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Space Math

Black Hole Information Loss Paradox Solution Proposed 252

Posted by ScuttleMonkey from the send-them-to-test-their-hypothesis dept.
Anuborn Satirak writes to tell us that Physicists from Case Western Reserve University claim to have cracked the black hole information loss paradox that has puzzled physicists for the past 40 years. "The physicists are quick to assure astronomers and astrophysicists that what is observed in gravity pulling masses together still holds true, but what is controversial about the new finding is that 'from an external viewer's point it takes an infinite amount of time to form an event horizon and that the clock for the objects falling into the black hole appears to slow down to zero,' said Krauss, director of Case's Center for Education and Research in Cosmology."
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Black Hole Information Loss Paradox Solution Proposed More

Black Hole Information Loss Paradox Solution Proposed

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  • 1/0 (Score:5, Funny)

    by eclectus ( 209883 ) on Wednesday June 20, 2007 @04:39PM (#19586913) Homepage
    It's what happens in the physical world when you divide by zero.

  • Solved tihs alrelady (Score:2, Funny)

    by Anonymous Coward
    Ah, esay one, I sloevd tihs one aegs ago, the irofntamion pbalbroy got lsot alnog the way.

  • obviously (Score:5, Funny)

    by Lord Ender ( 156273 ) on Wednesday June 20, 2007 @04:40PM (#19586929) Homepage
    Of course that's true, but is it also the case that a black hole can hold a stargate open, slowly sucking all of the surrounding area around the other gate into its time dilation bubble? Really, as a taxpayer funding this research, I want answers.

    • Re: (Score:3, Funny)

      by Anonymous Coward
      Of course that's the case. Living near Colorado, I can distinctly remember my friends near Cheyenne Mountain inexplicably losing hours on December 8th, 1998 [wikipedia.org].

    • Re: (Score:3, Funny)

      by kryten_nl ( 863119 )
      You are correct, it's known as the Tachyon-effect, in this case facilitated by the Einstein-Bohr-Hawking-Kryten-bridge. Can't find the wiki-page atm, I'll do a search later and post back.
      • Props for the random inclusion of everyone's favorite british robot butler - aside from Mr. Butlertron.

  • Link to paper (Score:5, Informative)

    by shma ( 863063 ) on Wednesday June 20, 2007 @04:41PM (#19586941)
    Here's the preprint [arxiv.org].

  • So... (Score:5, Interesting)

    by MontyApollo ( 849862 ) on Wednesday June 20, 2007 @04:43PM (#19586975)
    Are they saying black holes are perpetually in the creation phase, or they just don't exist at all unless they formed at the beginning of time?

    • Re:So... (Score:5, Informative)

      by lawpoop ( 604919 ) on Wednesday June 20, 2007 @06:23PM (#19588211) Homepage Journal
      Well, IINAP, but I think it's more like the actual hole part doesn't exist until the *end* of the universe.

      A black hole is not a thing that exists in time and space, it's an event or process that is a warping the space-time fabric. It's a fine point, but it bears repeating -- a black hole is not a 'thing' that warps time-space, it *is* a warping of time-space. An object actually moving to the center of the black hole takes an infinitely long time to get there, so when it actually does get there, it happens to arrive right at the end of the universe.

      So it kind of is like the black hole is perpetually in creation phase, but the matter doesn't disappear until the end of the universe. I read a post a few years back that the word for black hole in Russian is 'Collapsar'. Like a Pulsar always 'pulses', matter is always ( literally *always*, or, from now until the end of time ) collapsing in a Collapsar.

      • Re: (Score:2)

        by Quaoar ( 614366 )
        Except the black hole evaporates before the end of the universe, so the in-falling object never disappears. In fact, if you had a large enough black hole, the tidal forces at the event horizon would not be strong enough to rip you apart, and you could conceivably survive falling into one (from your point of view, the black hole would shrink in front of your eyes). Assuming you weren't baked by the x-rays produced by a supermassive black hole, you could travel trillions of years into the future unscathed.

        • Re: (Score:2)

          by lawpoop ( 604919 )
          Well, I think that the proponents of this theory are claiming that the matter does *not* actually disappear until the end of time.
      • "An object actually moving to the center of the black hole takes an infinitely long time to get there, so when it actually does get there, it happens to arrive right at the end of the universe. "

        While I understand your intent in that sentence, your wording is a bit misleading. If it arrives right at the end of the universe, then it has done so after a finite and terminating length of time (even if arbitrarily as long as the universe itself). This means that the item would in fact reach the mass point of the
  • I'm probably missing something here but from all I've read about black holes I've always read that it would appear to an observer that your clock would slow towards 0 (which is what they say in the article). So hasn't this been proposed in general already? Are they saying that you'd never appear to reach the event horizon?

    • Re: (Score:2)

      by Otter ( 3800 )
      Same here. I could swear we saw a movie in junior high school science class where a cartoon clock slowed and stopped as it fell into a black hole.

    • Re: (Score:2)

      by harrkev ( 623093 )
      According to "traditional" theory, the person going INTO the black hole would appear to never get there. Not so from a person who is a safe distance away watching with a telescope.

      What is new is that this new theory predicts that the person WATCHING would also never see the event horizon. How this works is completely unclear from the article. They seem to be saying that new black holes cannot form.

      However, simple physics predicts that if you get enough mass in a small-enough area, the escape velocity exc

      • Re:I'm confused (Score:4, Interesting)

        by Khashishi ( 775369 ) on Wednesday June 20, 2007 @05:59PM (#19587929) Journal
        No, that's not correct. Normal GR predicts that (in the frame of someone away from the BH) the person falling into the black hole will take an infinite amount of time to reach the event horizon. In GR infinite time isn't the same thing as never! In the frame of the person falling into the BH (the proper time frame,) the faller crosses the event horizon in finite time and hits the center quite quickly (for non-huge black holes). The confusion and controversy lies in the concept of infinite time. Some take it to mean that black holes can't actually form (and must either be primordial or not exist). But infinite time might be a finite distance away due to weirdness with coordinates. An object falling through an event horizon might pass through infinite future and then travel back in time from the infinite future to the current. In the outside viewers frame, there might be two copies of the in-falling person, one inside and one outside. In this scenario, black holes can exist, and can contain the mass of stuff that falls into the hole...before it falls into the hole! Or it could all be bullshit and artifact of a broken theory of gravity.
        • This article is identical to what we covered... in 300 level Modern Physics in college in 1983.

          I don't see how this is new or radical, except for the general population, who seem to think that for every "black hole" there is a corresponding "white hole", or that when you "fall into a black hole", you somehow end up somewhere else.

          You should read Feynman's lecture series; he has one from the 50's that debunks the idea of a "graviton" or a particulate carrier for gravity because of the need for it to have mas
      • >They seem to be saying that new black holes cannot form.

        Yes, I read the article, and I think this part of it is b.s. All black holes existed since the beginning...uh??? What about, you know, space, and time, and all that? I seriously doubt that black holes were pre-fabbed like houses.

        >Somewhere there is a contradiction. Can somebody explain?

        I think they just took it one step too far.

    • Re:I'm confused (Score:5, Informative)

      by kebes ( 861706 ) on Wednesday June 20, 2007 @05:11PM (#19587363) Journal
      The article preprint [arxiv.org] (Warning: PDF) is fairly readable (although obviously still quite technical). This is my understanding based upon that preprint. Note that I'm not a cosmologist, so I would appreciate others to point out any mistakes I make.

      Firstly, they emphasize in their paper that they are considering their problem from the point of view of an external observer, rather than the point of view of an observer falling into the black hole. They write:

      The process of black hole formation is generally discussed from the viewpoint of an infalling observer. However, in all physical settings it is the viewpoint of the asymptotic observer that is relevant. More concretely, if a black hole is formed in the Large Hadron Collider, it has to be observed by physicists sitting on the CERN campus.
      They also contrast their results with previously accepted analysis of black hole formation:

      In Sec. III we verify the standard result that the formation of an event horizon takes an infinite (Schwarzschild)time if we consider classical collapse. This is not surprising and is often viewed as a limitation of the Schwarzschild coordinate system. To see if this result changes when quantum effects are taken into account, we address the problem of quantum collapse using a minisuperspace version of the functional Schrodinger equation [2] in Sec. IV. We find that even in this case the black hole takes an infinite time to form, contrary to some speculations in the literature [3].
      So, in essence, they are presenting findings that suggest that even quantum effects are taken into account, the collapse takes an infinite amount of time. This is signficant because it means that while the collapsing mass can appear to get closer and closer to being a singularity, it can never really achieve this final state to an external observer. How this relates to information loss is then described:

      the shell, even as it collapses, radiates away its energy in a finite amount of time... we conclude that the evaporation time is shorter than what would be taken by objects to fall through a black hole horizon.
      So, in essence, the collapse of the black hole takes an infinite amount of time, during which time the black hole will evaporate via Hawking radiation [wikipedia.org]. So objects falling into a black hole will never actually be swallowed up into the black hole (though they will get arbitrarily close and arbitrarily crushed!). Since the collapse is never really complete, information about the objects is never entirely lost. The emitted radiation will thus contain 'information' about the infalling objects. This in some way can be seen to resolve the seeming information paradox, whereby black holes were seemingly able to 'swallow up' information and completely destroy it (whereas no other process in the universe appeared able to do so).
      • Good job explaining that. Thanks.

      • The process of black hole formation is generally discussed from the viewpoint of an infalling observer. However, in all physical settings it is the viewpoint of the asymptotic observer that is relevant. More concretely, if a black hole is formed in the Large Hadron Collider, it has to be observed by physicists sitting on the CERN campus.


        If they do make a black hole in the Large Hadron Collider, what makes them think that the CERN campus won't fall in?
        • It won't be big enough to avoid evaporating.

        • Re:I'm confused (Score:5, Insightful)

          by DragonWriter ( 970822 ) on Wednesday June 20, 2007 @06:12PM (#19588079)

          If they do make a black hole in the Large Hadron Collider, what makes them think that the CERN campus won't fall in?


          Because if the black hole was big enough to suck in the CERN campus with its gravity, the matter from which it was formed would have the same effect.
      • So the latest solution to the Hawking paradox is "black holes don't exist"?!

        • Re:I'm confused (Score:5, Interesting)

          by kebes ( 861706 ) on Wednesday June 20, 2007 @06:02PM (#19587955) Journal

          So the latest solution to the Hawking paradox is "black holes don't exist"?!
          In a strict sense, yes. However, the objects people typically think of as "black holes" would still exist. Let me be more clear.

          To my understanding, the suggestion is that the collapsing matter will never create a true event horizon (a boundary from which nothing can ever escape). However this doesn't prevent the matter from collapsing to an arbitrarily high density and creating an increasingly large escape velocity. Think of a dense chunk of matter (but not infinitely dense). It will warp spacetime around it significantly, and it will bend the direction of light rays significantly. If a ray of light strays too close to the center of this quasi-singularity, it will get caught in a tight orbit. Now, the orbit won't be truly stable, and the light ray will, after some rotations around the gravity well, finally escape.

          The denser the quasi-singularity is, the more rays will get trapped (temporarily) in these orbits, and the longer they will stay trapped. At a certain point, when light is being trapped for 10E80 year, the object could very sensibly be called a black hole. For all intents and purposes, infalling light does not escape. In principle, in a very long time the light may escape. Or, according to this new theory, the black hole may evaporate before actually forming (although this, too, will take a long time). But the massive curvature of spacetime will still lead to all the light-trapping and time-dilating effects normally predicted for black holes. This theory is merely suggesting that the containment is not absolute. Eventually, the stuff will escape. (Although for material objects, they will have been crushed and distorted beyond recognition. But at least in principle, the 'information' about them wasn't lost.)

          Under the new theory, objects of near-infinite density still form, and still (in any practical sense) trap all incoming matter. However the question comes down to whether the singularity at the center is a true singularity with a true event horizon, or a perpetually-collapsing mass that has not quite yet reached the point of being a true black hole.
          • I like it, thanks for explaining, but what happens to matter that was within the event horizon before the black holes form? So if a bit of matter is the center around which a black hole is forming, surely that bit of matter will be within the event horizon and its information will be lost?

            If you're feeling up to a challenge: how does matter get "evaporated" when EMR can't escape, why must information be preserved, and does this mean that after evaporating enough matter black holes would burst back out an

            • Re:I'm confused (Score:5, Informative)

              by kebes ( 861706 ) on Wednesday June 20, 2007 @08:14PM (#19589237) Journal

              So if a bit of matter is the center around which a black hole is forming, surely that bit of matter will be within the event horizon and its information will be lost?

              That's a rather zen question, actually. In some ways it amounts to asking "What's the difference between the matter that forms the black hole, and the matter that is falling into it?" Conventionally, the answer would be: all the matter inside the event horizon is part of the black hole, and everything outside the event horizon is falling into it (or, rather, is being gravitationally attracted towards it, and may or may not actually fall).

              If this new bit of theory is correct, then the answer actually becomes harder, because the event horizon never forms, so you can't really say that some matter is inside vs. outside. Of course there is probably a sensible way to define a "pseudo-horizon" based upon a threshold where the probability of light escaping sharply drops towards 0.

              I guess another way of thinking about it would be to say that this hypothetical matter that is "at the center of where the black hole is forming" would inevitably be included into the collapsing mass and would thus, itself, become part of the black hole.

              If you're feeling up to a challenge: how does matter get "evaporated" when EMR can't escape,

              It's true that EMR that enters the event horizon cannot escape. The evaporation process, called Hawking radiation [wikipedia.org], is a quantum effect that has no conventional analogue. Basically, in quantum mechanics (or rather quantum field theory), it is predicted that "virtual particles" randomly appear and disappear all the time. These virtual particles actually carry the force of things like the electric fields, magnetic fields, gravitational fields, etc. (they also avoid 'action at a distance' problems...). So in the vacuum, you will get random particle-antiparticle pairs appearing at random, and annihilating each other a moment later (these constant fluctuations are very important in modern theories, actually). If you imagine one of these random fluctuations occurring right beside an event horizon, you can imagine that one of the two particles gets sucked into the event horizon, but the other one escapes and sails off into the universe. The particle entering the black hole will actually reduce its mass (not increase it, as one would normally expect... though the proof of this requires digging into the math quite a bit), and the particle that escapes thereby carries away some of the mass of the black hole. Thus, over time, the blackhole is basically emitting radiation and slowly 'evaporating.'

              Now, I know this idea of "virtual particles" randomly appearing and disappearing sounds totally bizarre. In fact it sounds like pseudo-science or an overcomlicated story that particle physicists are weaving. However these effects do have experimental backing (e.g. Casimir forces [wikipedia.org]).

              why must information be preserved, and does this mean that after evaporating enough matter black holes would burst back out and let all the stuff they captured back out?

              It turns out the rate of evaporation increases as you decrease in size. So really "micro black holes" (it is predicted that they will be created in upcoming particle accelerators) will evaporate very quickly. Big black holes will evaporate slowly at first, but then faster and faster as they shrink, until they get very small and release the last of their energy, in some sort of burst, yes. However a fundamental, unanswered, question is whether the radiation being emitted by the black hole contains 'information' about the states of things that went into the black hole. No one knows for sure. The conventional answer was that any information that goes into a black hole is lost forever.

              However to many scientists, this answer was unsatisfactory.

              • Thanks, I can't wait to learn about this stuff when I get past Physics 101

              • But a black hole is time-asymmetric. In one direction, information is irrevocably lost, whereas if you run the equations backwards, information is spontaneously created... which makes no sense (mathematically) because you don't know what information to put in there!

                I'm curious: why not just put random information in there? There's effectively random information coming out of the black hole as it 'evaporates' over forward time, so what's wrong with having random particles 'fall out of' a black hole (so to speak) when you play the model backwards?

                I seem to recall from somewhere that, quantum mechanically speaking, the past is just as indeterminate as the future, as any number of slightly different recent pasts could have lead to a present indistinguishable from this on

                • Re: (Score:3, Interesting)

                  by kebes ( 861706 )

                  I'm curious: why not just put random information in there? There's effectively random information coming out of the black hole as it 'evaporates' over forward time, so what's wrong with having random particles 'fall out of' a black hole (so to speak) when you play the model backwards?

                  Indeed. That would solve the short-term mathematical problem, but not the deeper mismatch of the theories. Also, whether or not Hawking radiation is truly random, or whether it contains hidden information (in a non-trivially

              • Re: (Score:2)

                by ribuck ( 943217 )

                Big black holes will evaporate slowly at first, but then faster and faster as they shrink, until they get very small and release the last of their energy, in some sort of burst, yes.
                As the next "big bang", in other words.

          • Re: (Score:2)

            by Magada ( 741361 )

            (Although for material objects, they will have been crushed and distorted beyond recognition.
            This may be a stupid question, but... Is this matter compressed from its own frame of reference, or just from ours? It's something I've never quite understood.

      • Re: (Score:2, Interesting)

        by grimdawg ( 954902 )
        What about for the infalling observer?

        He's entered the black hole, and information has been lost to him. I can get my head around thinking that information is relative, but now the laws of the universe hold for some people but not others?

        OTOH, if I was falling into a black hole, entropy's the least of my worries.

      • Re: (Score:2)

        by TexVex ( 669445 )

        whereby black holes were seemingly able to 'swallow up' information and completely destroy it (whereas no other process in the universe appeared able to do so).
        What about photons travelling in an uninterrupted path towards the edge of the observable universe? I assume they would be irretrievably lost in ever-expanding space, with anything they could possibly interact with receding from them faster than they move.

      • Re: (Score:3, Interesting)

        by miskatonic alumnus ( 668722 )
        Not to start a flamewar or anything, but I would like to "put forth a slice of personal philosophy". Over the years I have come to be quite skeptical when I hear/read expressions like "infinite amount of time" and "arbitrarily close" as they relate to the real world (or our interpretation of it) rather than a purely theoretical treatment. Take for instance Newton's Law of Cooling which implies that your Betty Crocker brownies will take an infinite amount of time to reach room temperature after removing them

    • Re: (Score:3, Informative)

      by pavon ( 30274 )
      That is what I have always heard as well. I don't think that is the new part - probably just bad editorialism. It sounds like the new part is about the formation of the black hole itself - namely that to an outside observer, a star (or other large mass) will appear to take an infinite amount of time to collapse into a black hole and thus will appear to never form an event horizon.
    • Traditionally the idea is from an outside observer a object falling into a black hole never makes it as any information flowing from that object is slowed by gravity as it escapes. Until it cannot escape at the event horizon.
    • Early in the last century, people used to believe the nucleus was a loose 'plum pudding' of protons and neutrons that the electrons orgbited through as well as around. Rutherford was astonished when he got beta particles (helium nucleii) bouncing back from some tiny, hard central nucleus.

      What is the problem with a small nucleus? Well, if you believed in point charges then you would have light electrons orbiting a heavy nucleus like a small solar system. With a simple hydrogen atom, you would have a proton

    • You park your car in the countryside and consult the map, 1km away is what looks like a good picnic spot. So you haul your kit out of the car and set off.

      However the 2d map doesnt show the 3d reality of the ground and there is actually a mountain between you and the picnic spot. So instead of it taking you 20 mins to walk there it actually takes you over an hour. Despite the fact that you're walking at a leisurly 3km/hour a lot of that effort is being translated into a vertical displacement and your actual

  • 'from an external viewer's point it takes an infinite amount of time to form an event horizon and that the clock for the objects falling into the black hole appears to slow down to zero,'
    Huh? Does that mean that since we're external viewers, no black hole that we "view" will have an event horizon, because it takes an infinite amount of time to form?
    • You should RTFM, this is clearly stated in section 2.1, "Black hole event horizon formation"!

    • Re: (Score:2)

      by bwcbwc ( 601780 )
      ...or that all the black holes in the universe had already established their event horizons before the laws of relativity became valid. In other words, before or very shortly after the big bang/blowup.

  • Experiment (Score:5, Funny)

    by Rosco P. Coltrane ( 209368 ) on Wednesday June 20, 2007 @04:46PM (#19587009)
    from an external viewer's point it takes an infinite amount of time to form an event horizon

    Nothing like an experiment to verify theories. And indeed, a quick trip to the DMV or the social security office confirms that it does seem to take an infinite amount of time for any event to occur, and that the clock seems to stop locally.

    See? no need for black holes.

    • from an external viewer's point it takes an infinite amount of time to form an event horizon

      Nothing like an experiment to verify theories. And indeed, a quick trip to the DMV or the social security office confirms that it does seem to take an infinite amount of time for any event to occur, and that the clock seems to stop locally.

      See? no need for black holes.

      Yeah, but time, from the perspective of outside said offices, seems to speed up such that right after leaving the DMV it's time to go back again. This applies for jury duty, as well. I feel a GUT coming on...

  • Hawking's solution (Score:5, Informative)

    by EvilGrin5000 ( 951851 ) on Wednesday June 20, 2007 @04:52PM (#19587105)
    Anyone know what happened to Hawking's proposal for information loss?

    Basically what Hawking said (in a late essay entry in a science conference) was that Black Holes do 'digest' information and therefore you have information loss, however (and this is where his proposal was a bit controversial) Hawking suggested that the conglomeration of parallel universes will have a particular Black Hole present in one, and the same Black Hole missing in another, therefore the TOTAL information for ALL Universes, is retained.

    Here's a link to Hawking's Black Hole Paradox: http://en.wikipedia.org/wiki/Black_hole_informatio n_paradox [wikipedia.org]

    And from the wiki article, here's the line I'm mentioning in my post:

    "...On October 28, 2006, The Discovery Channel aired a show called "The Hawking Paradox". The show explained Hawking's conclusion that one must look at the universe as a whole, and that information lost in black holes is saved in parallel universes where no black holes exist."

    It seems that this new solution is completely disregarding Hawking's proposal and replacing it with a new, stretched solution.

    • Re: (Score:3, Interesting)

      by TexVex ( 669445 )
      Parallel universes that only exist on paper or in the minds of quantum physicists are such a copout. You can't detect them, measure them, interact with them, or otherwise find any way to prove they exist, yet some people believe in them anyway. Kinda like God.

      • Re:Hawking's solution (Score:4, Interesting)

        by Intrinsic ( 74189 ) on Wednesday June 20, 2007 @10:39PM (#19590181) Homepage

        Parallel universes that only exist on paper or in the minds of quantum physicists are such a copout. You can't detect them, measure them, interact with them, or otherwise find any way to prove they exist, yet some people believe in them anyway. Kinda like God.


        Ohh boy... isnt that like saying the world was flat back in the middle ages? Yet some people the world believe the world is round, sounds good on paper, but really since we cant detect that it its probabley just a belief anyway..

        • Ohh boy... isnt that like saying the world was flat back in the middle ages? Yet some people the world believe the world is round, sounds good on paper, but really since we cant detect that it its probabley just a belief anyway..

          No, because the information in other universes is undetectable in principle, whereas determining the geometry of Earth is, in principle and reality, possible.

          • It depends on how you define detection. If the quantum suicide [wikipedia.org] experiment actually worked, the parallel nature of the universe could be locally discerned (for an arbitrarily sized group of "local" observers, in principle), but it would actually be detecting the loss of parallel branches, rather than their continued presence.
      • Except that most people who believe in God also believe that He/She/It is in effect and affect, the Universe itself (or parallel universes if you must) and so avoid that question altogether by saying "God is all around you and YOU, you can't NOT interact, detect and measure Him, it's essentially the only thing you can do."

        Only children (and aetheists apparently) think of God as a big guy in the clouds or even as a separate entity from the Universe... and only because they have limited ability to think in ab

    • Anyone know what happened to Hawking's proposal for information loss?
      Isn't it merely supposition that information can't be lost? A desire for a neat and orderly universe, which once drove the (now abandoned?) notion that the curvature of the universe is "just right"?

  • They're doing it wrong (Score:5, Funny)

    by realmolo ( 574068 ) on Wednesday June 20, 2007 @04:52PM (#19587123)
    A Slashdotter would realize that if you don't want to see any information, you need to view the event horizon with a threshold of -1.
     

  • Zeno of Elea... (Score:3, Interesting)

    by idontgno ( 624372 ) on Wednesday June 20, 2007 @04:55PM (#19587155) Journal
    would be proud. [wikipedia.org]
  • I'm sure it's not that simple, but that sure seems like what the article is saying. Black Holes would take infinitely long to form, so we'll never see one form, so no information will be lost. It sure doesn't seem to add up to me, since I thought there was pretty good evidence for black holes--and the universe hasn't existed for an infinitely long time. Still, when has quantum stuff ever made sense?

    • Still, when has quantum stuff ever made sense?
      Alone, it makes sense in many cases. With gravity, never. With alcohol, always.
    • What we see in the centers of galaxies might not be black holes, but "almost" black holes--massive conglomerations of mass frozen in time, in the process of forming black holes which will never (in finite time) be complete.

    • Re: (Score:2)

      by lawpoop ( 604919 )
      Well, if this theory is true, that a black hole never completely collapses until the end of time, it means that we can see the event horizon of a black hole, but the hole part never forms until the end of the universe. The further we look into a black hole, the further into the future we look, because a black hole is a warping of time. And the center of it, the black hole part, exists infinitely into the future, or the end of time.

      Like I said in this other post [slashdot.org], a black hole is not a thing that warps ti
      • >IANAP, so feel free to chime in and correct me.

        It sounds to me like you understand the difference between time and speed better than most. The universe understands speed, there is a limit. Time is a reduction of that.

        Anything moving at perfect speed has, by definition, infinite time to complete its task. Observers at lower speeds get to watch and die in the meantime.

  • "It's complicated and very complex," noted the researchers

    What an understatement.

  • Rename 'Black holes' to 'Wholes' (Score:3, Funny)

    by Timesprout ( 579035 ) on Wednesday June 20, 2007 @05:10PM (#19587337)
    Then everything is complete and the Universe is in harmony. Problem solved.
  • 'from an external viewer's point it takes an infinite amount of time to form an event horizon and that the clock for the objects falling into the black hole appears to slow down to zero,' ...so surely if it takes an infinite amount of time to form an event horizon then we shouldn't have seen any yet. But we have.

    • No... (Score:5, Informative)

      by msauve ( 701917 ) on Wednesday June 20, 2007 @05:41PM (#19587725)
      we haven't (seen any black holes). You can't "see" a black hole (that's why they're named as they are). We have observed the effects of things which match our expectation of the effects a black hole would cause. I assume the authors of this paper explain how their black-hole-like-object-which-isn't-a-black-hole can cause the same effects.

      • Re: (Score:2)

        by JustNiz ( 692889 )
        you're missing my point.
        By 'see' I don't mean visibly. I mean that anything that takes an infinite amount of time to form will therefore never completely form, so therefore shouldn't ever exist in its entirety, yet black holes have been proven to have complete event horizons.

        • No... (Score:3, Insightful)

          by msauve ( 701917 )
          they haven't (proven that event horizons exist). I'll paraphrase my earlier response, maybe repetition will help you learn. We have observed objects which exhibit behavior consistent with what we would expect from observing an event horizon. I expect that the paper which is the subject of this discussion explains how their black-hole-like-object-without-an-event-horizon can also exhibit the observed behavior.

    • Re: (Score:2, Interesting)

      by grikdog ( 697841 )
      Achilles vs. the Tortoise all over again?

  • new scientist article (Score:4, Informative)

    by mrpeebles ( 853978 ) on Wednesday June 20, 2007 @05:26PM (#19587533)
    There is an article about this same thing in new scientist
    http://space.newscientist.com/article/dn12089-do-b lack-holes-really-exist.html [newscientist.com]
    It quotes 't Hooft as claiming that "The process he describes can in no way produce enough radiation to make a black hole disappear as quickly as he is suggesting." So I am skeptical.
  • So we finally have a possible answer to why we see so many dupes.
    1. They aren't dupes and they don't exist because they never form ....
    2. they are dupes but come from another universe where they have been deleted and saved here....

  • I found this idea about microscopic black holes [universetoday.com] much more interesting. They are talking about the idea that these things could be rattling around inside the sun, or inside Jupiter and causing it to heat up, or even inside the earth. It was also suggested that the new Large Hadron Collider might be capable of creating microscopic black holes through the collision of particles at relativistic velocities.
    I once read a scifi story decades ago about this tiny black hole that revolved around a planet close to th


  • That's so obvious I've been wondering for years why anyone thought there was a paradox.

  • the clock for the objects falling into the black hole appears to slow down to zero

    I don't know as much about relativity as I would like to, but hasn't this been known since forever?

  • A black hole does not mean matter vanishes...if it did, the law of physics that states 'energy is never lost or created, it simply changes shape' would be violated. So where is the paradox? the matter that falls into a black hole is crushed and compressed due to the enormous gravity...but it is not lost, it stays there forever.
  • Poul Anderson's Nebula award nominated short story "Kyrie" used the idea that it took infinite time to fall into a black hole.

    This story was published in 1968.

  • Sad (Score:2)

    by wiredog ( 43288 )
    A Slashdot article on black holes, with no goatse link.

    Slashbots these days. Boring, boring, boring. No hot grits, no Natalie Portman naked and petrified, no goatse links.

    Oh, for the halcyon days of OGG THE OPEN SOURCE CAVEMAN!

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