QM + GR = black holes cannot exist

Discussion in 'Physics & Math' started by RJBeery, Sep 24, 2014.

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  1. PhysBang Valued Senior Member

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    Of course you do. You can't do a physics problem, you haven't read through the science of your supposed holy idol, Einstein, but you have dogma.
    But it is your idea that the frozen star interpretation is equivalent to the Schwarschild solution and that this is the one true holy solution to the Einstein field equation (although you seem to gloss over the non-physicality of the solution).
    That much is obvious.
    I would prefer it if you could, just once, show how your physics works in an example. That would first require you to learn physics.
     
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  3. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Simple: lead is heavy.

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  5. nimbus Registered Senior Member

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    I wonder what Einstein would have thought of the Kruskal-Szekeres coordinates?
    After all, he agreed with Schwarzschild's solution to the Einstein field equations.


    Tashja, sorry about misspelling your name above..too late to edit that post now.
     
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  7. paddoboy Valued Senior Member

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    Quite unbelievably amazing the extent some people will go to to promote an Image that they know what they are talking about, when clearly no one is actualy listening.

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    How many copies did this "book of fairy tales" sell?
     
  8. Farsight

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    I don't think he would have liked them at all. He said light curves because the speed of light varies with position, which Don Koks agrees with. And we've already had Prof Moore and others say light doesn't get out because at the event horizon, the speed of light is zero. The speed of light can't go any lower than that. And if light doesn't move, you have no coordinate system.
     
  9. Farsight

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    I've done it already. See this thread. The missing image is this one:

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  10. paddoboy Valued Senior Member

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    No, wrong in all respects.
    You, as usual, have taken much out of context to reflect your own misgivings.
    [1] Light follows geodesics.
    [2] The speed of light, "c" is constant.
    [3] Time is never seen to stop, from any FoR.
    [4] Light does not get out of a BH simply because the critical nature of spacetime curvature inside the EH, has an escape velocity that exceeds "c ".
    In fact once inside the EH, all paths lead to the Singularity.
    Just as a fish swimming at 10kms/hr upstream in a river that is flowing at 20kms/hr downstream, will never make any head way.
    To illustrate that point further with that same analogy, if the fish was swimming at 10kms/hr upstream, and the river was flowing downstream at 10kms/hr, then from the PoV of an observer on the bank, the fish would seem to be stationary in one place.
    [5] Light emitted just on the EH of the BH directly radially away, will be like the fish swimming upstream at 10kms/hr against the rivers flow of 10kms/hr.
    The river's flow, is analogious to spacetime falling into the BH.
     
    Last edited: Nov 3, 2014
  11. paddoboy Valued Senior Member

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    With point [3] Anyone falling into a BH from a distant remote FoR, will be gradually redshifted further and further up the spectrum, until disappearing from the viewing capacity of the instruments used. He/she will never be seen to cross the EH.
    From the FoR of the person falling into the BH, he will proceed as per normal, with time proceeding normally as he crosses the EH into oblivion.
     
  12. krash661 [MK6] transitioning scifi to reality Valued Senior Member

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  13. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    The speed of light is a constant.
     
  14. Farsight

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    See Don Kok's response to tashja:

    "Many people maintain that light only ever moves at c. Not so. If you measure the speed of light that is right next to you, you'll always find it to move at c. Light that is not right next to you won't move at c if you're accelerating and using the coordinates that are completely natural to your accelerated frame. But how can you measure its speed if it's not right next to you? You do that through the standard mechanism, mentioned above, of employing a lattice of observers whose clocks always agree with yours, and who don't move relative to you. You then use the measurement of the observer who was right next to the light whose speed you wanted to measure..."

    Along with Tom Moore's reply:

    "An observer at rest relative to the star will always measure the outgoing light signal to have speed c *locally,* (that is, as the flash passes through a laboratory that is very small compared to scale over which spacetime is locally curved), but to talk about the speed of a signal emerging from the planet's surface and going all the way to infinity, one needs a *global* coordinate system (one that applies at all positions in spacetime, such as the Schwarzschild coordinate system) to talk about the signal's speed at various points. An observer using such a coordinate system will find that the light flash will move *slower* than c close to the planet's surface than it does at infinity..."
     
  15. krash661 [MK6] transitioning scifi to reality Valued Senior Member

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    some things are not right about your post above farsight.
    and you know what they are.
    don't you ?
    " intentional dishonesty "
    (shakes head)
     
  16. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Did you read your first two sentences?
     
  17. PhysBang Valued Senior Member

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    This is not a good question to ask Farsight. As he proved, it is one he can just say that he answered already. He just has super low standards for an explanation: if it is written by Farsight, then it is an explanation.

    What is beyond question is that Farsight has not tied his explanation to doing the physics of describing the fall of a pencil (or the fall of anything towards a black hole) with any mathematical details that we could ever compare to observations of physical systems. It is extremely likely that Farsight lacks the ability to do this.

    Not exactly. Koks pointed out that at any position, the speed of light is always the same; it is only when we are considering the speed of light over distances that the speed of light changes, and then the change is particular to the path that we consider light to take. Which is exactly the same thing that Einstein wrote into GR. Someone fixated on a single thing that Einstein wrote and ignorant of his work could hold the belief that the foundation of GR was simply that the universe is a 3D space with an entirely separate time dimension and that because of the scalar change in light in various places this produces certain relativistic phenomena. Of course, this is the opposite of what Koks wrote and the opposite of what Einstein wrote, both in his science and various other sources.

    This, of course, is more of the dishonest cherry-picking that one expects from Farsight.

    Again, a position against Einstein. In GR, Einstein clearly doesn't require the same stringent limitations on clocks and coordinate systems that he put into GR. Someone fixated on a single thing that Einstein wrote and ignorant of his work could hold the belief that the foundation of GR was holding to the same restrictions on coordinate systems introduced by special relativity. Of course, then one would miss entirely the use of the words "general" and "special" in the respective theories.
     
  18. Neddy Bate Valued Senior Member

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    I think it is the third sentence that he needs to consider more deeply:

    "If you measure the speed of light that is right next to you, you'll always find it to move at c."


    I'd say that throws a spanner into his whole "light stops" idea.
     
  19. Farsight

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    Huh? You have got to be kidding. I just quoted two of the physicists who have been good enough to respond to tashja's emails.

    No way. Here's another excerpt from Don Kok's response:

    "Now use the Equivalence Principle to infer that in the room you are sitting in right now on Earth, where real gravity is present and you aren't really accelerating (we'll neglect Earth's rotation!), light and time must behave in the same way to a high approximation: light speeds up as it ascends from floor to ceiling (it doesn't slow down, as apparently quoted on your discussion site), and it slows down as it descends from ceiling to floor; it's not like a ball that slows on the way up and goes faster on the way down. Light travels faster near the ceiling than near the floor. But where -you- are, you always measure it to travel at c, because no matter where you place yourself, the mechanism that runs the clock you're using to measure the light's speed will speed up or slow down precisely in step with what the light is doing. If you're fixed to the ceiling, you measure light that is right next to you to travel at c. And if you're fixed to the floor, you measure light that is right next to you to travel at c. But if you are on the floor, you maintain that light travels faster than c near the ceiling. And if you're on the ceiling, you maintain that light travels slower than c near the floor..."

    What's dishonest is to try and dismiss what people actually said as "cherry-picking". I will reiterate that Einstein said light curves because the speed of light varies with position, which Don Koks agrees with:

    "You can also infer that as a distant wavefront travels transversely to your "up" direction, the more distant parts of it will be travelling faster than the nearer parts. So, just as light bends when it enters glass at an angle, you won't be surprised to see the distant light bend toward you..."


    Have you even read the various replies? See Don Kok's reply and pay attention to this bit:

    "because no matter where you place yourself, the mechanism that runs the clock you're using to measure the light's speed will speed up or slow down precisely in step with what the light is doing..."

    And note this Baez article by Don Koks where you can read this:

    "Einstein talked about the speed of light changing in his new theory. In his 1920 book "Relativity: the special and general theory" he wrote: "... according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [...] cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity [Einstein means speed here] of propagation of light varies with position." This difference in speeds is precisely that referred to above by ceiling and floor observers..."

    The variable speed of light is not in doubt. It was Einstein's idea. The issue is what that means for a black hole. Moore and others agree with me on the "light stops" thing. Don Koks doesn't. Not yet at least.
     
  20. paddoboy Valued Senior Member

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    The speed of light is constant, and I don't believe anyone yet has agreed with you in totality at all.
    That and your obvious expertise at quote mining, and misinterpretations, leaves your claims in doubt.
     
  21. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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  22. paddoboy Valued Senior Member

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    Some quotes......
    "No, even with perfect instrumentation you cannot observe them forever.
    There is a ³last photon² that they emit/reflect before crossing the
    horizon. After that, there is no signal to detect. The same is true of a
    star that collapses to form a BH. This is a good in-practice
    observational definition of ³when the BH forms² .

    Don Marolf

    """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

    Prof. Moore:

    This is a good example of how intuitive models can go astray.

    The argument presumes that the light signal does not "slow down," but what exactly does that mean? An observer at rest relative to the star will always measure the outgoing light signal to have speed c *locally,* (that is, as the flash passes through a laboratory that is very small compared to scale over which spacetime is locally curved), but to talk about the speed of a signal emerging from the planet's surface and going all the way to infinity, one needs a *global* coordinate system (one that applies at all positions in spacetime, such as the Schwarzschild coordinate system) to talk about the signal's speed at various points. An observer using such a coordinate system will find that the light flash will move *slower* than c close to the planet's surface than it does at at infinity. This does not contradict the previous results, because time runs more slowly for observers close to the planet's surface than for those higher up, so what looks like something moving with speed c to an observer close to the surface looks like something moving slower to someone whose clock is running faster.

    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.

    This also does not contradict the statement about an observer at rest on the surface seeing the signal to have speed c, because as event horizon moves beyond the planet's surface, that surface can no longer remain at rest, but in fact must go to r = 0 in a finite time (as measured by an observer on the surface), just as surely as the past must go towards the future. Even then, an observer on the surface will *still* see the light moving outward at speed c, but from the perspective of the global coordinate system, it is simply that the observer is falling faster toward r = 0 than the signal is.

    To understand all this fully, I strongly recommend that the questioner take a course in general relativity!


    Best wishes, Tom M.


     
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  23. Farsight

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    There's no doubt about it. Have you even read what you yourself quoted above from Tom Moore's response?

    "An observer using such a coordinate system will find that the light flash will move *slower* than c close to the planet's surface than it does at at infinity...

    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..."

    What are you going to say next? That the speed of light is constant, and I'm just quote mining and therefore should be ignored? Then doubtless you'll be telling us again that space is falling down into the Earth or into the Sun or into a black hole.
     
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