On this page I collect permanent links to approved versions of some Wikipedia articles which I edited extensively (more or less).
Important notes:
Please do not edit this page. If you absolutely must, you can leave comments at my
user talk page, although it may take some time before I see these since I expect to be fairly inactive after early April 2006.
Please do not try to edit these versions of Wikipedia articles! You won't alter the versions pointed to on this page, but you will revert the current version of the page, which is sure to annoy active editors, so please don't do that. If you think you have spotted an error in one of these articles, please see the most recent version and edit that (or complain in the talk page).
Few if any of these articles were "complete" when I abandoned them to their miserable fate.
Some of them may even contain an error which I overlooked while hastily compiling this list (again, if you think you spotted one, don't complain to me, since I can't change the past; consult the most recent version and do what you will there).
If in any of these archived pages, you click on
an internal link to another article, you will get the current versions of the indicated article (if it still exists); I hardly need say that the same goes for external links!
an internal link to a category, you will get the current contents of that category, which may well contain all kinds of cranky pages, may no longer contain the article you were just looking at, or which indeed may longer even exist.
"history", you will the most recent history; to see the history up to the version archived here, you may need to increase the lookback or even to scroll through several history pages.
"talk", you will get the current talk page; to see comments contemporaneous with the version archived here, you may need to search archived talk pages for the article in question.
Wikimedia does not store webpages but rather reconstitutes them "on the fly" from various elements, so the Wikipedia site will try to serve archived articles as if they were written to comply with current wikipractices, which tends to result in progressively degraded appearance of archived pages. This is unfortunate, but beyond my control.
The following permalinks are organized with indentations roughly corresponding to the category tree as of 5 April 2006.
As a courtesy, I removed the todo lists from articles I was working on, since these were mostly notes to myself which probably won't make sense to other editors. (In a few cases, I just removed the items listing suggested improvements which I believe could only be implemented by myself.)
currently this article uses etc. for Rindler frame field and etc. for Bell frame field, while
Rindler coordinates uses for Rindler frame field and etc. for Minkowski frame field (corresponding to static observers in the Cartesian chart). This notational conflict should probably be resolved.
Tasks for anyone:
copyedit (at one point we changed notation t,x,y,z -> T,X,Y,Z, and hopefully got everything changed)
better explanation of motivation for theory, especially variable gravitational "constant" and Dirac large number hypothesis,
explain Jordan "frame", Einstein "frame" [sic],
write and link to background articles on decomposition of metric tensor (see Carroll; see problem book for utility in comparing gravitational radiation in Brans-Dicke and other theories with gtr),
explain Faraoni critique (weak-field limit),
add material comparing exact solutions in most important cases (plane waves, static spherically symmetric perfect fluid balls) and add a good citation
correct misspellings (I do see some of my own, but too lazy to correct 'em)
improve the citations by using citation templates,
improve obscure and clumsy writing (poor diction, inconsistent cases, split infinitives; this article is currently an grammarian's nightmare).
Tasks requiring expert knowledge:
the title and categorization of this article promise comparative discussion of gtr with other theories; this article should refer to articles (yet to be written) in
Category:General relativity; much material currently appearing here should be moved to new articles in this category (or better yet, entirely new articles should be written from scratch, using much better diction, figures, etc.).
this is a highly developed field which is surveyed in several fine review papers; most textbooks have one or more chapters devoted to gravitational radiation; since this is an encylopedia article, cite these rather than research papers.
We need an article on
Linearized theory of gravitational waves which first discusses the propagation and effect on test particles of linearized plane waves, especially monochromatic linearly and circularly polarized, then discusses multipole moments and the generation of waves.
Explain or at least mention linear perturbations of non-Minkowski backgrounds, but following standard textbooks this case deserves the most attention.
Why not an animation of the "cruciform motion" for linearly and circularly polarized waves? See MTW for hints. But don't forget to mention gravitomagnetic effects.
Don't forget to point out that not all radiation is quadrupole radiation.
This article should be contrasted with a new companion article on
Far fields in general relativity which focuses on using weak-field theory to derive stationary far fields. Both weak-field rapid motion (radiation generation) and far-field stationary use a multipole expansion of the (trace-reversed) metric perturbatation tensor, but in different ways. See the textbook by Stephani for hints.
Very possibly a seperate article giving the detailed computations alluded to in my rewrite of examples of various kinds of radiation or non-radiating systems. It would be nice to offer animated images illustrating the various examples I gave (check with me to make sure you understand what I have in mind).
These articles should reference new articles on relativistic multipoles and connect ultraboosts of Ernst vacuum objects (e.g. Kerr objects) to impulsive plane waves. See
Aichelburg-Sexl ultraboost for the simplest special cases.
The phrase perturbation from flat spacetime is usually avoided in classical gravitation because there are linear and nonlinear perturbations (e.g. there are exact solutions which are nonlinear perturbations of FRW dusts).
rewrite more along lines of most recent Mashhroon review article,
more NPOV,
be careful to explain that GEM is not the same thing at all as "gravity shielding" or EM fields allegedly producing antigravity; politely stress that GEM is mainstream but these two topics tend toward crackpottery,
write and link to background articles on "warp drives"; clarify relations to GEM alleged in current version,
maybe a small caveat about mainstream modes of partial interconversion between gravitational and EM fields; explain why these are not useful for "gravity shielding" or "exotic spacecraft propulsion" schemes!
in principle a better title would be gravitoelectromagnetism as per Mashhoon review but never mind,
distinguish carefully between weak-field, slowly moving test particle, and other assumptions,
explain relatation with Bel decomposition (valid generally) and mention strong-field cosmological GEM type extension of Dunbar et al.
distinguish between gravitomagnetism and gtr and other theories
make sure to start all articles with orientation/executive summary for general reader, try to explain all technical terms, and cite appropriate sources,
stress two main applications are far field of isolated rotating object and weak-field approximation study of
gravitational radiation,
expand and link to background article on
multipole expansion: motivate and define mass, momentum, stress monopoles, reduced quadrupole tensor, explain relation to harmonic expansion of potential, explain Newtonian, Weyl, and relativistic multipoles, cite Stephani's textbook and other sources, link to any relevant discusion of multipoles in Newtonian theory and electromagnetism (see
Category:Vector calculus and
Category:Potential theory for some possibilities),
write and link to separate article on
relativistic multipoles, explain the three extant versions are equivalent,
write and link to
decomposition of metric tensor: algebraic decomposition into spin 0 pieces (gravitational potential, trace part) , spin 1 piece (vectorial part), spin 2 piece (strain tensor), versus differential decomposition of spin 2 into longitudinal part, solenoidal part, tranverse part (c.f. transverse traceless gauge): cite Carroll's textbook,
explain competing gauges such as transverse, synchronous, harmonic (called Lorenz gauge in this context; named for Lorenz, not Lorentz), and discuss gauge transformations,
Lorentz gauge valid outside ball around the source,
transverse traceless gauge is a special case of Lorentz gauge suitable in smallist "box" far from source,
throughout state which approximating assumptions are being made,
rewrite and link to background article on
gravitoelectromagnetism following most recent review by Mashhoon, comparing with a strong field concept, the
Bel decomposition of the Riemann tensor,
write and link to background article on
linearized plane waves (general relativity), discussing these using TT gauge and computing curvatures, etc, discussing polarization, then discussing in terms of GEM formalism, then compare with and link to articles on strong field plane waves in gtr,
discuss examples including spinning disk, rod, spring oscillator, and simple binary pulsar model: compare far field expansions with gravitational radiation production (if any), use Newtonian energy balance to estimate how system adjusts to loss of energy due to gravitational radiation (if any), compare orbital decay for binary pulsar and rotating spring oscillator (where PE relevant since shape of system changes in response to radiation of energy) and spin-down of rigidly rotating objects (where PE irrelevant since shape of system does not change in response to radiation of energy).
everywhere distinguish notationally between space and spacetime indices, and between abstract tesnor equations and specific components,
explain how weak field limits can help one identify qualitative meaning of a parameter which has arisen in a solution of EFE from assuming some symmetry Ansatz, as in Schwarzschild,
links to general references, point out specialized articles contain specialized references.
Throughout, article should stress
intuitive meaning,
levels of structure,
degree to which a given mathematical technique/concept is special to gtr, Lorentzian manifolds, etc. (for example, triangularization via Gröbner basis methods is very widely applicable in applied mathematics, as are perturbation theory methods, appropriate bundling procedure very important for smooth manifolds).
write and link to proper article on Lienard-Wiechert potentials in electromagnetism,
write and link to article discussing conservation laws in flat versus curved spacetimes
article on
Einstein field equation should discuss the first-order covariant differential equation for Weyl tensor in gtr (e.g. 4.90 in Carroll); link to discussion of analogous first-order covariant differential equation in this article,
discuss degrees of freedom and compare with gtr,
cite Dicke article and discuss weak versus strong EP for Nordström's (second) theory,
discuss issue of effect of internal energy on motion of extended falling bodies,
write and link to article on double null coordinates, including discussion of the wave equation,
"already linearized" vacuum solutions and generation of gravitational radiation
Tasks for anyone:
correct typos
Defects in my last version include:
it is largely left to reader to distinguish between wave equation, raising/lowering/trace, wrt
it is largely left to the reader to figure out , so that small corresponds to weak fields, but due to arbitrary additive constants in gravitational potential, in weak fields either of these can be identified with Newtonian potential ( more natural for comparison with Einstein's later weak-field metric for gtr).