Content deleted Content added
{{reflist-talk|close=1}} |
m Archiving 3 discussion(s) from Talk:String theory) (bot |
||
| (7 intermediate revisions by 3 users not shown) | |||
Line 249:
:Please accept my apologies. I interpreted your statement "Find a quote yourself, or move it, I don't care" to mean that you thought the source could be removed instead of finding a quote. My mistake! [[User:Wpegden|Wpegden]] ([[User talk:Wpegden|talk]]) 15:04, 8 January 2012 (UTC)
== Brane World scenario section ==
This section is poorly written.
<span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/190.188.3.11 |190.188.3.11 ]] ([[User talk:190.188.3.11 |talk]]) 03:53, 14 July 2010 (UTC)</span><!-- Template:UnsignedIP2 --> <!-- [[User:DoNotArchiveUntil]] 22:05, 14 July 2009 (UTC) -->
== Construction ==
In the criticism section one could add string theory as a construction in order to combine gravity in the quantum world.
<span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/81.166.231.161 |81.166.231.161 ]] ([[User talk:81.166.231.161 |talk]]) 08:16, 19 February 2011 (UTC)</span><!-- Template:UnsignedIP2 --> <!-- [[User:DoNotArchiveUntil]] 22:05, 14 June 2011 (UTC) -->
== New intro to prediction section ==
:: "If we can come up with an example of an falsifiable prediction for the outcome of an experiment we believe could be performed in the next few decades where a string-theorist and non-string-theorist would give different predictions, it would be a great addition to the article." Not just to the article, to string theory - and if I knew of such a thing I wouldn't be wasting my time here, I'd be writing it up for publication. As I hope the article makes clear, the absence of such a prediction is probably the biggest single problem string theory has. Quantizing gravity simply doesn't have much effect at "low" energies, for the simple reason that gravity is a very weak force and hbar is a very small quantity. That makes any form of QG really, really hard to test. <small>'''<span style="color:Olive">Waleswatcher</span>''' [[User_talk:Waleswatcher#top|''(<span style="color:green">talk</span>)'']]</small> 22:22, 9 January 2012 (UTC)
That's great. I'm serious. I think we are close to consensus. Personally I feel the point on the swampland is a bit out of place in that paragraph, but we don't always get what we want, right? I'm completely fine with this so long as the introduction makes it clear, that, as you say, these do not correspond to unique predictions and that the absence of such a unique prediction remains a major problem for string theory. My issue has been that I didn't feel the paragraph were were discussing was clear on this (I personally mistook the sentence as being intended to give a possible example of such a unique falsifier, and was not able to get clarity on this issue by following through to citations, which is why I was so insistent about following guidelines on citations). I have rearranged the paragraph slightly and finished the paragraph with a sentence that clarifies what we're agreeing on here. (I removed the "de-facto untestable" line to preserve balance). I hope you like this change. I can't emphasize enough, this has been a very heated and sometimes antagonistic debate, but I think maybe we've reached a resolution we can all be happy with. I know we're in the habit of edit warring, but I have tried to be careful and not revert edits you have made. I've also tried to be balanced and careful in rewriting the paragraph. If you have some issues with it, can you try discussing it with me before reverting it back wholesale? [[User:Wpegden|Wpegden]] ([[User talk:Wpegden|talk]]) 22:58, 9 January 2012 (UTC)
: I'm pretty much OK with your wording. I re-wrote it some in an attempt to eliminate what I think were some redundancies and awkward words, hopefully while still keeping it clear. Please check and see what you think. I'm a little worried about the Gross cite because I can't watch it and I don't know what he said exactly. <small>'''<span style="color:Olive">Waleswatcher</span>''' [[User_talk:Waleswatcher#top|''(<span style="color:green">talk</span>)'']]</small> 23:18, 9 January 2012 (UTC)
I like the rewording, just have a comment on the second part. It now reads:
:''However, these predictions are not necessarily unique to string theory...'''
and the things listed in the previous sentences (confirming a swampland model or observing positive curvature) are not predictions, but ways of falsifying it. (I'm making a statement about the grammar not the science.) That was the reason for my cumbersome wording.
I didn't watch the video. The previous phrase supported was
:''Finding a way to confirm string theory with our current technology is a major challenge'''
and the new phrase is
:''and finding a way to experimentally verify string theory via unique predictions remains a major challenge.'''
which is indeed slightly different. Seems like a weaker statement though, which is why I didn't check it yet. I will try to check it or try to come up with a better one in the next few days. Feel free to add a tag if you feel the phrase is too different from the previous one. [[User:Wpegden|Wpegden]] ([[User talk:Wpegden|talk]]) 23:25, 9 January 2012 (UTC)
: I don't agree with that - they ''are'' predictions in the standard sense of that term, just not (perhaps) unique or particularly spectacular ones. <small>'''<span style="color:Olive">Waleswatcher</span>''' [[User_talk:Waleswatcher#top|''(<span style="color:green">talk</span>)'']]</small> 23:42, 9 January 2012 (UTC)
That's not what I mean. I mean that (pay attention to the grammar) "confirming a swampland model" is not a string theory prediction, and that's how the previous sentence is currently written. (string theory predicts we '''won't''' do this. Instead, it is a way of falsifying it.) There is a corresponding prediction ("no swampland models will be confirmed"). That's why before I had the following sentence saying something like "the predictions corresponding to these falsifiers" or whatever. This is just a wording issue.[[User:Wpegden|Wpegden]] ([[User talk:Wpegden|talk]]) 23:55, 9 January 2012 (UTC)
== Missing word? ==
This sentence, "This is because strings themselves are expected to be only slightly larger than the Planck length, which is almost orders of magnitude smaller than the radius of a proton, and high energies are required to probe small length scales."
appears to lack a word between "almost" and "orders". [[Special:Contributions/89.204.154.73|89.204.154.73]] ([[User talk:89.204.154.73|talk]]) 17:55, 4 February 2012 (UTC)
It should be "twenty orders of magnitude". I fixed it [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 18:15, 4 February 2012 (UTC)
== " The theory has yet to make novel experimental predictions at accessible energy scales, leading some scientists to claim that it cannot be considered a part of [[science]]" ==
First of all, the citation is to a popular book by [[Peter Woit]], who is not a scientist (at least not a professional one), so the cite is inadequate. More importantly, the sentence does not reflect the real status of the debate over string theory, isn't NPOV, and doesn't belong at the very beginning of the article.
There ''is'' a very important problem with ST not making novel experimental predictions that can be easily tested, and that should be mentioned somewhere near the beginning. But the idea that ST isn't science is absurd - it's funded by science agencies, studied by faculty and students in physics departments, tens of thousands of papers on it are published in scientific journals, it's a quantum theory of gravity, and it makes [[Falsifiability|falsifiable]] predictions. So, I'm going to replace this sentence, keeping the part that points out the serious issue (testability) while moving the part about science to the "Criticism" section, or simply dropping it. <small>'''<span style="color:Olive">Waleswatcher</span>''' [[User_talk:Waleswatcher#top|''(<span style="color:green">talk</span>)'']]</small> 22:35, 9 January 2012 (UTC)
:I agree. We should be very clear that predictions are a problem. It is silly to be saying it is not part of science. Certainly, one book is not enough for this. The Wikipedia guideline here is that "extraordinary claims require extraordinary citations." [[User:Wpegden|Wpegden]] ([[User talk:Wpegden|talk]]) 23:02, 9 January 2012 (UTC)
:This is not true, [[Peter Woit]] got his BS and Master's Degree in Physics from [[Harvard University]], he got his PhD in [[particle theory]] from [[Princeton University]] so he's definitely a valid source.
:--[[Special:Contributions/129.2.129.155|129.2.129.155]] ([[User talk:129.2.129.155|talk]]) 18:39, 26 July 2012 (UTC)
== Edit request on 7 September 2012 ==
{{edit semi-protected|answered=yes}}
<!-- Begin request -->
In "Extra dimensions" -> "Number of dimensions" -> paragraph 2
The phrase:
[...]completely different type of mathematical quantity
should be replaced with:
[...]complex number, which includes an imaginary part representing a factor of (-1)^(1/2)
I don't know how to typeset it, but (-1)^(1/2) should look like "the square root of negative one". This is a very simple correction, and should eliminate the "which?" tag. There is only ONE "completely different type of mathematical quantity" that relates to String Theory, and it is a complex-valued quantity. Keep the following in mind: 1) Real Numbers are a subset of the Complex Number Set. Although the number 7 is a member of the Complex Number Set, it is not (barring semantics) refereed to as a complex number. 2) Any so-called "mathematical quantity" that falls outside the Complex Number Set does not have any relevance to String Theory as it is understood today.
<!-- End request -->
[[Special:Contributions/71.134.236.38|71.134.236.38]] ([[User talk:71.134.236.38|talk]]) 19:01, 7 September 2012 (UTC)
[[File:Red information icon with gradient background.svg|20px|link=|alt=]] '''Not done:''' please provide [[WP:RS|reliable sources]] that support the change you want to be made.<!-- Template:ESp --> [[User:Jo-Jo Eumerus|Jo-Jo Eumerus]] ([[User talk:Jo-Jo Eumerus|talk]]) 13:40, 10 September 2012 (UTC)
Reliable sources? It's basic math Jo-Jo!... if you really want some good references, take an Intermediate Algebra course at your local community college. This is not mysticism, it's mathematics. It is just a language.
== New String Theory Website for the general public ==
{{edit semi-protected|answered=yes}}
<!-- Begin request -->
Please can you add a link to the "External Links" section to Why String Theory? (http://www.whystringtheory.com). This is a new online resource.
Why String Theory? aims to provide the general public with an introduction to the mysteries of string theory.
You’ll learn where string theory came from, why people research it and what they hope to find out. No prior knowledge of higher physics or mathematics is assumed, but nevertheless there is sufficient depth of material for you to be able to gain a true insight into current developments.
The site is supported and funded by the Royal Society and the University of Oxford.
<!-- End request -->
:[[File:Yes check.svg|20px|link=|alt=]] '''Done'''<!-- Template:ESp --> The resource appears to be informative so I have been [[Wikipedia:Be bold|bold]] and added the external link. Thanks for the suggestion. [[User:Michael Anon|<span style="color:#000">Michael</span>]] [[User talk:Michael Anon#top|<span style="color:#555">An</span>]][[Special:Contributions/Michael Anon|<span style="color:#555">on</span>]] 18:57, 26 September 2012 (UTC)
== Uh... ==
Isn't quantum theory just a multidimensional version of exactly this in the first place - one where the electron expands not into a string of any type, but a puffy cloud? An infinite cloud that can be bent, stretched, recompacted, etc by external influences, sure - but isn't that what string theory has happening anyways? What's the difference, other than string theory is trying to give simpler math at the end of the day? [[User:Zaphraud|Zaphraud]] ([[User talk:Zaphraud|talk]]) 21:21, 23 October 2012 (UTC)
:Not quite. Typical quantum mechanics describes an electron itself as a point particle. The trick is you can't actually pinpoint its ___location, so you have to describe it in terms of its probabilistic ___location, which is that infinite cloud you speak of. In short, point particle with a ___location determined by a wavefunction. String theory says that the particle is not a point, but rather it is continuous in (in typical string theory) one dimension. This is actually more or less equivalent to saying that one particle is an infinite number of particles connected by an infinite number of connections (like little quantum springs), and each one of those infinite particles is quantized and thus has its position determined by a wavefunction. Roughly, string theory really boils down to one simple claim - make Schrodinger's equation an integral. One more point - an electron isn't really a string. Strings are strings. The electron itself and its properties are all more or less consequences of how the string is moving and what way it wraps around spacetime and whatnot. So normal quantum mechanics say that an electron is somehow intrinsically distinct from, say, an antidownquark, but string theory says they're made of the same thing and you can transform one into the other by changing how the string vibrates.[[User:KagakuKyouju|KagakuKyouju]] ([[User talk:KagakuKyouju|talk]]) 04:29, 27 January 2013 (UTC)
== In layman terms, string theory is what? ==
I'm no physicist. Reading this article tells me close to nothing about what string theory is. I understand that we are at a very abstract level but nonetheless, there should at least be a section in here explaining string theory to someone who is not a particle physicist or the like. Even the Overview section, in my opinion, is too technical/complex.
[[Special:Contributions/188.61.27.214|188.61.27.214]] ([[User talk:188.61.27.214|talk]]) 20:00, 23 December 2012 (UTC) Acnicolet
:There's a small article [[Introduction to M-theory]] which is mostly about string theory. It could do with work and a possible renaming [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 20:20, 23 December 2012 (UTC)
== The String Theory is not science ==
Wikipedia and the science community in general is just a joke now. How is the String Theory science? Having something in journals and being funded ''does not'' make something scientific. Scientists can put whatever they desire in journals and fund whatever they desire. What makes something scientific is having empirical testability.
You can't show that something is scientific by pointing out what some authority figures say, that's just an [[appeal to authority]]. Authority figures can believe whatever they want and historically authority figures have been completely wrong about many things.
Right now '''the string theory matches the exact definition''' of [[pseudoscience]] (''a claim, belief, or practice which is presented as scientific, but does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status'').
The String Theory is a mathematical model that cannot be empirically tested, meaning it's mathematical speculation.
The String Theory has no falsifiable predictions. Things like General Relativity aren't falsifiable predictions because even if General Relativity is found to be inaccurate some how, you could just adjust the mathematics in the String Theory to match into the new observed phenomena (the string theory can be adjusted to match into virtually any low-energy prediction).
To help people understand:<br/>
- If the String Theory is completely wrong and false and there are no 1-Dimensional strings, you would still be able to adjust the mathematics to match into General Relativity (and many other things)
So adjusting the mathematics to match into General Relativity and other low-energy observations tells us nothing about whether the String Theory is true or false.
Testing General Relativity isn't equivalent to testing the String Theory. Even if 1-Dimensional Strings are completely non-existent we could test and have General Relativity just fine.
Using the String Theorist's pseudo-scientific reasoning we can claim that anything that pre-assumes General Relativity must be scientific. Meaning if I claim that aliens in another dimension exist and it pre-assumes General Relativity that makes it a scientific claim some how (you can falsify it by falsifying General Relativity), it doesn't matter if I can't empirically test the existence of the aliens in the other dimension.
I'm still waiting for any String Theory fan to '''give a valid reason''' as to how the String Theory is scientific instead of just using an appeal to authority.
--[[Special:Contributions/129.2.129.155|129.2.129.155]] ([[User talk:129.2.129.155|talk]]) 18:02, 26 July 2012 (UTC)
:you can post your question here [[WP:Reference_desk/Science]]. This page is for discussions about improving the article [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 19:10, 26 July 2012 (UTC)
:String theory is inspired by and based on verified theories and evidence from experiment, it has testable consequences, and it has led to many other discoveries and theories in mathematics, geometry, and physics. And at the very least, it provides a context in which verified scientific theories make sense. Even if you can't prove whether it's ''true'' or ''false'', it's certainly scientific. Of course, this largely depends on your definition of science, but that's a question of semantics and philosophy.[[User:KagakuKyouju|KagakuKyouju]] ([[User talk:KagakuKyouju|talk]]) 04:47, 27 January 2013 (UTC)
"Even if you can't prove whether it's true or false, it's certainly scientific." Right. It has led to more mathematical results, but it has not led to (testable) physical ones. That's the problem. <span style="font-size: smaller;" class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/79.97.241.139|79.97.241.139]] ([[User talk:79.97.241.139|talk]]) 09:57, 24 April 2013 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->
:::The article has a criticism section. You are welcome to contribute here as long as it is from reliable, published sources and not personal opinion. [[User:BashBrannigan|BashBrannigan]] ([[User talk:BashBrannigan|talk]]) 22:00, 14 May 2013 (UTC)
== Unintelligible ==
'''String theory''' is ..... what? Can someone make this article's lead more accessible to the general reader? [[User:The ed17|Ed]] <sup>[[User talk:The ed17|[talk]]] [[WP:OMT|[majestic titan]]]</sup> 23:39, 5 February 2013 (UTC)
== Little things... ==
As presented on Wikipedia, String Theory and its cousins are based on the
fundamental axiom: Strings exist. This is fundamental in that, if there were no
strings, there could be no string theory. In just over 40 years there have been
zero testable predictions that support or refute the existence of strings.
That's fine, but there have also been no conceivable experiments, real or
imagined, that could falsify their existence in the foreseeable future. When
sufficient energy levels are reached that could refute them, the lower energy
bound is increased and the theory is altered.
Its predictions are mutable and the theory non-falsifiable. Mutable means the
theory changes to match empirical evidence so as not to be refuted.
Non-falsifiable means that even if it was wrong, it can never be proven wrong.
These are real problems. Science, to quote Wikipedia, is:
"a systematic enterprise that builds and organizes knowledge in the form of
''testable'' explanations and predictions about the universe.[2][3]"
The theory is very interesting, but to present a non-falsifiable theory as
science is misleading. As it sits, string theory and cousins are based on a
fundamental axiom that, due to both the energy requirements and the mutability
of the theory itself, will remain non-falsifiable for the foreseeable future.
Despite any internal consistency, as it sits, string theory is a system
formulated on faith. Lay readers deserve to know this. Is there some kind
of an article wide label akin to:
"This article presents conjecture (suppositions)."
While any theory is by definition a conjecture, in places the article presents
itself as a viable alternative to empirically supported models. I think such
labels would help remind readers of the current state of things. There are
several science articles on Wikipedia that could use such headers. From a
purely neutral point of view we need to maintain the line between empirically
supported science as we know it and conjecture - even if the conjecture has a
lot of math and is intriguing.
Thoughts, ideas? <small><span class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Vcfahrenbruck|Vcfahrenbruck]] ([[User talk:Vcfahrenbruck|talk]] • [[Special:Contributions/Vcfahrenbruck|contribs]]) 20:38, 15 July 2013 (UTC)</span></small><!-- Template:Unsigned --> <!--Autosigned by SineBot-->
: The intro was a bit light on criticism. I added "... say that it is a failure as a theory of everything" which is sourced below in the criticism section. The article starts by saying it is a "theoretical framework" which I think infers that it is conjectures. [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 20:50, 15 July 2013 (UTC)
::You might find the following [[Peter Woit]] links interesting.
::*[http://www.math.columbia.edu/~woit/wordpress/?p=3333 Physicists Finally Find a Way to Test Superstring Theory]
::*[http://www.math.columbia.edu/~woit/wordpress/?p=5358 Forty Years of String Theory]
::*[http://www.math.columbia.edu/~woit/wordpress/?p=5880 String Theory and the Scientific Method]
::They each touch on important (I think) aspects of this hairy issue. <span style="font-size:0.75em; color:white; background-color:black; border-radius: 4px;"> —[[User:Sowlos|<span style="font-weight: bold; color:white;">Sowlos</span>]] </span> 09:33, 16 July 2013 (UTC)
== Why the refimprove tag ? ==
The rationale for placing a "refimprove" tag at the top of the article is unclear. There is no explanation in the edit history [https://en.wikipedia.org/w/index.php?title=String_theory&diff=next&oldid=563866531], and there is no explanation on this talk page. This article has 52 references, and therefore the same number of in-line citations. It also links to an ample body of literature (and maybe some other materials) available in the "Further reading" and "External links" section. This article may not actually need a refimprove tag. ---- [[User:Steve Quinn|Steve Quinn]] ([[User talk:Steve Quinn|talk]]) 22:14, 25 July 2013 (UTC)
:Whoever added that tag should have posted something. Tagging and running is not good form. However, after taking a look, I suppose it has something to do with so many sections carrying no citations, several others only carrying one, and usage of the present sources in such a sparse manner (there are only 52 inline citations for a very large article). I even found an unsourced explanation in reference #15. <span style="font-size:0.75em; color:white; background-color:black; border-radius: 4px;"> —[[User:Sowlos|<span style="font-weight: bold; color:white;">Sowlos</span>]] </span> 10:36, 26 July 2013 (UTC)
== The "Criticisms" section ==
I think this section can be improved. In the current version, three specific criticisms are mentioned, but the first ("High energy") just says unification theories are hard to test because of the high energies. That seems like a very generic fact, not a specific criticism of string theory. As the article says "It is widely believed that <i>any</i> theory of quantum gravity would require extremely high energies to probe directly, higher by orders of magnitude than those that current experiments can attain". Since this is widely believed to apply to <i>any</i> theory of quantum gravity, is it really appropriate to list it as a criticism of string theory? Notice that the article already has a Section on "Testability and experimental predictions" that mentions the same thing, so it's redundant. I suggest moving the words in the existing "High Energy" paragraph of the "Criticisms" section up to the "Testability" section. It would be okay to refer to this again, in passing, in the criticism section, but make it clear that it's not specific to string theory.
Having done that, I think the remaining Criticisms section could be beefed up with some more of the actual criticisms that have been raised specifically about string theory, such as those discussed in Penrose's book (e.g., degrees of functional freedom, questions about actual finiteness), and also criticisms of the "multiverse" aspects.
In addition, I think this might be the appropriate place to at least mention some of the methodological and sociological concerns that critics have raised regarding string theory. For example, the criticisms claiming over-hyped pronouncements in the popular media, concerns about too much focus on one particular (and highly speculative) avenue of research, lack of any clear principles or understanding of what string theory actually <i>is</i> according to its own proponents, excessive reliance on formal mathematical and aesthetic criteria rather than being guided by experiment, indeed being more about mathematics than physics, etc.
Also, I think the current section on "Number of solutions" could be clarified. It refers to "lack of uniqueness of predictions due to the large number of solutions", but this seems like an obtuse way of describing the actual criticism, which is (rightly or wrongly) that string theory (in its present state) makes no testable predictions at all. This seems like a more direct and clear way of expressing the criticism, rather than saying "critics charge that string theory has a large number of solutions, so its predictions lack uniqueness". (If I predict that either the American league or the National league team will win the world series, would that be best described by saying my prediction lacks uniqueness, or by saying I haven't really made a prediction at all?)[[User:Longerboats5|Longerboats5]] ([[User talk:Longerboats5|talk]]) 15:14, 13 August 2013 (UTC)
:Let me begin by saying that I agree with much of what you say. I agree that the point about high energies is not a criticism of string theory per se, and I think it's fine to move most of this discussion to the section on "Testability and experimental predictions". I also think it should be mentioned in passing in the "Criticisms" section. I agree that the section should probably discuss the sociological concerns that critics have raised. Since these criticisms are more subjective, the best way to do this would be to include quotes from prominent critics.
:On the other hand, I disagree with what you're saying about some of the technical points that Penrose has raised in his book. I would argue that some of his points are not completely accurate, and I think that discussing these points in the article would give them undue weight. For example, the point about the discrepancy in degrees of freedom in the AdS/CFT duality is a very idiosyncratic view expressed in Penrose's book. As far as I know, there is no other critic who has questioned the correctness of the duality in this way. On the other hand, there are literally tens of thousands of articles which study various aspects of AdS/CFT and find that it works exactly as expected. In many cases, we have a detailed understanding of exactly how the degrees of freedom in string theory map to degrees of freedom in the boundary conformal field theory.
:As the article says, the real problem with string theory is that it has a very large number of solutions. Given a particular compactification of the theory, it's possible to come up with predictive models, and indeed, there are models with large extra dimensions that have been ruled out by the LHC. The problem is that there are many different compactifications of string theory that lead to realistic models of low-energy physics, and therefore it's probably not possible to uniquely predict coupling constants and particle masses from string theory.
:One does sometimes hear the claim that "anything goes" in string theory, but this is not quite true, and I'm afraid that treating it as a legitimate criticism would compromise the technical accuracy of the article. There are definitely some observable phenomena that are not predictions of string theory. For example, if the Fermi satellite discovers violations of Lorentz invariance near the Planck scale, then string theory would not be a viable fundamental theory. Similarly, if we ever discover that the fundamental constants are time-dependent, then string theory could not be right.
:So to summarize, there are ways in which the "Criticisms" section could be improved. String theory models are in general very difficult to test, and the article should reflect this fact. But I think it's difficult to include all of these criticisms without compromising accuracy as some of these criticisms are known by the experts to be invalid. [[User:Polytope24|Polytope24]] ([[User talk:Polytope24|talk]]) 22:00, 13 August 2013 (UTC)
:: I agree that the article should avoid giving undue weight to technical criticisms that have been stated by just one individual (e.g., Penrose's degrees of freedom arguments). The focus should be criticisms that have been voiced in multiple sources. On the other hand, I'm not sure the article needs to necessarily exclude criticisms of string theory solely based on the fact that string theorists (even in "tens of thousands of papers"!) believe the criticisms are invalid. Indeed one of the meta-criticisms is the alleged group-think mentality, whereby a whole community is mistaken about something, so I'd be wary of using the "all string theorists know this criticism is invalid" criterion to decide - even if we were trying to decide, which of course we aren't. We're not here to pass judgement on the validity of the criticisms, merely to report them, in a balanced way, <i>if</i> they meet the notability and verifiability criteria. It's tricky, because there are notable, reputable, and verifiable sources (e.g., Penrose) that have voiced criticisms, and yet we may decide not to mention them to avoid giving undue weight to ideas that the experts know to be invalid. I suppose an alternative would be to mention those criticisms and then include caveats explaining that string theorists do not regard them as valid criticisms - but that might get tedious. Having said that, I guess it's okay to omit criticisms that are unique to any single individual, so I'd agree to not mentioning (for example) the degrees-of-freedom arguments - unless someone finds additional sources for it.
:: I think lack of falsifiability is a criticism that has been voiced by many people, including string theorists themselves. For example, the section could include some quotes from Weinberg, such as <i>"Since the 1980s string theory has not come up with a prediction of anything new that we could then verify in the laboratory in a way that could convince us that string theory is right"</i>, or <i>"The critics are right. We have no single prediction of string theory that is verified by observation. Even worse, we don’t know how to use string theory to make predictions. Even worse than that, we don’t really know what string theory is."</i> Many people, even many prominent string theorists, have made similar comments, so I think it would be okay for the Criticisms section of this article to convey a stronger sense of this criticism. Right now the article gives the impression that the theory is criticized for making <i>too many</i> predictions, whereas I think the general sense of the criticism is that no one has identified any firm prediction of string theory. Maybe it's semantics, like my baseball analogy, between too many predictions = no prediction. I understand your desire not to give the impression that "anything goes" in string theory. There's obviously some structure to each of the possible solutions of each possible development of string theory (so to speak), but I think the criticism is that there is enough flexibility so that it can't really make any firm prediction. We could cite Rovelli's comments on this:
::: <i>"The main shortcoming of string theory is definitely its failure, so far, to produce any concretely verifiable physical prediction. To be sure, string theory has provided numerous “predictions”, like short scale modifications of the gravitational force, black holes at CERN, dielectron resonances, or the existence of supersymmetric particles at low energy, but so far all these “predictions” have been falsified by observation. The theory has survived these failed predictions, because they were not solid predictions, but only hints of possibilities, effects compatible with the theory, but not necessary consequences of the theory. The real problem is that the theory does not appear, so far, to have any verifiable necessary consequence at accessible scales... If there is an accurate string description of the real world, then there are probably so many of them to make the discovery of the right one virtually impossible and in any case devoid of predictive power."</i>
:: To me, this kind of wording better conveys the sense of the criticism than the current wording in the article about "too many solution", which makes it sound like an over-abundance of goodness.
:: By the way, I would be wary of citing things like Lorentz invariance or gravity as falsifiable "predictions" of string theory. I know people sometimes say things like that, but I don't think those statements are taken by many people to represent the kind of predictions that Weinberg (for example) says are lacking.[[User:Longerboats5|Longerboats5]] ([[User talk:Longerboats5|talk]]) 04:34, 15 August 2013 (UTC)
:::That describes many of string theory's shortcomings as as scientific theory succinctly and would make for a very good quote in the criticism section, however if we collect a few reputable sources essentially saying the same thing (which is not hard), we can put it in our own words.<span style="font-size:0.75em; padding:1px; border:1px solid black; border-radius: 3px;"><span style="background:black; color:white;"> —</span>[[User:Sowlos|<span style="background:black; color:white;">Sowlos </span>]]</span> 07:49, 15 August 2013 (UTC)
== "Theory" vs. "research framework" ==
I'm going to go ahead and change the first sentence to say that string theory is a "physical theory" rather than a "research framework". If anyone disagrees with this description, I'd be happy to discuss it here.
My worry is that using the term "research framework" will give the impression that there are many different types of string theory. This is a very common misunderstanding. When physicists talk about "string theory" they're talking about a ''unique'' mathematical structure that cannot be modified without spoiling its consistency. There are, of course, many different models constructed from string theory, but these are all just solutions of the same ten-dimensional theory. The existence of these solutions does not make it a framework rather than a theory. You could argue, I suppose, that the existence of string theory is still conjectural in the sense that we don't have a non-perturbative formulation of the theory, but this does not mean that string theory is merely a research framework.
[[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 22:32, 10 May 2013 (UTC)
:It goes way back to this edit [[http://en.wikipedia.org/w/index.php?title=String_theory&diff=437889230&oldid=437836457]. There is an ambiguity with the word "theory". String 'theory' is ''not'' a theory in the sense of a 'group of hypotheses that have been supported with repeated testing'. So we agreed to replace 'theory' with 'mathematical framework' and eventually 'research framework'. [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 17:17, 11 May 2013 (UTC)
::Can't there be untested theories? Under your definition, most of the quantum field theories that physicists study are not really theories... [[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 20:37, 13 May 2013 (UTC)
:::[[scientific theory]] - "A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of knowledge that has been repeatedly confirmed through observation and experiment." String theory just isn't a theory in that sense of the word. [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 00:55, 14 May 2013 (UTC)
::::Okay, so string theory is not a theory in that sense. Neither is [[supersymmetric gauge theory]], [[supergravity theory]], [[Chern-Simons theory]], [[Seiberg-Witten theory]], [[Liouville field theory]], [[noncommutative quantum field theory]], or any number of other things that physicists call "theories". [[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 06:08, 14 May 2013 (UTC)
::::: [[Quantum field theory]] says it is "a theoretical framework", it doesn't say it is a theory and most of your links don't say they are theories. Anyway it is best not to be ambiguous, and "theory" in a science article would seem to mean [[scientific theory]] [[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 07:14, 14 May 2013 (UTC)
:::::: It is appropriate to say that quantum field theory is a "theoretical framework" because the term "quantum field theory" does not refer to a specific theory for describing nature. Rather, it is a huge class of theories obtained by quantizing classical field theories. The resulting theories include all the ones I listed above, as well as more phenomenologically interesting ones like ordinary Yang-Mills theory.
:::::: The difference between quantum field theory and string theory is that while there are lots of different quantum field theories, there's only one unique mathematical structure called string theory. This is an important point that should be emphasized in the article.
:::::: The definition in the [[scientific theory]] article is obviously trying to distinguish between the notion of theory used in science and the colloquial notion of theory. That's fine, but it doesn't capture all the different ways in which the term "theory" is used in science. As I've been saying, it's very common in mathematical physics to use the term "theory" for a particular collection of mathematical data (a state space, an algebra of observables, etc.) even if such a "theory" is not a realistic model of physics. This is absolutely standard and, I think, completely appropriate for an article on string theory. [[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 08:29, 14 May 2013 (UTC)
I can corroborate what 208.46.240.4 is saying regarding the use of the term "theory" in science. As a child I was taught that the term "theory" in science was reserved for well-tested and established sets of ideas, but as a professional scientist I can say with certainty that that is not at all how the term is used among actual scientists. (And considering that the title of the article - and the universally accepted name for the subject - is "string theory", it's a bit silly to argue that it is not a theory.)
However, I do not entirely agree that string theory is as unique as 208.46.240.4 says it is. While the five SUSY string theories are probably all related to each other by dualities, that's not exactly the same thing as saying that they are the same theory, nor is it well-understood how bosonic string theory is connected to them. Then there are theories like the little string theory on NS5 branes, non-critical string theories, confining gauge theories and whatever it is that is holographically dual to them, etc.
So I do think there's an important point that "research framework" may have helped get across, namely that we don't really know what kind of string theory describes the world, if any, and that much of the research in the field is not focused on that question specifically, but rather on understanding the mathematical breadth and structure of the theory.
Let me add that I think 208.46.240.4's edits to this article have been excellent across the board, and have significantly improved it. Thanks very much! <small>'''<span style="color:Olive">Waleswatcher</span>''' [[User_talk:Waleswatcher#top|''(<span style="color:green">talk</span>)'']]</small> 19:51, 14 May 2013 (UTC)
:Thanks for the comments and praise! You're right that there are different kinds of string theory if you count bosonic string theory, noncritical string theories, etc. I am open to suggestions on how we could include these topics in the article.
:I also strongly agree with what you're saying about string theory research. Much of the current research focuses on the mathematical structure of the theory and the relationships between different mathematically interesting QFTs. In my recent edits, I've been trying to change the emphasis of the article to focus on these topics. [[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 22:23, 14 May 2013 (UTC)
::Are we ok with going back to "research framework"? Waleswatcher agreed that it helped and as he says there are 5 string theories[[User:Bhny|Bhny]] ([[User talk:Bhny|talk]]) 04:26, 29 May 2013 (UTC)
:::Okay, I changed it back to framework, but I'm still not completely comfortable with this phrase. I think the article needs more work to emphasize the uniqueness properties of string theory. There's a lot of confusion about this point. For example, Bhny writes that "there are 5 string theories", but this completely misses the point that Waleswatcher was making. These five string theories are all supposed to be "equivalent" in some sense so that there's really only one string theory. If you're going to talk about multiple string theories, you're talking about things like bosonic and noncritical string theories, which are not viable theories of particle physics. [[Special:Contributions/208.46.240.4|208.46.240.4]] ([[User talk:208.46.240.4|talk]]) 17:05, 31 May 2013 (UTC)
:I'm going to vote that string theory is a theory. I'm fairly sure physicists in general define 'theory' as 'a mathematically consistent model of something happening', regardless of whether or not it makes any attempt to be accurate to the real world. Pretty much, anything with a lagrangian is a theory, by a physicist's definition. Whether or not string theory really describes all real-world particles completely, and whether or not it makes any testable predictions, is not the issue. And if you insist on testable predictions, keep in mind that string theory does make many testable predictions - they're simply not feasible with current technology. Much like nobody was going to make a higgs boson back when Higgs first talked about it. [[User:KagakuKyouju|KagakuKyouju]] ([[User talk:KagakuKyouju|talk]]) 07:26, 18 November 2013 (UTC)
== Three spatial dimensions implied (in inflation)? ==
See my question in: [[Talk:Inflationary epoch#Three spatial dimensions implied|Talk:Inflationary epoch]]. I'm not sure string theory in considered contradictory to inflation. I think not. Short answer: Yes or no? Please answer my question I point to there, or at least not duplicate. If more appriopriate here (lengthy discussion likely) then point people to here if appropriate. [[User:Comp.arch|comp.arch]] ([[User talk:Comp.arch|talk]]) 14:52, 24 March 2014 (UTC)
| |||