Talk:Physical cosmology

Update the main image of the CMB?

Wouldn't it make sense to update the main image of the CMB? The current image is the older and lower resolution WMAP image. The newer image, released in 2013, is the more scientifically up-to-date image. see below for NYT comparison: http://www.nytimes.com/interactive/2013/03/21/science/space/0321-universe.html?_r=0 Speedplane (talk) 17:14, 15 December 2014 (UTC)

Other cosmologies reference

J. V. Narlikar, Introduction to Cosmology, Jones and Bartlett Publishers, Inc., Boston, MA, 1983.(HCPotter (talk) 09:32, 12 February 2012 (UTC))

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Question

Wondering what is the difference between 'Physical cosmology' and 'Cosmic evolution'? I am thinking 'physical cosmology' is the study of the material aspects of the cosmos (which includes our universe, and all other billions & billions of universes) and all the stuff in it -- matter, energy, and it might include the subject of 'cosmic evolution', that is, how all this material stuff evolved? Or, is 'cosmic evolution' a separate area of study?--Tomwsulcer (talk) 23:25, 1 September 2014 (UTC)

"Excellent agreement with observations"

Should this phrase be removed: "which are in excellent agreement with many diverse observations." First, it lacks attribution. Secondly, because dark matter and dark entities are hypothetical entities introduced specifically to explain such observations, of course they will agree with those observations. Thus, just as WP is designed to prevent circularity in its own editing (i.e., WP articles may not reference each other for attribution), so too, if there is any circularity here, it will undermine the value of this article. Bob Enyart, Denver KGOV radio host (talk) 16:56, 5 September 2014 (UTC)

You seem to have posted the same thing twice. (Saw you fixed that -- thanks!) The "excellent agreement" sentence in the lead should be a summary of more extensive material in the body of the article. As such, it wouldn't ordinarily need separate sourcing. However, it might be appropriate to give an attribution in the lead given that the development of the body does seem to be lacking in some areas. We could add a citation of a review article or standard reference such as the PDG. Your second point is not really correct (there are many different observational tests, and in many cases successful predictions rather than just post hoc model-fitting); and it's also not relevant to the article without outside sourcing for the argument. --Amble (talk) 19:38, 5 September 2014 (UTC)

For some examples: dark matter is inferred from local observations of galaxies and galaxy clusters. Dark energy is inferred from supernovae at z<2 or so. When these are found to agree with cosmological data such as precision measurements of the CMB temperature power spectrum at z=1100, that agreement is far from trivial. --Amble (talk) 18:53, 6 September 2014 (UTC)

I've added the PDG citation. What do you think? --Amble (talk) 19:05, 6 September 2014 (UTC)

Discussion of capitalization of universe

There is request for comment about capitalization of the word universe at Wikipedia talk:Manual of Style/Capital letters#Capitalization of universe - request for comment. Please participate. SchreiberBike talk 00:44, 4 February 2015 (UTC)

Notification of request for comment

An RfC has been commenced at MOSCAPS Request for comment - Capitalise universe.

Cinderella157 (talk) 03:23, 22 March 2015 (UTC)

Slipher's conclusion

Regarding this sentence:

In the 1910s, Vesto Slipher (and later Carl Wilhelm Wirtz) interpreted the red shift of spiral nebulae as a Doppler shift that indicated they were receding from Earth.

I looked at a presentation by Slipher in 1917[1] and his conclusion then was as follows:

"We may in a like manner determine our motion relative to the spiral nebulæ, when sufficient material becomes available. A preliminary solution of the material at present available indicates that we are moving in the direction of right-ascension 22 hours and declination −22° with a velocity of about 700 km."

That is, as of 1917 he had not reached the conclusion as stated above, but instead suggested the redshift was due to the general motion of the Milky Way relative to the other nebulæ. The true interpretation came later, but it's not clear that happened during the 1910s. Praemonitus (talk) 22:51, 16 June 2015 (UTC)

I performed some more checking. This 1918 article appears to show that he was changing his views. By 1922 his findings showed that the velocities of the spiral nebulæ showed they were almost all moving away.[2] I'm going to add the last as the reference. Praemonitus (talk) 15:53, 17 June 2015 (UTC)

The original statement from the article is slightly vague, depending on whether you take "spiral nebulae" to mean "some spiral nebulae, those which he had observed, primarily in one region of the sky", or "spiral nebulae as a general class". The main thing to clearly state is that Slipher already measured redshifts and used them to find relative velocities, most of which were receding; too often all of this gets credited to Hubble along with his later work. Looks like your new reference is a good addition. --Amble (talk) 20:46, 17 June 2015 (UTC)

More cites needed in "Areas of Study"

The only inline citations now are for a debunked observation and the new subsection on gravitational waves. More are need in other paragraphs, especially for theoretical proposals and ideas. Layzeeboi (talk) 20:16, 31 March 2017 (UTC)

I've attempted to address this concern by adding many new references to the section. If there are still issues, inline tags can be used. Praemonitus (talk) 22:32, 11 April 2018 (UTC)

Nice work on improving the sourcing of this section. I concur that any remaining issues could be addressed with inline tags. --Mark viking (talk) 22:45, 11 April 2018 (UTC)

Main image caption needs to be rewritten

The main image caption says humanity is a red supernova, the internet is its core, and we live in the event horizon of a black hole. — Preceding unsigned comment added by 2600:8807:5601:8900:F061:21E7:222E:16D1 (talk) 16:49, 17 December 2018 (UTC)

Mmm, no. Praemonitus (talk) 17:58, 17 December 2018 (UTC)

Requested move 13 January 2022

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: withdrawn, will reformulate. (non-admin closure) Heanor (talk) 15:06, 13 January 2022 (UTC)

---

• Physical cosmology → Cosmology
• Cosmology → History of cosmology

– Cosmology looks now as an attempt for a WP:broad-concept article. But I do not think that a broad-concept article on this topic is possible. it is definetly fails "expert test": the expert on "cosmology" would need to have both physics and religiom in their knowledge base, along with philosophy. From three main meaning of 'cosmology', the physical cosmology is the primary topic. Heanor (talk) 14:32, 13 January 2022 (UTC)

Oppose: historically, cosmology began as a philosophical topic. The scientific study is a sub-topic of a broader theme. Praemonitus (talk) 14:56, 13 January 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

'Physical Cosmology'

Of all the sources listed here, only a single one mentions the term 'physical cosmology', and it disagrees with this page on what physical cosmology is. arxiv:0602280 ,

"Cosmology is the study of the large-scale structure of the Universe, where ‘the Universe’ means all that exists in a physical sense [104]. This is to be distinguished from the Observable Universe, namely that part of the Universe containing matter accessible to our astronomical observations, which is a subset of the Universe proper. Thus cosmology considers the vast domain of galaxies, clusters of galaxies, quasi-stellar objects, etc., observable in the sky by use of telescopes of all kinds, examining their nature, distribution, origins, and relation to their larger environment. Observational cosmology [114, 128, 99, 189, 18] aims to determine the large-scale geometry of the observable universe and the distribution of matter in it from observations of radiation emitted by distant objects, while physical cosmology [163, 193, 233, 202, 171, 38] is the study of interactions during the expansion of the universe in its early hot big bang phase, and astrophysical cosmology [193, 165, 160, 174, 38] studies the resulting later development of large-scale structures such as galaxies and clusters of galaxies. "

What's listed on this page covers what this source refers to as Observational cosmology, physical cosmology and astrophysical cosmology, not just physical cosmology. Why has this article been renamed from what it is actually referred to as almost unanimously, to physical cosmology which it is almost never referred to as? 2001:56A:F343:2700:54C0:7516:B1C4:A703 (talk) 07:06, 20 March 2022 (UTC)

The content of this page is specifically focused on a branch of astronomy rather than metaphysics, so in the Wikipedia style it could alternatively be named Cosmology (astronomy) to distinguish it from Cosmology (metaphysics). Praemonitus (talk) 15:02, 20 March 2022 (UTC)

Cosmology (astronomy) would be better (since again, physical cosmology just is not what this field is called), though Cosmology (physics) would be better still since there are parts of cosmology that don't come under astronomy. 2001:56A:F343:2700:5DE7:8C70:11F5:1323 (talk) 16:37, 20 March 2022 (UTC)

Physics and astronomy are closely linked, but scientific cosmology is generally considered a field of astronomy (with elements of physics). I think Cosmology (physics) may be more confusing to people. Praemonitus (talk) 19:28, 20 March 2022 (UTC)

This isn't true, cosmology is not a field of astronomy. A lot of cosmology is part of astronomy, but not cosmology in general, there are parts of cosmology that are not astronomy. Cosmology (physics) would be the correct term. e.g. arXiv puts cosmology under the subheading physics, because cosmology is a subfield of physics. 2001:56A:F343:2700:5DE7:8C70:11F5:1323 (talk) 20:07, 20 March 2022 (UTC)

Article naming in Wikipedia is about what people expect to find when they do a lookup. Most people expect to find cosmology covered under astronomy. This is why there is a WP:COMMONNAME. Praemonitus (talk) 20:29, 20 March 2022 (UTC)

Yes this is why the article should be renamed to be what it is actually referred to, not the term it is called here which is not used. 2001:56A:F343:2700:5DE7:8C70:11F5:1323 (talk) 20:38, 20 March 2022 (UTC)

Well then we're at an impasse, because when I see "Cosmology (physics)" I immediately think "early Big Bang"; not the entire field of observational cosmology. Praemonitus (talk) 20:45, 20 March 2022 (UTC)

I'm not really sure why you think that as that isn't what the term means. Again, for example you can look through cosmology in the physics section of arXiv for one example of many, the vast majority is not just about the early Big Bang. 2001:56A:F343:2700:5DE7:8C70:11F5:1323 (talk) 21:42, 20 March 2022 (UTC)