Talk:Ekpyrotic

From Wikipedia, the free encyclopedia

	Physics Portal This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
???	This article has not yet received a rating on the assessment scale. [FAQ]
???	This article has not yet received an importance rating within physics.
Help with this template Please rate this article, and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article.

Non-standard cosmology has a specific meaning in cosmology, and the ekpyrotic scenario is not considered non-standard by cosmologists I know.

User:Roadrunner

"Non-standard cosmology has a specific meaning in cosmology"? isn't that "non-standard cosmology is a cosmological theory that contradicts the standard model of cosmology"?

"ekpyrotic scenario is not considered non-standard by cosmologists I know"? umm that link seem, to me @least, to state otherwise ... [quote] "[...] _instead_ of a universe springing forth in a violent instant from an infinitely small point of infinite density [ed. singularity], the new view _argues_ that our universe was created when two parallel "membranes" collided cataclysmically after evolving slowly in five-dimensional space over an exceedingly long period of time" [see link]. That is or is not contradicting the BB? I guess that is the question ... JDR

Uh-oh, now you're going to incur the revert wrath of JDR! - Lord Kenneth 04:11, Jan 28, 2004 (UTC)

Which I don't understand. There is the plasma cosmology, ekpyrotic cosmology, and Arp's cosmology each of which are completely different from each other. Most ekpyrotic cosmologies assume that general relativity is more or less correct, and the idea that our universe might be the result of the collision of two higher dimensional branes is "so weird it might be correct" and the idea that we might be able to prove or disprove (using COBE data) makes cosmologists really giddy. User:Roadrunner

plasma cosmology and Arp's cosmology is interrelated [as far as I can tell) ... now the ekpyrotic cosmology is a brane thing (something different) ... ekpyrotic is a neat idea though ... Sincerely, JDR

It's possible that Arp is done some previous work on plasma cosmology that I don't know about, but the articles on this website clearly don't have anything to do with plasma cosmology.

http://www.haltonarp.com/?Page=Abstracts

Arp claims that GR is wrong and comes up with his own model of gravity. If you can find references where Arp supports plasma cosmology, feel free to put him back on the plasma cosmology page.

Personally, I think that the case for plasma cosmology is a lot stronger if you ignore Arp. If you use Arp, then you lose the one big thing that plasma cosmology has going for it (i.e. no weird physics). User:Roadrunner

"find references"? The Case for Plasma Cosmology

"put him back"? I did ...

"ignore Arp"? arp show one [of the various] problems with the standard model ...

"no weird physics"? IYO ... If Arp is right, it seems that the "weird physics" is on the BBT side of the equation ...

Sincerely, JDR

I hope I haven't trodden on any toes with my rewrite (I was going to include something about it in the brane cosmology article when I noticed this already existed); I have to say I'm rather surprised that such an abstruse bit of theoretical astrophysics is so controversial! I've tried to be even-handed about the theory's status; it would be nice if we could get this to a state where everyone could agree to remove the "disputed article" tag.

One thing to note, though: membrane (specific word for a 2-dimensional brane) is simply not correct as a description of our universe, the more general "brane" is. Bth

It's probably horrendously bad form to verify one's own version of an article, but I've removed the accuracy dispute header because the article is correct now, and no one's raised a fuss in a week and a half. What was the original dispute about anyway? The use of the term "non-standard"? If that's all it was, my take is that the current version is correct -- brane cosmology is an extension to standard cosmology, not an alternative to it such as plasma cosmology. -- Bth 10:11, 10 Mar 2004 (UTC)

[edit] 14 Jan 2005 additions

Hi!! I added a few sections. Background, Compared to The Big Bang Theory and Increase of Support. I thought that the idea of Brane Theory was a little vague and depended to much on links so a added a small sections, and also I though that I should add the Increase of Support sections as the ekpyrotic has become more noticed in recent times. I thought that the key explanation of the ekpryrotic model was great and left that how it was , I hope my modification were welcomed and please add to my explanations User:Jordan14 22:00, 14 Jan 2005

I applaud your enthusiams and thank you for your additions, but I'm inclined to believe, that you got one important point completely wrong:

• Ekpyrotic doesn't contradict Big Bang, it is a refinement of Big Bang. The vast majority of observable predictions of both Standard Big Bang and Ekpyrotic Big Bang, are identical or nearly identical. So the majority of Big Bang criticisms (which are held by small minority of scientists) would both apply to Standard Big Bang and Ekpyrotic Big Bang.

For example see the formulation in hep-th/0109050 of the reference section:

• We recently proposed a novel scenario for the early Universe in which the hot big bang is created by the collision between two M-theory branes

Of course from a philosophical point of view, it may be a major difference whether time and space started to exist 13.7E9 years ago or this being "only" a singularity and there was history before it. But trom the POV of abservational astronomy, the difference is rather subtle, if at all detectable.

Pjacobi 23:05, 2005 Jan 14 (UTC)

Sorry my article was really not that clear and I am going to go and rewrite my sections now. I really didn't mean to state that the Big Bang was in contrast to the Ekpyrotic model.

I also understand that most criticisms of the Big Bang Theory hold in ekpyrotic model, and I will reinstate the differences of the two in a more thoughtful wording.

'Thank you for the feedback'

Jordan14

OK I have decided to scrap Compared to the Big Bang Theory totally and I tried to better word Background and Increase of Support I hope that is better. I think more still needs to be added to background though.

Jordan14 10:41 Jan 15 2005

I more-or-less rewrote this page from scratch, for clarity. I tried to keep most of the old content in there, as well as emphasizing the reasons the theory is controversial, while making it more coherent. I did remove a number of references to how abstract the theory is, and how ideas in physics are becoming more abstract. I think that's POV -- the reader should judge that for himself.

--Joke137 21:46, 5 Feb 2005 (UTC)

I like the rewrite, however I think that the article could be more structured to make the article even clearer. What I mean is that I think that all the information below Background could be seperated into nicer subtitles.

Jordan14 11:05, 6 Feb 2005 (GMT)

I think the subtitles are superfluous in an article so short, but who knows, maybe someone will be inspired to fill in more details. In any case, I split it back up into sections. --Joke137 22:26, 6 Feb 2005 (UTC)

Thanks Joke137 I think that that works much better and looks more like an article rather than a collection of facts dumped on to the internet. Well done!

Jordan14 17:23, 7 Feb 2005 (GMT)