Talk:Big Bang

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Featured article Big Bang 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.
Main Page trophy This article appeared on Wikipedia's Main Page as Today's featured article on February 23, 2005.
          This article is of interest to the following WikiProjects:
WikiProject Cosmology (Rated FA-class, Top-importance)
WikiProject icon Big Bang is within the scope of WikiProject Cosmology, which collaborates on articles related to physical cosmology on Wikipedia.
Featured article FA  This article has been rated as FA-Class on the quality scale.
 Top  This article has been rated as Top-importance on the importance scale.
 
WikiProject Astronomy (Rated FA-class, Top-importance)
WikiProject icon Big Bang is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.
Featured article FA  This article has been rated as FA-Class on the project's quality scale.
 Top  This article has been rated as Top-importance on the project's importance scale.
 
WikiProject Physics (Rated FA-class, Top-importance)
WikiProject icon 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.
Featured article FA  This article has been rated as FA-Class on the project's quality scale.
 Top  This article has been rated as Top-importance on the project's importance scale.
 
WikiProject Skepticism (Rated FA-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Skepticism, a collaborative effort to improve the coverage of science, pseudoscience, pseudohistory and skepticism related articles 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.
Featured article FA  This article has been rated as FA-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 
WikiProject Spoken Wikipedia
WikiProject icon This article is within the scope of WikiProject Spoken Wikipedia, a collaborative effort to improve the coverage of articles that are spoken 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.
 
Warning
IMPORTANT: This is not the place to discuss how you think the universe began, or to discuss whether or not the Big Bang model is correct. This page is for discussing improvements to the article. The article is about the Big Bang model, with content based on information presented in peer-reviewed scientific literature about it or other appropriate sources. See Wikipedia:No original research and Wikipedia:Talk page guidelines. If you wish to discuss or debate the validity of the Big Bang please do so at BAUT forum or talk.origins.
Wikipedia Version 1.0 Editorial Team / v0.5 / Vital / Core
WikiProject icon This article has been reviewed by the Version 1.0 Editorial Team.
Taskforce icon
This article has been selected for Version 0.5 and subsequent release versions of Wikipedia.

possible FAR[edit]

There's already two [citation needed] template in place, and most section needs additional reference, like "Overview", "Cosmic acceleration", "Cosmic microwave background radiation", "Primordial gas clouds", "Dark energy", "Horizon problem" etc.--Jarodalien (talk) 11:51, 11 May 2015 (UTC)


higher harmonics birth cycle[edit]

Black Holes and matter evaporate as energy after zillion years. The Universe at it's last moments would have only photons, because only photons and gravitational waves can exist at very low energy levers. When the photons will be spread at an ultimum degree, all relativistic motion will cease. That hole Universe then, mathematically will be equal to a new Big Bang particle. Thus the Universe will change scale of reference, and it will explode to generate particles and galaxies of "higher harmonics". Some physicists though do not consider the new Universe as a high harmonics "event". The scale changes relativistically to the previous Universe, but that relativistic comparison makes no sense since the old Universe is dead! — Preceding unsigned comment added by 2.84.216.225 (talk) 15:02, 2 July 2015 (UTC)

WP:NOTFORUM. Specific suggestions for article improvement, backed up by sources, please.   — Jess· Δ 15:04, 2 July 2015 (UTC)

Suggest reversions, not replies[edit]

NOTFORUM is so basic, you are 100% allowed, even encouraged, to revert Talk page comments who bring up their pet ideas here. See WP:TPO. Anything less makes this page a crank magnet. Choor monster (talk) 15:11, 2 July 2015 (UTC)

Globular Cluster Age[edit]

While of historical interest, it currently sticks out like a sore thumb in our list of related problems in physics since it is the one that has been unequivocally solved while all the rest of the listed problems remain somewhat mysterious at least in part. I don't think it adds much to the discussion of the Big Bang generally. Maybe back in the 1990s when this was an interesting thing, but today the question is simply not on the table anymore and we risk giving it undue weight by highlighting it and not some of the other controversies and supposed "problems" that had cropped up with the consensus model along the way. We could, perhaps, include a sentence or two in the "history" section, but I think it deserves demotion from subsection status. Anyone else agree?

jps (talk) 01:56, 31 August 2015 (UTC)

I implemented this change. I also added some details about controversies in the 1970s-1990s over the Hubble Law and the density parameter. jps (talk) 14:07, 31 August 2015 (UTC)

Cambridge theoretical cosmologists[edit]

I removed this paragraph from the lede:

In the mid-20th century, three British astrophysicists, Stephen Hawking, George F. R. Ellis, and Roger Penrose turned their attention to the theory of relativity and its implications regarding our notions of time. In 1968 and 1970, they published papers in which they extended Einstein's theory of general relativity to include measurements of time and space.[1][2] According to their calculations, time and space had a finite beginning that corresponded to the origin of matter and energy.

This is all, I guess, correct but it is fairly unrelated to the Big Bang theory per se. It's more of just interest to those who are fascinated by the history of thought. I don't think it deserves inclusion at all on this page and, frankly, probably doesn't deserve inclusion anywhere in Wikipedia.

jps (talk) 02:04, 31 August 2015 (UTC)

  1. ^ Hawking, S.; Ellis, G. F. (1968). "The Cosmic Black-Body Radiation and the Existence of Singularities in our Universe". Astrophysical Journal 152: 25. 
  2. ^ Hawking, S.; Penrose, R. (27 January 1970). "The Singularities of Gravitational Collapse and Cosmology". Proceedings of the Royal Society A: Mathematical, Physical & Engineering Sciences (The Royal Society) 314 (1519): 529–548. Bibcode:1970RSPSA.314..529H. doi:10.1098/rspa.1970.0021. Retrieved 27 March 2015. 

These papers have everything to do with the Big Bang. They established broad conditions that guaranteed the existence of singularities in models of GR, including cosmological models. On the other hand, the description of those papers as "extending" GR to include "measurements of time and space" is flat out ludicrous. Choor monster (talk) 15:01, 31 August 2015 (UTC)

They are only related in the sense of providing conditions under which Big Bang universes occur generally. These papers are fairly incidental to the overall theory, however, which was elucidated to the level necessary by the earliest relativists. jps (talk) 15:53, 31 August 2015 (UTC)
And the relevant point is we apparently live in a universe where their conditions apply. That's not "incidental". Choor monster (talk) 15:58, 31 August 2015 (UTC)
No, that's not what interested the three of them the most in the two above cited papers. They were more interested in existence proofs rather than any attachment to the precise conditions of our universe. These investigations of Big Bang singularity conditions turned out to be not all that important in retrospect, especially with the subsequent development of inflation which can, in some formulations, completely miss the singularity. jps (talk) 16:44, 31 August 2015 (UTC)
You pretty much don't have a clue. The whole point was that singularities were inevitable, no matter what the "precise" conditions were. That was a major shock at the time. Physicists just didn't believe in singularities no matter what, and offered any old just-so story or back-of-the-envelope calculation why they didn't happen. It was Penrose's 1965 mathematical theorems regarding Einsteinian collapse that brought them to physicists' obligatory attention. Hawking time-reversed the work and applied it to the Big Bang. Before them, something like Gamow's Ylem was taken seriously. The perturbation calculations of Lifshitz-Khalatnikov were taken seriously. The work of Penrose, Hawking, and others changed everything.
Meanwhile, this is Wikipedia. We rely on what the RS tell us. Not our personal gut feelings and misinterpretations. And they tell us what I'm telling you:
  • Gribbin, John (1986). In Search of the Big Bang. 
  • Parker, Barry (1993). The Vindication of the Big Bang. 
  • Kragh, Helga (1996). Cosmology and Controversy. 
  • Longair, Malcolm S. (2009). "Cambridge cosmology in the 1960s". In Peebles; Page; Partridge. Finding the Big Bang. 
The first two are popular books. The last two are introductory technical.
At this rate, there really is nothing left to discuss. I am putting the paragraph and references back in, but rewritten to avoid the silly stuff. Choor monster (talk) 17:41, 31 August 2015 (UTC)
Offer quotes, page numbers, and direct connection of these existence theorems to the overall subject and we can discuss how to incorporate them into the article text. Trying to attach them to the lede is irresponsible per WP:MOSINTRO. jps (talk) 18:45, 31 August 2015 (UTC)
You're being ridiculous and childish. I gave four sources on the relevance. Look them up yourself: they all have indices, and they all make the claims I stated.
Whether they belong in the lede or not is a different discussion. It's certainly not irresponsible, it may simply be inappropriate. They were in the lede before, so I suggest you apply BRD and not edit-war. Choor monster (talk) 18:59, 31 August 2015 (UTC)

────────────────────────────────────────────────────────────────────────────────────────────────────They don't belong in the lede, and the current wording is poorly chosen for the body of the work too. I'll try to incorporate, but I can't make any promises. jps (talk) 19:05, 31 August 2015 (UTC)

This is about as good as I can do. The relevance of this particular idea is not all that much appreciated anymore, but I don't object to this as part of the story. A single sentence seems about the weight appropriate. In the lede, it does not belong. jps (talk) 19:12, 31 August 2015 (UTC)
It's extremely appreciated: all modeling takes the Hawking-Penrose singularity seriously. They have to, it's a theorem, not a model you can pick and choose your way through. Typically one just starts after the singularity (usual), or else rewrites everything (continuous inflation, ekpyrotic model). And as I explained to you, and the sources I cited above state, it was an extremely important part in changing people's expectations of what "Big Bang models" were supposed to look like even. Choor monster (talk) 19:22, 31 August 2015 (UTC)
Yes, except no one does those kinds of out-of-the-box big bang cosmologies anymore. Now it's all "inflationary landscape" this and "brane cosmology" that. Why even Hawking's imaginary time universe manages to avoid the singularity through an appeal to an additional degree of freedom. My point is that the theorem applies for a limited class of models which are now not seen as expansive enough to allow for a proper explication of all that is necessary in cosmological modeling. One could make the argument that "big bang" as properly understood must include a singularity, but in the way the term "Big Bang" is most often used in the literature today this is simply not the case. jps (talk) 19:31, 31 August 2015 (UTC)
And no one goes into contortions avoiding singularities anymore. Same with black holes. On a tangent, I'll mention the 1979 Schoen-Yau proof of the positive mass conjecture relied on their 2D extension of Penrose's 1D methods. Choor monster (talk) 19:50, 31 August 2015 (UTC)