Neutron Star & Black Hole - Some Misconceptions

Discussion in 'Astronomy, Exobiology, & Cosmology' started by The God, Nov 17, 2015.

  1. The God Valued Senior Member

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    This sub forum has substantial amount of pages on Black Holes, lot of issues are debated and many finer aspects get lost in the subsequent noise.

    The idea of this thread is to put forward certain finer points which are misunderstood, As per forum guidelines, copy pastes wherever link can be given should be avoided.

    I am starting with two burning issues, wherein lot of unwarranted bickering has taken place and real point is missed.

    Misconception # 1 : Charge Neutralization of a Black Hole as Electrostatic attraction.

    This should not be misunderstood as the charge - charge interaction between the inside of EH and the opposite charge outside the EH. The clear approach should be that an opposite charge is gravitationally accreted by the BH and in turn charge gets neutralized. It is not as simple as Electrostatic attraction between inners of BH and outside opposite charged particle.

    Prof Hamilton explanation is due to theoretical limitation as no meaningful coulombic interaction can be defined inside the EH from the outside perspective, so he puts forward the Electric Field at EH only which is a theoretical approach, like Gravitational Field at EH and Spin Energy at ErgoSphere.

    The immediate question which one can ask, if the field is at EH only, then when the charged particle is moving towards singularity then it must experience a pull back towards EH, similarly if the charged particle is of the same charge, then this field should act as a firewall. Whether Gravity wins is a different matter.

    Misconception # 2 : Strong Nuclear Force Getting Overcome by Gravity in Neutron Star

    This is an incorrect statement and requires lot of qualifiers.First and foremost the Strong Nuclear Force in the context is considered among P-P, N-N and P-N through some intricate mechanism, the idea of Strong Nuclear Force is derived from one of the facts that why Protons inside nucleus of an atom do not Electrostatically repel each other and disintegrate the nucleus. The nature of strong nuclear force is attractive if the distance between the center of two Nucleons (N - N Or N-P or P-P) is more than 0.8 fm and less than 2.0 fm ( 1 fm = 10^-15 meters) if the distance falls below 0.8 fm, then the force becomes exponentially large and repulsive, that explains the incompressibility of Neutrons lump.

    Prof Bennet Link stated that in Neutron Star we have repulsive Strong Nuclear force, suggesting that the center to center distance between nucleons is less than 0.8 fm...How ?

    1. The density of Neutron Star and observed radius of a 1.4 Solar Mass Neutron Star as around 12-13 Kms, do not support this view that the center to center distance between Neutrons is less than 0.8 fm.

    2. The Equation of state of matter of a Neutron Star is in the realms of speculation only, not correctly known.

    3. If we pull back and talk of formation of a Neutron Star in Supernova explosion then things will become clearer. A star of around 8-25 solar mass, at the fag end of its fusion process, gravitationally starts collapsing, the inner most core becomes all Neutron Due to final electron capture, there is an upper limit to this all Neutron Core size, but the Gravitational collapse continues, so what happens, Neutrons in the inner core are pushed back to the extent that they may be deformed and the center to center distance falls below 0.8 fm, bringing in the repulsive strong nuclear force, this acts as a hard surface, creating a massive shock wave and explosion. It is quite likely that in this process some innermost Neutrons get converrted into Quarks etc (only hypo) but who overcomes whom ? The strong Nuclear Force becomes repulsive and thwarts the Gravity, thus producing the Neutron Star.

    4. The Strong Repuslive Nuclear Force which creates a hard surface at the time of Supernova implosion of a core mass of around 20 Solar. The innermost core of around 1.5-2 Solar Mass Neutrons can throw back with ferocity the remaining 16-18 Solar Mass into debris, and in the same breath we are saying that Gravity of a 1.5 Solar Mass Neutron Star overcomes the Strong Nuclear Force ? Our beloved Arnie pushed back 1 huge Mastodon, but a goat overcame mighty Arnie?



    To be Contd....
     
    Last edited: Nov 17, 2015
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  3. paddoboy Valued Senior Member

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    What forum guidelines?
     
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  5. paddoboy Valued Senior Member

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    A charged BH will be negated over time, simple as that.....
    http://jila.colorado.edu/~ajsh/insidebh/rn.html

    GR dictating that when Schwarzchild radius is reached, further collapse is compulsory, means exactly that...Gravity in the end wins...Total gravitational collapse.
    No misconception at all, as per the many links I have already given supporting the fact that gravity will overcome all other forces.
    Here's another paper:
    http://arxiv.org/pdf/1201.3660.pdf
    At 3:1 it says...........
    A black hole is born: The Oppenheimer-Snyder-Datt model:

    "To understand the final state of collapse for a massive star, we need to trace the time evolution of the system or its dynamical progression using the Einstein equations of gravity. The star shrinks under the force of its own gravity, which comes to dominate other basic interactions of nature such as the weak and strong nuclear forces that typically provided the outwards pressure to balance the pull of gravity".


    Reference?
    Read a few of the links I have supplied in the other thread, or do you need me to reference them again?

    The accepted scenario re BH's and the points already raised are reasonable logical concepts, despite any alternative hypothesis you would like to put.
     
    Last edited: Nov 17, 2015
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  7. paddoboy Valued Senior Member

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    The so called issues you speak of have been discussed time and time and time again. There have been at least 1/2 dozen professional replies among many other references and links, and all have explained these fine points you speak of, but none in the way that suits your agenda.
    So once again, why can you not reference some of the claims you are making?
    Is there something wrong in asking that? You have asked it off me when it suits you, so why can you not offer the same reputable references and/or links supporting your claims?
    Do you expect everyone on this forum should take your word for what you claim? Which raises the other pertinent issue re your credentials.
    What are they? How do you expect others here to accept what you say, when all other recognised experts, references and links, have all disgreed with you.
    Then all we get in return is your usual cop out derision re pop science references, and/or the professionals are just plain wrong...or are not putting it as they should [or as you expect]

    If you want some respect and credibility, you need to supply references to support your claims, and reveal your own credentials so all here can judge fairly
    Ignoring these requests as you have done in all posts, will not see them magically disappear. They are legitimate requests that you need to take heed of.
    The balls in your court.
     
  8. The God Valued Senior Member

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    3,546
    Misconception #3 : That Stellar Black Hole will evaporate

    [Not talking about some weird Micro BHs, possibly could have been formed at or around BB], a stellar BH can only form if the core mass is greater than around 3 solar mass.

    The temperature of a stellar mass BH is around billionth of kelvin much smaller than the CMBR temperature of around 2.7 K in the present epoc. So as long as CMBR T > (BH / HR) T then Halking Radiation at least cannot evaporate the BH, in fact BHs are growing due to CMBR absorption itself (even if nothing else to accrete). So making any claim in this epoc about stellar BH evaporation through HR is vague and incorrect.

    In fact lets extend the argument a bit further, suppose the CMBR goes below HR (T) for a few stellar mass BH in some very very remote future and the rate of emission due to Hawking Radiation becomes higher than the rate of absorption through CMBR, then the mass of BH would start decreasing that means the temperature of BH would start increasing, so sooner or later a stage will come when CMBR (T) = HR (T) thus halting the evaporation. So as long as CMBR has non zero value a stellar mass BH cannot evaporate in any epoc through Hawking Radiation. Anyways we have no calculations or theory about reduction of CMBR T at around billionth of seconds.

    Misconception # 4 : That singularity is somekind of Physical Thing.

    Nope, it is nothing but mathematical anomaly, the calculations fail as the division by zero is encountered in metric equations. It is not a physical thing, like spacetime is not a physical thing.

    The problem is our inability to understand what happens to the matter once it gets inside the Event Horizon and starts collapsing towards what and to what? Thats why all the physical quantities like Electric Field, Gravity, and spin is associated at or on this side of EH.
     
    Last edited: Nov 17, 2015
  9. The God Valued Senior Member

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    There is still some doubts on Misconception # 2, may be below will help further.

    A Neutron Star has an average density of ~ 6x10^14 gm/cm3, similar to the density of atomic nuclei, suggesting that the distance between the two center > 0.8 fm, so there is no posibility of Strong Nuclear Repulsive Force. One must realise that a Neutron Star is a stable structure, and Gravity is in equilibrium with NDP, so there is no question of Gravity overcoming strong nuclear force in a Neutron Star. In fact Strong repulsive Nuclear Force thwarted the Gravity at the time of Supernova implosion as detailed in the OP.
     
    Last edited: Nov 17, 2015
  10. paddoboy Valued Senior Member

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    All BH's will evaporate over time if HR is valid.......It may take a long time, but in the end, poof!.........
    [/quote]
    No one yet has said that the Singularity is physically real, as far as I know.....Do you have any reference or is this another red herring?

    The professionals understand more than you give them credit for, and are logically and reasonably able to assign properties such as spin etc to the BH and even the mass, just as our professional experts have told you, hence the obvious misinterpretations and errors you are making.
     
  11. paddoboy Valued Senior Member

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    Of course not.....Is this another red herring? Who claimed that?
    But when a BH finally forms, the tidal gravitational effects increase to infinity as one approaches the singularity, which effectively means that gravity overcomes all other forces.
    This is general mainstream knowledge based on what we know and GR and as previous references support..


    And again, please support your erroneous claims with citations/links or references please.
     
  12. OnlyMe Valued Senior Member

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    The compressive force on the neutrons associated with gravitational compression, remains greater than the repulsive strong nuclear force.., which leads to the nuetrons being compressed to a density greater than otherwise possible.

    Gravitation overcomes the repulsive strong force.., assumably without degrading the integrity of the individual neutrons.., just packing them into a denser mass.

    I have no idea or opinion as to whether this actually occurs, but it seems a logical explanation of what the professor was suggesting.
     
  13. OnlyMe Valued Senior Member

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    If no one believes that a singularity is real, then any talk about the infinities associated with the singularity are also not real... And they cannot be used as an argument involving how gravity overcomes all other forces.

    You cannot use a theoretical force, which is not believed to exist, to negate any force that is believed to exist. Other than as a thought experiment.., perhaps?
     
  14. paddoboy Valued Senior Member

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    Firstly, why do you not question the experts on that then? Strange.
    Secondly with regards to what I said, once again you have misinterpreted it.
    Note "approaches Singularity", or the region of spacetime where GR and the laws of physics break down, anywhere from the Planck/quantum level onwards.
    To dumb it down even further, the tidal gravitational effects are increasing all the time as one approaches the region where our mathematical singularity reigns, or where our laws of physics and GR do not apply. The tidal gravity effects do not need to be infinite to overcome the strong force.
    And of course as most should realise, while cosmologists do not accept the physical singularity outcome, they do accept the mathematical singularity.
     
    Last edited: Nov 17, 2015
  15. OnlyMe Valued Senior Member

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    Cosmologists don't deal with what is inside of an event horizon and from outside it does not matter whether you model it as a point singularity or a frozen star, as long as the frozen star is inside of the event horizon.

    The infinities and mathematical singularity are the same thing. Gravity does not become infinite before the black hole's mass collapses completely (which is the theoretical end game in solutions to EFE). As long as there is no singularity in reality, there are also no infinities in the gravitational field.

    Whether gravitation actually ever overcomes the repulsive side of the strong nuclear force entirely, cannot be answered by GR and may never be answerable even by QM & QFT.., barring some significant change in our understanding about the fundamental origin of gravitation.

    The point I keep trying to make is that you are very often mixing cosmological conclusions, which do have some observational basis, with theoretical conclusions that not only are not believed to exist in reality, even if they did they could not be observed and confirmed while hiding behind an event horizon.
     
  16. paddoboy Valued Senior Member

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    As we have all been told by various professional experts, cosmologists/theorists are allowed to logically predict what is inside the EH, despite what you may think, and they do so with great skill.
    Yes, and as I have just told you in the previous post, the effects of tidal gravity do not need to reach infinity to overcome the strong force.
    http://arxiv.org/pdf/1201.3660.pdf
    At 3:1 it says...........
    A black hole is born: The Oppenheimer-Snyder-Datt model:

    "To understand the final state of collapse for a massive star, we need to trace the time evolution of the system or its dynamical progression using the Einstein equations of gravity. The star shrinks under the force of its own gravity, which comes to dominate other basic interactions of nature such as the weak and strong nuclear forces that typically provided the outwards pressure to balance the pull of gravity".

    Wrong. GR tells us that once the Schwarzchild radius is reached, further collapse is compulsory.
    The point I keep trying to make with regards to the point you keep trying to make, is that cosmologists/theorists are allowed to logically predict and assume what goes on inside the EH, and most probably with reasonable accuracy.
    And again this was re-enforced in other BH threads that you took part.
    Finally as I so often put to the god, and just as I put to rajesh, if you are unable to accept the existence of BH's based on current evidence, then you need to come up with an alternative that explains the space/time, matter/energy anomalies that we see.
    Best of luck with that.
     
    Last edited: Nov 17, 2015
  17. The God Valued Senior Member

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    If compressive force is more that repulsive nuclear force the collpase would continue, till both are equal.

    What you are suggesting is proposed and there are some papers on the shape of Neutrons in the Neutron Star, and they propose deformation of Neutrons in various shapes including cube type.



    The point which I am trying to make is that a Neutron Star is a stable structure and once it is formed making a statement that Gravity overcomes Strong Nuclear Force in a Neutron Star is bad. In fact opposite is a better statement that till Neutron Star (barring some small hypotheseized Quark Soup in the innermost core which could have formed during the initial push back at the time of Supernova implosion) the Nuclear Strong Repulsive Force dominates the gravity and saves it from collapsing to next stage (a Black Hole?)
     
  18. The God Valued Senior Member

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    Perfectly allright. As far as remote reference away from BH is concerened, even the time dilation is huge (i am not using the term infinity), so there is no means to know what happens inside EH, theoretically a fraction of nano second (dt = 0+)inside EH is equal to eternity on Earth, how do we understand such Physics ? Figure it out Gravitational Field, Spin, Electric Field...all these three properties of a BH are discussed from the EH (or outside EH) perspective, clearly hinting that science is not playing poker with inside of EH.


    Who allows them ? [forget it.]

    Logical predictions based on available data is fine......

    Now please write down one assumption which cosmologists / theorists are allowed to make inside EH. Only one will do.

    And also please tell us...is it logical to say that the mass has been compressed to to a point ? For that matter can you compress anything to a dimensionless point? And also please tell is it reasonably accurate ?


    It cannot be, point is a point, there is nothing logical about mass getting compressed to a point. It is not at all reasonable or accurate to say that density has become infinite. What scientists are logically and reasonably saying that look based on our observation of orbital motion of some stars there is some mass which appears to be inside its own Schwarzchild radius, so as per GR it must be a Black Hole. Scientists are still not clear what is the plight of this mass once inside its own EH.


    If you have any scientific paper to counter my last statement, you are most welcome to refer that. Do not repeat this assumption and reasonable story.
     
  19. paddoboy Valued Senior Member

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  20. paddoboy Valued Senior Member

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    Please Register or Log in to view the hidden image!

    If you have any scientific paper supporting anything you have said please supply it.

    http://arxiv.org/pdf/1201.3660.pdf
    At 3:1 it says...........
    A black hole is born: The Oppenheimer-Snyder-Datt model:

    "To understand the final state of collapse for a massive star, we need to trace the time evolution of the system or its dynamical progression using the Einstein equations of gravity. The star shrinks under the force of its own gravity, which comes to dominate other basic interactions of nature such as the weak and strong nuclear forces that typically provided the outwards pressure to balance the pull of gravity".



    http://jila.colorado.edu/~ajsh/insidebh/intro.html
    """"""""""""""""""""""""""""""""""""

    And there are many many more, but that depends on the state of your behaviour and your continued intellectual dishonesty.
     
  21. Farsight

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    There's some good stuff here.

    paddoboy: listen to The God, he's talking sense. Don't dismiss him because he's saying something that doesn't tie in with some popscience rubbish you've picked up. You'll eventually find out that the popscience rubbish comes from some guy who appeals to Einstein's authority whilst flatly contradicting him. And don't use bold. It's "shouting". It's impolite.
     
  22. paddoboy Valued Senior Member

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    Let's have a look at "the god's" misconception re HBH's as he himself has listed.
    Misconception # 1 : Charge Neutralization of a Black Hole as Electrostatic attraction.
    Obviously, and as usual directed at me.

    Please Register or Log in to view the hidden image!


    What I have said:
    A charged BH, Reisnner-Nordstrom, although probably a rarity, will gradually negate that charge over time. The same applies to any BH spin/angular momentum.
    Although various issues may exist that can cause complications, both spin and charge are negatable.
    This has been supported by reputable links.
    Conclusion: No misconception.

    Misconception # 2 : Strong Nuclear Force Getting Overcome by Gravity in Neutron Star:

    Again, directed at me:
    What I have said.......
    Tidal gravitational effects approach infinity as one approaches the Singularity,
    [Singularity understood as being where GR breaks down.] and will overcome all other forces including the strong nuclear.
    The initial progress of that scenario is called spaghettification.
    This has been supported by reputable links.
    Conclusion: No misconception.

    Misconception #3 : That Stellar Black Hole will evaporate.

    Please Register or Log in to view the hidden image!

    This is a new issue raised by "the god"in an effort to get around him saying that BH's to not have spin negated.
    Irrespective, all BH's will evaporate over time, and again other complications can come into vogue, but the finality is that the BH will evaporate, accepting that HR is valid, which general mainstream cosmology certainly does at this stage.
    Conclusion: No misconception.

    Misconception # 4 : That singularity is somekind of Physical Thing.

    Again, another red herring, since no one to my knowledge has said that the Singularity is a physical thing.
    A mathematical singularity certainly does, and is where our models fail at the Planck/quantum level.
    Conclusion: No misconception, just confusion and a red herring.

    While it is absolutely true that cosmology knows nothing for certain about what goes on inside the EH of a BH, just as logic and reasonable sensibility reign with regards to the isotropic and homogenous nature of the Universe, so to are cosmologists allowed to logically theorise and extend properties inside the EH, based on what is happening outside and the equations of GR. eg: An ergosphere logically infers a spinning BH and spinning mass, along with the ring singularity.
    This has also been supported in at least two other threads by professionals in the game.

    Cosmologists/theorists/physicists in general are hard at work at the coal face and have many state of the art technical advanced equipment supporting them such as Spitzer, Planck, Kepler, and of course ground based equipment.
    To continually dismiss scientific papers and other reputable links with "pop science"or "we just don't know" is no more than an outrageous cop out.
    It's akin to treating knowledgable learned men as Idiots, and coming from a lay person with no training or learning in the cosmological field, makes it twice as bad.
    But that in the end is what forums such as this are all about and the type of character they attract.
     
  23. paddoboy Valued Senior Member

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    Coming from you Farsight and your reputation for pseudoscience, I'll take your criticism as a compliment.
    Oh, and I'm not shouting I'm highlighting.
     

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