Do black holes really exist in the real world or are they just virtual objects

Discussion in 'Physics & Math' started by pluto2, Oct 30, 2013.

  1. Undefined Banned Banned

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    Hi Paddo, wellwisher!

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    Yes. In a BH 'feature' it's probably an equally exotic phase state(s) of energy-space/energy-matter similar to what exists in Neutron Stars; only more constrained in volume (BUT not, of course, 'infinitely degenerated' and 'compressed to infinite density' zero volume sense

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    ). As you both surmise also.

    Cheers guys!

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  3. Undefined Banned Banned

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    Hi Fednis48.

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    Yes, there's a lot of that sort of 'cross-purpose' discussions going around.

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    I applaud, as always, your impartial clarifications of discussion.

    However, I would advise caution when reading the last paragraph and its introduced assumptions regarding "MICRO black holes" as if they form/exist at all in the first place. As far as I have read the literature (whether Quantum Mechanics, GR/SR, String-/M-Theory), these alleged "MICRO black holes" are purely HYPOTHETICAL 'features' not YET actually observed like the Solar-plus Massed 'Black features' have been. So critique of RJBeery's arguments cannot fairly rely on such HYPOTHETICALS. Yes?

    Anyway, thanks again for your clarification. It was most appreciated, as usual; and I suspect by more than just me, mate!

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  5. RJBeery Natural Philosopher Valued Senior Member

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    Exactly, it's a timelike separation. It is necessarily in the future, and cannot be considered to be simultaneous to our immediate present.
     
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  7. RJBeery Natural Philosopher Valued Senior Member

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    Rather than field a dozen objections, I'm going to make this general comment: I find it hard to believe, almost impossible, that I'm the only person to think what I'm saying. Indeed, a quick search came up with the following paper
    This is identical to my statement earlier:
    This link also mentions collapsars
    ...which is my point earlier (even though I had never read about "collapsars" before):
    When I come up with questions and objections that are explained, great; when I come up with questions and objections that are acknowledged as being unanswered or at least controversial, great; when I come up with questions and objections that are impugned without reason...I get quite frustrated.
     
  8. paddoboy Valued Senior Member

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    Actually we see the effects of a BH as it was in the past, and infer that overwhelmingly it should still be in existence in the present.
    eg: Cygnus X-1 is 6000 L/years away. So we see it [or more correctly its effects] as they were 6000 years ago, and extrapolate that likelyhood to the present day to infer it really exists.
     
  9. RJBeery Natural Philosopher Valued Senior Member

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    Oh, here's another one.
    Compare that to when I wrote:
    Shame on many of you for purporting to hold the truth when it's obvious that this is not settled science.
     
  10. RJBeery Natural Philosopher Valued Senior Member

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    I've laid out my argument for all to see; Fednis is the only one to appreciate it. I personally think przyk gets it as well but perhaps would not admit it.

    So be it, I'm unsubscribing from this [BLANKING] thread. Good luck to you all

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  11. paddoboy Valued Senior Member

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    I have mentioned a few times scientific models and theories are based on observations and experimental results.
    All scientific models can probably be improved on.
    At this time GR BH are overwhelmingly thought to exist.
    If you dispute that, you need to exlain what causes the effects on matter and space/time we observe in a BHs vicinity, and come up with a better model.

    ps:
    You now appear to be scraping the bottom of the barrel.
     
  12. paddoboy Valued Senior Member

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    You have laid out some science, muddled with a heap of philosophical musings.
     
  13. Tach Banned Banned

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  14. Russ_Watters Not a Trump supporter... Valued Senior Member

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    This is perhaps what is most frustrating to both of us: as far as I can tell, no one is disagreeing with you on the basic principle that an outside observer never sees something fall through the event horizon! It's your fixation that that requires rejection of the name and the word "exist" that is the contention. Your argument tends to reduce to linguistics:
    No one is trying to refute the logic that we never see an object cross the event horizon. The point is simply that a rose by any other name still exists. Black holes exist even if the leading theory about how they operate is wrong.
     
  15. Undefined Banned Banned

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    It has often been tried, using that very same line of reality reasoning you put there, to point out that a Universal "NOW" does exist, even though the SR 'take' on it does not actually cover that 'external reality' irrespective of theoretical constructs which 'deny' the reality validity of universal "NOW" because of abstract modeling 'results' of the postulates FOR that abstract construct.

    So, like you say, reality exists whether we use 'correct' or 'incorrect' theories and hypotheses to argue over what is essentially already agreed to BE the external reality.

    So either Black holes 'exist' as much as Universal Now 'exists'. Or both 'do not yet exist'? Yes?

    One can't have it both ways; by arbitrarily choosing when to apply that external reality line of reasoning as the final arbiter of reality 'argument' like you just did for the 'existence' of Black holes. Yes?

    That is what your argument is based on, the fact that reality IS what it is, irrespective of theoretically 'excluding' it in some 'incomplete abstraction' OF that reality. Yes?

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  16. brucep Valued Senior Member

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    ?. Probably most things that happen in the universe are not simultaneous to 'our immediate present'. Whatever that means. A simple explanation of a timelike event would be all the information associated with the event would be found in our lightcone.
     
  17. brucep Valued Senior Member

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    So be it.
     
  18. przyk squishy Valued Senior Member

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    Identical? Hardly. The article you linked to[sup]*[/sup] speculates that a singularity and event horizon might not form if it happens that the collapsing mass radiates away quickly enough that it never reaches the critical density necessary to form a black hole.

    You, by contrast, claim that the singularity and event horizon logically cannot form, based largely on a false premise (that black holes are entirely contained in the causal future of any outside observer, which as I keep stating and you keep ignoring, simply isn't true). Not only is your conclusion wholly unjustified, but the same ArXiv article includes an illustration of how the process might occur as their Figure 8.

    Do black holes, complete with singularity and event horizon, really exist in nature? I don't know, and as far as I know there isn't any basis for anyone to know the answer to that. But that's as far as it goes: our understanding of black hole formation, when quantum radiative effects are taken into account, isn't very developed at the moment and the knowledge gap is large enough that it can accommodate the possibility that things might end up working out in such a way that the singularity never forms. It is by no means a necessity, and you are certainly not vindicated for having drawn conclusions like this:

    Whether or not it turns out that black holes exist in nature, it won't change the fact that your arguments against them range from thoroughly unconvincing at best to fallacious at worst.


    In other words, we can look forward to you trying to argue the same things based on the same shaky reasoning here again in the future.


    [sup]*[/sup]By the way, when linking to ArXiv articles, consider linking to the abstract page rather than directly to the PDF.
     
  19. brucep Valued Senior Member

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    The 'here's another one' is an advertisement for the paper you posted earlier. Which is another evaluation of the information loss problem. They specifically use the Schwarzschild time coordinate so the outside observer never predicts a black hole formed. They want to evaluate the path of information for the possible spacetime event 'black hole forms->black hole evolves->black hole evaporates'. Everything is evaluated from Schwarzschild coordinates so it's possible that the black hole event horizon never forms with respect to these coordinates since it's a dynamic process to start with. So you get predictions like the event horizon never actually forms and that's why no information is lost or like the Hawking prediction that it doesn't matter because the manifold [universe] is black hole free in the beginning and black hole free again in the distant future. They form and evaporate never to be detected from remote coordinates. Change coordinates if you don't want to deal with a problem like that. Doesn't say anything conclusive about black holes not existing. If it did then it would represent irrelevant science since we get to include the experimental side before we jump to 'frame dependent conclusions'.
     
  20. brucep Valued Senior Member

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    I might even look at the citations before I decide to read the paper. More interested in reading this one by Matt Visser
    Black holes in general relativity
    http://arxiv.org/abs/0901.4365

    Introduction reads like a deja vu of this thread.
    "What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?
     
  21. wellwisher Banned Banned

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    If you were sitting on a black hole within its reference, since space-time is so contracted, wouldn't the universe appear to be smaller compared to what we see in our earth reference? If the laws of physics, such as gravity, are the same in all references, doesn't this amplify the impact of black hole gravity on the universe at least from its POV. (smaller size means stronger gravity).

    Fr example we see the size of the universe as 15 billion light years in size. Since the black hole's space-time references is so contracted, doesn't it sees the same universe as being much smaller, say 1 light year in size ( to use a number). Since the law of physics are the same in all references, if we were in the black hole reference and did a universe gravity calculations based on the universe we see, gravity would appear stronger universe wide, due to the perceived smaller size of the universe.

    To get a true reading of the gravity in the universe, don't we have to average what all the various space-time references see with black holes having more long term impact on the universal gravity average, since they all see a much smaller universe where gravity becomes dominant if you did the math in that reference?
     
  22. paddoboy Valued Senior Member

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    If I'm reading you right and you are asking about what the Universe would look like if you were at/very near the EH, looking back outwards away from the EH, then yes, what you say is probably correct.
    Your view of the Universe would be more and more contained into a sphere just above your head........Inevitably from that point, as you fall towards the EH, the image of the sky above concentrates into a smaller and smaller circular sphere, until you cross the EH to your doom.
    NB: Your view of the outside Universe would not disappear once you cross the EH, but would be even further concentrated into a smaller sphere.
    Besides the gravitational lensing effects of your view looking outwards, other relativistic effects would distort what you see, as you reach "c"".

    What would you see looking towards the Singularity???? Not a damn thing, as space/time is falling faster than "c" towards the Singularity, and nothing, other than nothing can ever move outwards.
     
  23. pluto2 Banned Valued Senior Member

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    I can't speak for gravity and black holes but I think that psychology is more important than physics. The reason I think that is because science, and this includes physics, would not be able to function without human consciousness (by human consciousness I mean human thought) behind it.

    When ever you run an experiment you check your equipment. But do you check your mind and how you fit the pieces together? A lot of flawed science has come out of engaging in various biases. Some of those biases are very subtle if you have no awareness of them and how you are coloured by them. A lot of peoples own issues and difficulties with life also come a lot from those sorts of biases.
     

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