Talk:M-theory/Archive 1

Archive 1

Archive 2

This talk page is quite old. I have partially sorted out the somewhat garbled history and re-ordered some of the undated entries. Please add new material to the bottom of the page. --Blainster 00:07, 2 November 2005 (UTC)

11d vs 12d

On the article it talks about 11-dimensional spacetime. Shouldn't this be a 12-dimensional spacetime with an eleven dimensional space? I don't know very much about M-theory, but I'm pretty sure that in string theory and Kaluza-Klein models in general, you need an even dimensional spacetime in order to allow left-handed and right-handed spins.

Read this article. http://www.2think.org/t000104284.shtml . I'm not certain this helps. Will review my notes again. Remember I don't fully understand this, and to explain it is worse ! BF

Hmm, that says 11-D spacetime, and some further searching confirms it. How very odd that that permits chiral asymmetry, but maybe some property of the 'branes allows it. Hmm. Sorry for the unwarranted questioning, and feel free to delete this conversation.

There's no simple answer since the superstring theories are constructed on top of the bosonic string theory, which is 26 dimensional. So for all I know, chirality is related to dimensionality. I am curious where you got the idea though. -- ark

11-D M-theory is non-chiral, because it is odd-dimensional. However, it is possible to intruce chirality in compactifications down to lower dimensions, so this is not a problem. -ps

I am not a physicist or mathematician, but I just finished watching a special on strings via pbs broadcast here in the US that distinctly said 12 dimensions.....just a note, not an arguement.

Hi, I think I can clear this up. M-theory lives in an eleven-dimensional spacetime (ten spatial dimensions, one time). This is sometimes written "10+1 dimensions" to avoid just this kind of confusion. Superstring theories all live in 9+1 dimensions, and the bosonic string lives in 25+1. There are also proposals for another "unifying theory" called F-theory that lives in 11+1 dimensions, with one more spatial dimension than M-theory. Wesino 10:11, 6 December 2006 (UTC)

yet to produce testable predictions

"yet to produce testable predictions" can only come from a qualified physicist who is working in the field.. sorry" Boggle. WTF does that mean? Are you pulling rank? -- GWO

Of course not. I am explaining that whoever added that part must be researching M-theory, unless they are quoting someone who is. once again, that deletion was made because the THEORY has already been scrutinized by fellows of Witten, and stands. Someone chooses to assume or fantasize they are part of the M-theory group of physicists, outside wiki. That tiny addition to the main page was unsubstantiated presumption on someone's part. Moreover, I have read some recent journal abstracts(some Japanese scientists) which use M-theory to expand into new areas of superstring, meaning it works.

I found a site or paper (don't have it at hand) which had that section of the page (now moved/deleted) almost word for word. So I believe the person who wrote it was quoting a physicist, and not presuming to be a physicist. -- ark

Additions requested

Note: add a mention to Vafa's F-theory with 12 spacetime dimensions (2 time, 10 space).

Note 2: explain T-duality (between R and 1/R) and how it relates to energy; that there are two distinct measures for energy which give rise to different measures for dimensional size. -- 29 May, 2002

String theory is different.

String theory is different. Some people complain that it does not predict - but it in fact predicts a lot. To include gravity consistently to a quantum theory, we were forced to go to 10 dimensions, to discover supersymmetry, to allow topology change etc. Some people criticize string theory that it predicts nothing new, some people complain the string theory involves/predicts too much new stuff (excited strings, higher dimensions, SUSY etc.). Some critics happily belong to both categories and they do not realize how inconsistent their position is... ;-) (http://www.lns.cornell.edu/spr/2001-06/msg0033389.html)

Nice job cleaning up the article I originally wrote. The LD Learning Lab at Caltech does help a lot! I noticed some formulas painstakingly added with symbol fonts were removed by someone. This is very annoying to see on a science page. Not sure if wiki supports pdf yet, so restore the formulas, or I will. BF 22:55 Dec 12, 2002 (UTC)

Not well written

I'm a mathematician and I've written a number of articles about analysis, and sometimes people complain that my articles are too specialized and don't make any sense. (For instance, see Lebesgue integration or Riemann surface.) However, I'm almost certain you guys are doing a poorer job than I am. There are a zillion and a half technical terms that aren't defined at all. In fact, almost every word of every sentence is some undefined techincal term. Here's a specific example:

The T duality infers the existence of open strings with positions fixed in the dimensions that are T-transformed.

T duality? T transform? What does it mean to have open strings with positions fixed in whatever dimensions?

Do you mean open as in f:[0,1]->X with f(0) \ne f(1) or as in f:(0,1)->X? Articles such as Riemann integral are long, not because the topic is complex, but because a more terse discussion missing numerous definitions is inappropriate, especially for an encyclopedia.

I think a lot could be done to disambiguate, clarify and otherwise make this very interesting article even better. Loisel 00:06 Jan 30, 2003 (UTC)

I agree absolutely. Sentences like The theory requires mathematical tools which have yet to be invented in order to be fully understood make me instantly assume that the following paragraphs are not going to be too enlightening. If nobody understands the theory because we don't have the mathematical tools - well, what kind of theory is that? Chas zzz brown 03:40 Feb 1, 2003 (UTC)

Right, that sentence is not particularly good. Some fields of physics haven't been completely axiomatized yet, and sometimes many mathematical details are unproven (I believe this was the case for much of Witten's work, which was otherwise excellent and warranted a Fields medal.) So I would understand if some of the theory hasn't been worked out to a mathematician's satisfaction. However, with the article as it is now, much more profound changes are needed than an axiomatization. Right now, the article is unreadable to non-experts and probably useless to experts.

Please merge

This article is still poorly written (see my comments below); however, the article at M-theory (simplified explanation) is actually good. I suggest that this "simplified explanation" replace the current article. What little information is present in the current article and not in the other article could possibly be merged in. Stuff like the "Strominger and Vafa D-brane quantum microstates" Star Trek technobabble could possibly be merged or, even better, made nice like in the "simplified" article (really, not much simplified, just clearer.)

If it stays as is, I might have a "moment of lucidity" and move the current article to "M-theory (obfuscated)" and move the simplified one to the current article. Loisel 04:31, 18 Apr 2004 (UTC)

When I first read the merge proposal I was skeptical. But after looking at the two articles I think it's an excellent idea. Almost the entire M-theory article is taken up by "Basics" and a section on what the "M" stands for. In other words, the current article is a simplified account of M-theory. It takes more knowledge (mostly of vocabulary) to be able to read the M-theory article, but the reader learns less. The content of the present article is just more jargony than the "simplified" account but the content is pretty much the same. Wesino 10:30, 6 December 2006 (UTC)

Rewrite attempt aborted

April 27, 2004

Was bored, rewrote the whole thing. Unfortunately, I have a bad feeling the thing's completely incomprehensible now. Still, the simplified page is out there. It probably needs a lot of linking now. Feel free to change it back if it's hopelessly obscure.

April 27, a bit later at night... Ugh. Changed it back. It needed too much work to be comprehensible, I think. If anyone else wants to grab from it and make it better, they're more than welcome to it.

Extra Dimentions.

I read with interest the theory that extra spatial dimentions exist. However, this view is at variance with one expressed by Professor Stephen Hawking, who remarks that " if there were more than three spatial dimentions, the orbits of planets around the sun or electrons around a nucleus would be unstable and they would tend to spiral inward." Derek R Crawford. 20 June 2005

See an answer here

the orbits of the planets about tne sun are unstable (at least as observable from our own planetary system, there is currently no way of observing the orbits of others) and they are tending to spiral inward... that is to say our planet is falling toward the sun in an observable manner, as are all of the orbiting planets, planetoids, asteroids, moon, etc... do you honestly think that if a human being was able to clearly observe an atom for an unlimited amount of time, in a perfect manner, they would find something different? it will take longer than the life of the universe (as can be predicted by thermodynamics), but guess what, earth will fall into the sun... why are atoms any different? seems to me, and grant this is a completely unsupported view, but fractals and thier repeating patterns from as far out as you can go to as far in as you can zoom, could go a long way toward explaining the universe....

New Article version

Saw this entry and thought it needed rewriting. The exposition is incoherent. I'm trying to clean up the exposition by incorporating some aspects of the "M-theory simplified" article. --User:Ajt, 10/28/05

Corrected some errors and some miscorrections. In particular, please leave intact the fine distinction about Witten proposing the EXISTENCE of M-theory. He didn't actually propose M-theory, as the theory has not been fully defined. Likewise, M-theory itself does not explain the string dualities: the theory is not yet thoroughly developed enough to support this sort of proof. However, such a theory, if it does exist and could be fully defined would (presumably) explain the known string dualities. I wrote the introduction to gloss over this point. It's unfortunately easy to change the language, and in doing so, introduce technically incorrect statements. --User:Ajt, 11/1/05

The words "proposed the existence of", do not suggest that the theory is merely not completed, rather they say that the theory has being apart from it's creation by a human being. This is not the way science understands the concept of theory. Theories are created, not discovered. The relationships or facts which support a theory are discovered by experiment. A scientific theory such as the theory of gravity is a human conceived model for the way we understand reality. Theories provide a structure for understanding the established facts of existence; they do not in themselves constitute that existence. See article: theory. --Blainster 19:13, 2 November 2005 (UTC)

I'm using "theory" as it's typically used among my colleagues in mathematical physics. In particular, the term "M-theory" refers to a specific mathematical model. I apologize if you found this confusing and have corrected the article.

I'd caution you, by the way, that the terminology in the wikipedia theory article does not conform to the terminology commonly used by working physicists. In particular, most of us would read the sentence "Witten proposed M-theory" as giving Witten credit for creating the model itself. --User:Ajt Nov 2 2005

Wikipedia is written for the general educated public, and should not conform to the ways of specialists in any one field. It is up to specialists who contribute to it to use either non-specialist language, or to define special terminology they use. Hyperlinking provides an easy way to do this. (WP should read more like Scientific American than the Journal of Mathematical Physics). That said, my misunderstanding of what you wrote was not due to technical jargon, but because the phrase you used previously suggested the meaning I explained in my previous post.

The article makes clear further on, that Witten's proposal was that the physics community should work towards uniting the various string theories into a single model, and that he did not propose a particular expression of it. That is what the introduction should say. The article could state in the opening paragraph that Witten provided a name for a yet-to-be formulated theory. It can be surprisingly difficult for advanced researchers to switch gears into language that general readers can follow, and I think you explained things well in the body of the article. --Blainster 11:07, 3 November 2005 (UTC)

Inaccuracies / mistakes

In "The Theory": "So when one studies string theory at low energies, it becomes difficult to see that strings are extended objects—they become effectively one-dimensional (points)."

One-dimensional objects are lines - they can be measured in one dimension, like a string. Points have zero dimensions - they can't be measured. I believe this sentence was supposed to say that they become effectively zero-dimensional, but since I'm a little out of my league I'll let someone else correct the mistake. --nunocordeiro 20:38, 6 December 2005 (UTC)

Good point! --Blainster 22:14, 6 December 2005 (UTC)

suprised

I am suprised at how there a longer passage for the possibility of what the "M" stands for than the background of the theory! The background did not have any metion of Witten, which there should be. After all, M theory was the byproduct of the second superstring revolution. M-theory should deserve better than this. The pointer outer 03:11, 19 January 2006 (UTC)

Well that's probably because 'what the "M" does or doesn't stand for' is all most people can comprehend about the theory ;) This article is in poor shape and should probably be merged with its "layman's fork" M-theory (simplified). -- Fropuff 03:45, 19 January 2006 (UTC)

Why is there a hoax template at the top of the article?

Notwithstanding the legitimate scientific controversy of M-theory and/or string theory, is there any evidence that some poser was deliberately inserting plausible garbage in the article? if not, the hoax template should be removed. r b-j 03:06, 12 February 2006 (UTC)

Branes and Matrixes

The branes may be the fisical manifestation of the shapes allowed by the law and the four forms of energy allowed by the order: fabric (relativistic), fluid (quantic), light (photons) and spirit (thought-form). Mass probably is the knotting of the underlying branes.

It is interesting to remember that tachyons are entities of imaginary mass different from zero that may travel at speeds greater than the light. Certainly life forms are entities with real and imaginary mass (or energy, it's the same). They travel at under-light speeds in the real world and may achieve super-light speeds in the other dimensions of lighter matter.

It may be that these "enveloped" dimensions include the integral and fractal parallel dimensions of the astral, the subjacent divinely omniscient quantic computation and the gravitational time webnet and other sets of multiverse.

Knowing these concepts of dimensions, one may quickly percieve time as imaginary and translate this in the natural Rhythm of the underlying branes. Count time and discover the natural oscillation of the local brane. Then time becomes imaginary, existing in a transform of the reality.

These comments go there or here?

Definition of "M" in "M-Theory"

Yes, it's debated. I know that. The problem is that the M-Theory Article (this one) differs from the String Theory's explanation. Quoted from the first guess on the "Naming Conventions..." part says:
When Witten named M-theory, he did not specify what the "M" stood for, presumably because he did not feel he had the right to name a theory which he had not been able to fully describe. According to Witten himself, "'M' stands for 'magic,' 'mystery' or 'membrane,' depending on your taste." Also suggested, has been 'matrix' (see below) and 'mother of all theories'.

The String Theory article has this to say about Witten believes the "M" stands for:
According to Witten himself, as quoted in the PBS documentary based on Brian Greene's The Elegant Universe, the "M" in M-theory stands for "magic, mystery, or matrix according to taste."

And the M-theory (simplified) version has the same thing as the String Theory article. Should I just assume that whoever wrote this article wasn't thinking?

Yeah, they conflict. My question is: which one is correct? Xgamer4 02:26, 8 April 2006 (UTC)

The normal practice would be to use whichever one has a good reference - David Gerard 18:44, 4 May 2006 (UTC)

Copyedit, please check

Some of the grammar struck me as clumsy and it was peppered with typos. As such, I did a copyedit for clarity. Since I know nothing about the theory itself, could someone please check I haven't inadvertently made it inaccurate? - David Gerard 18:44, 4 May 2006 (UTC)

What ???

I've looked through the article, and still have no idea what M-theory IS. If someone reads the first few paragraphs, they should have some idea how this idea ties in with what they already know. Otherwise it's "for members of the club only" and isn't encyclopedic.
And I majored in the physical sciences. This page has to be gobbledy-gook to laymen. Which is fine if that's what M-theory is. Otherwise someone who can write for intelligent laymen needs to step up to the plate.

Difference Between String & M - Theory

         For quite a few years a debate raged - 

Was string theory based in 10 or 11 dimensions? The 10 - dimensional viewpoint was later worked out and disproven, and when one turned to the 11 - dimensional viewpoint, two things happened :

         1. The strings merged, forming a single membrane constituting the known universe.
         2. The five string theories were found to only be 

different manifestations of one theory, which later became M- Theory.

Wow

I have nothing of substance to add. I just wanted to give enormous kudos to the authors of this article. In spite of knowing nothing about string theory and very little about physics, I was able to understand every word. The contrast with our articles on advanced math is enormous. It's enough to restore one's faith in Wikipedia, if it needed restoring! Thanks!

Information

There is A LOT of vital information within M-Theory that is not being presented in this article. Furthermore, the article has a confusing format, and at one point even talks about the unification of electromagnetism (??).

Ora, Labora Gagueci 20:34, 31 July 2006 (UTC)

NAturally the subject is very big ,complicated, technical and quite new. I dont't think full mathemtaicl forumalization is needed, not now at least.

The unification of EM has everything to do both historically and physicall with M-theory unification of different sting theories. --Procrastinating@^talk2me 10:44, 5 August 2006 (UTC)

Sub Sections

I think these would do:

Introduction (done)

Overview of Unification (some of this has already been done)

M-Theory and Extra Dimensions (needs work)

M-Theory and Membranes (needs work)

Cyclic Cosmology (Brief)

Gagueci 19:37, 1 August 2006 (UTC)

please help those are watching this article to do just that, by reverting your HUGE edit and using 5 different edits including summaries, so we can help make this article better. thnak you. --Procrastinating@^talk2me 10:45, 5 August 2006 (UTC)

Supersymmetry

There should be some inclusion of the concept of supersymmetry. Supersymmetry is a major compenent of M-Theory and explains sparticles, dark matter, etc. Even though this excluded the article is pretty good at introducing M-Theory.

Well...most of these sare of still spculative nature, even the whole the theory is dubbed by some to be unscientific...the dark matter supersymetry subject can and should be added with great caution...there are still some contradictions in this theory..--Procrastinating@^talk2me 10:47, 5 August 2006 (UTC)

This article is a joke

It's hard to tell where one error ends and another begins. 1. The discussion of "Spiritual speculations and analogies" has NO place in this article. 2. Many concepts are left unexplained, described only in vague terms or actually incorrect. 3. The analogy with electromagnetism in the opening paragraph is very poor.

The article is beyond repair. Recommendation: Delete it. Let "M-theory (simplified)" stand in its place.

Albertod4 18:52, 30 September 2006 (UTC)

Scientific Spirituality

I was please to find a discussion on the spiritual implications of M-theory in this article, only to have them disappear seconds later. The opinion expressed by Albertod4 in comment 22 implies that there should be separation of science and spirituality, an inherently flawed sentiment in my view of things. The radical changes in perspective which M-theory and Superstring theory have brought us should have spiritual implications for humanity. It was once believed that God lived literally above us in the the sky and that the Devil took residence in the earth beneath our feet. There are many educated people who follow the Christian faith. Few still believe these things about God and the Devil (at least so literally) and it is due to advances in scientific knowledge and the changes in perspective these advances bring. Any time discussion or the expression of insight is limited humanity's ability to progress becomes limited. Please at least make that section it's own cross referenced article.

Ally Lorton '01 Reed College

I agree.--Procrastinating@^talk2me 22

43, 6 November 2006 (UTC)

Well, the deletion has been reverted, along with my re-write of the big bang section, which again reads really badly now.

It's extremely sad that `spiritual speculations' are now considered a relevant part of an encylopaedic entry about a

mathematical/scientific theory. Even putting that aside, the actual content of the section shows utter ignorance of the

ideas of extra-dimensional physics. Students or other interested beginners derive no help at all from such nonsense.

Shambolic Entity 03:57, 9 November 2006 (UTC)

I am a student of physics, and I find this interesting. if you feel in undershoots the level neede, please feel free to add information.--Procrastinating@^talk2me 15:39, 11 November 2006 (UTC)

The inclusion of the metaphysical gobbledogook in the section Scientific spirituality has no more right to a place in this article than a section on numerology has a right to space in an article on number theory or a section on astrology has a right to a place in an article on astronomy. There is a clear distinction between scientific subjects (which are based on experiments, models, well-defined theories, mathematics and logic) and wooly superstitions (which are based on the unsubstantiated pronouncements of mystics). It is not a matter of objecting to such beliefs, it is merely that such beliefs do not form part of science. I propose that if enough people think the ideas in the section justify inclusion in Wikipedia at all, that they be moved to a non-science article. Elroch 15:27, 12 November 2006 (UTC)

Agree with Elroch. This material needs to be deleted or moved to another article. It has no bearing on M-theory. It is also unreferenced. -- Fropuff 01:21, 13 November 2006 (UTC)

There is absolutely no reason to have spirituality in this article. There is no info in the spirituality section that has ANYTHING to do with M-Theory, and nothing in that section is referenced. I erased it. Nly8nchz 01:12, 14 November 2006 (UTC)

I do not agree. When Stephen Hawkings, who is an agnostic as I understand it, speaks of the Cosmos and esoteric theories he often (nevertheless) refers to God. Other cosmologists also do. It is an odd thing but science seems to be investigating and encroaching slowly on "spiritual" things. Certainly this is happening faster than spiritual people are embracing science! Cosmology is one is one of the areas where science starts to touch onto metaphysics and I think it is ok to keep that stuff in. Particularly given the original purpose of wikipedia -- to be an organized collection of information. Since others have put it in previously and had positive things to say, I do not think it should be deleted without a discussion.--Blue Tie 03:21, 14 November 2006 (UTC)

But what does any of that material have to do with M-theory? You could just as well stick it in an article on general relativity or an article on magnets. -- Fropuff 03:29, 14 November 2006 (UTC)

These specific contributions dealt with spiritual significance of visualized strings of unusual characteristics. This is how it relates to M-theory and branes or n-dimension strings. --Blue Tie 03:37, 14 November 2006 (UTC)

Numberology shoudl not be included in number theory, because it does not have causual connection. The many world interpretation of quantum theory have Many spritualistic views that uses that interpretation of ampirical results as their rational. M-theory's many world's as viewed my the spiritualist may act an yet another rational of the same view. The view it self may be excluded or at least be very quintesential, yet the connection should be in the article. --Procrastinating@^talk2me 13:17, 14 November 2006 (UTC)

• This is all just nonsense. The sprituality section has no place in this article. The philosophizing of Shamans, Yogis and Monks has had no part in the development of M-Theory, and has no bearing on the theory. Religious people have the right to look at scientific theories however they want, but please don't put their uninformed views in an encyclopaedic artile on M-Theory. We might as well put my 10-year-old brother's views on M-Theory into this article - they're more scientifically informed anyways.
• If anyone would like to make an argument that the spirituality section does anything more than present the views of nonscientists who have no real idea what M-Theory is (they have only a vague idea that it includes extra dimensions), that argument will be considered. However, as things stand, the only argument for this section's continued existence has been that these people's unscientific views should be "represented." If that is the only argument, the section should be deleted forthwith. --Thucydides411 21:47, 2 December 2006 (UTC)

That's where you wrong. First, you are repeating the arguments already put forth and disregarding the discussion here. That is disrespectful.

Second, your very point does the same dis-empathic act again by stating that those view (albeit non-scientific) are not worthy of inclusion. This is a major issue for many people, and for this reason alone a section should exist. this is NOT britanica's 1911 snobish edition. Just look at the page's history to see how many people actualyl added anything to the article.--Procrastinating@^talk2me 22:26, 2 December 2006 (UTC)

I would appreciate it if you would answer the question I posed, which you can read in my second paragraph above. How can you seriously claim that anyone's view is fit to be represented in this article? If it is, I'll go right ahead and add my personal view, which is that the Olympian gods reside in the extra dimensions; in the eleventh dimension, of course, sits Zeus, and in the tenth his wife, Hera, sits by his side. I hope nobody is so snobbish as to prevent me from adding my views to this article. --Thucydides411 23:11, 2 December 2006 (UTC)

Just to weigh in here, it is true that in some of his popular books and lectures Steven Hawking (who may not appreciate the extra "s" in his last name) has mentioned God and so on. But he hasn't in any papers in a scientific journal or in his textbook on GR. And he hasn't proposed any models based on God or really anything other than mathematics and science. You have to draw a line between S.H. as a scientist, doing science, and S.H. as a person, speculating on the mysterious facts of life as we all know them.

In general, it seems that a lot of the Wikipedia science articles (especially cosmology ones) suffer from a kind of obligatory last section on mystical connections or spiritual interpretations or whatever. I think that, for scientific theory X, having a page "Spiritual Dimensions of X" is fine, and even linking to it from the page on X is ok. But the stuff doesn't belong on the page talking about the scientific theory itself. It isn't science. That doesn't mean it isn't true, or "worthwhile," but just that it isn't science.

A lot of people feel strongly that there is some kind of convergence between physics and religion (or mysticism, or spirituality). But it isn't happening, and can't happen. As others have pointed out, they are different modes of thought. It could be that one or the other is "true," but if it turns out that religion/spirituality/mysticism is, that doesn't make it science, and if it turns out to be science, that doesn't make it religion/spirituality/mysticism.

I think even the strongest objectors to the inclusion of the religion/spirituality/mysticism comments on this page are in favor of merging them to another page. Perhaps those who feel strongly about the value of these speculations could comment on this proposal? Wesino 01:29, 6 December 2006 (UTC)

The problem with merging these spiritual interpretations of M-Theory to another page is that one would have a hard time deciding which to mention and which to leave out. One really has no criteria, because each is equally contrived. Say we were to include the Samskara interpretation but leave out the Zeus interpretation, what possible justification could we give? Neither really has any relevance to M-Theory, and both are attempts to find evidence for a certain religion where no evidence exists. The article fares best when it deals only with the theoretical underpinnings of M-Theory, its history and scientific implications. --Thucydides411 09:09, 7 December 2006 (UTC)

When this section grow to a suifficient size we can excommunicate it from the flok of righteous physicists. --Procrastinating@^talk2me 16:30, 7 December 2006 (UTC)

Building spaces from circles?

I'm dubious regarding the sentence that says that you can "build any space from gluing together circles in various ways" in the Basics section. It's almost certainly false, but it's hard to judge this because it's not clear what "gluing" is. Certainly you can build many spaces from circles, depending on what you mean by "gluing." But all? I think not. Wesino 14:59, 26 November 2006 (UTC)

please be more specific as to what do you mean. The definition of space is what is described here, not it's content. --Procrastinating@^talk2me 22:29, 2 December 2006 (UTC)

I can't be more specific because the article isn't. But I'm not talking about the content of a space, I'm talking about the space itself. Probably what this article is referring to is a topological space such as a manifold (though this is not clear), and possibly "gluing" is supposed to be a direct product or some other operation (also not made clear). But with pretty much any choice of "gluing" operation I think the claim is false -- though a reference to the contrary would be interesting.

What certainly is true is that IIB on a torus Tⁿ (direct product of n circles) is equivalent by T-duality to IIA on a different torus (provided we do an odd number of T-dualizations).

Since I'm pretty sure the assertion that "all spaces can be made from circles" is false, I'm hoping the author of the passage could weigh in with what they had in mind -- otherwise I think it needs to be modified. As it is, it vastly overstates the case. Wesino 01:11, 6 December 2006 (UTC)

Massive factual inaccuracies

I've looked through the article a few times, and I'm getting increasingly disturbed by the fact that it's rife with factual errors and false statements, which are obscured by jargon which gives them a kind of false appearance of truth.

A few samples,

• The business about building any space from circles (spoken about elsewhere on the talk page). A ref would be nice here, but I'm not sure you could find a professional mathematician who would make that statement. If you can, reference a textbook or journal article where they do.

• The heterotic SO(32) and heterotic E8×E8 string theories also reduce to Type IIA and Type IIB supergravity in the low-energy limit. No, they don't. They reduce to N=1 supergravity coupled to a super-Yang-Mills gauge theory. IIA/B are N=2 supergravities without gauge fields. This is made clear in any reasonable textbook on string theory -- such as Polchinski's String Theory, or Superstring Theory by Green, Schwarz, and Witten.

• dimensional reduction [of M-theory] to a line segment yields the heterotic SO(32) string theory. Dimensional reduction on a line segment (known technically as a S¹/Z₂ orbifold) yields the E₈ x E₈ heterotic theory in ten dimensions, not the SO(32) one. A reference would be the Polchinski's textbook, or "Eleven Dimensional Supergravity on a Manifold with Boundary," by Petr Horava and Edward Witten (which can be found by searching the arXiv [1]) or even the figure in the M-theory (simplified) article (!!).

• The beginning of the "M-Theory and Membranes" section, the article suggests that the low-energy effective supergravity equations are "too weak" to reveal p-branes. But they do! The p-branes were discovered as black hole-type solutions to these supergravities. Polchinski's insight was that these black hole solutions corresponded to an extended object in string theory -- the D-brane. Again, this should be in Polchinski's book.

This is in addition to a whole lot of garbled explanations of things, which many others on this talk page have noted.

What worries me much more seriously though is that some of the statements made in the article don't sound garbled and have the appearance of truth, but are wrong.

Elsewhere on this page, there is a discussion going on regarding a merge proposal with M-theory (simplified). I've noted that I'm in favor of the merge, but given these factual issues I'm not so sure what the content of this article has to contribute to the M-theory (simplified) one. To the extent that M-theory (simplified) touches on these issues, it actually gets them right -- for example, regarding my third point above, the diagram at the top of the M-theory (simplified) article actually has the right relationship. I think the 'what M stands for' section is more extensive in this article than the other one, so it could be moved over without too much trouble. A lot of the factual information is either duplicated or wrong, so should be checked carefully (citing sources) before being merged over.

...but a more efficient use of time would probably be to nuke a lot of the content in this page and replace it with a stub (with technical references left intact for the interested reader), or a redirect to the simplified page. Wesino 11:18, 6 December 2006 (UTC)

I opt you gradually upgrade this page, trim out any factual inaccurcies and replace them with cited and well worded truths. Be Bold. thank you. Procrastinating@^talk2me 16:44, 6 December 2006 (UTC)

Multidimensional Mathematics

Through interest in string theory and M theory I have been exposed to the term "multidimensional mathematics". I believe it should be noted that "multidimensional" does not refer to actual spacial dimensions but are levels of complexity in the equations. The three spatial dimensions and time are reduced to variables in order to be manipulated in the equations. The added "dimensions" are other variables that are added in order to maintain the integrity of the equations and do not represent actual spatial dimensions. I believe this should be noted somewhere in the article. —Preceding unsigned comment added by 168.216.168.161 (talk) 12:10, 17 October 2007 (UTC)

Spiritual speculations and analogies

The section Spiritual speculations and analogies is entirely inappropriate for this article and should go. Its a hotch-potch of vague statements that have nothing to do with M-theory. Pray how is Spaghetti Monsterism relevant, for example? It is admittedly a parody religion! -- 131.111.8.104 18:18, 14 December 2006 (UTC)

It should probably be deleted, as it contributes nothing to the article. I'll delete the section unless its deletion is disputed. Michael Slone (talk) 21:29, 14 December 2006 (UTC)

I object to the deletion of the comment on Spaghetti having three flavors in the article. That is one unscientific comment on M-Theory among a range of others in the article; if it is to be deleted, the others must go as well. If the others stay, it must stay. --Thucydides411 06:08, 15 December 2006 (UTC)

Because apparently certain sections of the Spiritual Analogies section which have every bit the same amount of merit as the rest have been repeatedly deleted - in the latest case by 68.144.82.234 - the entire section must lack merit. I am therefore deleting it. If anyone feels it needs inclusion, please restore the entire section. --Thucydides411 20:48, 15 December 2006 (UTC)

Thanks for deleting that section. You've restored my faith in Wikipedians' sanity and common sense when I was beginning to doubt it. This section was useless, and it should stay deleted. -- Ekjon Lok 15:47, 25 December 2006 (UTC)

If "M" Theory is to be the theory of everything, Spiritual speculations and analogies cannot be dismissed as hotch-potch. As science and religon are technically intwinded in certian aspectes of looking at it, like how "M" theory needs eleven-dimensional hyperspace to exist. This may seem impossible and illogical to one that doesn't factor it in, the truth being that we are no longer closer to finding the "Meaning of Life" or the creation of the universe, A.K.A. the big bang, where with Schrödinger's cat paradox that factors with "M" theory, religon's view of spiritualism and some of science's dismissive aproach to religon and the conscept of Spiritual speculations , which might actually be able to translate into science. Sadly, at this point of time , with war going on, the world cannot come together to experiment enough to find some important answers. Sadly, I must say that you are right and yet wrong with your veiw of Spiritual speculations and analogies

Religion and "spritual speculations" have existed for thousands of years, so there have been plenty of time to find just a single reliable case where it actually has any influence at all. Yet in the time natural science has gone from thinking blodletting is a good idea to transplanting hearts, religion still can't cure a simple cold.

Uh, um, "whaaatever"? As an analogy or as a spiritual speculation or maybe even as a spiritual analogy or some combination of such things, is mathematism any more or less spiritual, analogical, speculative, or any combination thereof, than any other ism? (Hail Eris! ;)) Isn't this entire article some such thing? Indeed, is it not at present in a way a kind of prayer, offered up to the the divine forces entities spaces or ontologies of mathematism in hopes that the divine power or attribute(s) known by some as mathematical insight, or possibly by others as encoding, representation, explication, explanation, comprehension, computation, processing, cogitation, or some such notion(s), will answer our sincere desire and/or intent to perform this operation efficaciously and/or have it result in an efficacious conglomeration of tokens, symbols, representations, or some such notion? Some of the tokens you employed I grok potential usefulness in, but your construction seems thus far inefficacious to me. By all means let us not forget how rigourous, computable, complete, etc etc etc bytestreams such as this page might or might not be as we continue to wield such bytestreams in pursuit of our mathemat{h|}eological goal of efficaciousness... Hail Math! (No offence intended to Eris, of course (BTW Kudos Eris on ousting the pretender Pluto hahahahah)) Knotwork (talk) 22:25, 18 April 2008 (UTC)

Unverifiable source

On the internet I found this: Real numbers are one-dimensional, they exist on an axis. Imaginary numbers exist in two dimensions, as explained above. What about three-dimensional numbers? As it happens these do not obey laws that are consistent. If you combine "ordinary" 2-D complex numbers you end up with 2-D complex numbers, the results exist in the same plane as the initial numbers. Three-dimensional numbers are not well behaved like that. However Four-dimensional numbers (quarternions) are consistent. The next set of well behaved numbers are the eight dimensional numbers (octonions). So we have real, complex, quarternion and the octonion numbers: 1-D, 2-D, 4-D and 8-D numbers. The next in the sequence are the 16-D numbers. But by some strange property of mathematics, the algebraic rules become more dilute as the dimensions of the numbers increases. No algebra can be found for 16-D numbers, so it is as though they do not exist. (If a number can be said not to exist, or conversely, to exist for that matter).

Complex numbers made from quarternions consist of one real number and three different numbers that, when multiplied by themselves, make -1. Octonion complex numbers consist of one real and seven octonion numbers that all equal -1 when multiplied by themselves. (But they are distinct numbers: any two octonions multiplied together produces a third, different octonion).

It turns out that octonion numbers crop up in the Theory Of Everything that physicists are searching for: in particular M-Theory, which is physics on steroids. According to M-Theory, we are made of minute particles that are really strings of energy, or membranes or multi-dimensional shapes. These vibrate in up to ten space dimensions, but most of the dimensions are so tiny we don't see them. Strange how we can only see one type of number, when the universe may be made up of eight of them. Wikisquared 17:05, 11 January 2007 (UTC) Oh I forgot to mention this was from www.eadon.com in the philosophy section under imaginary numbers. Wikisquared 17:07, 11 January 2007 (UTC)

You may wish to look at Wikipedia articles about quaternions and octonions, which give good and accessible introductions to these fascinating subjects. -- 131.111.8.102 20:44, 15 January 2007 (UTC)

Thanks, I couldn't find anything on wikipedia about this strangely Wikisquared 17:37, 20 January 2007 (UTC)

Some paragraphs of this article

have been lifted from Smolin's book "The Trouble With Physics." 207.237.10.120 05:01, 11 April 2007 (UTC)

The enigmatic M

The "M" most likely stands for "membrane" since one of the propositions of the theory is that universes can exist on large strings called membranes. —The preceding unsigned comment was added by 216.188.248.220 (talk) 06:27, 26 April 2007 (UTC).

      That the maths involved are multi-dimensional, the most sensible "M" would be "manifold," or 
      perhaps the German, "manigfeltigkeit" (sp?) is better still. It is the same term in German 
      math texts, but it can also be loosly translated as "many-fold."

             I heard that "M" stands for monkey, as we are just monkeys that do not understand this theory.--Sebastien.Gilmour 11:18, 1 September 2007 (UTC)

I thought that the idea was that it would be better to decide what "M" stood for once the theory was, in fact, specified. Until then, it is a conjecture that such a theory exists, and its name is as ambiguous as its definition. Martin | talk • contribs 04:45, 6 November 2007 (UTC)

In the beginning it was "Matrix theory". When Witten named M-theory, he did not specify what the "M" stood for, presumably because he did not feel he had the right to name a theory which he had not been able to fully describe. According to Witten himself, "'M' stands for "magic," "mystery" , or "membrane", according to taste.""The Theory Formerly Known As Strings" (page 64). According to the BBC/TLC documentary Parallel Universes, the M stands for "membrane". Other suggestions by people such as Michio Kaku, Michael Duff and Neil Turok in that documentary are "mother" (as in "mother of all theories"), and "master" theory.

The older Wiki article said "According to Witten and others, the M in M-theory could stand for master, mother, mystery, membrane, magic, or matrix. Some have speculated that the M is actually an upside down W (for Witten)." I think that was good info to have in the article. DavidRavenMoon (talk) 02:50, 21 July 2008 (UTC)

six string theories?

A recent edit [2] by Holt27 changed the statement that M-theory unifies the five superstring theories to that the statement that it unifies six. I only count five -- type I SO(32), type IIA, type IIB, heterotic E₈ x E₈, heterotic SO(32). What's the sixth? My best guess is bosonic, but there are a few bosonic theories, and I'm unaware of any dualities between M-theory and the bosonic strings(s). Is there a reference for M-theory relating six string theories? Wesino 21:16, 26 April 2007 (UTC)

M-theory is supposed to connect the 5 string theories with a sixth theory known as 11-dimensional supergravity. The bosonic theory has nothing to do with it. —Preceding unsigned comment added by 76.200.134.215 (talk) 17:02, 11 September 2007 (UTC)

The bosonic theory does having something to do with it. From "Cambridge Relativity: M-theory, the theory formerly known as Strings" http://www.damtp.cam.ac.uk/user/gr/public/qg_ss.html

"The original String Theory only described particles that were bosons, hence Bosonic String Theory. It did not describe Fermions. So quarks and electrons, for instance, were not included in Bosonic String Theory."

"By introducing Supersymmetry to Bosonic String Theory, we can obtain a new theory that describes both the forces and the matter which make up the Universe. This is the theory of superstrings. There are three different superstring theories which make sense, i.e. display no mathematical inconsistencies. In two of them the fundamental object is a closed string, while in the third, open strings are the building blocks. Furthermore, mixing the best features of the bosonic string and the superstring, we can create two other consistent theories of strings, Heterotic String Theories." DavidRavenMoon (talk) 03:14, 21 July 2008 (UTC)

In need of correction

In the following sentence,

"Unlike more conventional views of creation in modern physics, that are ex nihilo, the M-Theory vision, although not yet complete, is of the whole observable universe being one of many extended 4 dimensional branes in an 11 dimensional spacetime.",

I believe it is incorrect to say that modern physics has any "ex nihilo" views, as physics only addresses the early physical universe, but not the "physical pre-universe", if you can use such a term, i.e. a state in which physical existence does not yet exist. "Creatio ex nihilo" is a theological term, which implies the existence of a supernatural creator (or creators), who created the physical universe out of nothing. While I personally believe in a supernatural creator/creators, I think this lies beyond the realm of physics as it is currently formulated. Also, to say that modern physics has views of "creation" I believe is also inaccurate, again, as physics does not address the "physical pre-universe", but only the early physical universe, a "post-creation" state of affairs. Am I wrong? 68.46.96.38 15:09, 4 July 2007 (UTC)

I agree with you on your assessment of that particular sentence. It seems to be an opinion based sentence, also, which I think is a point you are getting at.

On another note, I think this article needs lots of work and revisions/add ons. I will attempt to do my best at improving this article in accordance with Wikipedia policy. Master Shake 9 19:00, 31 July 2007 (UTC)

???In need of correction???: In section on IIA and IIB: "it would seem that any space described by the IIA string theory can also be seen as a different space described by the IIB theory." ... a different space? You sure? Not merely a different description of the same space? Knotwork (talk) 21:56, 18 April 2008 (UTC)

???Ambiguity???: In Final step section: "Consequently, the quantum theory describing the low energy limit is a theory that describes the dynamics of these points moving in spacetime, rather than strings." ... Moving in spacetime rather than oving in strings? Or points, rather than strings, moving in spacetime? Or just strings, without need to mention spacetime at all being as how (for all I know) spacetime is one of the aspects or components or features of strings, or a way of describing some corrollary of stringness or the existnece of strings? Knotwork (talk) 22:11, 18 April 2008 (UTC)

Speculations Section

I am deleting this section for what I believe to be good reason. It is poorly written and improving on the style of writing would hardly justify this section, anyways. These "speculations" seem to be a disguised opinion of some user as well. Master Shake 9 19:20, 31 July 2007 (UTC)

More Technical

I need help making this article more technical, for as of now it stands not much different from the simplified version. Master Shake 9 20:02, 31 July 2007 (UTC)

Since no one has responded yet, I am going to continue at revising and adding to M-Theory. If I get out of hand, or am misguided, anyone can rein me in, or give their suggestions, or add themselves. As fo making the article more technical, I will find a hard time achieving this. Master Shake 9 19:47, 4 August 2007 (UTC)

Cleanup: Rewrite

I have tagged this article for potential rewriting, as the article needs: - To be made more technical (reasons suggested above by Master Shake 9) - To be re-worded/ punctuated differently (i.e. First Sentence a little clumsy: ... proposed "master theory" (or "mother theory", "mistery", "magic" or the W of Witten up side down from the creator, Ed Witten) K^rowe —Preceding unsigned comment added by Krowe (talk • contribs) 10:29, 3 September 2007 (UTC)

The Universe For Dummies

Simply put, "M" stands for "MECHANISM". A subatomic particle basically is a very, very small device. These devices operate within a set instructions that are fractal in their nature.140.211.8.7 (talk) 21:52, 16 January 2008 (UTC)LUCY140.211.8.7 (talk) 21:52, 16 January 2008 (UTC)jonascartwright@yahoo.com140.211.8.7 (talk) 21:52, 16 January 2008 (UTC)

Narrative form

I do not know how to message the editors of this page, but i believe that the below description of the M-theory is better put in narrative form, as it is highly technical information, and it is easier put this way. I am a student writing a paper on the string theories, and found this section very helpful. 04:52, 25 February 2008, 71.176.229.16 (Cut from the article by 90.230.54.138 (talk) 19:13, 25 February 2008 (UTC))

Citation needed?

In section on IIA and IIB: "Second, because it is possible to build up any space by gluing circles together in various ways," ... We know this how? Knotwork (talk) 21:48, 18 April 2008 (UTC)

Big Bang Section

I deleted the Big Bang section, which was full of inaccuracy in both its details and its premise. M-theory inspired the ekpyrotic scenario, which led to New York Times articles, but has otherwise gone nowhere. M-theory simply does not lead to predictions about the Big Bang, and which the section misleadingly implies.PhysPhD (talk) 17:16, 1 June 2008 (UTC)

Major Re-Write?

This article is in need of a major re-write. There ought to be much higher quality for such an important subject.PhysPhD (talk) 17:16, 1 June 2008 (UTC)

M-Theory is pure speculation without a shred of physical evidence

Invoking James Clerk Maxwell was a helluva stretch! As someone famous once said: "Not all mathematics is science, and not all science is mathematics". —Preceding unsigned comment added by Dalton h (talk • contribs) 02:24, 18 August 2008 (UTC) << THE TRUE M . THEORY OF MARK K. C. MA >>

  M =  MARK K. C. MA  , MAVITY (1999) =  ANTI- GRAVITY (1666) : ISAAC  NEWTON .  7-10-2008  H.K.

<< http ://www.xanga.com/markkcma >> : WELCOME TO VISIT MY TRUE M . THEORY  !

M-theory is the highest energy approximation neccessary

It is the only theory ascribing to the nature of Quantum Field theories without infinities. —Preceding unsigned comment added by 92.232.91.38 (talk) 11:43, 28 October 2008 (UTC)

How about a lay explanation?

Something like this: M-Theory is a theory of the structure of the universe that speculates our universe may have emerged from the collision of two membranes of energy which exist in higher spatial dimensions than we can currently perceive. --jlw/11/18/2008 —Preceding unsigned comment added by 75.175.190.240 (talk) 01:19, 19 November 2008 (UTC)

Here's a lay explanation of M-Theory: Scientists currently have no idea what the "theory of everything" is. 128.194.39.250 (talk) 20:27, 2 March 2009 (UTC)

Below is one possible lay explanation of the article's paragraph:

"In the early 1990s, it was shown that the various superstring theories were related by dualities, which allow physicists to relate the description of an object in one super string theory to the description of a different object in another super string theory. These relationships imply that each of the super string theories is a different aspect of a single underlying theory, proposed by Witten, and named "M-theory"."

Possible Lay Explanation:

---

"Imagine that math were 1000 times more difficult for us to understand and we know nothing of the relationship between addition and multiplication. Our greatest scientists have come up with something called "Multiplication Theory," and a seemingly unrelated alternative theory called "Addition Theory." Only the brightest people in the world can work with these theories. After decades of experimentation, we've come up with the following observations: In Multiplication Theory, 7X8=56 while in Addition Theory, 8+8+8+8+8+8+8=56. We see 56 as a result when we add a bunch of 8's together and we see 56 when we multiply 8 by a particular other number. All we see is a weird coincidence. But then similar coincidences pop up in labs around the world. For example: 6X6 = 36, while 6+6+6+6+6+6 also = 36. Magic numbers like 56, 36, 64, etc appear as solutions to problems in both theories. Now our best scientists begin to think the two theories are somehow related. They have no idea how they are related but they are working on the problem. They speculate that perhaps a broader theory theory called M-theory (Math-Theory) can explain the relationship between multiplication and addition at some time in the near future.

This is the situation with the varying forms of String Theory. We can't see the relationships yet, but coincidences between different sets of string theories make scientists think there is some larger theory that encompasses all of them."

---

No citations--I'm asking if this original analogy has any validity that warrents inclusion in the main article. I am not a particle physisict so I invite corrections and comment from same.

75.161.210.7 (talk) 22:10, 4 March 2009 (UTC)

It's ridiculous to say that scientists have no idea what M-theory is. At anything but the highest energy, we know exactly what it is (the precise particle and brane content, and how they interact).PhysPhD (talk) 16:35, 7 March 2009 (UTC)

I erase this text:

"According to Witten and others, the M in M-theory could stand for master, mathematical, mother, mystery, membrane, magick, or matrix. Witten reluctantly admits the M in M-theory can also stand for murky because the level of understanding of the theory is so primitive. [1] Yet other physicists in jest suggest it is an anagram by flipping the M to a W to stand for Witten."

It is not really informative about the subject of the article and adds to its size diluting its meaning and making it more time-consuming to read. —Preceding unsigned comment added by 190.134.154.129 (talk) 05:34, 19 May 2009 (UTC)

gluing circles

The statement regarding building any space by "gluing circles" is dubious, as any algebraic topologist will tell you. - 99.249.183.96 (talk) 04:45, 20 May 2009 (UTC)

God could have 12 dimensions.

Theory M could be updated to include one additional dimension for God. 75.139.214.136 (talk) 08:42, 25 December 2009 (UTC)

And/or a 13th dimension for brain-washed sheep. —Preceding unsigned comment added by 70.177.166.253 (talk) 04:40, 21 January 2010 (UTC)

Strange; there's no section in the main article which outlines the predictions made by M-theory. If it's falsifiable (scientific), there ought to be one. Maybe there is one somewhere among those 10 to the 500th power universes... —Preceding unsigned comment added by Gorkelobb (talk • contribs) 03:38, 7 April 2010 (UTC)

face palm --Super2k (talk) 15:19, 24 February 2010 (UTC)

The M-theory says nothing about any god. There is still no scientific paper that relates them. When there will be one, I assure you it will be included in Wikipedia. There is no evidence of the 12th dimension. There was strong evidence for theories of 5 dimensions, 6 dimensions, 10 dimensions, 12 dimensions, 20 dimensions, 25 dimensions, but they all proved to be the same theory (the M-theory) simply written using different mathematical equations. The one that unified the string theories into one was the modest, brilliant Edward Witten and others have since extended his work. 79.114.62.169 (talk) 12:20, 2 May 2010 (UTC_

Rewrite article?

M theory describes the size and shape of our universe, as compared to the size and shape of a separate surrounding universe (SU).Four dimensions in our universe; gravity, time, dark matter and dark energy, compare to four opposite dimensions in the (SU). The four opposite dimensions in the SU universe are: anti-gravity, GRB's, dark matter's opposite, which may be very similar to our dark matter, since it represents most of the universe, and times' opposite, anti-time, meaning to us, the other universe brings a new beginning.SU's current boundary is only known by the gamma ray bursts(GRB's) seen all over the edge of our universe, which actually is coming from the SU universe and illuminates its boundary to us. The boundary between our universe and the SU, is obviously, still in debate, but at some point in time, this boundary is crossed from a fixed point in space, as the boundary is constantly shifting. and at that point of intersection of this boundary lies the "big bang", on which this "wavely, rippley moving sheet" is what "M theory is all about". M theory is currently trying to define the boundaries and properties not only of our dimensions, but the opposite dimensions found in the SU. One thing we do know, from our reference point of view in our universe, we are completely surrounded by the SU. It is 6 billion light years to 14 billion light years away depending on the direction we look from any place on the planet. The current question is.... is the SU getting closer..or further away? Indications support that our current universe is in expansion, but this could be a temporary effect due to the opposite properties found in the SU. These opposite properties seen in the SU indicate that the separate universe is actually increasing speed, instead of normal properties in our universe which would slow it down. This is the result of opposite dimensions (at work) in the separate dimension. For more information on this subject contact: gunther.j@sbcglobal.net Jgunther2 (talk) 04:07, 28 June 2010 (UTC)jgunther2Jgunther2 (talk) 04:07, 28 June 2010 (UTC)

If someone would find the courage to rewrite this article, it should be rewritten with the purpose of explaining, first of all, what the M-theory itself states. How it complements - or changes - other theories, and who contributed what, is all very interesting, but not essential; all this should be separated from the explanation of the theory itself. Nice example: Quantum Field Theory.

3 dimensions -> 4D -> 10D -> 11D -> ?D -> an infinitum of dimensions?

I want to write here:

The 11D theory have been created only because 10D theory was not neat. But there is no any reasons to say, that there are exactly 11 dimensions - the theory is just enough suitable with the nature, but not supposed to be final one. There is no reason to claim, that the quantity of dimensions is exactly 11 - it may be 12, 26, 994, or even 100500 - but there is no any real reason to say, that the quantity of dimensions is limited. Also, fluctuations may be results of "another universes".

I just want to say three things:

1. There may be an infinitum of dimensions; 2. The fluctuations are result of existing "inner universes" and theirs' sizes change; 3. If I am right, we can get resources from "upper universes".

212.41.32.125 (talk) 01:30, 24 July 2010 (UTC)

What is this supposed to say?

"(The Type IIA and Type IIB string theories also contain open strings, however these strings are bound to that is to say, they are tight)."

Is that a real sentence? 68.54.104.18 (talk) 01:31, 14 September 2010 (UTC)

does M-theroy gives energies difference between vacuum and matter

first, are matter's physical dimensions (namely:length, width, depth) are (infinitesimally) small. meaning does matter, acutely, can go in dimensions to match vacuum. No, because the string theory says: there are "strings floating in space" which means that a string occupies a volume in space that is denser with "energy" or mass. by defention (languge)then matter must have a higher energy than vacuum. what is the minimum possible energy difference between vacuum and matter, which is then matter would "float" in space, matter would become denser. Then vacuum would exert density forces on matter (water vs wood). then gravitational forces becomes a complex form of density forces with vacuum and separate matter entities. --e:Y,?:G 04:31, 5 October 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs)

M-Theory name meaning

the text says its because of "membrane" but shy witten will not agree.

maybe its because its named after Maldacena, the string expert that got first to the proposition of a unifying theory? —Preceding unsigned comment added by 201.254.115.51 (talk) 04:40, 6 November 2010 (UTC)

Disagree

I have gotten the impression that the M-theory is not a theory, but instead a research programme (directed towards finding an "M-theory") where Witten creates mathematics sketching relationships between various string theory models. I.e. he doesn't describe M-theory, he just prepares way for finding it. Rursus dixit. (^mbork³!) 10:36, 29 November 2010 (UTC)

i've got a 12d model

ok if anyone's interested i have a 12d model of the physical unverse, and it's not that esoteric or difficult. It's based on 'nullities' and singularities. 0s and 1s. These are Implied Forms, meaning they can only be implied by definition, like a mathematical Point. Now, at the 11th dimenson, singularity is at maximum concentration, nullity is at it's most diffuse. At the 1st dimension, singularity is at it's most diffuse, nullity is at it's greatest concentration. There is a force known as Novelty, at 11th d. As you go down the dimensions, you have: 11-9,novelty, 9-7,gravity, 7-5, Electromagnetism, 5-3, weak nuclear force, 3-1, strong nuclear force. strangely enough, S.N.f interacts with Novelty, W.N.F with Gravity, magnetism with electricity. This is a result of the 1's and 0's trying to come together to find equilibrium. Also as you go down the d's, forces get stronger. This is a result of concentrated nullity. As you go up the d's matter gets more concentrated. This is a result of concentrated singularity. Novelty and S.N.F alone created the Big Bang. novelty is the force that brings the abstract chaos into definition, and light. It's all based on the dimensions being bound by Implication to add up to 12. Implication is another force, that resonates through the non local abstract realm, and the entire physical universe. Natmanprime (talk) 21:18, 20 January 2011 (UTC)

Find a publication that reliably reports about it. ≡ CUSH ≡ 22:22, 20 January 2011 (UTC)

Constructive proposal (hopefully)

Trying to answer Rursus I would propose to categorize the article under the "Geometry Category"" (+ [[Category:Geometry]] and/or [[Category:Geometric topology]]).

This could be the first step towards shifting from a theory towards a research programme.

What do you all think about it?

Thanks for your attention.

The remark cited as [dubious] in section labelled 'types IIA and IIB' regarding building spaces from circles sounds like a mathematical (specifically topological) assertion. It is true that every open neighborhood in a metric space can be expressed as a union of open balls. There will be stronger analogous statements regarding arbitrary topological spaces. — Preceding unsigned comment added by 94.192.156.93 (talk) 00:42, 23 August 2011 (UTC)

Please, see also

• Imre Lakatos (1922-1974)
• Prototype theory

Maurice Carbonaro (talk)

Monkey Theory

Ed witten said that "m" stands for monkey, so as to describe the human race Thor cherubim (talk) 09:12, 30 May 2011 (UTC)

7-dimensional manifold

Need clarification for laymen: Is the 6-dimensional Calabi-Yau manifold still accounted in M-theory or it must be replaced with 7-dimensional one?Mastertek (talk) 03:50, 6 December 2011 (UTC)

Yes, a 7-dimensional manifold would be necessary to compactify 11-dimensional M-theory down to our familiar 4-dimensional space, in the same sense that a 6-dimensional manifold is necessary when starting from 10 dimensions. The usual generalization of the Calabi-Yau condition to 7 dimensions is to use a G2 manifold. --Steuard (talk) 21:05, 21 March 2012 (UTC)

Question on Sentence Structure.

The following sentence seems to be grammatically incorrect, please tell me if I am right: "Finally, since superstring string theories are supersymmetric for supersymmetry is needed for consistency, one expects to see supersymmetry appearing in the low-energy approximation." I am a laywoman, but this sentence seems incorrect in it's structure. Thank you for you time and consideration on a matter, no pun intended, that I find very interesting.

Cristykay — Preceding unsigned comment added by Cristykay (talk • contribs) 19:56, 10 October 2012 (UTC)

Ridiculous logic?

The article has a long-standing statement in the introduction: Because the dimensionality exceeds that of superstring theories in 10 dimensions, proponents believe that the 11-dimensional theory unites all five string theories (and supersedes them).

This seems ridiculous. The condition of higher dimensionality may be necessary for the second clause to be true but it is certainly not sufficient. If a fuller description of why it is believed to unify all the string theories can't be given, it would be better to simply point out its dimension is one higher and leave the second clause as a simple statement of the views of proponents rather than saying one is a consequence of the other. Elroch (talk) 00:38, 6 November 2012 (UTC)

Yes, I agree. I've been meaning to change it. How about something simpler like this-

Proponents believe that the 11-dimensional theory unites all five 10 dimensional string theories and supersedes them. Bhny (talk) 01:47, 6 November 2012 (UTC)

no objections so I'll make the change Bhny (talk) 22:06, 7 November 2012 (UTC)

Small thoughts

• Roughly speaking, bosons are the constituents of radiation, while fermions are the constituents of matter.

I associate bosons more with mediating forces than radiation.

• Such objects had been considered as early as 1962 by Paul Dirac, and they were reconsidered by a small but enthusiastic group of physicists in the 1980s.

A reference to a Dirac publication would be nice.

• Branes are dynamical objects which can propagate through spacetime according to the rules of quantum mechanics. They have mass and can have other attributes such as charge.

Do all branes have mass?

• There is a small amount of inline LaTeX. As always, it looks awful AWFUL when using PNG rendering on a large screen.

Suggestion: Use the math templates like in xy ≠ yx and ⁠1/g⁠ or 1⁄g.

YohanN7 (talk) 05:39, 5 February 2015 (UTC)

Hi YohanN7, these are really good comments. I don't know if you're aware, but this article is currently a featured article candidate, and it would be great if we could include your feedback on this page. If you'd like to participate in the review process, please leave your thoughts there, and I'll respond with changes to the article. You can then choose to support or oppose the nomination. Thanks! Polytope24 (talk) 16:33, 5 February 2015 (UTC)

Ok. I copied my post over there, so lets close this thread. YohanN7 (talk) 16:43, 5 February 2015 (UTC)

---

A final note (I'll comment there, also): Wikipedia:WikiProject Mathematics has a "guideline" that {{frac}} should not be used in mathematical formulae. That might not apply to this article, but I would not be at all surprised if {{math|frac{{1|g}}}} might fail at some point. — Arthur Rubin (talk) 19:04, 12 February 2015 (UTC)

Inline citations

Is there a reason not to use clickable Harvard style citations? I changed one to the {{TL:harvnb}} for demonstration. I can change the rest too if it is to your liking. Better yet, YOU do it. (If you hate it, just revert my last two edits.) YohanN7 (talk) 18:11, 12 April 2015 (UTC)

I have no objection to changing the citation style, but I'm busy with other projects at the moment and won't be able to do it myself. If you decide to change it, please be *extremely* careful. The article has lots of cross referencing, and the cross references are easily broken (as happened with your edit). Polytope24 (talk) 18:58, 12 April 2015 (UTC)

Okay, I'll probably do it. No time table though. YohanN7 (talk) 19:41, 12 April 2015 (UTC)

10-dimensional String Theory and 11-Dimensional M-theory

The BIGGEST difference between string theory and M-theory is that string theory is 10-dimensional while M-theory has 11 dimensions of spacetime. The article previously used "ten" and "eleven" but they don't stick out to the reader as much as 10 and 11. It's also a writing practice to spell out single digits numbers, i.e. nine but use numerals for two digit numbers and larger, i.e. 10 & 11. - The Messenger 50.153.104.253 (talk) 16:04, 19 April 2015 (UTC)

Pea Branes?

In dimension p, these are called p-branes.

One sometimes wonders whether the physicists are having us on.... ;-) Praemonitus (talk) 17:52, 22 June 2015 (UTC)

Lack of balance

This article lacks a balanced viewpoint with only a brief nominal comment that "some" have questioned M/String theories utility (tho utility is a kind word). Notably..perhaps as an effort to appear objective, the only citation given to criticism (which is currently mounting) is to Peter Woit's 2006 book. Even if we stick with criticism of 10 or more years ago, shall we ignore Glashow's criticism, Smolin's, etc...? Not to mention the current crescendo. Get a life guys...stop writing articles that are about things you hope to work. Be objective. Look in a mirror. It is never too late. Juan Riley (talk) 00:31, 23 June 2015 (UTC)

Invitation to submit to the WikiJournal of Science

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Sylvain Ribault (talk) 20:27, 24 October 2018 (UTC)

an example of ADS to conformal field would help for non physicists

The wikipedia article says:

"The claim is that this quantum field theory is equivalent to the gravitational theory on the bulk anti-de Sitter space in the sense that there is a "dictionary" for translating entities and calculations in one theory into their counterparts in the other theory. For example, a single particle in the gravitational theory might correspond to some collection of particles in the boundary theory."

I don't fully understand this point. Could someone give an example with a specific particle in mind.

Also who is the M theory page intended for? I doubt a non physicist or mathematician would understand much of what is written.Is it unrealistic to expect a layman to grasp M theory relativity etc , so is the article aimed just at people with knowledge of the physical sciences? Thanks for your help.

Carovingian Carovingian (talk) 17:41, 12 July 2019 (UTC)

3D, 4D, 10D, 11D, 11-dimensional spacetime

The general public is used to seeing 3D, therefore, writing 4-dimensions 4D, 10-dimensions, 11-dimensional spacetime. 2601:580:7:2C63:79D7:6AC1:B636:D324 (talk) 23:20, 14 November 2019 (UTC)

M-theory includes Superstring Theory: 6D Hyperspace + common 4D and/or Supergravity Theory: 7D Hyperspace + 4D

This article should simply state in its introduction... M-theory includes Superstring Theory: 6D Hyperspace + common 4D and/or Supergravity Theory: 7D Hyperspace + 4D. 99.169.79.198 (talk) 14:46, 7 December 2021 (UTC)