Neutron Star to Black Hole

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

  1. paddoboy Valued Senior Member

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    It's the "over the top" Farsight like arrogance and dictatorial attitude that makes one laugh so heartedly! Coming from a rank amateur "would be if he could be," supposed self claimed scientist.
     
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  3. RajeshTrivedi Valued Senior Member

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    No one predicts this, thats high school Physics, only Paddoboy may find it knowledge-worthy, did you see how he is goofing up about linear Momentum Conservation in another thread....mercy-fully salvaged by 'OnlyMe' otherwise DMOE had almost demolished him.

    Thats no science, that is pure continued incredulity.

    I had the same doubt, thats why I asked the question in OP, that where does Angular Momentum go, I had in my mind that singularized mass cannot spin, but you responded by a simple "Angular Momentum' conservation response.....without realising the significance of the question. I have understood the theory due to professors response that angular momentum is associated with the spacetime like Rotational Energy, but you are still stuck.........


    Singularity in case of Kerr BH is a Ring Singularity. But assigning any spin to singularity is meaning less. In fact it is pure die hard foolishness to stick to this statement after so many clear guidance by professors.


    By the way, why not answer those two simple questions, which I asked Paddoboy...you are taking the same line as him.
     
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  5. RajeshTrivedi Valued Senior Member

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    Please answer the questions or concede that you are a Troll.....
     
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  7. RajeshTrivedi Valued Senior Member

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    Thats it, Paddoboy......you have again committed Harakiri...self goal. You talk so much of BH, EDP, NDP and know nothing about the mechanism.
     
  8. paddoboy Valued Senior Member

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    27,543

    That's it!!!!!

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    Who do you think you are fooling.?
    As all here have already stated, it is you sonny who continues with the patronising arrogant attitude, coming from someone who has no credentials, no knowledge, refuses to read links, refuses to comment on relevant issues...etc etc It is you who trolls!


    Let me say it again......
    Or better still, let me show what you say.....
    ↑RajeshTrivedi said:
    Moreover spacetime within EH cannot be rotating. Please correct me if my understanding is wrong.

    Now after that little humdinger of a statement, I say it is you who needs to, and must answer questions, and read all links, not just take one sentence from one professor out of context.

    Let me state it again, in no uncertain terms...
    A Kerr BH by definition spins...that's it short and sweet. If you like I will elaborate on that FACT!!!!
     
  9. paddoboy Valued Senior Member

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  10. paddoboy Valued Senior Member

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    Prof. Carlip: Does a Kerr BH singularity spins?
    I don't know what it means to say that a singularity
    "spins." The singularity isn't really part of the
    solution -- it's the place where the equations break
    down. But the Kerr black hole certainly has nonzero
    angular momentum, and this is present arbitrarily close
    to the singularity, in the sense that (for instance)
    frame-dragging takes place arbitrarily close to the singularity.


    There are ambiguities in defining local angular momentum
    in general relativity, but in all of the approaches I
    know of, the spacetime in a finite region arbitrarily
    near to the singularity of the Kerr metric carries angular
    momentum. An observer near the singularity will be
    dragged along an angular direction because of this.

    Steve Carlip
    """""""""""""""""""""""""""""""""""""""""""""


    And a wise statement made by OnlyMe.......
    "Frame-dragging and angular momentum do not begin and end with the ergosphere".
    DO YOU UNDERSTAND WHAT THAT MEANS?
    Or are you saying the EH is some sort of physical surface preventing any angular momentum inside?
    And again, if that were the case, what makes the frame dragging, frame drag?

     
  11. paddoboy Valued Senior Member

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    There certainly is no science in any of the last two threads you have started, just self promoted glory, lies, childish threats and grandstanding about you writing a paper on your pseudoscience nonsense.

    Go ahead, it would be nice to see to see you demolished to use your own language.

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    Or is that just more ranting and raving to impress?
     
  12. OnlyMe Valued Senior Member

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    First when I raised the issue of gravitation vs the strong nuclear force, I was raising an issue that is not addressed by GR or any of its solutions I know of... No one knows anything about mass as it exists inside an event horizon. No one knows whether gravity ever actually overcomes the strong force.

    Singularities are mathematical artifacts of solutions to the EFE, that assume the mass of a black hole is a point mass just as the same equations assume the mass of a planet or star are point masses. If that were the case a singularity would be a logical end point. However, we know that stars and planets are not point masses and we have no logical reason to believe that the mass of a black hole is a point mass either... We do not know the form the mass of a black hole might exist as, because it cannot be observed and measured... That said if it has any significant remaining size, as in it is not a point mass or even near a point mass, the gravitational field described by GR and the solutions being discussed, would be describing the field to a location arbitrarily close to the surface of that mass, just as they do for planets and stars.

    That mass, not being a singularity, in the THEORETICAL sense.., or a point mass, would retain angular momentum as it collapses, to what ever final state it winds up in. And that mass and its angular momentum is the mass that generates the graviationnal field of a black hole.., and any associated frame-dragging of the surrounding spacetime.

    Rajesh, you are.., it seems to me intentionally either ignoring what has been presented by several outside knowledgeable people, tashja has obtained comment from, or you are intentionally trolling the discussion.., or you have become stuck in what I earlier referred to as a naive understanding of the issues being discussed.., or what ever else I do not know.

    While I am at it. You earlier commented on Bruce's knowledge and understanding and while there are obvious conceptual differences in how Bruce and I approach many of these issues, there is no question that Bruce understands both the math and the physics of GR, far better than most.., and certainly far better than anything you have demonstrated, so far.
     
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  13. RajeshTrivedi Valued Senior Member

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    Paddoboy,

    Can you not read the first line of Prof Carlip, when he says I don't know what it means to say that a singularity "spins."

    Still you are stuck with this lollipop that singularity spins.....You are suggesting that Prof Carlip does not know but you know that it spins...then come forward and answer the question at what RPM this singularity is spinning...it is very simple to find out...you know the radius of singularity ring and you know the mass (refer the maths paper I referred) and do the simple conservation math you will get it...but mind you Profs do not do that.


    And after that may be you would like to educate people how Gravity overcomes Nuclear Force ?
     
  14. paddoboy Valued Senior Member

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    27,543
    Still with the kindagarten name calling.... So hard to realise that you have no credentials, and no one is taking any notice of you, isn't it?

    Can you read the last paragraph?

    but in all of the approaches I
    know of, the spacetime in a finite region arbitrarily
    near to the singularity of the Kerr metric carries angular
    momentum. An observer near the singularity will be
    dragged along an angular direction because of this.


    and compare this to your infamous declaration.....

    ↑RajeshTrivedi said:
    Moreover spacetime within EH cannot be rotating. Please correct me if my understanding is wrong.

     
  15. paddoboy Valued Senior Member

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    double post
     
  16. paddoboy Valued Senior Member

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    Never a truer word spoken!
     
  17. RajeshTrivedi Valued Senior Member

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    This is pretty vague and silly....

    there is no reference (not required) about Nuclear Force when we talk about degeneracy beyond and including EDP.....In brief beyond EDP and if the mass is more than 1.44 M, the almost relativistic electrons get captured by protons to form Neutrons and this Neutron Dense Matter again following the Fermi Energy levels on account of Pauli's Exclusion Principle will create a Hydrostatic balance with Gravity, thus forming a Neutron Star, if the core mass is still more (Say > 3 m) then even this process (NDP) will not help to counter the Gravity and BH formation gets into process. So...reference to Nuclear Force is wow !!


    This you should tell your friend Paddoboy, who is shouting over the hill, that singularities are at Plancks level. And secondly possibly a slip on your part, singularities are not at all the solution of any equation. so do not make these loose statements after taking a high position.


    And that mass and its angular momentum is the mass that generates the graviationnal field of a black hole ?????

    What is this ???? Problem with language or you are adding up mass with angular momentum...

    Ignoring this possible slip, all this you should explain to scientific community how a point mass, mathematically termed as singularity, can spin or retain the angular momentum. Can you not see the beauty of Maths/Physics that this momentum is analysed only after associating it with spacetime. You are not able to differentiate the theories between normal planetary or star Frame Dragging vis a vis frame dragging by a Kerr BH. In case of former, energy and angular momentum are assigned to the planet/star directly but in case of Kerr BH the same is associated with the ErgoSphere.

    Elaborate please, If required I will concede and make amends. But by these comments if you are supporting Paddoboy version, then I am sorry you are not making any objective assessment. And by the way tell me what do you think I have understood.

    My stand is very clear that 1. singularity does not spin, 2. singularity is not at Planck's level, and 3. frame dragging has everything to do with angular momentum...why not ask Paddo and Brucep on these three issue and ask them to reply in their language not some copy paste. I have not objected to any of the Profs statement, Paddo is spreading misinformation by making opposite of the above two statement and opposite of the third is attributed to Brucep.


    [/QUOTE]

    Brucep already has one senior advocate, why you now ?

    My concept is very clear that for an 8th standard student, his science teacher is awesome in knowledge, but here the subject involves even the post graduate level and beyond. So if you are making this statement to keep Brucep in good humor, then fine with me, otherwise my above blue colored remark fits well. Just remember that he is sticking to Paddo like stand on two points: Singularity spins and angular momentum plays no role in frame dragging...These statement do not put him in a class which you are advocating.


    By the way please try to answer those two questions which Paddoboy is strenuously avoiding, may be you will know who is trolling and also why not read over the statement of Prof Carlip (first line only) to Paddoboy and then ask him how singularity is spinning and at what angular speed.
     
  18. RajeshTrivedi Valued Senior Member

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    This is your last weapon, Paddo, probably after that you will stop shouting...because you are mixing up this EH term which is used for Rs by me..

    I asked you a question on this thread itself that Schwarzschild radius (Rs) is independent of spinning BH or non spinning BH..That means once inside the Schwarzschild radius not even light can come out....Now please take a particle which is approaching the r = Rs with a substantial speed due to the pull of BH, now if you do the simple high school law of motion, you would get that speed of object will be more than the speed of light by the time it reaches the singularity....(Angular component + Radial Component)....So how do you explain this ?? Answer is there in Physics but I want to know from you whether you are just trolling or know anything at all ? And do not say that particle will be spaggetized.

    Now you have three questions to respond...
     
  19. paddoboy Valued Senior Member

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    27,543

    Still hamming it up Rajesh?
    You said what you said, more than once, along with your silly thoughts on BH densities and the fact that they don't exist.



    No I have nothing to respond too, that wasn't answered a few pages back, but which didn't happen to suit your agenda.

    The rest of your post is you again posturing, pretending and being obtuse.
    Let me say again, Kerr BH's by definition spin....despite your trollish unsupported pretentious claim that they do not.

    As an amateur, you need to read all links and not take people out of context.
    That puts you immediatley behind the eight ball without a cue.
    Have a good night...I have and am now off to bed.





     
  20. tashja Registered Senior Member

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    More replies from the experts!
     
  21. tashja Registered Senior Member

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    One more..

     
  22. OnlyMe Valued Senior Member

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    What are you referring to by EDP and NDP?

    You do understand that GR does not describe the structure of matter in any way, don't you? The singularities that occur in solutions to the Einstein field equations (EFE) are theoretical. They assume only the force of gravitation associated with an unopposed collapse, of an initial mass.

    Reference any significant work that compares the force of gravitation to the strong nuclear force, during the collapse of a gravitationally significant mass.

    You are riding on assumptions that are based on mass, mass density and a gravitational field alone.

    You are correct! Singularities are not a solution, but they do arise in solutions.... Solutions that in some cases predate any real understanding of quantum mechanics (QM) and so do not include any opposing forces associated with the quantum structure of matter.

    From http://en.m.wikipedia.org/wiki/Gravitational_singularity#Curvature
    An example is the Schwarzschild solution .... In coordinate systems ... far away from the black hole, a part of the metric becomes infinite at the event horizon. However, spacetime at the event horizon is regular. The regularity becomes evident when changing to another coordinate system (such as the Kruskal coordinates), where the metric is perfectly smooth. On the other hand, in the center of the black hole, where the metric becomes infinite as well, the solutions suggest a singularity exists.


    Where is there any addition? A rotating mass is described as having angular momentum. When describing any gravitational field associated with a gravitationally significant mass, both its mass and any angular momentum are involved in the field's description.

    You are obviously confused! Kerr black holes are theoretical solutions to Einstein's field equations. And again, they begin with a mass. A mass which has angular momentum. But the solution does not describe the atomic structure of that mass, at any point in the solution. It assumes a point mass, which describes the gravitational field very well.., until the mass density relative to distances from the center of mass, begins to return infinities. At that time it becomes a singularity. Which is not described by any physics, because it represents a location in the field where the physics no longer makes any sense!

    By the way, if the collapsing mass, which we have not described from the context of quantum mechanics, reaches a stable state (configuration), before the theoretical solution to Einstein's field equations reaches the point that it encounters infinities, the gravitational field will be well described right to the surface of that mass and there would then be no singularity. And all of that would occur inside of the event horizon.., where it cannot be observed.

    Only you can demonstrate what you understand, by clearly presenting it. From what you have been posting I cannot tell what you do or do not understand.

    I don't believe that anyone has said that a singularity spins! Though in the case of the Kerr metric it can be thought of as having angular momentum and at least one of Tasha's professors, has said they don't have an issue with people thinking of a singularity in that way.

    Frame-dragging has everything to do with the angular momentum of a gravitationally significant mass and its affect on the spacetime surrounding it.

    Cite your reference! I don't believe the above is even close to anything Bruce has said. If you cannot provide a link that supports your interpretation, a retraction is in order!

    Restate your questions. You keep referring to them, without any restatement or link to the original post.
     
    Last edited: Jan 31, 2015
  23. Farsight

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    3,492
    I'm not troll, I make a good contribution to various threads. For example we had an interesting discussion on this thread about why the light can't get out of a black hole. Professor Tom Moore gave the correct answer:

    "As the planet's mass approaches the black hole limit, the signal emitted from the surface will seem to move more and more slowly away from the surface (and will also be seen to be increasingly red-shifted as observed from infinity). When the surface of the planet coincides with the black hole's event horizon, the signal will stop moving outward from the surface (and the redshift observed at infinity will go to infinity). So light no longer escapes."

    The light is stopped at the event horizon. And since nothing can go faster than light, the black hole isn't spinning. It's that simple. All the stuff you read about point singularities and ring singularities is lost-in-maths nonsense from people who don't understand general relativity, and who have never read Einstein's original papers. They've never read this:

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    They've been taught general relativity from a textbook written by people who thought the speed of light is constant and who believed in time travel, who similarly could not have read Einstein's original papers. The speed of light is spatially variable. It's zero at the event horizon, and it can't go slower than that, so the central point singularity is just a mathematical fiction at future infinity in a never-never land beyond the end of time. So is the ring singularity.
     

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