Black Hole.... Not so Black

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

  1. paddoboy Valued Senior Member

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    Would you like to elaborate on that a little bit further?
    I mean I do believe you are a little bit more logical then what that sentence seems to project, so maybe I'm misunderstanding something.

    What I will say is that probably all BH's are born with spin [Kerr metric] for obvious reasons, and that spin along with any charge, is negated over time. The amount of time is the essence here, as imo to negate all spin, would take a heck of a long time.
    So in essence most BH's would be Kerr metric, Kerr-Newman, or Reissner-Nordstrom.
    Is this what you are referring to?
     
    Last edited: Dec 14, 2014
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  3. paddoboy Valued Senior Member

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    It's actually quite amazing how he flew off the handle so quickly, [especially since I'm such a nice bloke

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    ] simply due to my claim that gravity is non-linear and gravity begets gravity...nothing more, nothing less.
    Actually I have an hypothesis, [not quite a scientific theory at this stage] due to two tiny pieces of evidence so far, that this bloke maybe "undefined".
    I'll keep working on it anyway.

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  5. OnlyMe Valued Senior Member

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    You sort of answered the question about Schwarzschild BHs yourself... It is a simplified BH gravitational field that is useful, but so far does not resemble anything observed... Thus they remain theoretical.

    The idea that a BH that begins with angular momentum might spin down, so to speak.., would require that there be an inertial interaction across the event horizon... That does not seem a likely thing, unless a BH were some version of Farsight's resurrected frozen star.., whose surface is the event horizon. Barring that, the process of a BH spinning down, would seem to require an exchange of information.., from the BH across the event horizon. Again not consistent with current theory.

    The geon also is not observed to exist. It is a theoretical construct. As far as I am aware the only observed evidence that might originate from a geon, is associated with dark matter graviationnal lensing, not otherwise associated with an observed mass... But then if those observations were due to geons, it would remove dark matter from the picture.

    In the case of the geon, even if the gravitational field were initially generated by the presence of some mass, tye fact that the gravitational field propagates at the speed of light and the initial mass could not be displaced or dissipate, at anywhere near the speed of light.., changes in the field would occur faster than any potential displacement or dissipation of the initial mass. Thus, geons are also, theoretical constructs and remain so.
     
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  7. paddoboy Valued Senior Member

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    Agreed, it's just that the word "theoretical" conjurs up all sorts of extensions amongst those that don't see BH's per se existing.


    I don't quite accept that, as within a Kerr BH's ergosphere, it is possible to extract energy.
    see.....
    http://en.wikipedia.org/wiki/Ergosphere

    and
    http://www.astro.sunysb.edu/rosalba/astro2030/KerrBH.pdf

    With regards to the Kerr metric, and ergosphere, if that included the familar polar jets, those jets would be extracting energy from the ergosphere I suggest.

    I wouldn't mind hearing some more thoughts and that situation regarding spin and whether it can and is negated totally.
    I was of the opinion that it certainly was but am now uncertain..
     
  8. paddoboy Valued Senior Member

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    http://phys.org/news/2014-11-black-hole-jets-power.html
    A team of space scientists working in Italy has found more evidence that suggests the energy needed to emit jets from supermassive black holes comes from the spin of the black hole itself. In their paper published in the journal Nature, the team describes how their survey of data from NASA's Fermi Gamma-ray Space Telescope allowed for comparing two types of emissions from the black holes, which showed a correlation.

    Read more at: http://phys.org/news/2014-11-black-hole-jets-power.html#jCp

    """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

    So what I get from that, is that a feeding Kerr BH will lose spin easier, the a spinning Kerr BH that is relatively dormant.
    I say relatively dormant, as I would reckon it would be very rare for a BH to be 100% totally dormant.
     
  9. OnlyMe Valued Senior Member

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    Any real answer will have to wait for a better understanding of quantum gravity. If you follow the line of reasoning that begins with nothing.., including light, escapes from within the event horizon, then polar jets have to be the result of dynamics completely external, to the event horizon... Most of the discussions about information transfer around here stick pretty much the assumptions originating with GR.

    The last post quoted above seems to cast some doubt on the information issue. One either has to accept that a massive black hole does interact with mass outside of the event horizon or all angular momentum we observe associated with a BH is a remnant of pre-colapse dynamics... Meaning it is left over from angular momentum existing before the BH formed. In that case it would make no difference whether the BH had any angular momentum or not, and we would have to assume that over time any remnant angular momentum would dissipate.....

    I don't often get into this kind of discussion or debates about the BB, because how one arrives at any conclusions on either issue depends entirely from what theoretical basis one begins...
     
  10. Q-reeus Valued Senior Member

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    We have no real way of knowing why Rovelli's original reply was just 6-words (could have been reduced to 2). My guess is he was either very busy or in a bad mood.

    As to the matter of post quoting, firstly, only some posts qualify for that description. Secondly, the recipients are not children and one assumes perfectly capable of sorting out chatter from relevant content. It's always better if they have access to full context. Thirdly, if you have any sense of balance and fairness you will acknowledge paddoboy is far and away the chief chronic offender, both in initiating and continuing uncalled for and unjustifiable abuse, lies, slander etc. etc. Am I wrong? You may think it's ok for paddoboy and ilk to mouth any crap they like and not be called to account, but that's not me! A big part of the problem at SF is imo that such flamers/trolls are allowed to run amok basically unchecked.
    See above.
     
  11. Q-reeus Valued Senior Member

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    Actually I was deeply dismayed at what amounted to a moral failure on Sascha's part. His speaking in riddles was imo out of fear of being pitted against other authorities, as mentioned before. You will notice tashja has not responded to my request for clarification as to precisely what was presented to Sascha. My guess is it included what amounted to a blunt contradiction to his earlier clearly expressed position, by Rovelli's piece on GW pulse. It's understandable he then reacted as he did, but imo not excusable. What I quoted from earlier statements of his had no such rambling cryptic style. Too bad he would not stick to his guns here. As you can see, I'm not out to win friends, just establish truth.
    Yes, because there is no real honest choice. The EFE's do have a clearly defined meaning and relation, but the GR community has long 'gravitated' to a situation where use of pseudo-tensors has been slipped in to create a butchered redefinition of what is still officially presented as 'the EFE's'. Few will acknowledge this as a 'having your cake and eating it to' position. That allows such absurdities as 'eternal black holes' or 'geons' to mathematically exist in defiance of what 'pristine' EFE's actually allow.
    Yes - see above.
    As for the last two you mention, they simply chose to avoid dealing with the obvious contradictions, and just point to generally accepted 'solutions' of the (redefined) EFE's that amount to sourceless sources existing by sleight of hand. Or to put it another way, turning what by the EFE's should be sourceless, into a source through pseudo-tensors that all acknowledge have at the least consistency issues. Recall I mentioned Krauss as one advocate of 'zero energy universe' - and gave you a few names of those denying such concept. All of them accomplished in GR. Go figure. Unanymity in GR is on a very narrow base, despite PR to the contrary.

    The remaining posts #85-#90 are not worth commenting on, save to say paddoboy's dragging in the link http://phys.org/news/2014-11-black-hole-jets-power.html
    is just irrelevant chaff tossing. As expected. And btw, there is one well-known situation where the accepted GR position amounts to on a reasonable interpretation as implying gravity anti-gravitates! Let's see if paddoboy can figure out what I'm referring to. Of course he will not, but let's see if he's up to risking taking a wild stab at it.
     
  12. OnlyMe Valued Senior Member

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    Right now there are about 12 staff members. That's a tough job when you look at the site wide traffic.

    You seem to be reading more into the comment(s) than I saw in the post.

    That was in reference to a separate side discussion that came up because of one of my comments. Had nothing to do with the earlier discussion, so I have difficulty understanding your comments above as anything more than out of line.
     
  13. Q-reeus Valued Senior Member

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    Which implies 12 are not enough to keep up with monitoring all thread entries at SF. In other words it's a bit of a casino as to getting away with rule violations. I'd suggest it is a casino situation in one sense, but not because posts go unread by at least one mod/admin. There just isn't that much posting input as to overwhelm 'resources'.
    You're entitled to your opinion, but my analysis is imo the only one making sense.
    I will concede on this occasion to have been careless and should have read the relevant posts more carefully. Apologies.
     
  14. Q-reeus Valued Senior Member

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    Overlooked that inference earlier. Don't insinuate unless you can back it up. Do so, or apologize for such slanderous insinuation. And btw, you never answered my challenge given in last part of #73. Do so now - either verify your insinuation or apologize for doing so.
     
  15. paddoboy Valued Senior Member

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    What I insinuate and claim is there for all to see in black and white...Namely your uncalled for attack on me.
    Who I think you are also stands at this time, although as I admit, I have nothing concrete.
    And no, I will not apologise. What for?
    I'm not interested one iota in any challenges you make...I'm also not the only one you are ordering about...tashja has also been on that end of your arrogant style.

    In your recent couple of posts, all I see is you trying to get out from under, and making excuses for the professionals, and spitting the dummy, instead of admitting you may have been in error.
    My comment which seemed to have started all this, and which has not been refuted stands.
    That is gravity/spacetime has a property called nonlinearity which means gravity begets gravity....
     
  16. paddoboy Valued Senior Member

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    I see it as irrelevant chaff tossing.
     
  17. paddoboy Valued Senior Member

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    http://www.einstein-online.info/spotlights/gravity_of_gravity
    One reason why the physics of general relativity is much more difficult than that of Newton's theory of gravity or the theory of electrodynamicsis a property called non-linearity. In short, gravity can beget further gravity - where gravitational systems are concerned, the whole is not the sum of its parts.
    more.....
    http://www.einstein-online.info/spotlights/gravity_of_gravity
    ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

    And of course further supported by tashja's many professional replies.
     
  18. Q-reeus Valued Senior Member

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    If I were to hire any competent lawyer to go through all our exchanges, you would be left swinging in the breeze. And you know it. Or rather should if not clinically mentally ill.
    So; you unrepentantly continue to insinuate I am a sock-puppet of undefined. You have cooked your goose. I will not let this slip away. You will be made to account.
    Again you simultaneously refuse to be accountable while adding further lying/distorting. Where have I 'ordered about' either you or tashja? A cheap attempt to get me off-side with him/her as the case may be.
    You think so? Well then, try and answer the substance of my position. We all know you can't, but just try. It would be amusing.
    Well done - parrot. And further stock parroting for the umpteenth time in #98.
    And btw your comment in #97 is point-blank refusal to acknowledge my apology given in #94 for a rare slip-up. Contrast that with your refusal to properly deal with two issues in my #95. Such is paddoboy.
     
  19. paddoboy Valued Senior Member

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    I have been wondering why the animosity towards me since my friend Q-Reeus, put in his bib at post 32....
    And I have found it.
    It was he who initiated the "free fall to singularity is B/S " in the science section and then admitting....
    Continued to push this alternative crap as science until it was shifted to the proper alternative section....This and myself and others opposing such crap obviously cheesed him off somewhat.

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    As usual with most alternative cranks, the request to follow the scientific methodology and get peer review saw him stumbling from grace.

    http://www.sciforums.com/threads/fr...-is-bs-or-dont-just-trust-authorities.142870/
     
    Last edited: Dec 15, 2014
  20. Q-reeus Valued Senior Member

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    If you wish to honestly further pursue the above issues you chose to bring up here as some kind of pathetic diversionary tactic, do so in that thread which remains open. Trust me, you will be sorry for doing so.

    In the meantime, either back up with facts or concede your factual and moral error on the outstanding multiple issues presented in #99 - which in turn refers back to earlier posts. You are a coward for attempting the above disgraceful diversionary ploy.
     
  21. tashja Registered Senior Member

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    Yes, of course. I should have clarified that the replies from Vongehr, Baez, Krauss, Unruh, and now Maldacena, were in regard to your post #70, and should be read in the context of that post. Apologies for any confusion it may have caused. Here's Prof. Maldacena's:
     
  22. paddoboy Valued Senior Member

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    The issues above have already been pursued, and done and dusted and you were shown to be wanting, to put it mildly.
    And no its not a diversionary tactic, its a most likely cause why you have been acting so irrationally, and why I raised it.



    I'll let our peers here be the best judge of who is a coward and who is twisting and trying to get out from under.
    That started at post 32 btw.
     
  23. Q-reeus Valued Senior Member

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    Thanks tashja for that clarification - full context is always a good idea. So one may tentatively assume Sascha was not aware of earlier material then. Ummm...makes his convoluted reply all the more difficult to fully understand. I do know he advocates using nutmeg as a spaceing-out 'legal narcotic'

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    - but hell no way will I insinuate he may have been so spaced-out why replying to my #70!

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    Yes, for the record, that was just a fun bit on my part.

    As for the eminent theorist Prof. Juan Maldacena's response, well I accept that if one assumes there is a 'suitably space-time averaged' stress-energy-momentum density in a gravitational field be it of 'static' or 'dynamic' nature, then logically one should include it as part of RHS SET. In which case though one has a redefined set of EFE's that necessarily differs from that I referenced in #70. As further discussed in e.g. #92.
    Thing is, the 'averaging procedure' is equivalent to evaluating from some suitably chosen coordinate frame, and integrating over the 'g-fields' so determined, treating such g-fields analogously to E & B fields in EM.
    Yet there is as I mentioned in last part of #92, a well-known result that implies 'gravity anti-gravitates' on above basis. Still waiting for paddoboy to take the bait. Waiting in vain no doubt.
    Anyway, why does Wikipedia etc. continue with 'vintage' GR EFE's and not the 'new' version(s)?

    Now to reiterate #73, my claim is a fully self-consistent picture is one in which there is no stress-energy-momentum in a gravitational field at least in the classical regime. One then has no GW's with which to argue as above or earlier by say Rovelli and others. It's a radical position in the sense one ditches the usual Lagrangian requirements, but not so radical when realizing many GR authorities already recognize the usual energy-momentum conservation laws fail in GR in general. But not all - hence the divided camps I referred to twice earlier. And btw my proof of non-existence of quadrupole mode TT-gauge GW's is of a different nature to either just assuming above or of that given by the likes of 'maverick' GR expert A.Loinger here: http://arxiv.org/abs/0709.0490
     

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