Neutron Star to Black Hole

Discussion in 'Astronomy, Exobiology, & Cosmology' started by RajeshTrivedi, Jan 12, 2015.

  1. OnlyMe Valued Senior Member

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    Bruce, the two posts you quoted were not directly connected, to one another. I did respond to Rajesh's post earlier. The post of mine was a response to a different issue... Though there is some overlap...

    Putting them together as you did, makes it difficult for me to understand what your point was or was meant to be.

    My intent or at least one of the things I was trying to convey, perhaps poorly, was much the same as in Prof. Moore's comment in tasjha's post # 95. Both the mass of the black hole and the spacetime rotating with a Kerr black hole have angular momentum. That would be true in my estimation, in the case of any black hole with angular momentum. They can in some instances be thought of as a single entity or inertial system, with a combined angular momentum... And yes all of these speculations involving the relationship between black holes and spacetime, can raise questions including conservation issues, and separately the speed of light and information transfer.

    Equation 21 is dealing with the infalling stone, so yes it was clear that the stone itself has no angular momentum and its path is one with angular velocity. It is the is the angular momentum of the spacetime it is infalling through, that leads to its angular velocity. Another one of those circumstances that could lead to unresolved questions...
     
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  3. RajeshTrivedi Valued Senior Member

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    Thank you Tashja. Prof Moore response is very educative and informative for me. I did not know that like Energy, Angular Momentum can also be associated with the field. My understanding was that angular momentum must necessarily be associated with mass directly. This response answers the question in totality.

    If you see the thread, even after 100 posts, multiple clarifications our resident teacher and copy paste maestro were dragging themselves with non sense...absolute lack of understanding beyond superficial terminology. Prof, the very erudite and knowledgeable man cleared the question in one shot. Hope these two kids also understand the nuances of subject involved (or at least attempt to understand), then only they can respond with conviction, otherwise they will continue to babble around and will create noise only.
     
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  5. RajeshTrivedi Valued Senior Member

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    You do not understand the difference between question and hypothesis. Do you ? I have not hypothesized anything yet in this thread.

    See the colored statement of yours above...and please explain to OnlyMe again, what it means ? You are kind of converting a Schwarzschild (non rotating BH) to a Kerr BH. Thats the pitfall of copy paste or unclear understanding of the subject.
     
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  7. paddoboy Valued Senior Member

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    Whatever face you try to save is OK with me...More to the point was the weight of evidence and numbers explaining your silly error/s, was just culminated with the good professor's confirmation of all the noise and babble.
    Best of luck until your next venture to attempt to derail accepted physics/cosmology.
     
  8. RajeshTrivedi Valued Senior Member

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    My doubt was that in case of Kerr BH, the angular momentum cannot be associated with the mass because we really do not know about the whereabouts of mass. Prof Moore clarified the stand that the Angular Momentum is linked with the field....I would presume that prof Moore is concurring with the fact that it cannot be associated with the mass of BH. Your opinion that angular momentum is with spacetime as well as mass, may create a further issue of how much with the spacetime and how much with the mass ?
     
  9. paddoboy Valued Senior Member

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    Sure he does. The problem/s was you not understanding, firstly that [1] BH's in all likelyhood do exist. Nothing else as yet can explain the effects we see on matter/energy spacetime, [2] To talk of BH density is not valid, considering that all the BH is, is critically curved spacetime, with a Singularity at the center, consisting of degenerate mass, [3] GR fails at the quantum/Planck level, and that is by definition what determines the singularity, [4] Once any mass collapses past its schwarzchild limit, further collapse is compulsory, [5] The Schwarzchild metric although highly unlikely, is used for ease of conveniance and mathematical calculations, [6] When we refer to a Kerr metric BH, all the metric, including inside EH, ergospher and to a lesser extent beyond the static limit is rotating.
    Apologies if I have unintentionally missed any other aspect you have misunderstood.
     
    Last edited: Jan 17, 2015
  10. RajeshTrivedi Valued Senior Member

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    1,476
    To : Those who are following this thread

    Can it be said by the posts of Brucep or Paddoboy.....that they knew about the fact that Angular Momentum in a rotating Kerr BH is associated with the field ? I am pretty sure they have equally benefited out of the response of good professor. But they are dishonestly pretending that they knew it.
     
  11. paddoboy Valued Senior Member

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    No not at all. It appears you have learnt nothing.
    Our best model tells us that the mas/singularity is rotating, and takes on a ring formation, as is the rest of the BH, as is the ergosphere, and even slightly beyond to a much lesser extent.
     
  12. paddoboy Valued Senior Member

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    21,647

    I knew it and I said it a dozen [well a few] times.
    Grow up and admit you were wrong.
     
  13. RajeshTrivedi Valued Senior Member

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    Why are advocating for Brucep....let him respond if he understands or not. Do not act like his assistant.

    Yes in all likely-hood. So you are also uncertain about their existence, then why crib on me.

    Bad statement. You are giving shape to the mass inside BH. As soon as you do it, you will get stuck with your previous statement about density [2].

    Someone other than me must fire you for this consistent, insistent, diligent, blah, blah, blah....I have lost energy to fight you on this issue.

    One last try : Just please briefly let me know which parameter of Planck's Level (length, mass, time, energy, volume, density, charge, angular momentum, area, speed etc.....) just name one, you are associating this singularity with ? This is a fair question, because you have made this statement at least 100 times in last 30 days in one form or the other.

    I am reserving my comments for few days on this point..

    You are talking about Schwarzschild BH ? But Penrose says a Kerr BH may convert into a Schwarzschild BH...and looking at the time scale involved...we do not know, you still may have one lurking around the corner.

    If inside EH, you are referring to r/m< 1 (on both sides as per Chandrasekhar paper), then GOD bless you for this.

    Lesser Extent : Is a relative term...please google and see the frame dragging mathematics, this lesser otherwise is quite a drag.

    I never misunderstand....sometimes I do not understand then I follow it up till I understand...
     
  14. OnlyMe Valued Senior Member

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    Rajesh, the field is created by the mass of the black hole and spacetime is a description of the field. The angular momentum of the field is the result of the frame-dragging effect that the angular momentum of the mass of the black hole has on the space around it, which again to be clear is described by GR and the spacetime model.
     
  15. RajeshTrivedi Valued Senior Member

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    You are omniscient !!

    Am I wrong this time ??

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  16. OnlyMe Valued Senior Member

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    I believe so.
     
  17. tashja Registered Senior Member

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    You're welcome, guys. And thank you, Prof. Moore, for helping us so many times.


    Raj, see Prof. Ashtekar's comment below:

     
  18. paddoboy Valued Senior Member

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    You are a funny one [funny peculiar, not funny haha] Brucep has put his postion quite clearly and given reputable links. I don't need to ask him what he meant.


    No, I'm not uncertain. I do realise that as yet no one has come up with any alternative to explain the critical effects we see on spacetime and matter/energy.


    Wrong on both issues. The mass is degenerate at best and confined to the Planck/quantum arena, as predicted by GR and the Schwarzchild limit.
    Density is a non issue when speaking of BH's.

    In reality, you are the only one in a totally confused state re the Singularity and where and when it exists.

    One last try...Don't be so obtuse and pretentious. It's been explained many times.

    What you are doing is reserving "common sense" and logic.
    Again, when any mass collapses to its Schwarzchild radius [equal to where the EH would be] then further collpase is compulsory according to our best model of gravity.


    If you were not so blinded by your agenda and excess baggage, you would know that I have said the same thing.
    Again, The Schwarzchild metric is used for ease of conveniance although it is probably unlikely to exist.
    Time scales for spin to be negated maybe over similar time scales for a BH to evaporate due to Hawking radiation.


    You are being obtuse again.
    Let me put it in kindergarten language...the BH's mass spins [singularity] the spacetime of the BH itself spins...Frame dragging occurs beyond the EH proper and which we call the ergosphere....and some spacetime spinning can also occur to a much lesser extent beyond the ergosphere's static limit.

    Lesser extent means what it means and what any school child would know what it means.


    Yes you do misunderstand, sometimes quite frequently, and sometimes quite horribly amiss.
    It's there in at least two threads in black and white.
     
  19. RajeshTrivedi Valued Senior Member

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    Thanks, Tashja, Last attempt and your kind efforts in getting the response of Prof Abhay....has now put a lid on this singularity dispute. All along I was maintaining that this singularity has no business with Planck's level.

    Prof Abhay said..

    I think the two sides (Rajesh, Paddoboy) are implicitly using the term `singularity' in
    different ways. The term is a well-defined notion in classical
    general relativity and
    therefore does not refer to the Planck/quantum
    scale
    . But perhaps the other side thinks of the singularity as a place
    where, in the real world, classical general relativity fails. This would
    happen once the curvature becomes Planck scale (much before the classical
    singularity where it is infinite
    ).


    *******************************
    Abhay Ashtekar, Director
    Institute for Gravitation
    and the Cosmos


    This is what professor Carlip said in Tasja post # 261 in another BH thread...

    ......In classical GR, "the Planck scale" doesn't mean anything -- it
    is a scale that explicitly involves Planck's constant. But
    classical singularities are predicted to occur at zero size and,
    typically, infinite curvature and density,
    which is certainly
    smaller in size and larger in energy than any quantum scale
    .....

    Steve Carlip


    -----> This post is not directed to Paddoboy to score any point, this is just to put the singularity in right perspective..with the help of kind words by both the professors...Thanks Tashja once again..
     
    Last edited: Jan 17, 2015
  20. RajeshTrivedi Valued Senior Member

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    1,476
    No it is not confined to Planck's area ?? Pl see Prof Abhay response...


    This is not kindergarten language...this is kindergarten understanding level of yours....the BH mass and singularity is not known to spin....spacetime is fine. Tell a physics prof that BH mass spins at singularity, he will go silent on you.


    Yeah !! Change in statement...now the inner part is conveniently takes off. Thats cool, you understood.
     
  21. paddoboy Valued Senior Member

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    21,647
    Let me explain again.....The Schwarzchild limit/radius begins the compulsory stage of gravitational collapse according to GR, which you seem to doubt.
    That refers then to the classical point Singularity of which most physicists and cosmologists do not now accept anyway.
    Because firstly due to the infinities that would naturally surface, like spacetime curvature, and secondly due to GR being limited anyway to just beyond the theoretical Planck scale and quantum level.
    Where theories fail and nothing else is available to explain situations, are also referred to as Singularities.
    Is that clear yet?
    Remember, it is not me questioning your classical Singularity and infinity, it is you questioning the fact that GR fails at the quantum/Planck level, and the inference you have that this Planck scale is something physical, when it is just a conveniant mathematical scale.


    Sure! why not? Always happy to alleviate confusion
    "But perhaps the other side thinks of the singularity as a place
    where, in the real world, classical general relativity fails. This would happen once the curvature becomes Planck scale (much before the classical singularity where it is infinite)"


    The Singularity begins where GR fails and that is at the quantum/Planck region of spacetime, and I'm sure the professor would have no problems with that, which he doesn't and nor did the others.


    The BH's mass/Singularity, and the spacetime that makes up the critical curved nature of the BH is certainly without question spinning in the Kerr metric.
    If it wasn't, we would have no ergosphere. Again, you are being deliberately obtuse.


    No silly, no change in statement. If the BH was not spinning, that is the Singularity [which takes on a ring topology] and the critically curved spacetime, we would have no ergosphere and no Kerr metric.
    Are you from Hollywood by the way?...Or maybe you are part of the Bollywood clan?

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    Now along with the rest of your misconceptions about BH's, this just shows the pretentious nonsense, and misleading you will stoop to to achieve some respectibility in the nonsense you are claiming
     
    Last edited: Jan 17, 2015
  22. paddoboy Valued Senior Member

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    That says it clear enough.
    In other words, if we had no spinning mass, we would have no spinning BH, and no ergosphere/frame dragging, and no Kerr metric.
     
  23. paddoboy Valued Senior Member

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    21,647
    From the man himself...Roy Kerr.
    Now Rajesh you misconstrued it once, see what you get the second time round. Let's see how your pretentious acting ability interpets Kerr's mathematical solution this time round.
    Your first interpretation was given the gong, what have you this time?
     

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