Singularity Vs Quantum Theory of Gravity

Discussion in 'Astronomy, Exobiology, & Cosmology' started by RajeshTrivedi, Feb 15, 2015.

  1. RajeshTrivedi Valued Senior Member

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    There were two prolonged threads about BH in recent past. After a stage the involvement of the posters was more of scoring brownie points over each other rather than imparting or sharing the true information, but still thanks to Tashja, many professors got chipped in and I am confident that both the threads provided some learning to at least few of the members. I certainly got benefited out of those two threads.

    In those two threads a very interesting point came about, which was even indicated by at least one of the professors who responded through Tashja. The point is "that singularity of BH may get resolved as and when we have a Quantum Theory of Gravity". Although the good professor was very clear and very cautious and indicated his fingers crossed, but two of the posters kept on insisting repeatedly on this point.

    Fine a theory is required to reconcile GR with QM, but how the same will resolve singularity ?? Is it just the blind statement or there is any basis behind this statement ?? My take is that at least QGT (as and when it gets on fully) may not help much in resolving the mechanism inside Event Horizon. There has to be something else which would resolve the BH mechanism inside Event Horizon.
     
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  3. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    Perhaps actually being able to study such a manifestation - "Up Close and Personal" - so to speak.
    Theoretical Physics are just that...Theoretical.
    If and Until scientists are actually able to monitor/examine/experiment on/with such a manifestation in Reality...then there are numerous resolutions/answers/conclusions that will continue to elude Science.
     
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  5. paddoboy Valued Senior Member

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    Yep, I was one of them, and my thoughts have not changed, once we are successful with a validated QGT. And more then one professor was far more positive about a QGT then "cautious" as you insinuate.
    "The singularity in general relativity is not a "thing" so ascribing properties to it is not really a good thing to do - but when we have a better description of gravity, telling us what it is the singular nature of the GR equations are hiding, it will have an angular momentum associated with it".

    Cheers - G

    Prof Geraint F. Lewis,
    Professor of Physics & ARC Future Fellow,
    Sydney Institute for Astronomy,



    My take on it is that we will probably never resolve 100% what is at the Singularity/Quantum/Planck level, or even beyond the EH. But much of what we know at this time can allow us to make reasonable assumptions. And when any future QGT can be validated to any degree by observation, then we will be logically and sensibly able to extrapolate that to BHs and their masses/singularities.
    Of course herein lies the great difficulty. To observationally verify a QGT, we would need to be able to observe at the Planck scale, and even our most powerful accelerators are unable to achieve this goal.
    We actually have QGTs right now...string theory and its many derivitives describe gravity at the quantum/Planck scale but we are unable to verify by observation, although they appear mathematically sound and beautiful.
    String or one of its derivitives could still be the answer....We dont know.

    What our present knowledge does, is allow us to make logical assumptions on regions we are as yet unable to view. Science does that quite a bit.
    We assume our Universe to be isotropic and homegeneous, based on a reasonable large sample size.
    We speculated DM to explain the rotational rates of galaxies. That speculation through the gathering of evidence has grown to be a reasonable scientific theory now.
     
    Last edited: Feb 15, 2015
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  7. paddoboy Valued Senior Member

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    Theoretical physics has been in vogue since Newton.
    1. Theoretical physics is a branch of physicswhich employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimental tools to probe these phenomena.
    2. https://www.google.com.au/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=theoretical physics
    Theoretical physics uses maths to describe possible solutions of scientific problems.
    Who in there right mind would say the Sun does not shine via nuclear fusion?
    Who can doubt the existence of BHs, while observing the catastrophic effects on spacetime and matter/energy that is evident?
    There are no other alternatives for either as yet. And as such, those two best guesses, reign supreme and generally undoubted, especially with the Sun/fusion processes.
     
    Last edited: Feb 15, 2015
  8. paddoboy Valued Senior Member

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    I mentioned in post 3 about string theory and its derivitives.
    Here's an interesting article re LQG, and how using that we are able to eliminate the Singularity......
    http://www.insidescience.org/content/black-hole-cores-may-not-be-infinitely-dense/1020
    extract:
    "This is a clean treatment of what happens inside a black hole, using a quantum theory of gravity," said theoretical physicist Carlo Rovelli at Aix-Marseille University in Marseille, France, who did not take part in this study. "It has long been expected that the singularities in the centers of black holes are cured by quantum gravity, and this is the conclusion that this work supports."

    Theoretical physicists had previously shown that with loop quantum gravity, they could eliminate the singularity that past research suggested existed at the Big Bang. Instead of emerging from a point of infinite density, their work proposed the cosmos was born from a "Big Bounce," expanding outward after a prior universe collapsed.

    "Perhaps in the future it can be shown that all singularities are removed by the theory," Pullin said.

    Just as loop quantum gravity replaced the singularity at the Big Bang with a bridge to another universe, these new findings replace each singularity in black holes with "a bridge to another region in the future of our universe," Pullin said. Although prior studies also suggested black holes harbored such bridges, researchers had believed the singularities in black holes prevented any way of crossing those bridges.

    "I think that this shows that loop quantum gravity is very vital and bubbling, and continues to produce exciting new results and new ideas," Rovelli said.
     
  9. QuarkHead Remedial Math Student Valued Senior Member

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    Sorry to appear rude, but this question makes no sense. Until a coherent theory of quantum gravity emerges, this remains an open question.

    Or to put it smother way, the Big Bang and Black Hole "singularities" must be explicable by a quantum theory of gravity, otherwise such a theory is worthless
     
  10. RajeshTrivedi Valued Senior Member

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    No, its fine, in fact that is the question....on what basis these couple of posters and a prof made a statement that QGT (as and when) will resolve the singularity ? What is that they find in singularity which will get resolved by QGT ?? What is the base for this statement ?


    This need not be the case.
     
  11. tashja Registered Senior Member

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    I now find myself wondering who's the professor you're mentioning lol.
     
  12. RajeshTrivedi Valued Senior Member

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    I will revisit those two threads soon, and get the specifics and will understand the context as well. Paddo, says more than one in post #3, Hope I find at least one.
     
  13. wellwisher Banned Banned

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    • The pseudoscientific content here is inappropriate for the Science sections. Please post to appropriate forums in future.
    The easiest way to resolve the BB singularity is to use the assumption that the speed of light is the ground state of the universe. This can be inferred by matter based force, giving off energy (at C) as potential lowers. Lowering potential transforms matter into C. Also there is a net conversion of mass to energy within our universe; mass burn. If force potential were increasing (C is net absorbed) and energy was net converting to mass (new matter was net constantly forming in the universe), the lowest potential state would be in the direction of matter and inertial. This is not the case, yet we like to use inertial reference as the ground state even though this conflicts with observations; up side down.

    Secondly, although energy moves at the speed of light, energy is not entirely in the C ground state reference, since wavelength and frequency are space-time reference dependent. Energy is sort of half in the C ground state reference, with the other aspect of energy in the inertial reference; frequency/wavelength will change due to matter. The C ground state is not energy but sets a potential with energy via wavelength/frequency attributes.

    Gravity is an artifact of mass and energy, both trying to lower the potential with the C ground state. The clumping of mass into stars is causing the more open space-time reference of the matter to contract in the general direction of a C reference; toward the C reference singularity. The remaining forces of nature, all give off energy, as they lower the potential of matter with the C ground state. These all reflect other ways matter can return to C ; lower potential with the ground state.

    If C is the ground state of the universe, then since infinite wavelength energy has the lowest energy value (as it interacts with matter) these quanta set the lowest potential with the ground state. The red shift due to universal expansion is a way for energy to approach the pure C reference. All roads lead to Rome, while different paths often compete. It is very simple if you use C as the ground state.

    Since mass and energy will clump, due to gravity, so local space-time can contract and approach the C reference, the BB singularity was a step down from the C ground state. Because the BB singularity came from C ground state, instead of approaching the C ground stat from inertial, like a black hole, the potentials are different. The BB contains added potential for the boom, that black holes do not possess; They still have one more step.

    How you make a BB singularity from the C ground state is not too hard. The C ground state is where the fabric of space-time (to use a visual analogy) breaks down into separate threads of space and time. Energy is overlaps the fabric of space-time as well as the C ground state in the gaps of the weave.

    If we break down the fabric into separate threads, in the C ground state, one can move in time without space and move in space without time. This is not an artifact of space-time, which has limits imposed by the potential with the C ground state.

    Below is an approximation of space-time and separated threads of time and space. Space-time is where the weave is balanced, while the extensions of time and space threads are connected to the C ground state, where one move in time without space and space without time.

    The BB singularity occurs where separated threads of time and space meet at a junction. The separated threads of time (potential) and space (potential) due to the ground state continue to overlap space-time (space-time is encompassed by the C ground state) to allow an overlap for other phenomena like entropy, chaos and simultaneity. If we add extra time to space-time we get accelerations; forces.

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    Last edited: Feb 16, 2015
  14. OnlyMe Valued Senior Member

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    Prof. Moore ended a comment in response to one of Farsight's posts with,
    Of course, in some future quantum theory of gravitation, the classical singularity will probably not be a mathematical point, but be "smeared out" in some sense yet to be defined. In such a theory, one might be able to connect the vacuum spacetime to the spacetime inside the source through matching in a similar sense to what one can do with extended objects. Then maybe we can talk about the properties of the source and how it is connected to the properties of the Kerr spacetime in the vacuum around it. But this will not change the fact that we can "mine" the Kerr spacetime for *its* angular momentum and *its* energy. In absence of a quantum theory of gravitation, we cannot say anything about how this mining affects the source.

    Sorry I did not grab the post info, the above was pulled from an off cite note pad that had not been discarded yet, but came from one of your posts.

    There have been other professors who included similar comments suggesting that the issues singularities introduce, might be or will be answered by some future QTG.
     
  15. paddoboy Valued Senior Member

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    Along with Professor Geraint Lewis, and I'm sure a few others.
    I reiterate, it's hard for these professors to reveal all as it should be, as they are not a part of the debate, and the obvious inferences and agendas that some members base their interpretations on.
    They are helpful but are again not privileged to exactly what is going on online.
     
  16. paddoboy Valued Senior Member

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    Simply put in layman's terms, a validated QGT by definition gives us insight and information on the Quantum/Planck scale, which is where the Singularity/mass is thought to be. That may reveal a surface of sorts.....or even even strings.
    This is explained somewhat with links at posts 4 and 5



    If it's not, then what use is it to describe the quantum level of gravity?
    It wouldn't be a QGT.
     
    Last edited: Feb 16, 2015
  17. RajeshTrivedi Valued Senior Member

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    The QGT need not be for exclusively resolving the issue of singularity....resolution of singularity may (or may not) be one aspect of such theory.

    Your present take is somewhat difficult to digest........take for example your stand is that the entire singularity mass is at Planck's Level.......even if we foresee that QGT will link gravity/graviton with the Planck's scale....it is difficult to digest how it will explain presence of such a huge mass at Planck's level....at the best QGT may say that 'quantum of gravity' (or mass or string of Graviton) has certain properties around Plankcs level...this will never say that a 3M (to millions) mass BH entire mass is at Planck's level....Hope you get the point.
     
  18. paddoboy Valued Senior Member

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    I get the point that it is indeed difficult to understand, especially for lay people, but I also get the point that GR tells us that once the Schwarzchild limit/radius is reached, further collapse is compulsory.
    Adding that most physicists of course, see that pulled up prior to reaching the classical point singularity of infinite density and spacetime curvature. That's even more difficult to accept.
     
  19. RajeshTrivedi Valued Senior Member

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    Can you please enlighten which part or formula or Equation or statement of GR...repeat of GR only...tell us this ?

    What is this pull up ?? Can you elaborate, because this is quite a scientific term..I mean what do you think this Pull Up is and by whom ??
     
  20. paddoboy Valued Senior Member

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    Rajesh, you have been informed of this fact before. This fact being that once the Schwarzchild radius/limit is reached, further collapse is compulsory.
    No, I can't point you to the exact formula or equation that shows this, but a nice diversionary tactic!

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    As a lay person, like yourself, I see as far as I do, by standing on the shoulders of giants.

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    Irrespective, I did find some more info for you supporting the compulsory collapse scenario which for some reason you cannot accept.
    Would this have to do with the fact that you believe BHs per se do not exist?
    Anyway see the following.......
    http://hyperphysics.phy-astr.gsu.edu/hbase/astro/blkhol.html
    Black Hole Conditions
    After collapse to the neutron star stage, stars with masses less than 2-3 solar masses should remain neutron stars, gradually radiating away their energy, because there is no known mechanism for further combination, and forces between neutrons prevent further collapse. But this neutron force is the last stand, and our best calculations indicate that this repulsion which prevents collapse cannot withstand the gravity force of masses greater than 2 to 3 solar masses. Such neutron stars would collapse toward zero spatial extent - toward a "singularity". Once they collapsed past a certain radius, the "event horizon", then even light could not escape: black hole. Since black holes by their very definition cannot be directly observed, proving their existence is difficult. The indirect evidence for the black hole Cygnus X-1 is a good example of the search for black holes.
    """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
    and this...........
    http://www.pbs.org/wgbh/nova/blogs/physics/2011/12/the-schwarzschild-radius-natures-breaking-point/

    Really though Rajesh, as this is accepted mainstream BH cosmology, the onus is on you to shown that this "compulsory collapse" once the Schwarzchild limit is reached, is not valid.
    I'll keep checking in to see if you have come up with the necessary evidence.


    I'm sure you know what I mean, and what I'm referring to.
    But let me reiterate again, and which all links and all professors in two threads have agreed upon.
    Most cosmologists do not believe the classical point Singularity will be reached, meaning that it doesn't really exist.
    Since GR breaks down totally at the quantum/Planck level, most believe that a surface of sorts should exist between the Planck/quantum realm, and the point singularity.
    I'm pretty sure that this has also been explained to you.

    Finally, it seems obvious you do not accept the existence of GR type BHs.
    Nothing wrong with that in actual fact, providing you are able to show some other means or some other entity that can affect the mass/energy and spacetime within their vicinity as BHs do.

    I will offer one myself.....the simple basic Newtonian/Michell BH with a surface just below the EH.
    But then one would naturally ask why a near certain theory such as GR, that has passed all tests and observations, should not also hold with regards to BHs and Schwarzchil limits?
     
  21. OnlyMe Valued Senior Member

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    Rajesh, I don't believe you are being honest in starting these threads. It seems to me your only purpose is to question the mainstream consensus as it relates to black holes. You are not asking questions that sound like you are interested in any answer, since it seems you reject all attempts to provide an answer, without any real explanation why.

    Did you honestly want something explained.? Or do you have something to say that others could then straighten out? Or maybe you have already made up your mind and your intent is just to keep argueing the validity of the theory? If this last is the cast, perhaps you should take it to Alternative Theories.

    From where I sit it does not seem that you are really I terested in anything anyone has to offer.
     
  22. RajeshTrivedi Valued Senior Member

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    Paddoboy,

    You made a specific statement that GR predicts compulsory collapse once inside Rs...My repartee was how GR...repeat GR..predicts this ?

    GR describes the gravity as the warping of spacetime around a mass/object...How this warping can predict/make the mass to compulsory collapse ?? In my opinion and as per Physics this collapse is on account of Inward Gravitational Pressure which has no known counter balance mechanism beyond NDP and once the object is inside Rs. So where does GR prediction come into picture ?? Can we not say that once the star falls inside Rs, Newtonian Mechanism makes it compulsorily collapse ?


    You did not clarify this Pull Up yet ??
     
  23. paddoboy Valued Senior Member

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    Once the Schwarzchild radius is reached, further collapse is compulsory.
    You have denied that from day one. That is the issue I am trying to convey.
    I've told you that a dozen times and you will not accept it due to your obvious agenda. The accepted model for BHs is the GR type.
    You now accept compulsory collapse. Good to see.

    Being a nice bloke, I'll add to that with a link. You will accept that won't you?
    http://en.wikipedia.org/wiki/Schwarzschild_radius
    The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the radius of a sphere such that, if all the mass of an object were to be compressed within that sphere, the escape velocity from the surface of the sphere would equal the speed of light. An example of an object where the mass is within its Schwarzschild radius is a black hole. Once astellar remnant collapses below this radius, light cannot escape and the object is no longer directly visible.[1] It is a characteristic radius associated with every quantity of mass.The Schwarzschild radius was named after the German astronomer Karl Schwarzschild who calculated this exact solution for the theory of general relativity in 1916.



    Yes I have. Are you unable to read? Or are you just trolling? Or doesn't my answer fit your anti BH agenda?
    I'll repeat.....
    I'm sure you know what I mean, and what I'm referring to.
    But let me reiterate again, and which all links and all professors in two threads have agreed upon.
    Most cosmologists do not believe the classical point Singularity will be reached, meaning that it doesn't really exist.
    Since GR breaks down totally at the quantum/Planck level, most believe that a surface of sorts should exist between the Planck/quantum realm, and the point singularity.
    I'm pretty sure that this has also been explained to you.

    Finally, it seems obvious you do not accept the existence of GR type BHs.
    Nothing wrong with that in actual fact, providing you are able to show some other means or some other entity that can affect the mass/energy and spacetime within their vicinity as BHs do.

    I will offer one myself.....the simple basic Newtonian/Michell Dark Star with a surface just below the EH.
    But then one would naturally ask why a near certain theory such as GR, that has passed all tests and observations, should not also hold with regards to BHs and Schwarzchild limits?
     
    Last edited: Feb 18, 2015

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