Talk:Introduction to M-theory

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This article was nominated for deletion on 14 April 2008. The result of the discussion was nomination withdrawn.

I kind of like the idea of having an introductory level entry on m-theory, but I agree that the article was fundamentally flawed in many ways, so I decided to write my own. I would appreciate hearing your thoughts on it and whether or not you think it is still best to combine it with the regular M-theory page. Thanks. Jcobb 10:03, Feb 21, 2004 (UTC)

The use of words, as opposed to mathematical notation, is the right approach for the simplified article, which I propose to submit to Featured articles, if it is all right with you all. Ancheta Wis 18:46, 28 Feb 2004 (UTC)

Should this not be organised such that article is at "M-theory" and we give each section sub-articles where the more in-depth stuff goes? Joe D (t) 12:44, 17 May 2005 (UTC)

IMHO, it makes more sense to have the simplified article at M-Theory, and further information in (technical). The whole encyclopaedia is meant to be accessible to non experts, so a "technical" article is a departure from that. FWIW. 217.128.193.40 16:39, 6 January 2006 (UTC)

This article should eventually be merged into M-theory. We can't have different articles on the same subject. I do not agree, however, that all of wikipedia has to be accessible to a general audience. The technical stuff, should be farmed out into subarticles of M-theory.--345Kai 21:45, 11 October 2007 (UTC)

[edit] Greene or Green?

Is Greene spelled Green? I have it on the authority of Dr. Scott Wolpert, head of the math department at the University of Maryland, that it "probably has no e on the end" Sabrebattletank

Brian Greene is a known author. Nice appeal to authority, though. Have you seen his books in the stores?

Yup. Just checked out The Elegant Universe and the Fabric of the Cosmos. Thanks. Now, thanks to Greene, I am more versed in String Theory.Sabrebattletank 22:41, Apr 14, 2005 (UTC)

But there is also the Green of Green, Schwarz(sp) and Witten. --MarSch 15:38, 2 Jun 2005 (UTC)

[edit] Approximation statement

If you are changing the radius from R to 1/R to change from theory to theory, I would appreciate some explanation of whereabouts '1' is - obviously not metres, or 1/R would be larger than a planet. How long is the unit in this case?

Probably the units are natural units, subject to transformation of variables. At this level, the names of the units are immaterial, as most of the 10, 11, 16, 26 dimensions don't even have names. So it's all abstract right now. --Ancheta Wis 01:42, 13 February 2006 (UTC)

1/R is also a general way to denote the multiplicative inverse of a number. Thus 1/R would have the same units as R (presumably meters). Since the extra dimensions are all spatial dimensions, they would be measured with meters (or units of length/distance of any type, natural units included). Yill577 23:47, 4 October 2006 (UTC)

In this case the full formula is $R \to \alpha' / R$ , where

α'

is a constant appearing in string theory with the dimensions of mass^-2, or equivalently length². Usually, since

α'

pops up so often, people just leave it out of the equations and set it to some convenient value -- like "1" or "2." $\sqrt{\alpha'}$ is probably near the Planck length, so another way of interpreting the formula is that T-duality takes a circle that is R Planck lengths in radius to one which is 1/R Planck lengths in radius. Wesino 11:25, 6 December 2006 (UTC)

My background isn't in physics so I appreciate my basic ignorance, but every time I encounter m-theory I wonder, "So, what is our universe's brane?" Is it "now?" My understanding has been that "now" is basically just a coincidence, less and less causally connected as events' connections and shared causes diminish and become more distal. If that is true, then what is our brane?PMELD5 (talk) 03:26, 4 February 2008 (UTC)