Black Hole.... Not so Black

Discussion in 'Astronomy, Exobiology, & Cosmology' started by RajeshTrivedi, Oct 1, 2014.

  1. OnlyMe Valued Senior Member

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    That is a better read on the context Rovelli was answering from, which seems to be with respect to general relativity. I don't know how much of his work on Loop Quantum Gravity has an impact on the view presented. I have tried to get through few of Lee Smolin's papers, but it is far beyond me. Still he uses the qualification, in the following sense or in this sense, which suggests.., to me.., he is responding from a theoretical perspective rather than some absolute position, of authority. Which is emphasized by the last sentence. Overall, it is more what I would expect in the way of an answer from a respected physicist.

    I disagree with the underlying implications... But as long as the discussion is limited to exploring the stand alone implications of GR, anything further would not be constructive.
     
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  3. tashja Registered Senior Member

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    OnlyMe, what is your opinion of Dr. Pössel's reply?
     
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  5. OnlyMe Valued Senior Member

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    Do you have a post number?
     
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  7. tashja Registered Senior Member

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    You are not following the discussion? Post 60
     
  8. OnlyMe Valued Senior Member

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    I did see that post but missed Pössel's comments.., I did not expand that section for some reason.

    His comment on the temperament of discussion is pretty much the way I see it.

    The rest of his comment I would say is the kind of comment I would expect from, again a respected physicist. Some aspects I would probably personally like to explore a little deeper with him, but again that diverges from the discussion here.

    Some years back now I began to shift from a ridgedly GR perspective of gravitation, influenced by some of what I have been able to gather from work on quantum gravity..., so how I read some of these statements is filtered through a different.., bias.., rather than a clear application of SR and/or GR.
     
  9. Q-reeus Valued Senior Member

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    I had prepared quite a detailed list of point-by-point replies to posts on p3, but in the intervening time there has been a flurry of activity (no email notification of such!) that makes it too burdensome and outdated to properly reply to all such now. Also a somewhat inconvenient local power failure hasn't helped. Anyway, will start here by pointing out that paddoboy's pathetic response in #59 is an admission he simply was not up to addressing my clear request of #53. But 'the Devil looks after his own' it seems and he has been handed more cheer and comfort. I care not.

    Still, I do appreciate the elaborated response of Markus Pössel in #60, the key passage there being:
    "But in Einstein's equations, the source term on the right-hand side contains no gravitational energy - which is presumably what Q-reeus is referring to."
    Indeed it was. And I would like to think Markus will take note of the confusion his online statement can generate, and act to amend and elaborate there accordingly. By definition, in GR the sole source of gravitational curvature (LHS of EFE's) is the RHS of EFE's:
    https://en.wikipedia.org/wiki/Einstein_field_equations#Mathematical_form
    That RHS SET (stress-energy tensor) by definition consists of all sources of strictly non-gravitational stress, energy, and momentum: https://en.wikipedia.org/wiki/Stress–energy_tensor
    (emphasis added)
    The meaning ought to be clear; in matter-free vacuum, any 'gravity' present cannot be acting as it's own source. Not according to the EFE's. Synonymous with saying the region is Ricci-flat: https://en.wikipedia.org/wiki/Ricci-flat_manifold
    Further explanation (esp. last two para) in terms of 'coffee grinds': http://math.ucr.edu/home/baez/gr/ricci.weyl.html
    Basically, by analogy with Maxwell-Gauss in EM, if there is no 'gravitational charge' = SET (as defined above) within some closed bounding curve, there are no net 'field lines' entering or leaving such. Rather intuitive.

    I like the way Sascha Vongehr (bio: http://www.science20.com/profile/sascha_vongehr) puts it here:
    http://www.science20.com/alpha_meme...gy_conservation_law_questioned-71641#comments
    (emphasis added) And reiterated here:
    http://www.science20.com/alpha_meme/not_afraid_dark_dark_energy_ultimate_sisyphus-73745
    (emphasis added)

    For a fuller and arguably more 'balanced' take on it: https://www.physicsforums.com/threads/does-gravity-gravitate.768604/
    Note carefully the 'gravity does gravitate' bits refer to speculative quantum gravity which lies outside the jurisdiction of stock-standard GR!
    Carlo Rovelli's response in #63 is imho stretching things in a certain way that I find hard to reconcile with my above. It suggests a subtle remake of 'vintage GR' to 'GR version 2.0'. In that somehow part of the LHS of EFE's has indeed managed to 'walk around to the RHS', to use Sascha's vernacular. Sure it can be mathematically manipulated as such, but in doing so bastardizes the very definition of curvature on the 'remake' of LHS (and also definition of RHS). Hello, is GR still there somehow? I guess this get's down to whether there is indeed a solid, unambiguous position within the GR community on such things. I would say for sure no - witness diverging schools of thought on e.g. 'zero energy universe'. Sascha, Sean Carroll etc. say no, Krauss, Stengler etc. say yes. Pick your side, pick your champion.
     
    Last edited: Dec 13, 2014
  10. paddoboy Valued Senior Member

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    Whether you care not, or otherwise is of no concern to me.
    You started this little childish tit for tat with you and myself in post 32.

    I've stated my position, and given examples as put to me by a GR theoriest in whom I have the utmost respect for and whose qualifications and professionalism is well known to me.
    That along with the other's support does leave me satisfied to say the least.

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    Your lengthy post actually doesn't say too much although once again your animosity towards me is quite obvious

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    Not that it worries me too much.

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    PS: I did notice your first link, the WIKI one, and although I also find WIKI helpful and use it on occasions myself, I did notice this at the bottom of the article " This page was last modified on 8 December 2014 at 18:47."
    Now I'm not going to accuse you of any foul play or attempted deception, but in another debate I was having with another anti mainstream, alternative adherent, [this one claimed to have a TOE] who has since been permanently banned, his referencing to two WIKI articles to attempt to support his erroneous concept, had also been updated/changed within 24 hours of his referencing them.
     
  11. tashja Registered Senior Member

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    Q-reeus, does the quote above^^ sum up your position?
     
  12. Q-reeus Valued Senior Member

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    I pulled you up on your mindless parroting there, knowing you could not personally defend it since you have no real basic knowledge of GR. It was you turning it into childish tit for tat.
    Yes, mindless parroting - as per your abject failure in #59 to address my #53. You have no personal understanding, just an animal cunning that recognizes who are established authorities. To quote from "Escape from the Planet of the Apes" - "Ape follow strong."
    And the same abject sycophantic praise would be offered to any others that bolster your ego. But so far here just the one.
    What others support? You think Pössel's elaboration in #60 supports you? It overall supports me. As does every other relevant passage or article I linked to in #70. That you have not offered a single counterargument to any of it is consistent with your total inability to do so. And I'm prepared to say that if Rovelli were to be completely forthright he would be forced to admit his 'pulsed GW' argument can only mean my bit re 'vintage GR' -> 'GR v 2.0' is necessarily true. Fact is there has been not one confirmation of GW's in all the years of trying at LIGO and similar sites. The arguments or rather excuses given that they never really expected to get a signal from these 'early' efforts is just so much PR BS spin imo. Wasting billions on projects never expected to work until many years later and only then after maybe the second or third major upgrade is a laughable notion if it were not so serious. If their spiel is true they should all be horse whipped and strung up as frauds.

    I claim to be able to prove the so-called quadrupole mode TT-gauge GW's illustrated on many sites like yes here at Wikipedia:
    https://en.wikipedia.org/wiki/Gravitational_wave#Effects_of_a_passing_gravitational_wave
    are an utter impossibility. (Which doesn't automatically rule out other possible modes but according to GR there are no others.) Won't attempt to justify that claim here - still tossing up over whether to attempt cashing in on such knowledge. Not expecting anyone here to take that claim seriously, but when the time is right it will be shown as incontestably true. Used to argue in favor of 'energy in the gravitational field' (in particular - as gravitating SET source), but now believe there is probably none - sans normally tiny residual effects that may be required for a successful quantum gravity theory. As for the binary pulsar data apparently confirming GW's, well consider the possibility it is just another if generally unexpected manifestation of Vongehr's fine pieces:
    http://www.science20.com/alpha_meme/energy_not_golden_holy_cow_urine
    http://www.science20.com/alpha_meme/dont_stop_presses_energy_conservation_law_questioned-71641

    If Nature can at various stages both give and take in LCDM/FLRW cosmology, why should it not also be able to take in case of binary pulsar etc. in-spiral? The latter possibility is admittedly only my speculative hunch at this time, but imo it makes more overall sense than the 'sourceless source' conundrum Rovelli's GW pulse argument leads to. The miserable and humiliating debacle that is/was BICEP2 was a great relief for me, but obviously not for the much initially fanfared team that 'proved' primordial GW's were really there. Yes there just might be a strong comeback much later down the track, but I sure wouldn't lay any bets on it.
    Ignorance is bliss then?
    It's so easy to shoot down your vacuous nonsense. If you aren't aware, virtually every Wikipedia article includes a tab to the right that's titled 'View history'. Go to it paddoboy - click away. Go back as far as you like. You are inferring either I was selective or that article is unreliably changeable in the relevant quoted part. Prove it - or admit your deviousness.
     
  13. Q-reeus Valued Senior Member

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    It's a minimal core but not really sufficient tashja - given the ideologically charged situation any missing context and/or elaboration may well be seized on to distort, or just misunderstood. Best, if you wish to do more polling, to just quote the entire post to get the entire context - sans the personal first paragraph. And btw it would be good to restore any bold emphasis - I used it for a purpose. Also, if you counter-quote Rovelli's piece using GW pulse argument in #63, best then include my newer comments in #73.
    I take it your strategy is to just anonymously present quoted passages to authorities while avoiding letting them know which forum they belong to? Otherwise I can't think why you wouldn't just refer them to particular posts to get the context in entirety.
     
  14. tashja Registered Senior Member

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    Sorry; I won't be polling regarding this topic any further.

    I leave you with Prof. Vongehr's response:

    And Prof. Baez:

    And Prof. Krauss:


    And Prof. Unruh:

     
    Last edited: Dec 14, 2014
  15. paddoboy Valued Senior Member

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    My mindless parroting as opposed to your own erroneous mindless parroting you mean.
    Again, let me say that gravity has a property called non-linearity, and that leads to the fact that gravity makes gravity to put it as simplistic as possible.
    The Eternal BH is an example of that.

    Listen old Son, you'll have a coronary if you don't calm down.

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    More baseless assumptions???
    I know my place....I have no ego to boost or otherwise. I leave that to you and the Farsights of this world, in your continuing delusional rants.


    Certainly they support my position as stated. If you see differently then you are letting whatever agenda it is that's troubling you skew your view and opinion.


    Most of our trolls and alternative hypothesis pushers here are also fond of claiming that they can prove this or that or that they have a TOE.

    This forum has some smart people. If your claim had any validity it would be accepted. But my money after the unstable nature of some your posts is on the negative.

    Pray tell me, what was this debacle and humiliating aspect you are talking about?
    All I saw was science in action, as did most here. Just because it wasn't what they originally thought, does in no way detract from that science.
    And to claim any different, is to once again, show your hidden agenda and baggage that is so badly reflecting on you.


    That actually is more of a self reflection my friend.
    My remark stands on the animosity you obviously have towards me, and the length of your posts that don't actually say too much.
    You don't happen to know another poster with the latest handle of "undefined" do you? He was finally given what he was asking and begging for...another alternative hypothesis pusher, with an over inflated ego.

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    My dear friend...I claimed one thing, and I stand behind that. If that claim is affecting you so much, and leading to this bubbling ferocity and animosity that you are exhibiting, then you need to sit back, take a deep breath, an aspro or two, and calm your self down.
     
  16. paddoboy Valued Senior Member

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    The science on whether empty space expands (as predicted by *gravity* theory) or gravitational waves propagate through “empty” space, or GR’s “self-interacting” nonlinearity for example, are not in question. Are suchlike phenomena “gravity in GR gravitating”? I refuse discussing verification transcendent distinctions. You must make up your own mind about what you mean by “gravity in GR” and “gravitating”. Intrinsically curved space-time? Then see whether you can live with further language preferences that would make “curved space-time does curve space-time” or suchlike acceptable to you, whether it ‘means what you meant to say’. You may as well defend that nothing gravitates, because with space-time as a given, there is no further time to do anything anyways – after all, “there is no gravity in GR” but just self-consistent geometry.

    S


    -----------------------------------------------
    Dr. Sascha Vongehr


    Thanks again tashja....I also agree with you about not undertaking any further polling. The nature of some of the people here, would just see more stubborn uncalled for derision of respected professionals.
    You have as usual. done a great job!
     
  17. Q-reeus Valued Senior Member

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    An extremely guarded response from dear Sascha that gives no-one room for comfort or discomfort. And I suspect the reason being he was aware it could turn into a 'Prof vs Prof' contest that understandably was to be avoided like the plague. So, please now include here just exactly what was presented to Sascha. That after all has been your practice on other occasions. Would he for instance likely have been aware of the earlier postings? Also, would you mind answering the question I posed to you last time? Cheers.
     
  18. Q-reeus Valued Senior Member

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    Really paddoboy? Really!?

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  19. paddoboy Valued Senior Member

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    I missed the other bunch of professors tashja.....
    Vinaka vakalevu again!
    Great job.
     
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  20. tashja Registered Senior Member

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    Sorry; I'm too overwhelmed to respond further.
     
  21. Q-reeus Valued Senior Member

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    Too overwhelmed?! Well when you finally recover please do respond as requested tashja. And naturally I had responded before you *unexpectedly* decided to add in further responses from Baez, Krauss, and Unruh. All essentially negating my position. Oh dear. Guess I should throw in the towel at this point. But not really. Stand by comments and references given in #70. Maybe any or all of the gents quoted in your late-edited #75 might care to explain how the definition of SET 'traditionally' associated with EFE's can be coherently reconciled with notion of geon! Coz I can't.

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  22. OnlyMe Valued Senior Member

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    Because when you quote whole posts you include a lot of petty childish bickering and name calling! The context of that first post of yours Rovelli responded to is one example and why I believe the quote was just six words.

    Try just sticking with the physics!
     
    Last edited: Dec 14, 2014
  23. OnlyMe Valued Senior Member

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    Though a little difficult to get down to what I believe he intended, Vongehr's response in this group is one of the best... Mostly because I enjoyed it... Basically it seems he is saying there are many interpretaions and none have any meaning in a discussion unless you first agree on exactly what you are talking about.

    Baez, begins by acknowledging the origin of Q-reesus' position, then ends that sentence with a phrase including, in a sense... which suggests other interpretations, like the entirely theoretical example(s) that follow. We have no evidense to believe that Schwarzschild Black holes or geons exist in reality. They are pure theoretical excursions into possible implications of the math.



    Assumming the posts being responded to were the same as earlier quoted in the Rovelli response, Krauss was succinct! However, by concluding with the statement that the debate is one of semantics, it is difficult to know what he understood the fundament intent of those posts was. It boils down to definitions (I.e. Semantics), of which there has been no consensus in the debate or even, it seems the responses from authority... The email responses seem clear that they, Prof., at least understand that.

    Unruh, seems to have gone over fully into the theoretical.., it would be interesting to know if he believes that things like Schwarzschild black holes and geons actually exist in reality.

    There is a big difference in what is acceptable in discussion, depending on whether it is understood that the discussion is about what we believe is real or what we understand as theoretical!

    Notice also none of the responses here or earlier, included any personal commentary directed at the person(s) on the opposite side of the discussion. At least as I read them.
     

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