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Thread: Black Hole Paradox

  1. #1 Black Hole Paradox 
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    Quote Originally Posted by Wiki
    The black hole Information Paradox results from the combination of quantum mechanics and general relativity. It suggests that physical information could "disappear" in a black hole. It is a contentious subject since it violates a commonly assumed tenet of science—that information cannot be destroyed. If it is true, then cause and effect become unrelated, and nothing science knows, not even our memories, can be trusted.
    Basically, I don't understand anything What information are we talking about, and why is it a problem that this information is lost? I guess the "No hair theorem" also goes under this, which is also something I'm not that familiar with.

    Anyone care to enlighten me? (If possible?)

    I suspect there's a whole lot of other things I need to understand in order to understand this, correct? Then what is it I need to know more about?


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    You know the wierd thing is that I stunmbled across that the other day and never knew about it before. Maybe some unknown force is trying to get someone to understand it :|. I need to read the other parts like the 'no hair theorem', quantum states and Liouvelles theorem. I don't get it.

    I think the principle of this paradox is that it comes from energy creation/destruction, perhaps if we use that instead of information it is easier to understand, because information after all is what? Energy.


    "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
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  4. #3  
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    I think when they say information they mean mass or a particle that isn't able to be destroyed. When mass enters a black hole it doesn't come out, it gets destroyed somehow.
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    Quote Originally Posted by 425 Chaotic Requisition
    You know the wierd thing is that I stunmbled across that the other day and never knew about it before. Maybe some unknown force is trying to get someone to understand it :|. I need to read the other parts like the 'no hair theorem', quantum states and Liouvelles theorem. I don't get it.

    I think the principle of this paradox is that it comes from energy creation/destruction, perhaps if we use that instead of information it is easier to understand, because information after all is what? Energy.
    I was thinking along similar lines.

    There's also a lot of complicated things going under this which I don't understand. Apparently, one of the laws of physics says that energy cannot be created nor destroyed, so that is why it is called the black hole information(/energy) paradox. But what makes us think that it gets destroyed, what evidence or mathematical formulation states that it gets destroyed, and why?

    Quote Originally Posted by BumFluff
    I think when they say information they mean mass or a particle that isn't able to be destroyed. When mass enters a black hole it doesn't come out, it gets destroyed somehow.
    But doesn't the information/energy get compressed into a singularity or something? Would that make black holes "containers" of some sort?
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    Quote Originally Posted by Obviously
    But doesn't the information/energy get compressed into a singularity or something? Would that make black holes "containers" of some sort?
    I don't think anyone really knows what happens to matter or energy when it enters a black hole as every other forum I've discussed this on has various theories as to what occurs. Some even think that anything that falls into a black hole will never actually reach the event horizon as time slows down and comes to practically a complete standstill before it even reaches it. If this is true then most likely the matter would just pass through the black hole after it becomes non existent.

    I've even posted my own crazy theories as to what happens ot matter after it enters a black hole. At one time I believed as you do that the matter just gets enveloped in the singularity itself but why then does a black hole lose mass as it ages? (As Steven Hawking thinks.) Another crazy idea I had was perhaps a black hole isn't really matter at all but dark matter. Dark matter has a gravitational effect on energy and mass around it so perhaps a black hole is merely a large collection of dark matter that tranforms the material it draws in to either dark matter or dark energy.
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    Quote Originally Posted by BumFluff
    I don't think anyone really knows what happens to matter or energy when it enters a black hole as every other forum I've discussed this on has various theories as to what occurs. Some even think that anything that falls into a black hole will never actually reach the event horizon as time slows down and comes to practically a complete standstill before it even reaches it. If this is true then most likely the matter would just pass through the black hole after it becomes non existent.
    Hmm... What's the temprature in a black hole? Near absolute zero, light itself stops up. I don't know if this is relevant or not though...

    Quote Originally Posted by BumFluff
    I've even posted my own crazy theories as to what happens ot matter after it enters a black hole. At one time I believed as you do that the matter just gets enveloped in the singularity itself but why then does a black hole lose mass as it ages? (As Steven Hawking thinks.) Another crazy idea I had was perhaps a black hole isn't really matter at all but dark matter. Dark matter has a gravitational effect on energy and mass around it so perhaps a black hole is merely a large collection of dark matter that tranforms the material it draws in to either dark matter or dark energy.
    Doesn't dark matter have more mass than visable matter? :?
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    Quote Originally Posted by Obviously
    Doesn't dark matter have more mass than visable matter? :?
    I have no idea as I'm only on the second chapter of the book I'm reading and I've never really looked into it in the past.
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  9. #8  
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    Is there a limit to how much matter a black hole can consume?
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    Quote Originally Posted by Obviously
    Is there a limit to how much matter a black hole can consume?
    I highly doubt it, if it actually does consume matter. If it did my belief is that it would continue to get more massive and more powerful until the forces behind it ceased. But thats just a guess on my part.
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  11. #10  
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    So I've been skimming halfway through the wikipedia article on black holes (I've come as far as Formation and Evaporation to be exact) and have become a little wiser

    It appears that the problem arises at the singularity in the event horizon, that's where nobody knows what happens. General relativity predicts a singularity in a non-rotating black hole, which has zero length, width, and heigh, but according to quantum mechanics, objects aren't allowed to have no size. On the other hand, the singularity is described as an infinitely small and dense point, and if it's infinitely small, it doesn't mean it has no size. This is something I don't understand. Why is it a problem when it's infinitely small?

    As for rotating black holes, their singularity is... Ah, I'll just quote wikipedia:

    Quote Originally Posted by Wiki
    General relativity predicts that a rotating black hole will have a ring singularity which lies in the plane of the "equator" and has zero width and thickness—but remember that quantum mechanics does not allow objects to have zero size in any dimension (their wavefunction must spread), so general relativity's prediction is only the best idea we have until someone devises a theory that combines general relativity and quantum mechanics.
    Does inifinitely small mean it has no size? I just don't understand why quantum mechanics doesn't allow there to be a singularity...

    How weird, by the way, that this is my #666 post
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    Quote Originally Posted by Obviously
    I just don't understand why quantum mechanics doesn't allow there to be a singularity...
    Wavefunction can't spread? Violates Uncertainty Principle? We would know exact position and momentum> Etc etc et c?
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    Quote Originally Posted by sunshinewarrio
    Quote Originally Posted by Obviously
    I just don't understand why quantum mechanics doesn't allow there to be a singularity...
    Wavefunction can't spread? Violates Uncertainty Principle? We would know exact position and momentum> Etc etc et c?
    I'm sorry. I have an extreme lack of knowledge within this subject (which is part of the reason why I'm so interested in it). I'll definitely take a closer look at the things you mentioned. Perhaps you could explain them to me
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  14. #13  
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    Quote Originally Posted by Obviously
    Quote Originally Posted by sunshinewarrio
    Quote Originally Posted by Obviously
    I just don't understand why quantum mechanics doesn't allow there to be a singularity...
    Wavefunction can't spread? Violates Uncertainty Principle? We would know exact position and momentum> Etc etc et c?
    I'm sorry. I have an extreme lack of knowledge within this subject (which is part of the reason why I'm so interested in it). I'll definitely take a closer look at the things you mentioned. Perhaps you could explain them to me
    Fundamental principle of Quantum thingname is Heisenberg's Uncertainty Principle - ie the position and momentum of a particle can be known to only a certain degree of accuracy (related to Planck's Constant), and the more accurately you know one, the greater the inaccuracy in your knowledge of the other.

    As a result of this (well, not exactly, but it's a good starting point), all particles in motion are described using their 'wave function' which is basically a function describing the probability of that particle interacting (with an observer, say, to let in all the old Copenhagen mystics) at any particular place and time in the universe.

    The wave function for an electron, for instance, can be a fuzzy spherical shell around the nucleus, or even a dumbbell shaped one, or something else.

    If this probability wave function did not exist for a particle, if there were no fuzziness, it would violate the Uncertainty Principle.

    If a singularity existed, its momentum and position could be (I'm presuming) accurately observed/calculated without any fuzziness. This would violate the Uncertainty Principle and hence cannot be allowed by quantum Physics.

    General Relativity has no such restrictions, and it is Relativity that helps calculate the structures of Black Holes. At some stage, though, the scientists know they will have to reconcile all this with Quantum Theory (possibly in some TOE or GUT), and at that time we will have to figure out a way to resolve the issue of Relativity, and gravitational theory, predicting a body of infinite density, and Quantum Physics disallowing it.

    That, at least, is how I interpreted that Wiki statement.

    And I've pushed far beyond the boundaries of my reliable knowledge, so much of this may be speculative poppycock...

    Edited for typos.
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  15. #14  
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    Ooh, good thread! :P

    Quote Originally Posted by Obviously
    Apparently, one of the laws of physics says that energy cannot be created nor destroyed, so that is why it is called the black hole information(/energy) paradox. But what makes us think that it gets destroyed, what evidence or mathematical formulation states that it gets destroyed, and why?
    Destroyed is more of a general term. If we assume that all the "information" gets taken into the black-hole, then it could be said that for all intents and purposes it is gone. However, that's not something that is known for certain.

    Unlike matter we see in regular instances (such as stars) which gets broken down and recycled continually, it seems matter that enters a black-hole never gets recycled back into the universe.

    There's also the concern in the changes in mass that black-holes inexplicably experience. If 3 tons of matter go in, and later the black-hole shows as being only 2 tons in mass, is something missing? And if so, does that indicate that the matter was destroyed?

    Quote Originally Posted by Obviously
    But doesn't the information/energy get compressed into a singularity or something?
    Kinda. The matter doesn't doesn't get turned into a singularity, it becomes part of it, kinda like making a snowball from snow.

    Quote Originally Posted by Obviously
    Would that make black holes "containers" of some sort?
    Yes, although it is that very concept that causes a lot of problems.

    For starters, what is the nature of matter that is essentially trapped in a black-hole? Second do black-holes actually trap matter, or can the matter get out?

    Quote Originally Posted by BumFluff
    Some even think that anything that falls into a black hole will never actually reach the event horizon as time slows down and comes to practically a complete standstill before it even reaches it. If this is true then most likely the matter would just pass through the black hole after it becomes non existent.
    Most people think that a black hole consists of a simple point of no return boundary (event horizon). Black-holes are far more complex than that. A single event horizon exists only in a black-hole which isn't spinning, known as a Schwarzschild Black Hole.

    Given current theories behind black-hole creation, it's unlikely that any Schwarzschild black-holes exist. Instead, black-holes are considered to be spinning or rotating entities, which are commonly known as Kerr Black Holes.

    In a rotating black-hole, things get more complex. You end up with more than one event horizon, and the space inbetween is almost as great a topic in black-holes as the interior of the singularity itself.

    Quote Originally Posted by Obviously
    Hmm... What's the temprature in a black hole? Near absolute zero, light itself stops up. I don't know if this is relevant or not though...
    It's believed that due to the speeds of the matter traveling around the black-hole, that the event horizon is extremely hot. As for the inside of the black-hole, no one knows, since in order to get a temperature we would have to receive some sort of wavelength from the singularity. It may also be true that the nature of the physics within the black-hole prevents standard thermal behaviors.

    Quote Originally Posted by BumFluff
    Another crazy idea I had was perhaps a black hole isn't really matter at all but dark matter. Dark matter has a gravitational effect on energy and mass around it so perhaps a black hole is merely a large collection of dark matter that tranforms the material it draws in to either dark matter or dark energy.
    I'm not sure you can work with the idea of what a black-hole is made of. I think a black-hole is more of a physical behavior or function of physics.

    That said, if dark-matter behaves in relation to normal matter, then it is probably true that a black-hole engages both normal matter AND dark-matter alike.

    Quote Originally Posted by Obviously
    Doesn't dark matter have more mass than visable matter? :?
    If we assume that dark-matter helps make up for the mass discrepencies in the universe, maybe so.

    Quote Originally Posted by Obviously
    Is there a limit to how much matter a black hole can consume?
    No one knows. It's been theorized that a black-hole has a mass limit.

    This article from 2005 shines a bit of light on this "feature" of black holes.
    Black Hole Limit

    Quote Originally Posted by Obviously
    ...On the other hand, the singularity is described as an infinitely small and dense point, and if it's infinitely small, it doesn't mean it has no size. This is something I don't understand. Why is it a problem when it's infinitely small?

    Does inifinitely small mean it has no size? I just don't understand why quantum mechanics doesn't allow there to be a singularity...
    It's been a while since I crawled through this bit, but I believe the issue is in the properties of "infinite." If something is "infinitely irrelevant" then it's not a tiny bit irrelevant, it IS irrelevant. If it's "infinitely relevant" then it's not largely relevant, it IS relevance itself.

    Someone else probably has a better explanation...I'm getting hurried atm.
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  16. #15  
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    Wow, that's a lot of information! :P Thanks :wink: :-D I'll get back with more questions soon
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    That article I linked to is pretty interesting...

    Also, you might want to just spend some time looking at the basics for Schwarzschild and Kerr-Newman black-holes. Wikipedia has good articles on these that get you started.

    The difference between the two has little to do with the inside stuff, but more to do with the event horizons, stationary limit(s), and the cool realm of the ergosphere!

    Enjoy. :P
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  18. #17  
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    Quote Originally Posted by Wolf
    That article I linked to is pretty interesting...

    Also, you might want to just spend some time looking at the basics for Schwarzschild and Kerr-Newman black-holes. Wikipedia has good articles on these that get you started.

    The difference between the two has little to do with the inside stuff, but more to do with the event horizons, stationary limit(s), and the cool realm of the ergosphere!

    Enjoy. :P
    I read the article, and I'll see if I find more time to check the other things as well. Things that sunshinewarrio (is his nick missing an "r" btw?) mentioned for example: Planck constant, uncertainty principle etc... Only problem is that it seems to be an awful, and I'm sorry to use that word, lot of things to learn. I just don't know where to start It seems that for everything I need to learn, there's something else I need to learn in order to understand it. I'm only 17, knowledge have mercy on me
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  19. #18  
    Forum Professor sunshinewarrior's Avatar
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    Quote Originally Posted by Obviously
    Quote Originally Posted by Wolf
    That article I linked to is pretty interesting...

    Also, you might want to just spend some time looking at the basics for Schwarzschild and Kerr-Newman black-holes. Wikipedia has good articles on these that get you started.

    The difference between the two has little to do with the inside stuff, but more to do with the event horizons, stationary limit(s), and the cool realm of the ergosphere!

    Enjoy. :P
    I read the article, and I'll see if I find more time to check the other things as well. Things that sunshinewarrio (is his nick missing an "r" btw?) mentioned for example: Planck constant, uncertainty principle etc... Only problem is that it seems to be an awful, and I'm sorry to use that word, lot of things to learn. I just don't know where to start It seems that for everything I need to learn, there's something else I need to learn in order to understand it. I'm only 17, knowledge have mercy on me
    1. Yes, I think when I registered I typo'd my own nick and missed out the final 'r'.

    2. If you have enough schooling to understand algebra, Newtonian physics and, perhaps, the Periodic Table, then you should have enough to get your head around these concepts - even at the age of 17! :P

    3. The first book I read on quantum physics was a pretty daft one: Gary Zukav's The Dancing Wu Li Masters, but at least it gave me a start. If you're interested in finding out about Black Holes from one of the foremost theoreticians in the field, and ar4e happy to give your brain a bit of a workout, Hawlings' A Brief History of Time is much easier to read than most of the reviewers make out, and is still a relevant and hugely informative book.
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  20. #19  
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    Quote Originally Posted by sunshinewarrio
    2. If you have enough schooling to understand algebra, Newtonian physics and, perhaps, the Periodic Table, then you should have enough to get your head around these concepts - even at the age of 17! :P
    Agreed.

    You might require some brain damage to work with the equations properly, but you don't really need to in order to have a decent understanding of the current theories. There's a LOT to read and look at concerning black holes, so unless you want to get mired down in the numbers, there's plenty of "fun" to be had.

    Quote Originally Posted by sunshinewarrio
    3. The first book I read on quantum physics was a pretty daft one: Gary Zukav's The Dancing Wu Li Masters, but at least it gave me a start. If you're interested in finding out about Black Holes from one of the foremost theoreticians in the field, and ar4e happy to give your brain a bit of a workout, Hawlings' A Brief History of Time is much easier to read than most of the reviewers make out, and is still a relevant and hugely informative book.
    Also "Black Holes and Baby Universes" which comes to mind.
    Wolf
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