Template talk:Theories of gravitation

Why minimized

• Why is this template always minimized now? —The preceding unsigned comment was added by 155.198.210.66 (talk) 12:36, August 20, 2007 (UTC)

Stub labelling

Why are stubs marked? It is not easy to maintain, and we should avoid self-references of this sort. –Pomte 17:06, 22 January 2008 (UTC)

Have to agree, I'm taking them out. If some wikiproject wants to keep track of these things they should do it in the Wikipedia namespace, IMO. Bryan Derksen (talk) 09:30, 31 January 2008 (UTC)

External links

I recommend to replace the internal wikilinks in this template by external links. For example: Everytime I click in Le Sage's theory of gravitation on "What links here", all gravity related articles of that template appear in the created list. I now corrected that for "Mechanical explanations of graviation" and "Le Sage's theory of gravitation". --D.H (talk) 12:11, 12 March 2008 (UTC)

Undid this - using external links for internal pages significantly impairs reusability of Wikipedia content. While the effect on backlinks is a little unfortunate, you should really talk to MediaWiki developers about changing the way template-generated links work if this is a significant issue. Spot-fixes like this aren't the way to go. Zetawoof_(ζ) 12:33, 12 April 2008 (UTC)

The easiest way (I think) to do this is including "w:" within the links. See also: Wikipedia:Village pump (technical)#How to avoid backlinks? --D.H (talk) 08:57, 22 June 2008 (UTC)

Template style

I've reverted the design of the template back to how it was, as the new style didn't seem to work well to me: each section of it was automatically hidden, requiring me to open each one, and also the sub-bullets didn't appear correctly as everything was aligned to the centre. The design of the template as it is should look fine on any monitor with over 800 by 600 pixels, which should be pretty much any modern computer, unless you have the text size increased. I was going to switch the template over to rows, e.g. like {{Manchester B&S}} uses, but I'm not sure how that can be done while keeping the existing sub-bullet points. Mike Peel (talk) 12:11, 12 April 2008 (UTC)

Hmm - don't know what you're using, but on my machine (Safari 3.1, Mac OS X) the infobox is nearly 1000px wide - too wide for a 1024x768 monitor, to say nothing of 800x600. I'm not using an unusual font, so I'm kind of at a loss as to why it'd look so different for you.

With regard to a more standard infobox, I tried that myself but wasn't able to figure out any sensible way to lay it out. Part of the problem, though, is that I'm not quite familiar enough with the topic to judge which parts of the structure are critical. Zetawoof_(ζ) 12:28, 12 April 2008 (UTC)

Vandalism by 128.196.210.67

A user from the IP address 128.196.210.67 deleted the intra-Wikipedia link Omega Point quantum gravity TOE from the template with the explanation "removed pseudoscientific theory". This is an explanation without merit as any cursory examination of the article it links to would show. Prof. Frank J. Tipler's Omega Point quantum gravity Theory of Everything (TOE) was first published in a 2005 paper in the journal Reports on Progress in Physics.

Out of 50 articles, Prof. Tipler's said paper was selected as one of 12 for the "Highlights of 2005" accolade as "the very best articles published in Reports on Progress in Physics in 2005 [Vol. 68]. Articles were selected by the Editorial Board for their outstanding reviews of the field. They all received the highest praise from our international referees and a high number of downloads from the journal Website." Reports on Progress in Physics is the leading journal of the Institute of Physics (based on its impact factor, according to Journal Citation Reports), Britain's main professional body for physicists.

Further, Reports on Progress in Physics has a higher impact factor than Physical Review Letters, which has for a number of decades been regarded as the most prestigious American physics journal (one, incidently, which Prof. Tipler has been published in more than once). A journal's impact factor reflects the importance the science community places in that journal in the sense of actually citing its papers in their own papers. (And just to point out, Tipler's 2005 Reports on Progress in Physics paper could not have been published in Physical Review Letters since said paper is nearly book-length, and hence not a "letter" as defined by the latter journal.)

Indeed, Prof. Tipler's Omega Point quantum gravity TOE is exceptionally orthodox, in the sense that it accepts all the known fundamental laws of physics (i.e., the second law of thermodynamics, general relativity, quantum mechanics, and the Standard Model of particle physics) while proposing no new such fundamental laws, unlike with, e.g., string theory, which proposes the existence of a new fundamental substance, i.e., strings, which make up elementary particles.

It's the ultimate future-state conclusion of the Omega Point which is intrinsic to this quantum gravity TOE which seems to incite the most ire of some people, but regarding the Omega Point Theory by itself (i.e., without the quantum gravity TOE component), it has been published in numerous peer-reviewed scientific journals. The most recent of which was in Monthly Notices of the Royal Astronomical Society in August 2007, which is one of the world's leading astrophysics journals.

So what this user at IP address 128.196.210.67 rather means is that he desires that the Omega Point quantum gravity TOE be pseudoscience. For the above-detailed reasons I'm reverting this user's deletion.--67.232.59.169 (talk) 08:23, 25 April 2008 (UTC)

Don't be so quick to start crying vandalism, I just saw a frankly retarded theory being pushed by some crackpot sitting in the same section as legitimate theories. If you're trying to sell this Prof. Frank J. Tipler nonsense, then by all means go ahead and add it again. I just thought it'd be better to make wikipedia accurate for once and representative of actual research. But whatever, you just got to hope people go to that article, see the NPOV flag there and see how ridiculous the theory is, and make a judgement call themselves. Cheers! General Epitaph (talk) 00:10, 21 May 2008 (UTC)

Your present edit is especially vandalism, since I already clearly pointed out above that the Omega Point quantum gravity TOE most definitely qualifies for inclusion in this Wikipedia template. It qualifies based upon Wikipedia's own rules, i.e., its "Policies and guidelines," namely under "Attribution," subsection "Reliable sources."

Clearly you are vexed to a great extent regarding Prof. Tipler's Omega Point Theory, with you giving the fallacious explanation "removed nonscientific [sic] theory about God or something" in your edit note, even though I already clearly demonstrate above that Prof. Tipler's Omega Point Theory has been published in many mainline peer-reviewed physics journals, including a number of leading physics journals; furthermore, that citations information is already contained in the "Omega Point (Tipler)" article entry which the "Omega Point quantum gravity TOE" template link points to.

Moreover, the Omega Point quantum gravity TOE has been published in Reports in Progress in Physics, the leading journal of the Institute of Physics (based on its impact factor, according to Journal Citation Reports), Britain's main professional body for physicists. Said journal has a higher impact factor than Physical Review Letters, which is regarded as the most prestigious American physics journal. Further, Prof. Tipler's Omega Point quantum gravity TOE paper was selected as one of 12 for the "Highlights of 2005" accolade as "the very best articles published in Reports on Progress in Physics in 2005 [Vol. 68]. Articles were selected by the Editorial Board for their outstanding reviews of the field. They all received the highest praise from our international referees and a high number of downloads from the journal Website."

Indeed, so vexed are you by the Omega Point Theory that it has caused you to rudely make the ad hominem attacks of "crackpot" and "nonsense" upon it, thereby slurring quite a number of mainline peer-reviewed physics journals and the professional physicists who referee for them, which includes some of the leading physics journals.

You have here amply demonstrated that you have a total disregard for the scientific peer-review process and the rules of Wikipedia when it concerns an issue which upsets you to a great enough extent.

For the above-detailed reasons I'm reverting your deletion, and I request that you refrain from vandalizing the template henceforth.--74.4.219.197 (talk) 15:49, 23 May 2008 (UTC)

Jesus Christ you write alot. Ok, fine, let's lump together string theory, m-theory, and the God-resurrection omega point theory. And as someone who actually does science, yea I can tell you that particularly in theoretical physics, peer-review is a joke. Take care! xoxo General Epitaph (talk) 02:44, 29 May 2008 (UTC)

String theory and M-theory violate the known laws of physics and have never had even the slightest experimental support. Whereas the only way to avoid the Omega Point quantum gravity TOE is to violate the known laws of physics (i.e., the second law of thermodynamics, general relativity, quantum mechanics, and the Standard Model of particle physics), and hence requires rejecting empirical science.--74.4.219.197 (talk) 03:23, 1 June 2008 (UTC)

What?! String theory (which includes M-theory) does not violate any laws of physics! General Relativity and the Standard Model come right out of String theory! Go learn some actual string theory to see the derivation of the EH Lagrangian Density and EFE from the Polyakov Action and Beta functionals! . Omega point crap is just some nonsense made by a crackpot with no knowledge of physics! . Dimension10 (talk) 07:53, 17 July 2013 (UTC) .

Thanks for the short reply, I could read it this time. I see why I was wrong, Professor Frank J. Tipler's peer-reviewed theory about resurrection is unavoidable. I guess there's nothing left to argue about. You win. <3, General Epitaph (talk) 05:34, 3 June 2008 (UTC)

Until and unless the known laws of physics have been experimentally, or otherwise, refuted, your immediate comment above is correct.--74.4.219.197 (talk) 01:04, 4 June 2008 (UTC)

Omega point is just crackpot (it doesn't contain any mathematics) and string theory does not violate any physical laws. Please read Becker, Becker and Schwarz "String theory and M-theory" befrore writing nonsense.203.188.230.188 (talk) 13:51, 25 June 2013 (UTC)

References

Fringe science

Since neither Tipler's nor Yilmaz's theory are taken seriously by the scientific community, I've moved those links into the new "fringe" section. --D.H (talk) 14:29, 21 June 2008 (UTC)

That's gutsy, see the above section where some user accused me of vandalism and just kept reverting anything I did. Anyway, I think the move is a good idea, so people will still be able to see it, but it'll be separated from the TOEs that are actually being investigated by scientists. Good call. General Epitaph (talk) 03:46, 24 June 2008 (UTC)

Hi, D.H. Prof. Frank J. Tipler's theory is taken seriously by the scientific community. Tipler's Omega Point Theory has been published in a number of the world's leading peer-reviewed physics and science journals.[1] Even NASA itself has peer-reviewed his Omega Point Theory and found it correct according to the known laws of physics (see below). No refutation of it exists within the peer-reviewed scientific literature, or anywhere else for that matter.

Below are some of the peer-reviewed science and physics journals in which Prof. Tipler's Omega Point Theory has been published:

- Frank J. Tipler, "Cosmological Limits on Computation," International Journal of Theoretical Physics, Vol. 25, No. 6 (June 1986), pp. 617-661; doi:10.1007/BF00670475. (First paper on the Omega Point Theory.)

- Frank J. Tipler, "The Omega Point as Eschaton: Answers to Pannenberg's Questions for Scientists," Zygon: Journal of Religion & Science, Vol. 24, Issue 2 (June 1989), pp. 217-253; doi:10.1111/j.1467-9744.1989.tb01112.x. http://theophysics.110mb.com/pdf/tipler-omega-point-as-eschaton.pdf , http://www.webcitation.org/5nY0aytpz Republished as Chapter 7: "The Omega Point as Eschaton: Answers to Pannenberg's Questions to Scientists" in Beginning with the End: God, Science, and Wolfhart Pannenberg, edited by Carol Rausch Albright and Joel Haugen (Chicago, Ill.: Open Court Publishing Company, 1997), ISBN: 0812693256, pp. 156-194.

- Frank J. Tipler, "The ultimate fate of life in universes which undergo inflation," Physics Letters B, Vol. 286, Issues 1-2 (July 23, 1992), pp. 36-43; doi:10.1016/0370-2693(92)90155-W.

- Frank J. Tipler, "Ultrarelativistic Rockets and the Ultimate Future of the Universe," NASA Breakthrough Propulsion Physics Workshop Proceedings, National Aeronautics and Space Administration, January 1999, pp. 111-119; an invited paper in the proceedings of a conference held at and sponsored by NASA Lewis Research Center, Cleveland, Ohio, August 12-14, 1998; doi:2060/19990023204. Document ID: 19990023204. Report Number: E-11429; NAS 1.55:208694; NASA/CP-1999-208694. http://www.webcitation.org/5nY13xRip See also: http://ntrs.nasa.gov/search.jsp?Ntk=DocumentID&Ntt=19990023204 , http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19990023204_1999021520.pdf

- Frank J. Tipler, "The Ultimate Future of the Universe, Black Hole Event Horizon Topologies, Holography, and the Value of the Cosmological Constant," arXiv:astro-ph/0104011, April 1, 2001. http://arxiv.org/abs/astro-ph/0104011 Published in Relativistic Astrophysics: 20th Texas Symposium, Austin, TX, 10-15 December 2000, edited by J. Craig Wheeler and Hugo Martel (Melville, N.Y.: American Institute of Physics, 2001), ISBN: 0735400261, which is AIP Conference Proceedings, Vol. 586 (October 15, 2001), pp. 769-772; doi:10.1063/1.1419654.

- Frank J. Tipler, "Intelligent life in cosmology," International Journal of Astrobiology, Vol. 2, Issue 2 (April 2003), pp. 141-148; doi:10.1017/S1473550403001526. http://theophysics.110mb.com/pdf/tipler-intelligent-life-in-cosmology.pdf Also at arXiv:0704.0058, March 31, 2007. http://arxiv.org/abs/0704.0058

- Frank J. Tipler, Jessica Graber, Matthew McGinley, Joshua Nichols-Barrer and Christopher Staecker, "Closed Universes With Black Holes But No Event Horizons As a Solution to the Black Hole Information Problem," arXiv:gr-qc/0003082, March 20, 2000. http://arxiv.org/abs/gr-qc/0003082 Published in Monthly Notices of the Royal Astronomical Society, Vol. 379, Issue 2 (August 2007), pp. 629-640; doi:10.1111/j.1365-2966.2007.11895.x.

- F. J. Tipler, "The structure of the world from pure numbers," Reports on Progress in Physics, Vol. 68, No. 4 (April 2005), pp. 897-964; doi:10.1088/0034-4885/68/4/R04. http://math.tulane.edu/~tipler/theoryofeverything.pdf Also released as "Feynman-Weinberg Quantum Gravity and the Extended Standard Model as a Theory of Everything," arXiv:0704.3276, April 24, 2007. http://arxiv.org/abs/0704.3276

Monthly Notices of the Royal Astronomical Society, in which the above August 2007 paper was published, is one of the world's leading peer-reviewed astrophysics journals.

Prof. Tipler's paper "Ultrarelativistic Rockets and the Ultimate Future of the Universe" was an invited paper for a conference held at and sponsored by NASA Lewis Research Center, so NASA itself has peer-reviewed Tipler's Omega Point Theory (peer-review is a standard process for published proceedings papers; and again, Tipler's said paper was an *invited* paper by NASA, as opposed to what are called "poster papers").

Zygon is the world's leading peer-reviewed academic journal on science and religion.

Out of 50 articles, Prof. Tipler's 2005 Reports in Progress in Physics paper--which presents the Omega Point quantum gravity Theory of Everything--was selected as one of 12 for the "Highlights of 2005" accolade as "the very best articles published in Reports on Progress in Physics in 2005 [Vol. 68]. Articles were selected by the Editorial Board for their outstanding reviews of the field. They all received the highest praise from our international referees and a high number of downloads from the journal Website." (See Richard Palmer, Publisher, "Highlights of 2005," Reports on Progress in Physics. http://www.iop.org/EJ/journal/-page=extra.highlights/0034-4885 )

Reports on Progress in Physics is the leading journal of the Institute of Physics, Britain's main professional body for physicists. Further, Reports on Progress in Physics has a higher impact factor (according to Journal Citation Reports) than Physical Review Letters, which is the most prestigious American physics journal (one, incidently, which Prof. Tipler has been published in more than once). A journal's impact factor reflects the importance the science community places in that journal in the sense of actually citing its papers in their own papers. (And just to point out, Tipler's 2005 Reports on Progress in Physics paper could not have been published in Physical Review Letters since said paper is nearly book-length, and hence not a "letter" as defined by the latter journal.)

For much more on these matters, particularly see Prof. Tipler's above 2005 Reports on Progress in Physics paper.

The only way to avoid the conclusion that the Omega Point exists is to reject the known laws of physics (i.e., the Second Law of Thermodynamics, general relativity, quantum mechanics, and the Standard Model of particle physics), and hence to reject empirical science: as these physical laws have been confirmed by every experiment to date. That is, there exists no rational reason for thinking that the Omega Point Theory is incorrect, and indeed, one must engage in extreme irrationality in order to argue against the Omega Point cosmology.

Additionally, we now have the quantum gravity Theory of Everything (TOE) correctly describing and unifying all the forces in physics: of which inherently produces the Omega Point cosmology. So here we have an additional high degree of assurance that the Omega Point cosmology is correct.

Because Prof. Tipler's theory is in fact taken seriously by the scientific community, and because it is simply nothing more or less than mainline physics itself (i.e., the known laws of physics), I am moving the template's Omega Point entry to its original location.

-----

Note:

1. While there is a lot that gets published in physics journals that is anti-reality and non-physical (such as string theory, which violates the known laws of physics and has no experimental support whatsoever), the reason such things are allowed to pass the peer-review process is because the paradigm of assumptions which such papers are speaking to has been made known, and within their operating paradigm none of the referees could find anything wrong with said papers. That is, the paradigm itself may have nothing to do with reality, but the peer-reviewers could find nothing wrong with such papers within the operating assumptions of that paradigm. Whereas, e.g., the operating paradigm of Prof. Tipler's 2005 Reports on Progress in Physics paper is the known laws of physics, i.e., our actual physical reality which has been repeatedly confirmed by every experiment conducted to date. So the professional physicists charged with refereeing this paper could find nothing wrong with it within its operating paradigm, i.e., the known laws of physics.

--71.0.146.150 (talk) 13:11, 7 March 2010 (UTC)

I concur that those "theories" are not taken seriously by the scientific community. That the Omega Point theory is possible in a collapsing universe is accepted, but it's not true that everything possible will happen, still making it speculative. — Arthur Rubin (talk) 15:40, 7 March 2010 (UTC)

Hi, Arthur Rubin. You made a demonstrably false statement. As I just proved in my post above, Prof. Frank J. Tipler's Omega Point Theory is taken seriously by the scientific community.

I just cited eight peer-reviewed papers by Prof. Tipler on his Omega Point Theory appearing in a number of the leading peer-reviewed physics and science journals. (Indeed, even NASA itself peer-reviewed and approved for publication Tipler's Omega Point Theory.)

Unfortunely, critics here of Prof. Tipler's Omega Point Theory are using their fallacious opinions in order to come to erroneous conclusions, instead of using reliable sources, and so are thereby violating Wikipedia's policy on this. Because Arthur Rubin and similar critics here are in violation of Wikipedia's reliable sources policy, the template entry must be reverted back.

Regarding your irrelavant and fallacious opinion that "it's not true that everything possible will happen, still making it speculative": (1) the Omega Point Theory is the only non-speculative quantum gravity Theory of Everything (TOE) in existence: all other such theories introduce new physics that have never been confirmed and which violate the known laws of physics (such as with string theory); and (2) no one here claimed "everything possible will happen", making this statement a non sequitur. It's at any rate irrelavent, since it's not up to Wikipedia editors to decide what is or isn't true: instead, Wikipedia operates on its reliable sources policy, and based upon that policy, Prof. Tipler's Omega Point Theory is a mainline physics theory, published in a number of the world's leading peer-reviewed physics journals.--71.0.146.150 (talk) 18:47, 7 March 2010 (UTC)

A few points, Prof. Tipler.

Reports on Progress in Physics is a tertiary source, at best; we generally prefer secondary sources.

I presented an "invited paper" at the 1977 AMS meeting. It indicates that the session organizer thought my papers would be interesting, not that the presentation I would be making is necessary accurate. The subject of the presentation was not specified by the organizers. The same is true for invited speakers, and even the "principle" invited speaker, at those conferences. To translate to terms more familiar to non-professional Wikipedia editors, it's more similar to the organization finding that I am a generally reliable source per WP:SPS, rather than the specific paper is a WP:RS.

The claim that evaporation of black holes violates unitarity seems to be primarily Tipler's (Hawking's paper quoted in Omega Point (Tipler) does not actually support the claim), and cannot be taken as an accepted view. Whether it's WP:FRINGE or merely a minority view is unclear. — Arthur Rubin (talk) 21:39, 7 March 2010 (UTC)

Hi, Arthur Rubin. Prof. Frank J. Tipler's 2005 Reports on Progress in Physics paper on the Omega Point is a primary source, not a tertiary source.

The points you make about invited papers still make my case, since NASA in 1998 was obviously aware of Prof. Tipler's main line of work, i.e., on the Omega Point, and yet still regarded Tipler as a reliable source.

Your statement that "The claim that evaporation of black holes violates unitarity seems to be primarily Tipler's (Hawking's paper quoted in Omega Point (Tipler) does not actually support the claim), and cannot be taken as an accepted view. Whether it's WP:FRINGE or merely a minority view is unclear." violates Wikipedia policy. It's not up to you or any other Wikipedia editor to decide whether this claim is true or not: all that matters vis-à-vis Wikipedia is that it meets Wikipedia's reliable sources policy. In this case, it's a claim that's been repeatedly published in peer-reviewed papers in a number of the leading peer-reviewed physics journals (in this case, five different peer-reviewed papers, including in Monthly Notices of the Royal Astronomical Society, one of the world's leading peer-reviewed astrophysics journals, and in Reports on Progress in Physics, the leading journal of the Institute of Physics, Britain's main professional body for physicists).

And yes, contrary to your false claim, Hawking's paper "Breakdown of predictability in gravitational collapse" (Physical Review D, Vol. 14, Issue 10 [November 1976], pp. 2460-2473) is the paper wherein Hawking showed that if black holes evaporate to completion then unitarity is violated. As Jacob D. Bekenstein wrote in "Black holes and information theory" (Contemporary Physics, Vol. 45, Issue 1 [January 2004], pp. 31-43 http://arxiv.org/abs/quant-ph/0311049 ): "Hawking [28] was led by this to assert that gravity violates the unitarity principle of quantum theory", with reference No. 28 being "[28] Hawking S.W., 1976, Phys. Rev. D, 14 , 2460".

Your confusion on this matter apparently stems from Hawking not using the word "unitarity" in his said paper. Hawking instead therein refers to the unity of quantum probabilities, which is a different way of referring to the quantum mechanical law of unitarity. You're obviously in over your head on these matters, i.e., attempting to second-guess Prof. Tipler (joint professorship in physics and mathematics), who is a formally-trained global general relativist (the same rarefied field of Hawking and Penrose), as well as an expert in quantum mechanics, the Standard Model of particle physics (which he closely studied as it was being developed), and computation theory; and according to Prof. John A. Wheeler (the father of most relativity research in the U.S.), "Frank Tipler is widely known for important concepts and theorems in general relativity and gravitation physics." Here we also see a perfect illustration of why Wikipedia's policies on original research and reliable sources are good policies, as otherwise we get people not knowing what they're talking about attempting to use Wikipedia's articles and templates in order to argue the truth-value of certain positions.

It's through Hawking's papers that the position that unitarity would be violated if black holes were allowed to completely evaporate became the standard position in physics: it's what's known as the black hole information paradox. In standard physics (i.e., general relativity and quantum mechanics), unitarity unavoidably would be violated if black holes were allowed to completely evaporate. There have been proposals to preserve unitarity while still allowing complete evaporation (such as Hawking's 2005 proposal which is dependent on the conjectured string theory-based AdS/CFT correspondence), but they all involve unconfirmed new physics.

Regardless of your misunderstandings, you seriously need to get over the idea that it's up to you or any other Wikipedia editor to decide whether something is true or not, since that's a violation of Wikipedia policies regarding truth and no original research. All that matters on this issue is that Prof. Tipler's Omega Point Theory is mainline physics per Wikipedia's reliable sources policy. Per Wikipedia policy, the template must be reverted back.--71.0.146.150 (talk) 08:42, 8 March 2010 (UTC)

Restructure based on experiment?

This template seems a little wishy-washy with how it classifies theories. The "standard" part at the top, broken into "NG" and "GR" is fairly straightforward. The rest is kind of arbitrary. Why are some listed under "alternatives to general relativity" whereas others are listed under "other theories"? Wouldn't the average reader assume the "other theories" are the "alternatives"? I think a clearer way of classifying would be based on experimental constraints. We could have an "experimental status" section subdivided into subsections (examples) named "compatible" (EC), "constrained" (tensor+vector), and "excluded" (scalar). "Other" could be reserved for lower-dimensional theories or whatnot if need be. Teply (talk) 09:38, 6 September 2012 (UTC)

I'll boldly commit my suggested changes. I can't guarantee I put everything in the right place. Improvements are always welcome. Please discuss any really major objections here. Teply (talk) 06:12, 14 September 2012 (UTC)

First, please do not take anything I say personally! I merely wish to bring up some points, and I may be entirely wrong in my understanding of certain aspects.

I was going to ask about this approach, because Euclidean quantum gravity is not "Fully compatible with observation"...to be more precise, there has yet to be any experimental prediction/confirmation for it! (There are even severe theoretical difficulties with it.)

Also, some theories are difficult to place. Semiclassical gravity, for example, do we place it under "experimentally constrained" thanks to Paige & Geilker's work (as well as Eppley and Hannah's work) or do we place it under "Experimentally excluded" since both groups conclusively shown semiclassical gravity fails empirically?

Furthermore, Conformal gravity has both experimental support and theoretical difficulties (the opposite of Euclidean quantum gravity!). Mannheim's spontaneous symmetry breaking approach adequately describes galactic dynamics.

Consequently, I think perhaps it would be better to group it by paradigm. Just an alternate point of view... --Pqnelson (talk) 15:19, 14 September 2012 (UTC)

I'm not familiar with many of those theories (e.g. Euclidean quantum gravity). For some of them I had to make educated guesses based on the content of the Wikipedia articles, often stub/start class (again e.g. Euclidean quantum gravity). If you think I misplaced some of them, go ahead and switch them around. Here's how I was interpreting the labels:

1. "Fully compatible with observation" = The theory passes solar system tests and any additional free parameters in the theory are as yet unconstrained by experiment. An exemplar is gauge theory gravity. It passes the usual tests of general relativity because it satisfies the strong equivalence principle and supports the Schwarzschild solution, Friedmann equations, etc. It even predicts, to its benefit (is my bias showing?), that a homogenous, isotropic universe must have $\Omega _{k}=0$ to be compatible with the Dirac equation. It mostly differs from GR in stuff like black hole interiors. Good luck testing that.
2. "Experimentally constrained" = The theory passes solar system tests provided that additional free parameters are very small/large so that they get the theory to lie close enough to GR in some limit within experimental error. I was thinking of Brans–Dicke theory when I wrote this because it passes the solar system tests as long as $\omega >40000$ or whatever. Looking more closely at its Wikipedia page, I see an unreferenced claim that it doesn't support the strong equivalence principle...
3. "Experimentally excluded" = The theory does not yield a model compatible with observation, no matter how you tune its free parameters. Nordström's theory of gravitation is an obvious example. It gives the wrong answer, plain and simple.
4. "Developmental or disputed" = The theory is kind of new to the scene or having some "theoretical difficulties" as you call them making it unknown whether it contains GR properly (supergravity) or there have been recent loud, conflicting claims to its experimental status (entropic gravity). This label may show some of my own ignorance, and you can definitely move stuff around or reorganize.

I had thought about grouping the theories by paradigm but decided against it. Some of the theories are just a little hard to categorize cleanly into "classical," "quantum," and "TOE." If you're feeling bold, though, you're welcome to try it. There also used to be a fringe science section with entries Omega Point and Yilmaz theory of gravitation. This eventually got commented out, and I just plain removed it. Grouping by paradigm would run the risk of reopening the fringe section. Teply (talk) 05:06, 15 September 2012 (UTC)

Well, can we at least separate them into "classical" and "quantum" theories of gravity, and then divide up the classical theories according to "degree of experimental confirmation"?

I believe it'd get too...contested if we try to determine "Ah, this theory of quantum gravity is correct and that one incorrect." We may as well lump them all together, and lump all the classical theories together too. Just my two cents... --Pqnelson (talk) 16:50, 17 September 2012 (UTC)

Sure, you can do that if you like. That's roughly in the spirit of how the template was organized prior to my changes but hopefully cleaned up... Part of the trouble is that classical theories of gravitation redirects to an article all-inclusively named alternatives to general relativity, but the content of that article really only focuses on the classical ones. You should probably move/rename the "alternatives" to "classical theories" and significantly modify quantum gravity to have an appropriate of list of theories (an improvement of quantum gravity#Other approaches. Teply (talk) 05:52, 18 September 2012 (UTC)