BLACK HOLES Tutorial based on observations and GR

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Sep 9, 2015.

  1. brucep Valued Senior Member

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    4,098
    You're a liar and you felt you needed to change your handle for obvious reason. You made a fool of Rajess.
     
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  3. brucep Valued Senior Member

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    You're orbiting the dunce stool. You probably need somebody to balance your checkbook. The likelihood you understand any mathematical concept is slim to none.
     
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  5. James R Just this guy, you know? Staff Member

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    There seems to be some confusion about the Schwarszchild radii of the Sun and Jupiter. The formula for the Schwarzschild radius is:

    \(r_{S} = \frac{2GM}{c^2}\)

    Data:
    \(G=6.67\times 10^-11\)
    \(M_{sun} = 1.99\times 10^30\)
    \(c=3.00\times 10^8\)
    where SI units are understood.

    Plug in the numbers and we find that for the Sun the radius is about 2.9 km, so a black of hole mass equal to the Sun would have diameter 5.8 km.
    You can repeat the calculation for the planet Jupiter if you wish.

    brucep posted all the relevant numbers earlier.
    The God seems to have been pussy-footing around the issue rather than simply posting his own result.

    I hope this clears any remaining confusion.
     
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  7. paddoboy Valued Senior Member

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    I am aware of all that James, that's why all my figures [well there was only one approx 5kms

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    ] are approximations.
    Exactly what I said was.....
    This means that if we squeeze the Sun into a volume of around 5 kms, it would reach its Schwarzchild radius, further collapse would continue and it would become a BH.

    One can only imagine why anyone would make such a song and dance about it.
    [Although I'm fairly sure I know why]
     
  8. paddoboy Valued Senior Member

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    With regards to Jupiter, I said....
    "if you squeeze Jupiter to within a volume of approx 4mtrs, it would "breach" its Schwarzchild radius.

    Otherwise my reference to calculations and figures did not occur.
    I gave approximations which for some reason set off a freight train in my direction!

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  9. The God Valued Senior Member

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    James R
    You missed my post #6 and #37,

    I posted the results as early as Post # 6 for Sun

    My Posr # 6
    "G = 6.67408 × 10-11 m3 kg-1 s-2
    Solar Mass M = 1.9891 × 10^30 kilograms
    Light Speed c = 299 792 458 m / s

    r = 2GM/c^2 = 2.95 km.....well around 3 Kms."

    And Jupiter, I posted in #37, when Paddoboy incorrectly brought in some figure of 4 meters

    My Post #37
    "The Schwarzchild diameter of Jupiter is 5.63 meters not 4 mtr....Refer the formula in my Post #6, mass of jupiter is 1.898*10^27 Kg."


    Hope you will be kind enough to acknowledge.
     
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  10. paddoboy Valued Senior Member

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    21,225
    No once again wrong. I only ever mentioned 2 figures with regards to the Sun and Jupiter and both were approximations. Those approximations stand.
     
  11. paddoboy Valued Senior Member

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    21,225
    Now the god, we have a few facts I have listed about BHs, none the least being that their validity seems certain in the face of no explanation re effects on spacetime and matter/energy.
    You claim BH's are not likely to exist.....you claim you do not adhere to mainstream cosmology, you are reluctant to let us know what credentials you have, and you arrogantly totally refute and deride all links that do not support your anti BH cosmology status.
    And you expect me, and the forum to accept what you say. Perhaps your new handle "the god" has gone to your head.
    You have 11 points to discuss which I stand by at post 47.
    Please have the intestinal fortitude to address them.
     
  12. The God Valued Senior Member

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    3,546

    I will discuss, my dear, whats the hurry. Most of your new points are stupid interpretation of Mainstream stuff, very poorly worded by you.
     
  13. The God Valued Senior Member

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    3,546

    Persistent stupidity. Further embolden by James R's incorrect observation.

    In the light of now established fact that Schwarzschild radius of the Sun is 2.95 Kms, what does 5 Kms approximately refer to? You seem to have silent support of many for reasons best known to them, but I am sure someone else will ask, what is this 5 Kms nonsense and why can you not correct it?
     
  14. OnlyMe Valued Senior Member

    Messages:
    3,914
    The argument is stupid!

    The only issue is the degree of uncertainty in several approximations. Even both Bruce and James presented results that are approximate.

    This being the case it seems there must be some other reason, to argue...

    P.S. No one can give an exact figure for the Schwartzchild radius of a real astronomical body..., the mass begins as an approximation.
     
  15. The God Valued Senior Member

    Messages:
    3,546

    Post # 33 of Paddoboy
    "Your maths has been questioned and shown to be in error in the past, so I'll just stick with my thought experiment of squeezing the Sun into a 5km volume [please note: volume not Schwarzchild radius]"

    Post # 37 of Paddoboy
    "Two points: I never spoke of any Schwarzchild diameter and I don't believe the phrase is used in professional circles very much"

    As per him it is not the diameter, it is not the radius, so please tell me where is he applying this "degree of uncertainty in several approximations" and which other paremeter can be 5 Kms.

    I can tell you one thing, he is devoid of basic decency to correct a small numeral value to 6, he is making contradictory statement after statement to latch on to that 5 Kms without telling what that 5 kms refers to.
     
  16. Daecon Kiwi fruit Valued Senior Member

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    3,048
    Why do you have such a hate-on for Paddoboy?
     
  17. The God Valued Senior Member

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    3,546

    Could you figure out from Paddoboy posts..what is this 5 kms?
     
  18. paddoboy Valued Senior Member

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    21,225
    No hurry, we have discussed many of them before and I showed you the light.
    Interesting to see if you have changed your mind about any of the facts.
    They are all proper interpretations of mainstream cosmology and I have plenty of links to support them.
    You have nothing, zero, zilch...no credentials and no credible links.
     
  19. paddoboy Valued Senior Member

    Messages:
    21,225
    Persistent stupidity certainly on your part.
    My approximations stay as does my tutorial.
    I'll wait for someone that's reputable to ask...otherwise the answer is obvious.
    My approximations stand as is as does my tutorial.
     
  20. Daecon Kiwi fruit Valued Senior Member

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    3,048
    Doesn't explain your obvious vendetta.
     
  21. paddoboy Valued Senior Member

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    21,225
    For those interested in BH's, the tutorial was pretty basic stuff, and I did not touch on aspects that are associated with Kerr metric BH's or the Kerr-Newman, such as ergospheres, [frame dragging] ring singularities, cauchy horizons, and even the hypothetical naked singularity.

    On those aspects, I will need to go to Thorne's book, "Black Holes and Time Warps" or get some reputable stuff off the net.
    Will leave it though for the near future.
     
  22. paddoboy Valued Senior Member

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    21,225
    Here are three excellent papers though for those interested.

    http://arxiv.org/abs/gr-qc/0411060
    The river model of black holes
    Andrew J. S. Hamilton, Jason P. Lisle (JILA, U. Colorado)
    (Submitted on 12 Nov 2004 (v1), last revised 31 Aug 2006 (this version, v2))
    This paper presents an under-appreciated way to conceptualize stationary black holes, which we call the river model. The river model is mathematically sound, yet simple enough that the basic picture can be understood by non-experts. %that can by understood by non-experts. In the river model, space itself flows like a river through a flat background, while objects move through the river according to the rules of special relativity. In a spherical black hole, the river of space falls into the black hole at the Newtonian escape velocity, hitting the speed of light at the horizon. Inside the horizon, the river flows inward faster than light, carrying everything with it. We show that the river model works also for rotating (Kerr-Newman) black holes, though with a surprising twist. As in the spherical case, the river of space can be regarded as moving through a flat background. However, the river does not spiral inward, as one might have anticipated, but rather falls inward with no azimuthal swirl at all. Instead, the river has at each point not only a velocity but also a rotation, or twist. That is, the river has a Lorentz structure, characterized by six numbers (velocity and rotation), not just three (velocity). As an object moves through the river, it changes its velocity and rotation in response to tidal changes in the velocity and twist of the river along its path. An explicit expression is given for the river field, a six-component bivector field that encodes the velocity and twist of the river at each point, and that encapsulates all the properties of a stationary rotating black hole.



    http://arxiv.org/abs/gr-qc/0411061

    Inside charged black holes I. Baryons
    Andrew J. S. Hamilton, Scott E. Pollack (JILA, U. Colorado)
    (Submitted on 12 Nov 2004 (v1), last revised 26 Apr 2005 (this version, v2))
    An extensive investigation is made of the interior structure of self-similar accreting charged black holes. In this, the first of two papers, the black hole is assumed to accrete a charged, electrically conducting, relativistic baryonic fluid. The mass and charge of the black hole are generated self-consistently by the accreted material. The accreted baryonic fluid undergoes one of two possible fates: either it plunges directly to the spacelike singularity at zero radius, or else it drops through the Cauchy horizon. The baryons fall directly to the singularity if the conductivity either exceeds a certain continuum threshold kappa_oo, or else equals one of an infinite spectrum kappa_n of discrete values. Between the discrete values kappa_n, the solution is characterized by the number of times that the baryonic fluid cycles between ingoing and outgoing. If the conductivity is at the continuum threshold kappa_oo, then the solution cycles repeatedly between ingoing and outgoing, displaying a discrete self-similarity reminiscent of that observed in critical collapse. Below the continuum threshold kappa_oo, and except at the discrete values kappa_n, the baryonic fluid drops through the Cauchy horizon, and in this case undergoes a shock, downstream of which the solution terminates at an irregular sonic point where the proper acceleration diverges, and there is no consistent self-similar continuation to zero radius. As far as the solution can be followed inside the Cauchy horizon, the radial direction is timelike. If the radial direction remains timelike to zero radius (which cannot be confirmed because the self-similar solutions terminate), then there is presumably a spacelike singularity at zero radius inside the Cauchy horizon, which is distinctly different from the vacuum solution for a charged black hole.


    http://arxiv.org/abs/gr-qc/0411062

    Inside charged black holes II. Baryons plus dark matter
    Andrew J. S. Hamilton, Scott E. Pollack (JILA, U. Colorado)
    (Submitted on 12 Nov 2004 (v1), last revised 26 Apr 2005 (this version, v2))
    (Abridged) This is the second of two companion papers on the interior structure of self-similar accreting charged black holes. In the first paper, the black hole was allowed to accrete only a single fluid of charged baryons. In this second paper, the black hole is allowed to accrete in addition a neutral fluid of almost non-interacting dark matter. Relativistic streaming between outgoing baryons and ingoing dark matter leads to mass inflation near the inner horizon. When enough dark matter has been accreted that the center of mass frame near the inner horizon is ingoing, then mass inflation ceases and the fluid collapses to a central singularity. A null singularity does not form on the Cauchy horizon. Although the simultaneous presence of ingoing and outgoing fluids near the inner horizon is essential to mass inflation, reducing one or other of the ingoing dark matter or outgoing baryonic streams to a trace relative to the other stream makes mass inflation more extreme, not the other way round as one might naively have expected. Consequently, if the dark matter has a finite cross-section for being absorbed into the baryonic fluid, then the reduction of the amount of ingoing dark matter merely makes inflation more extreme, the interior mass exponentiating more rapidly and to a larger value before mass inflation ceases. However, if the dark matter absorption cross-section is effectively infinite at high collision energy, so that the ingoing dark matter stream disappears completely, then the outgoing baryonic fluid can drop through the Cauchy horizon. In all cases, the solutions do not depend on what happens in the infinite past or future. We discuss in some detail the physical mechanism that drives mass inflation.
     
  23. OnlyMe Valued Senior Member

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    3,914
    In post #3 you seem to have understood the intent behind paddoboy's comment, because you responded as quoted below..,

    You did not begin by asking did you mean radius or diameter? You just said using 3kms would be more prudent... Which would have been an even greater error, than what initially appeared to be an error in using the word volume instead of diameter.., since taken literally it suggests a 3km volume..,

    That seems to be where this stupid argument began, with you focusing on an error in the words chosen, rather than asking or providing clarification. Still you initially seem to have understood his intent, because you just provided a better approximation of what the Schwarzchild radius should be.

    Technically if you accept paddoboy's use of volume instead of diameter, as intentional.., his statement would still be correct, since at a volume of 5 cubic kms, the sun's mass would have been forced into a volume for less than the volume represented by its Schwarzchild radius and it would continue to collapse......, assuming one accepts that is how gravity works at quantum scales which is not yet understood.

    As I said the argument is stupid! And it appears you were arguing just to be challenging paddoboy personally.... And then he responded in kind... Most of the debate in this thread can be reduced to personal.

    This happens far to often these days and inhibits potentially good discussion on what ever subject is raised.
     

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