Talk:Big Crunch

Edgar Allan Poe
Poe discusses something very similar to the big crunch in Eureka, near the beginning. It's facinating because the big crunch wasn't officially proposed until the 1920s. — Preceding unsigned comment added by 24.113.208.209 (talk) 19:54, 3 October 2017 (UTC)

A paper
Can someone point me to a paper which refers to this:

However there is yet another possibility which will pave way for Big Crunch. When many of the outer cosmological objects lose their gravitational pull to other objects, they assume certain constant velocity. But the objects moving from inner universe with increased velocity approach them and hit them with unimaginable speeds creating huge energy storm. This will cascade to other objects also and finally Big Crunch will take place though the origin may then be different

Roadrunner 19:48, 27 Apr 2004 (UTC)


 * No, but I can tell you that is is plain wrong. You see, there is no "inner" and "outer" part of the universe, as the universe has no center. So, for the closed universe (cf. Friedman models : There is no specific spot, where the Big Bang happened, because space grew with the expanding matter. At the time of the Big Bang, space itself exploded. There was no surrounding, and so you cannot pinpoint a spot, saying: This is where the Big Bang happened and ther it will all come back again at the Big Crunch. The usual way to imagine this is a balloon: Imagine an inflatable children's balloon with stars drawn on it. The two-dimensional surface corresponds to three-dimensional space. As you inflate the ballon, the stars will move away from each other, so if you take a specific star, the ones in its direct vincinity seem to recede slowly, the ones farer apart faster. An if you let the air out, all the stars fall towards each other, but there is not one star which is in the center, the others falling towards it.


 * But, of course, that's all outdated now, as we know that the universe will not recollapse, because the expansion is not being slowed down by gravitation, but accelerated by some so far still mysterious dark energy, and hence the end of the universe will be not the Big Crunch, but the Big Rip. -- Simon A. 12:05, 19 Jul 2004 (UTC)

The "gravitation will be too feeble to completly counter gravity" excerpt from the 3rd paragraph sounds suspiciously. Should it read "gravitation will be too feeble to completely counter inertia" instead?


 * Paul Pogonyshev 00:19, 19 Jul 2004 (UTC)


 * Yes, of course. I'll change it. Simon A. 12:07, 19 Jul 2004 (UTC)

Wait...
If the big crunch was real, how could the universe been "born"? Like, was is all spread out or something? We know its not happening, but i'm curious. --BrandiAlwaysSmiles (talk) 00:28, 24 March 2010 (UTC)

Time during the Big Crunch
During the Big will time go sideways I know the Big won't happen, but I just want to know. 04:13, 7 Dec 2004 (UTC)

Big Crunch vs. big crunch
I renamed the page back to the capitalized version.

Google seems to show "Big Crunch" is more common than "big crunch". The usage seems to depend on whether the context is "the" Big Crunch (a hypothetical one-time event) or "a" big crunch (in an even more hypothetically cyclical universe). But the capitalized version does seem to prevail in actual usage. -- Curps 20:25, 7 Mar 2005 (UTC)

Aren't we in the middle of a Big Crunch?
As the article states, the apparent (!) expansion of the universe is accelerated. Isn't this indicative of a Big Crunch? See also Reference_desk/Science. DirkvdM 09:27, 24 September 2005 (UTC)
 * On the contrary, the fact that the expansion is accelerating has actually ruled out (or at least made very unlikely) the chance of the Big Crunch happening, in favor of the Big Rip or the Big Freeze. -- ironcito 05:51, 27 February 2006 (UTC)

Im glad, the big crunch was abit of a s*it theory to be honest. —Preceding unsigned comment added by 90.211.189.159 (talk) 12:54, 21 February 2008 (UTC)

Umm... rumor has it that the universe it shrinking (for lack of a better term) in some places and expanding in other areas. --BrandiAlwaysSmiles (talk) 00:34, 24 March 2010 (UTC)

CLEANING UP!!!!
What is posted under literature, etc... does in no way belong here but on specific simpson pages et al. This is a disgrace to a serious article, and whether or not comics et al are literature is someone each should decide for himself. I am glad it certainly isn't for me.


 * You haven't signed, but I can see it's you who changed the heading to "off-topic". I didn't want to revert it right away, but the contents of that section are not off topic. It is a valid list of works where the Big Crunch has been referenced, seriously or otherwise. If it were off topic, it wouldn't belong in the article in the first place. However, I do agree that listing it under "literature" may be misleading, as literature would mean scientific, as in "further reading". Maybe it should read something like "The Big Crunch in popular culture". Someone with better knowledge of how to properly cite sources should rename the heading and clean that section. Cheers! -- ironcito 11:17, 28 February 2006 (UTC)

Critical Density?
Critical density redirects here, I'm hoping this is just a linking error and the real page is somewhere else. In case it isn't, critical density is the density that will lead to a flat universe, and is just enough to bring the expansion of the universe to a halt, not collapse it again! Critical density should not redirect here! 15:07 12 March 2006

The Big Crunch is the Most Likely Scenario
Before any kind of cosmic explosion, we typically see an internal material collapse. This is true in supernovae and in the ejection of planetary nebulae, both of which feature the collapse of stellar cores prior to the burst, in the first case collapse to nuclear density, in the second case collapse to the density of a degenerate electron sea as a white dwarf is formed, ejecting exterior stellar shells with the collapse energy. In the case of classical novae, the prior mass collapse is to the surface of a white dwarf from a companion star. In all cases, prior material collapse is the most natural way of satisfying the equation of continuity and the basic conservation laws for energy and momentum. Thus we expect prior material collapse in the case of the Big Bang, also. For further details, see http://greenwdks.tripod.com/bigbangabundan.html.


 * That's untrue, and even if it were it's opinion and probably OR. Stating that collapse is some sort of natural order of things is not empirical evidence for the universe collapsing.  Given recent calculations, a universal collapse is nearly impossible, so it is actually the least likely scenario.  Also, that website links to "page cannot be found", so as of now you have no sources.


 * I also really don't understand what you're saying. If you could put your point into either layman's or scientific terms, I could perhaps verify it, but you say "In all cases, prior material collapse is the most natural way of satisfying the equation of continuity and the basic conservation laws for energy and momentum."  I don't know what "the most natural way" can mean, except that you simply see a pattern and expect it to continue.  I don't know what the "equation of continuity" is; perhaps a link, ref, or explanation would suffice there.  Finally, conservation of energy and momentum (which, by the way, does not quite exist; momentum needn't be conserved in instances of, for example, annihilation) do not lead to your conclusion.  In a big crunch, conservation seems violated, not preserved.Eebster the Great (talk) 23:34, 8 April 2008 (UTC)

Possible pop-culture reference
Restaurant at the End of the Universe in the HitchHiker's Guide to the Galaxy?

Also referenced in Futurama. — Preceding unsigned comment added by 199.212.215.11 (talk) 19:55, 17 March 2020 (UTC)

Big Crunch vs. Black Hole
If the theory of the big crunch is correct than wouldnt the universe in its final stages indefinitly become what is known now as a black hole ? and if that is true than couldnt it be possible that the black holes we know of today could be past universes that have undergone the same conditions that are suspected to happen to our universe in the future? -- bianca -- email me to demonic_lillies@yahoo.com if you have an anwser and wish to discuss this ... thanks buh biie


 * I realize this is probably 12 years old, but no, a black hole is just an object in space that physics as we know it doesn't do a good job of describing, a Big Crunch is the implosion of all space time itself. Lqstuart42069 (talk) 07:01, 29 January 2018 (UTC)

Response To Big Crunch vs. Black Hole
It is really not the same because it is a portion of are own universe not another, but it is a good representation i guess — Preceding unsigned comment added by 72.219.182.149 (talk) 02:53, 17 July 2012 (UTC)

List of doomsday scenarios
Could use votes to save this article, thanks MapleTree 22:16, 28 September 2006 (UTC)

Gnab Gib
It appears that Gnab Gib is really in use as a nickname for the Big Crunch. A Google search finds a long list of references, including these three:

http://www.science.org.au/sats2004/schmidt.htm

http://cfa-www.harvard.edu/oir/Research/supernova/newdata/fate.html

http://zeus.colorado.edu/astr1040-toomre/Lectures/lecture28--27apr06.pdf

— WikiPedant 04:18, 30 October 2006 (UTC)

I think there should be a section like "In media". And H2G2 should be added here. Most of the professional physicists use this term when on informal levels.

— Usernamekiran —Preceding undated comment added 20:54, 18 October 2013 (UTC)

acceleration
This hypothesis has been ruled out by the discovery that the expansion is accelerating. ...how does the acceleration of expansion say that the hypothesis must be ruled out? by token of this fact we simply deduce that it will be a more accelerated crunch! frummer 20:19, 13 January 2007 (UTC)


 * No, see, the expansion is accelerating. If we continue to expand, we cannot crunch.  We need decelerating expansion, aka accelerating contraction, to end up in a big crunch.Eebster the Great (talk) 23:36, 8 April 2008 (UTC)

Which One?
Ok, so I know it doesn't happen ALL the time, but usually when two futuristic theories are presented, one is scientifically more probable than the other - I was wondering if such was the case with the Big Crunch/Big Rip theories, and if there is it should be stated in the articles.-- DanielFolsom T|C|U 08:34, 14 January 2007 (UTC)
 * plz rephrase. dont get it. frummer 19:26, 14 January 2007 (UTC)
 * Uhh - I know that it's not always the case one theory being more probably than the other, but if that is the case here (in other words if scientis consider the Big Rip to be more likely than the Big Crunch or vice versa) it should be noted . That make more sense? -- DanielFolsom T|C|U 23:18, 14 January 2007 (UTC)
 * you can be bold and add it in, but please put it well. frummer 19:13, 16 January 2007 (UTC)

Multi-level Cosmology
I deleted the information on multi-level cosmology. Recently, a standalone article on multi-level cosmology was deleted, and was even considered as a scientific notability test case. After a unanimous vote for deletion, it was speedily deleted. Given the strong consensus about deletion, and for the reasons cited in this test case, I feel it's justified to delete the information from this article. Kevinwiatrowski 04:45, 24 February 2007 (UTC)

1969?
In the overview, there is a link to 1969. What is this in reference to? I didnt remove it incase it had some relevance I'm not seeing. Coradon 19:02, 27 March 2007 (UTC)

Could there be a "mini crunch"?
The electrostatic attraction between negative and positive objects is 1036 times more powerful than the gravitational force. This wouldn't be a significant factor in the universe’s “shape” as long as protons and electrons (and possibly anti-protons and positrons) are largely bound together in neutral atoms or degenerate stars, but it would come into play as protons decay into positrons and anti-protons decay into electrons. This electrostatic attraction may seem negligible at cosmic distances, but as more baryons decay it would have plenty of time to do its work. Eventually the negative and positive electrons could reverse their outward expansion and move inward, coming together in a “mini-crunch” if they don’t annihilate each other first.

The term “mini-crunch” is relative, in that the black hole that forms wouldn’t encompass the entire universe as it would in a “big crunch”, but it would still be many times more massive than the black holes at the center of today’s giant galaxies--Robert Treat (talk) 07:31, 16 September 2008 (UTC).


 * This can't happen because like charges repel. A collection of particles with a net charge of either sign will push itself apart, and with a net neutral charge it will neither expand nor collapse. Only at the scale of individual particles can you get a net attraction and "collapse". The formation of hydrogen is an example of that. Also, there's no such thing as an electromagnetic black hole because light (for example) has no electric charge and there's nothing to stop its escaping. -- BenRG (talk) 11:46, 16 September 2008 (UTC)


 * My thinking was that if you had alternating positrons and electrons there would still be a net attraction, because opposite charges would be closer together than same charges (This is why static electricity is able to attract neutral objects.). Since these particles have mass, the black hole I envision would still be a gravitiational black hole--Robert Treat (talk) 18:35, 16 September 2008 (UTC).


 * Although this is a bit off-topic, a photonic cloud could collapse into a black hole. — Arthur Rubin  (talk) 05:29, 5 January 2017 (UTC)

Big Crunch Chocolate Bar
In Canada, there is a chocolate bar called "Big Crunch", shouldn't it be mentioned on here somewhere? --192.197.60.2 (talk) 05:53, 25 October 2009 (UTC)

No... —Preceding unsigned comment added by 72.197.179.66 (talk) 09:46, 19 November 2009 (UTC)

No Religion Please
I removed the entries about the Qur'an predicting the Big Crunch. This is an article about a scientific theory. I do not believe religion should be mentioned in this article what so ever. —Preceding unsigned comment added by 72.197.179.66 (talk) 09:46, 19 November 2009 (UTC)


 * Agree 21:46, 22 November 2009 (UTC) —Preceding unsigned comment added by 202.70.51.44 (talk)


 * Seems like User:Khan197khan want to keep about Harun Yahya in this page, should we keep it? I dont think so. User:Adi Jayanto 202.70.51.240 (talk) 16:50, 25 November 2009 (UTC)


 * The article has to mirror the reliable sources. If there are more "religious" than "Scientific" that would make the latter a fringe view in light of the entire body of knowledge. You may be able to argue about "reliable" but maybe a disambiguation page would be called for if there are two uses for the same term that don't have much common ground. We had a similar situation come up recently about a technical term, or law actually. There were many scientific statements over the years but one contrib wanted to make the entire topic about Author X's law in contradiction to the body of literature. There is no reason to allow his view point any more than there is to ignore a "religious" comment on this topic if it is supported by relevant literature. To exclude it, you would need to claim all the coverage is unreliable or otherwise defective. This is not about merit, just verifiability. There may indeed be no independent coverage, but here too you need to argue about independence- if you say all Muslims are dependent on each other, like arguing all scientists are, then ok maybe you have no supportive significant reliable coverage. There are a lot of issues here ( presuming the religious view is given significant coverage somewhere). Wikipedia covers many topics that are not scientific or have different interpretations within differenet cliques. Nerdseeksblonde (talk) 18:43, 25 November 2009 (UTC)

New Cosmic Crunch research- if it useful
http://phys.org/news/2015-03-universe-brink-collapse-cosmological-timescale.html Jcardazzi (talk) 19:23, 25 March 2015 (UTC)jcardazzi

Last sentence of lede
This is unclear to me: "Sudden singularities and crunch or rip singularities at late times occur only for hypothetical matter with implausible physical properties." Isn't the article about a crunch singularity at a late time? Does that sentence therefore mean a big crunch scenario is highly implausible? We see the same sentence at the end of the lede of Big Rip (I posted there also). --Middle 8 (t • c &#124; privacy • COI) 22:34, 4 May 2015 (UTC)

popular culture BS
i have taken the initiative to purge the popular culture section entirely due to the sheer amount of uselessness in them. honestly, it's an embarrassment to the collaboration model that fantards have been allowed to mark their territory, their ramblings allowed on erstwhile serious pages for so long.
 * 1) i expect to learn about the scientific concept called the big crunch when browsing through a page called the big crunch. i fail to see how bowser/galactus/all other miscellaneous cruft from various fandoms have any relevance to understanding that concept in the real world.
 * 2) really, the popular culture section is longer than the serious content? spin it off if you really want the pop culture refs kept. or better yet, put those on other sites that actively cultivate fannish tendencies. like tvtropes or something.
 * 3) speaking of refs, there aren't even any for the fancruft.

120.29.74.249 (talk) 02:00, 12 August 2015 (UTC)

Academic Sources
Television shows should not be used as a primary source if this is not where the information originated from. I am specifically referring to source 2: ''How the Universe Works 3. End of the Universe. Discovery Channel. 2014''. — Preceding unsigned comment added by 104.148.141.176 (talk) 00:19, 13 March 2017 (UTC)

References for strong claim
"The vast majority of evidence disproves this theory" --- This is a strong claim. It shooriginal dogmatic claimuld be accompanied by in-text citations of two or three independent and reputable sources. NOTE: not my area of expertise. Just going off of general guidelines for supporting strong claims. MaxwellMolecule (talk) 18:04, 10 July 2019 (UTC)
 * I have tried to edit the later section to provide support for the strong-but-true claim up top (people don't get Nobel Prizes for discoveries where the evidence is equivocal). The prose still needs a lot of work, though &mdash; it seems to have been based on ideas filtered through several layers of popularization, rather than, e.g., cosmology textbooks. Such is the fate of science articles on topics in the public eye. XOR&#39;easter (talk) 19:26, 14 July 2019 (UTC)

I too am concerned about such a certain claim for something that has not been proven beyond doubt. To say that the theory of the Big Crunch is now off the table with the "vast majority" is not a true statement. And which wiki author had the authority to say that the theory is "not correct." There are zero sources referenced for this bold statement. The Big Crunch theory has fallen in and out of favor through the years but as of late many are seriously revisiting it. Could someone correct this wording. As is, it is too dogmatic. CWatchman (talk) 23:31, 5 September 2020 (UTC)

Since I have received no responses on this, I proceeded to change it myself. Thank you. CWatchman (talk) 19:57, 26 September 2020 (UTC)
 * The source you provided is from a predatory publisher and is not reliable. The accelerating expansion of the universe won the Nobel Prize . XOR&#39;easter (talk) 00:49, 27 September 2020 (UTC)

You provided better references but the same ole' statement. Should such a dogmatic claim be made in the lede whilst some are still considering the theory? Shouldn't this be battled out in the body of the article? Thank you. CWatchman (talk) 16:56, 28 September 2020 (UTC)
 * Every idea that was ever at some point taken seriously will always have die-hard adherents and people willing to say the occasional positive thing about it out of sheer contrarianism. That doesn't change either the state of the evidence or the community consensus. XOR&#39;easter (talk) 17:28, 28 September 2020 (UTC)

I understand that, however, when you have such eminent scientists (Penrose among them) who are not sure that the Crunch is off the table, it seems a bit premature for the lede to blatantly say the theory is "not correct". CWatchman (talk) 18:59, 28 September 2020 (UTC)
 * Penrose has advanced a speculation that even he admits is manifestly incomplete, which presumes physical processes that have never been observed, and whose predictions have not panned out. This has no bearing on the wording of the lede, which in this respect is fine. XOR&#39;easter (talk) 20:52, 28 September 2020 (UTC)

The information in the provided references do not match "theory is not correct." I DID find "it’s very hard to see how a big crunch would happen", and "we don't believe it is going to happen", and "we may never be able to rule it out," but I never found a single statement saying that the Crunch or any other theory "was not correct." CWatchman (talk) 14:55, 1 October 2020 (UTC)

The energy released in the Big Bang
regretfully misses the point. The original deeply naïve rant obviously suggested something like “the Big Bang may release sufficient [kinetic] energy to overcome the attraction”. In FLRW the Hubble parameter (that is, the logarithmic time derivative of the scale factor) is responsible for it, whereas “energy” is, contrary, the source for gravitation. spared this specific phrase when removed most of the crap, but its meaning is currently obscure. Incnis Mrsi (talk) 08:39, 16 July 2019 (UTC)
 * XOR'easter found a better phrasing now. --mfb (talk) 21:02, 16 July 2019 (UTC)

Effects on humanity?
If the universe contracts during a Big Crunch, do we know what would happen to solid structures such as Earth? If so, should we add that in the effects? Cha010 (talk) 18:29, 10 May 2021 (UTC)

Unreliable source?
Source [4], McSween 2015, doesn't strike me as a reliable source. It is a self-published website advocating a nonstandard theory of cosmology that is not peer-reviewed. Unless I am wrong in this assessment, it seems [4] should be removed. 2600:1700:1D8A:100:2865:DE14:F03:B8D8 (talk) 16:30, 29 October 2022 (UTC)

Over and Over Theory
Wait... If the big bang happen. Then It should continue again and again. Maybe there is infinite of us over again and again. OfficialDavitYT (talk) 11:41, 29 December 2023 (UTC)

"Gnab gib" listed at Redirects for discussion
The redirect [//en.wikipedia.org/w/index.php?title=Gnab_gib&redirect=no Gnab gib] has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at  until a consensus is reached. Utopes (talk / cont) 06:21, 11 April 2024 (UTC)

"Gnab Gib" listed at Redirects for discussion
The redirect [//en.wikipedia.org/w/index.php?title=Gnab_Gib&redirect=no Gnab Gib] has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at  until a consensus is reached. Utopes (talk / cont) 06:22, 11 April 2024 (UTC)