Q-reeus

You claim nobody else in a 100 years seems to have noticed that problem with GR. Maybe not voiced in the particular way I have here, but e.g. Sir Arthur Eddington and Nathan Rosen were entirely skeptical of existence of GW's, owing to their 'phantom' nature. From the outset there were critics of certain other features of GR that made no sense to them. Their views, not all relevant but not all misplaced either, were side-lined as a matter of historical fact. One easily derived rigorous result that undermines one of the foundational bases of GR (known by Einstein in 1907 but later abandoned by him on aesthetic grounds), is shown in appendix A here: https://arxiv.org/abs/1606.01417 Feel free to point out here any flaw in that derivation btw. Or you would rather argue that because the GR community has not accepted that longstanding finding, the finding itself is therefore is ipso facto wrong and not even worth investigating? I also see you or someone has seen fit to simply vanish a post (maybe others - only noticed this one by chance) of mine formally in p2 here: https://www.scienceforums.net/topic/117103-no-energy-conservation-in-photon-by-ehf-f↓-in-space-of-expansion/ Now have an idea of the kind of editorial freedom wielded here. And a fair idea who successfully pressed for that particular case of 'post -> poof'. Regarding the snide remarks and outside issues dragged in, please go back and check who initiated, on several occasions, snide remarks and bringing in of extraneous issues from elsewhere. All before I decided to respond. I'm betting though no official warning notice appears against that member's offending posts. I can live with that kind of thing. Lastly, if you also persist in characterizing my arguments re GR issues here as above, well nothing more I can see worth adding to change that perception.

Then the thread appears to be in the right place. No. That was merely an overall opinion, excised by you and without any greater context, not a specific line of argument (which WAS given in various posts in various ways). OBVIOUSLY. I'll add a bit more. Down to -1 as of this post. Now have a much better idea of the general climate here at ScienceForums, and what tactics are typically employed by some. Have a nice day.

Whoever made the decision to move this thread here obviously has monitored it beforehand. Moving it was a public act. I'll wait some and see if I get a publically viewable response here in this thread. If none comes, then further action my part would be pretty pointless. Silence is a message in itself. Yet again? Combine for instance my very first post this thread with the last main para in this post (dammit, why no post numbering here?): https://www.scienceforums.net/topic/117191-doubts-about-gr-split-from-exclusive-grave-doubts-over-ligo’s-discovery-of-gravitational-waves/?do=findComment&comment=1083090 Or last part this post: https://www.scienceforums.net/topic/117191-doubts-about-gr-split-from-exclusive-grave-doubts-over-ligo’s-discovery-of-gravitational-waves/?do=findComment&comment=1082944 Various other posts have covered it, but how many ways of pointing out the same basic issue is needed?

After all the posts so far, best you can figure is I seem to be saying sort of incoherently that GR is wrong somehow? Wow. Then this thread has evidently run it's course. Given I have imo spelled out perfectly well enough what ails GR re 'gravity' gravitates' or rather not, and how that then conflicts with the assumed always valid stress-energy-momentum continuity relation. Enough of repeating myself on that, to no good effect here. But I still expect an answer as to who had a hand in booting it here, and exactly on what grounds. I have made my case on that much quite clear. And expect nothing less back from those involved in it being in Speculations.

Which above quoted is what one (currently) reads when pressing on link https://www.scienceforums.net/forum/29-speculations/#elForumRules [Edit: Oh well, turns out copying and pasting 'direct link' to Speculations Forum Rules only results in Speculations main page. One has to then click on that 'direct link' to bring up the Forum Rules box. So weird.] Hmm... I will ask again - who had a hand in booting this thread from Physics/Astronomy and Cosmology, to Speculations? What exactly is the notional objective criteria for doing so, in light of above reproduced Forum Rules re Speculations sub-forum? Where is there any hint of a hypothesized 'new idea/theory' being promoted, as opposed to what is obviously true to me - a straight out disagrement over the basic character and implications of an established theory, namely classical GR? That other theories were incidentally and occasionally referred to in passing, but never promoted as 'fact' or made a focus, seems also too obvious to deny. Or do I simply have to meekly accept that 'discretion of moderators' is the be all and end all of this decision?

Wrong. For instance Philip Gibbs is well known as arguing a zero-energy universe that includes all forms of matter-energy including so-called DE: https://www.quora.com/How-is-the-zero-energy-universe-hypothesis-compatible-with-the-accelerating-universe/answer/Philip-Gibbs-1?share=1

You learned from me over there, having made the fool error of hanging onto Schneibster's coat-tails, thinking he was an 'authority figure'. Until his exposed ignorance, of both SR and GR, which I had a major part in revealing, led to his crashing and burning. But of course you'd rather forget such things. I don't. As for supposed 'manufactured lies' - what lies exactly? Either put up or shut up. And btw, your repeated reference to extraneous issues SHOULD count as violation of forum rules - I would expect anyway. Let's see if any mods pick you up on that repeated abuse.

Could someone in the know tell me who exactly had a hand in having this forked thread booted to Speculations?

Bingo huh. Yet over at that other forum, your understanding was as for studiot's earlier here. And I was the one to straighten YOU out then. Well at least that much you have retained here. Incidentally, too late to edit it now, but I should have wrote '...universe of zero longitudinal thickness.' in my last post So this post affords that chance to 'edit it'.

Stop trying to tell me what do - GR fanboy. Remember - this is a FORUM. People are free to post thoughts as they see fit. You don't even understand SR let alone anything significant in GR. As evidenced many times at that other site.

So I need to repeat - nonlinearity is NOT equivalent to 'gravity gravitates'! What you are suggesting is that PeterDonis's clear exposition of why gravity does NOT gravitate in classical GR is wrong, and further that he continually contradicts himself. Not in that particular exposition. Later, he does fall into the trap of using a common pseudo tensor type approach that as I have said, skirts that 'gravity does not gravitate in classical GR' finding. And yes that then does lead to self-contradictory predictions. Which is what I have picked up on here. That such skirting the basics in EFE's is very widespread in GR community gives it a weight of authority you and others here evidently find compelling. That's imo at heart a sociological issue not actual physics. So you say. See my reply to swansont last post. (Oh gawd, this system insists on merging my posts - even when I logged out, then back in again to try and beat that feature!) If perchance there is someone else here at ScienceForums who understands GR and would like to make a fresh contribution, I would likely engage. Otherwise, it's very clear where the current lot of posters each stand. In my view, it's a pointless time-wasting exercise to keep up this circular circus act. I'll cut and paste my very brief position, from last post of mine: A brief recap. In say a binary merger -> GW's. The two supposedly mutually compatible GR relations div T_μν = 0, and R_μν = 0 (in vacuo), are not. I tire of repeating why. It's all been written earlier. Retention here is atrocious probably owing to innate faith in GR. Hence an unwillingness to seriously countenance anything casting doubt on it. Especially if it's simple, basic in character. That's it. I'm done with going in circles on this. Let's stop this not-so-merry-go-round now.

There can be no such thing as 'a photon's pov' i.e. 'in the rest frame of a photon'. The more you try and catch up to a photon i.e. head in it's direction of propagation, the more it redshifts in energy. In accordance with E = hf. Ignoring even that regardless of one's boost in that direction, it's still moving at c relative to you, the photon would redshift out of existence in the hypothetical sci-fi case you also 'caught up' and thus also moved at c. It's notional wavelength goes to infinity. An infinitely diffuse, zero energy phantom. In a universe of zero lateral extent. Bizarre enough? Got it?

The only logical way to interpret that first passage that doesn't conflict with the later one is to realize PeterDonis is being a bit loose with language. 'Curvature present' need not imply such curvature is itself a source of gravitation. Weyl curvature is source free but is nevertheless a type of curvature. It's only Weyl curvature that exists in exterior Schwarzschild solution. It's non-linear in character but not thereby a violation of R_μν = 0 (in vacuo) - the Ricci curvature is zero there. 'It' i.e. gravity gravitating is not present at all within classical GR! As above covered, and indeed the point made in almost every other post I have made here. Why confuse things by adding in speculative considerations of a speculative quantized version of GR in its high energy regime? But I have, beginning with the very first post here. A brief recap. In say a binary merger -> GW's. The two supposedly mutually compatible GR relations div T_μν = 0, and R_μν = 0 (in vacuo), are not. I tire of repeating why. It's all been written earlier. Retention here is atrocious probably owing to innate faith in GR. Hence an unwillingness to seriously countenance anything casting doubt on it. Especially if it's simple, basic in character. PS - I note my score has gone from +2 to +3 and back to 0. Pissed someone off. Too bad. Unlike one here in particular, I don't covet such approval rating tokens.

Nice try at cherry picking there MigL. Omitted from above quoted are these two preceding paras: So, real message there is any actual 'gravitons gravitate' theoretically kicks in perceptibly only at enormous energy densities where classical gravity is assumed to fail to an appreciable extent. We are no longer in the strictly classical GR energy regime. Do try and be more careful to provide full context next time. The summary part: Only (1) is relevant here - my repeated point you have chosen to ignore twice now. Which in itself is I suppose a subtle message. Another message is your failure to address the plain significance of that single expression R_μν = 0. Here, again, reproduced from earlier post addressed to you: Let me make it real clear what that single equation means. Every in vacuo gravitational field in classical GR regime is not a source for more gravity i.e. specifically gravity does not gravitate. It covers e.g. inspiral of 'BH's' and subsequent GW emissions of any strength. That there is iirc notionally observational evidence of reduced final merged mass consistent with calculated energy-momentum loss in GW's can be taken as evidence against GR and supporting theories where gravity does gravitate as an inherent feature of that theory. I have mentioned this earlier but it goes in one collective ear and out the other. That clear statement R_μν = 0 (in vacuo) is routinely skirted in practice via 'creative accounting' as mentioned way back. GR is an inconsistent hodgepodge where ad hoc procedures give the appearance of a coherent whole. But I get the message. Folks here have an unfailing trust in the rightness of GR, and that's that.

As do you. Always having to have the last word. And - see my last post.

And you have made that (admittedly very widespread) assertion without looking through all that was previously posted in particular by myself?! Why should I bother further here. OK, one last stab, from a slightly different but equivalent perspective. See single simple expression under 1.6 here: www.pas.rochester.edu/~rajeev/phy413/Grav13.pdf Please - actually THINK about it some. If you cannot see a direct contradiction to what you wrote above, then forget it. I will have totally wasted time and effort trying to get through to anyone here. Testament imo to just how effective has the GR brigade been in presenting it as an internally consistent 'perfect' classical theory of gravity. Again, you did not read my earlier remarks on that? You know, where I wrote to leave it out as we are really focusing on classical gravity. Sigh. Sigh Given you are simply a GR fanboy with no real grasp of the issues, it's not worth my while responding to each irrelevant point you make. Feel free to consider yourself 'the winner'. That's what matters to you, is it not? I well recall your enthusiasm for keeping arguments going non-stop back in that other forum. Bye bye.

See my reply below. As per your above comment, and below, you are mixing up quantum concepts - QFT's electromagnetic field, with classical - EM waves as critters propagating in a distinctly different entity namely classical vacuum. I like to compare apples to apples. Thanks to swansont's tip last post, I now know to double press Enter key for a clean separation. I had thought using supplied " quote function was sufficient. It certainly seems sufficient in my browser view - a clear vertical bar distinguishes that quoted from my response. So sorry if that was still confusing for you and swansont. See above. Classical paradigm vs QFT paradigm. Best not mixed up imo. If you had followed my general drift that statement is more or less accurate. GR is inherently self-contradictory imo. For reasons given ad nauseum. But I refer you to the last main para in response to swansont last post of mine. Take it or leave it. Preferably leave it. When there is clear ideological commitment at play, it becomes time wasting and farcical to go on and on with intent to only point score and/or deliberately misrepresent/undermine the other side's position. Hope that is not actually happening here but looks it to me. Cheers. And? Is air an elastic medium? Does it support shear waves (umm...no) which are the nearest analog to GR's transverse GW's? Nitpicking irrelevant diversions here? My bad. Still, we do tend to think these days of EM waves as a bunch of coherent photons, no? But that goes against my admonition to keep classical and quantum concepts separated. OK. Rrrright. And this gets back to the matter of GW's gravitating or not how exactly? Maybe if we just referred to what the standard EFE's has to say, analogues can be dispensed with. Yes too vague. Like right there. Please - actually quote specific passages, preferably in proper context. Have I? Please, again, actually quote where and how exactly. Bearing in mind my actual overall position. It may sound like it to you. To me the situation is as explained by PeterDonis - there is no room for gravity gravitating in standard GR's standard EFE's. Period. Want to keep this up? Play a game of attrition? If so, you 'win'. Right here and now. If otoh there is still genuine misunderstanding at play, it's still a case of 'this will never end happily for both sides'. So - Good night, again.

Incorrect comparison. 'Atoms and molecules' would be appropriate analog to a quantized extension of GR - so-called quantum gravity aka quantized spacetime, with GR as 'emergent' classical limit. Instead, stick to what should be the obvious appropriate analog to classical GR spacetime - a continuum elastic 'medium'. So explain how your example of photons propagating in vacuum, better captures the essence of GR's picture of GW's as purely propagating ripples OF spacetime WITHIN spacetime, than acoustic wave analogy does. All analogies have limitations. Some are better for the intended purpose than others. You are too vague. I have differentiated between his application to classical GR, vs application to gravitons on flat background. What are YOU referring to, and where and how? Look, the situation is not difficult to grasp. Standard GR as expressed in standard EFE's has NO room for gravity gravitating. Period. That situation is routinely skirted by redefining EFE's in a way doing violence to the originally formulated clear distinction between cause and effect. (Hypothesized quantum gravity extensions of GR involving spin-2 gravitons etc. lies outside that arena.) Evidently you and most others here are happy with that situation. I am not. Is there any point in extending this obviously fundamental ideological impasse on further? Good night.

If by field you mean a notionally flat background Minkowski 4D spacetime manifold as 'field', I suppose. But then, both GW's and light waves are themselves fields, so what meaning exactly to 'fields propagating within fields'? And I already explained via quote from AE's 1922 Leyden lecture, that one is drawn to the position spacetime itself has to take on some kind of ether/aether 'medium' character. Not a material medium, owing to requirement of Lorentz invariance, but having the similarity of being a disturbance OF that medium - not something else propagating within it. Well that's what GR implies. One that imo cannot be fully consistent with GR's founding definition in EFE's. Unless one thinks non-gravitating GW energy-momentum can be self-consistent with divT_μν = 0 (to repeat yet again). See above. The gravity as gravitons on flat background = gravity gravitates argument later there is btw a half-way house to Yilmaz gravity, or, with a radical rejection that gravitons must be spin-2, to Svidzinsky's Vector Gravity. Both the latter theories insist, in different ways, something other than pure spacetime curvature is needed for self-consistency. Again, since you have evidently taken over from swansont in responding, I will ask you to point to any logical error in PeterDonis original article - that part dealing strictly with classical GR. Which is what we are supposed to be dealing with. Yes? If you agree he makes no error there, how is subsequently making GW's self-gravitate also self-consistent? I maintain it is not.

You disagree that acoustic waves as propagating distortions in a medium is a better analogy with GW's than photons propagating through an absolute vacuum? Bare in mind we are here merely asking 'what is the most obvious analog to GW's' - from purely within GR framework? Imposing e.g. Lorentz invariance on any such 'aether' is separate consideration. How would you reconcile energy momentum in a GW with 'pure geometry' if the latter is nothing more than a way of relating distortions of clocks and rulers? On an historical note, AE himself, on pondering the different implications of GR vs SR, back-pedalled wrt his earlier total dismissal of existence of any kind of aether - see e.g 13th para and further on here: http://www-history.mcs.st-andrews.ac.uk/Extras/Einstein_ether.html "More careful reflection teaches us however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether; only we must give up ascribing a definite state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic which Lorentz had still left it. We shall see later that this point of view, the conceivability of which I shall at once endeavour to make more intelligible by a somewhat halting comparison, is justified by the results of the general theory of relativity." One cannot imo achieve self-consistency within GR's insistence gravitation is pure spacetime curvature. As my previous posts argue. See my previous response to beecee - especially link to PeterDonis's Insights article: https://www.physicsforums.com/insights/does-gravity-gravitate/ You have misunderstood my basic argument it seems. Have a closer re-read. What should be conserved, in accordance with divT_μν = 0, is conservation of NET gravitating source - inclusive of GW emissions. I hope we don't go around in circles here. See above. In particular, please point out specifically any disagreement you may have with the analysis and finding gravity does not gravitate in that article already linked to: https://www.physicsforums.com/insights/does-gravity-gravitate/ See my contributions in Vector theory of Gravity thread, beginning here: The matter is currently in dispute and not likely to be resolved real soon.

Oh my. I made a slight technical error in using 'self' together with gravitating. Try and deal with my clear intended usage instead of pressing a technical definition. You insist on repeating something earlier dispatched as an irrelevancy. And that in red is another meaningless, disjoint statement. An example imo of an erroneous online source. And as you may recall from that other forum, when I confronted that author he admitted his position was not fully self-consistent. You always did rely on quote mining and a show of hands as determinant of truth. Which approach and outlook I don't subscribe to. Yes one can go on quoting authorities to bolster a particular pov. That is of course just appeal to authority - as substitute for personally having a clear understanding. You should also recall from that other forum where I linked to someone who gave a somewhat detailed defense for why gravity does NOT gravitate in GR: https://www.physicsforums.com/insights/does-gravity-gravitate/ Which analysis is imo rigorously logical. And respects the meaning of the very definition of EFE's. Later in that series he then proceeds to argues that, contrary to what he shows in above linked, GW's can be made to gravitate. By the process of swapping over from LHS to RHS. Which imo is logically inconsistent with his above. Again - I never slavishly follow authority figures. Best to actually think things through for oneself. If you can of course. Your quasi-religious devotion to GR and its creator is well known in that other forum. PS - above will suffice to cover your later quote-mining post.

Strange - what was not clear in my previous posts? You can easily check for yourself that RHS of EFE's, the SET or SEMT, specifically excludes gravitation as source term(s). To repeat from my last post - that limitation is routinely circumvented via pseudo tensor formulations that of necessity violate the original formulation. Which basically makes a clean statement: Effect i.e.spacetime curvature (LHS) = cause i.e. non-gravitational stress-energy-momentum density (RHS). That's a founding physical statement defining GR. Sure mathematically one can move LHS curvature terms to RHS and make them into a source, but doing so violates the foundational physical meaning of the standard formulation. One of necessity, to 'make gravity gravitate' means removing curvature terms from the LHS over to RHS. Requiring source to produce a reduced set of effect - curvature terms. Where is the fundamental coherency in doing that? As I wrote, it's an inconsistent situation owing to the original aesthetic choice of AE to make gravity to be purely spacetime curvature. I can certainly back my pov via links to other articles, but where has my earlier posting, which this recapitulates, not been clear to you?

No, still not relevant to what was at stake. Which is the issue of self-gravitation of GW's or rather lack thereof in GR. 'So to speak'? Umm...actually gravity does NOT make gravity within GR. There is nonlinear interactions but that is not synonymous with 'making more gravity'. Notwithstanding various online articles erroneously claiming otherwise. Here, check out this Wikipedia article re definition of what constitutes source terms in RHS of EFE's: https://en.wikipedia.org/wiki/Stress–energy_tensor First para there makes it clear only non-gravitational stress-energy-momentum is a source for gravitation. Later there, the notion of pseudo tensor formulations that claim to give GW's etc a sort of well defined source density are given some space. Fact is any attempt to circumvent the founding definition - that excludes gravitational curvature as source - is actually a sneaky reformulation of GR as something other than 'pure GR'. It's the kind of thing that is inevitable when sticking tenaciously to a theory that has inherent consistency issues.

?? Perhaps reword that bit as it makes no coherent sense. Either you understand my earlier point re lack of universality within GR of stress-energy-momentum as source of gravitation, and it's consequences, or you don't. Doesn't have to. Some folks here do understand that there is a supposedly universally valid continuity law within GR, div T_μν = 0. Well that law certainly fails outside of its differential form when GW emissions enter the picture. As per that pointed out earlier. And? A moot point not relevant to above. I sure hope it's without any fear or favour. And, once again, I don't have all my eggs in one basket. I consider at this stage Vector Gravity has many points favouring it over GR, but make no firm endorsement of it. Similarly re Yilmaz gravity. The final decider will be Nature. Once all the expected many challenges and criticisms are resolved. How long that will take is anybody's guess. You obviously fail to grasp the context of my earlier statement on that. Gravitons are a fundamental tenet of that theory, not a hypothesized modification as is the case in GR. Hence that gravitons propagating within a notionally fixed background will self-gravitate is a consistent and inherent feature of that theory. Got that?

Well within GR paradigm GW's are nothing other than purely spacetime ripples. The better analogy then is one between sound waves and GW's. Both are distortions of a medium, and not something else propagating on top of or through the medium. Anyway there is a logical issue with GR's take on GW's as pure transverse spacetime distortions. Given GW's carry away energy and momentum, they should also self-gravitate like all other forms of energy-momentum-stress do within GR. But by definition, the vacuum gravitational field - both static and dynamic i.e. GW's, is NOT a source of further gravity in GR. Hence a self-consistency issue exists - there is an overall loss of gravitating mass when a binary BH or NS merger sheds GW's. That portion converted to GW's no longer gravitates. In some other gravity theories, there is no such dilemma. For instance, Svidzinsky's Vector Theory of Gravity posits GW's are comprised of quanta - gravitons. Propagating on a notionally flat background metric. In that scenario gravitons self-gravitate similar to photons do.