure, they are closely related mathematically. But it would not be standard to call a blueshift a redshift.) Aseyhe (talk) 18:56, 25 October 2025 (UTC)[reply]