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Hawking Gracefully, Formally Loses Black Hole Bet 485

Posted by timothy
from the fails-to-give-wheelchair-ride dept.
Liora writes "Today at the 17th International Conference on General Relativity and Gravitation in Dublin, Cambridge University professor Stephen Hawking said in his talk titled The Information Paradox for Black Holes that he was wrong about the formation of an event horizon in a black hole, and that matter is not destroyed in a way defying subatomic theory, as he had previously believed. According to the talk's short, "the way the information gets out seems to be that a true event horizon never forms, just an apparent horizon." A New York Times story and a Wired story are available, both apparently based on Reuters information." (This is the formal announcement promised last week.)
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Hawking Gracefully, Formally Loses Black Hole Bet

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  • obNoRegLink (Score:5, Informative)

    by Anonymous Coward on Wednesday July 21, 2004 @07:39PM (#9765236)
    I once asked the Slashdot editors why they didn't replace reg-required NYT links with reg-free links. They pointed out that there is a chance that the NYT could get its panties in a wad, and do something stupid. Lawsuits, goatse redirects, the works. Lawsuits... that would just be wrong!

    Anyway, here's the obligatory reg-free link:
    Are you looking at ME? [nytimes.com]

    (Courtesy of these fine folks [blogspace.com])
    • Re:obNoRegLink (Score:2, Informative)

      by dynamo (6127)
      better than that is bugmenot.com which will give you a user/pass for any website on the web - or if there isn't one yet, allow you to add one to their database. it's great for reading news and avoiding any kind of compulsory registration.

      we have to show web sites that forcing registration for marketing / tracking purposes leads to a reg database full of crap.
      • Re:obNoRegLink (Score:3, Insightful)

        by Pharmboy (216950)
        we have to show web sites that forcing registration for marketing / tracking purposes leads to a reg database full of crap.

        Actually, doing this leads to the NYT having a smaller database, including one entry for all users that share the login. I think the site is a good idea, but its probably doing them a favor, by letting many users who almost never view their site use a single logend. This is better (for them) than a database full of people that visit the site every 6-12 months. But it is probably no
        • Re:obNoRegLink (Score:2, Informative)

          by smclean (521851)
          I don't think he meant quantity of the crap, but quality.

          Sure, there is less information from using bugmenot logins, but that isn't what NYT wants. If NYT didn't want a database full over people who visit the site every 6-12 months, they wouldn't require registration at all.

          NYT wants a database full of individual readers, so they can track their reading habits, see what people click on, what people are interested in.

    • Trailer is right here [newgrounds.com] Site: www.mchawking.com
  • by d474 (695126) on Wednesday July 21, 2004 @07:42PM (#9765252)
    I've been hearing about this for like 4 days now... Is Slashdot turning into a News Black Hole?
  • Good for Hawking (Score:5, Insightful)

    by neilcSD (743335) on Wednesday July 21, 2004 @07:43PM (#9765257)
    It's great to see such an eminent scientist willingly admit that he was wrong, or at least only partially right. It seems that all too often the path that people and organizations choose is to deny, spin, and turn things on their heads to avoid embarassment. Hawking showed he is a good sport, proving not only does he have a brilliant mind, he is a classy person as well.
    • by BCW2 (168187) on Wednesday July 21, 2004 @07:46PM (#9765288) Journal
      I agree. A true gentleman and brilliant mind. It would be nice if others could follow his example, like Politicians, SCO, everyone in Hollywood.
      • Re:Good for Hawking (Score:4, Interesting)

        by bs_02_06_02 (670476) on Wednesday July 21, 2004 @08:07PM (#9765459)
        I think most university researchers or professors have a tremendous ego problem. I don't see Hawking having that problem which makes him far more likeable. He's almost humble, and has a great sense of humor.

        I've never been very tolerant of arrogant professors. They often believe they can't be wrong, and that it's absurd to suggest that there's an alternative to their way of thinking.
        I've also seen professors claim others' ideas as their own.
    • by Realistic_Dragon (655151) on Wednesday July 21, 2004 @07:49PM (#9765311) Homepage
      A sad state the world is in when someone not being an asshole is surprising.
    • Re:Good for Hawking (Score:2, Informative)

      by Owndapan (789196)
      According to the legend Hawking made the bet against what he believed with the intention of proving himself wrong. That way if he has wrong he could say at least he won the bet (as a consolation prize). So I don't know if hedging your bets counts as admitting you were wrong!

      Some more info here [slashdot.org], but you can probably google for some *real* information ;)

    • What is nice here is that not only did he admit he was wrong, but he's also the one that brought the "proof" that he had been wrong.
    • It's actully a great way of manipulating the public. What Hawking does is formulate a hypothesis, in true homage to the Scientific Method, then he makes a bet AGAINST said hypothesis. This makes him certain to win in either case. If he's wrong, he still wins the bet, and if he's right, then he gets to add another twist into the realm of Physics.
    • Good for Physics (Score:3, Insightful)

      by toxic666 (529648)
      Some people who deal with him say he is difficult and arrogant.

      He has been debating the issue for 30 years, and only now has he changed his mind. It took a lot of other evidence for him to change his theory, and it was a hot debate all the way. Hey, he made a bet of honor and stood by his opinion until others proved (to his own satisfaction) he was wrong.

      That is what dealing with people in his realm of intelligence can be like. It may not always be pleasant and it may take a long time to get them to ad
    • by zerocool^ (112121) on Wednesday July 21, 2004 @10:49PM (#9766402) Homepage Journal
      I don't know about Charisma, but that guy must have a crazy high INT.

  • More info.. (Score:4, Funny)

    by JohnFluxx (413620) on Wednesday July 21, 2004 @07:44PM (#9765266)
    Wired says: The best-selling author of "A Brief History of Time"

    I didn't know hawking sold so well ;-)

    Anyway, to be on topic - can someone give more technical information on this? Many of us probably have a fairly high understanding of maths and physics, and want more details...

    • Re:More info.. (Score:2, Informative)

      by MrDigital (741552)
      Maybe I'm missing your obvious sarcasm, but "A Brief History of Time" was a monster hit.

      You can read more here: National Academies Press [nap.edu]

      "Entering the Sunday Times best-seller list within two weeks of publication, it rapidly reached number one, where it remained unchallenged throughout the summer. The book had already broken many records and indeed went on to break them all stay- ing on the list in Britain for a staggering 234 weeks, and notching up British sales in excess of 600,000 in hardback before Ha
      • Maybe I'm missing your obvious sarcasm, but "A Brief History of Time" was a monster hit.

        It referred to him as a best-selling author of the book. Not the author of the best-selling book. This sentence structure tends to indicate that the author was sold many times, as "best-selling" modified the author. It wasn't sarcasm. It was a grammar flame.
        • But a particularily pedantic at best, and wrong at worst, grammar flame. The construction 'best-selling author' is used very frequently and is well established. You are being much much too literal.

          For instance, I could say "Best-selling author Stephen King's new book Big Scary Stuff comes out on Friday", meaning that King has best-selling books. This is distinct from "Stephen King is the author of the best-seller Jurassic Park", for the latter means that particular book was a best-seller. For one final exa
          • For instance, I could say "Best-selling author Stephen King's new book Big Scary Stuff comes out on Friday", meaning that King has best-selling books. This is distinct from "Stephen King is the author of the best-seller Jurassic Park", for the latter means that particular book was a best-seller.

            The latter also means that Michael Crichton's lawyers will be around to your house any second now to corpse you up.

            • You know, and all the time I was writing that I was thinking "there's somethnig wrong here".

              So, uh, sorry Mr. Crichton and Mr. King about that... my mistake
        • Well I'm glad one person got what I said... even if it wasn't that funny.

          Oh well.
      • by Finuvir (596566)
        600,000 books sitting unread on pretentious people's coffee tables. That's only rivalled by Ulysses. Well some of them were read but I imagine most people didn't get very far into it.

        (Lousy /. making me wait before I post again)
  • BBC Article (Score:5, Interesting)

    by Tremyl (789061) on Wednesday July 21, 2004 @07:44PM (#9765269)
    For those avoiding registration, the BBC also has an story [bbc.co.uk]. My favorite part was the response of John Preskill, the other side of the bet. From the BBC article,
    Later, Preskill said he was very pleased to have won the bet but added, "I'll be honest, I didn't understand the talk." He said he was looking forward to reading the detailed paper that Hawking is expected to publish next month.
    Physics is a wonderful place, where not even the physicists know what the hell is going on!
    • Re:BBC Article (Score:2, Interesting)

      by Carnildo (712617)
      Physics is a wonderful place, where not even the physicists know what the hell is going on!

      Seventy years ago, Einstein estimated that there were only two people in the world who understood general relativity, and he was one of them.
      • Re:BBC Article (Score:5, Interesting)

        by ebassi (591699) on Wednesday July 21, 2004 @08:00PM (#9765397) Homepage

        Seventy years ago, Einstein estimated that there were only two people in the world who understood general relativity, and he was one of them.

        Einstein said that, at that time, only three people in the world understood General Relativity. When a reporter asked Arthur Eddington (the second best person that, in fact, did know general relativity) for confirmation, he replied that he could not recall the third one.

      • That statement is complete nonsense. Einstein never said it, and MANY people understood it in 1934.
  • by oneiron (716313) on Wednesday July 21, 2004 @07:44PM (#9765272)
    I really don't understand why the bet sneaks into every headline about this story. Why are humans so obsessed with who was right and wrong? That we have the information is all that really matters...
    • The bet is an interesting story in its own right.

      We care about who was right and who was wrong because we look to these people to be our guides and priests in their chose areas of expertise. Reports on who was right and who was wrong are important to us when we make decisions about who to trust, and who to respect in matters of physics.
    • really don't understand why the bet sneaks into every headline about this story. Why are humans so obsessed with who was right and wrong?

      It's more to show that even the most eminent and revered are human, and it's reassuring to know these people aren't so far out of touch as to not have a bit of fun now and again.

      For example, I went to a lecture by Sir Patrick Moore [wikipedia.org], at which he was asked questions as to whether he believed the electrical universe theory [kronia.com] could be correct. His answer? "I hope not, I owe

  • by straponego (521991) on Wednesday July 21, 2004 @07:45PM (#9765275)
    ...that was the best thing I had going for me. It's what got me through the day. What do I have to look forward to now? Nothing, that's what!
    • Well, at least you've still got that alternate reality you live in. ;)
    • Parallel universes (Score:5, Informative)

      by phyruxus (72649) <[moc.oohay] [ta] [knildnapmuj]> on Wednesday July 21, 2004 @08:42PM (#9765705) Homepage Journal
      Technically, the article said Hawking said that black holes do not lead to another universe. So if you want to think that there are other universes, you just have to look elsewhere.. String theory posits high dimensionality and "universes next door"; I'll remain parallel universe agnostic for the moment, but Hawking's point seems to have been that black holes do not eat information, and so they return the matter to the universe, and so he says, black holes are not an exit. If Hawking said definitively that our universe was the only existence, I would listen but I think unless we actually poke a hole into another universe with funky clues like, only 2 spatial dimensions (we could just be making a tesseract) or something, parallel universes will remain mostly philosophical.

      Summary: Parallel universes aren't ruled out (at least by this article) so keep dreaming big! We'll need those other universes when entropy runs out in this one. Even better, ask someone who knows string theory whether the idea of multiple universes would be ruled out IF Hawking is right. Remember, he just lost a bet. He may be sure this time, but who's to say some bright kid 200 years from now won't have a different perspective... blah blah hypothetical
    • You can still believe in paralell worlds via the "Many Worlds" [wikipedia.org] interpetation of Quantum Physics. This just says that Black Holes probably don't lead to them.
  • Yikes (Score:2, Funny)

    by dirty (13560)
    "The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent h
    • Re:Yikes (Score:4, Informative)

      by Carnildo (712617) on Wednesday July 21, 2004 @07:53PM (#9765342) Homepage Journal
      You don't understand it? It's pretty straightforward: a black hole has an event horizon, but nothing ever actually crosses it. The information can be retrieved from the black hole because it was never inside the event horizon.
      • I don't see how that's straightforeward at all. Why doesn't anything ever cross the event horizon? So stuff that falls into a black hole just stops halfway to the center??
        • Not having read the FA, heard the lecture or read the paper I'd hazard a guess that nothing crosses the horizon because time stops at the horizon. From our perspective outside the stuff would fall towards the horizon getting slower and slower the closer it got but it would never reach it.
      • Re:Yikes (Score:3, Insightful)

        by lazyl (619939)
        I'm sure he's not that clueless. All you did was restate the last sentence of the paragraph with a slightly different wording. Obviously it was the first three sentences that were confusing. If you want to sound impressive then explain those.
    • Re:Yikes (Score:5, Funny)

      by photonrider (571060) on Wednesday July 21, 2004 @07:53PM (#9765344)
      dang! babelfish doesn't have a "genius to english" translation.
    • Re:Yikes (Score:3, Funny)

      by EvanED (569694)
      That man is way too smart to be a human.

      I think it's just conclusive proof he writes his papers with a program similar to the following:
      for(i=0 ; i<5000 ; ++i)
      {
      cout << dictionary[rand() % NUM_WORDS] << " ";
      if((p = double(rand())/RANDMAX) < .05)
      cout << ". ";
      else if (p < .07)
      cout << ", ";
      }
  • by Anonymous Coward on Wednesday July 21, 2004 @07:46PM (#9765283)
    Userfriendly.org [userfriendly.org] had a funny take on the payment of this bet.
  • by Kenja (541830)
    So, does this mean that you cant go to hell, [imdb.com] and back, bringing god knows what into our universe? What a rip off!
  • I'm probably not alone in that my understanding (flawed as it is) of the Theory of Relativity, Quantum physics, and other Big Science Questions is based almost entirely on "A Brief History of Time" and "The Universe in a Nutshell". Well, that and "Cosmos" :-). But in those two books, he does an excellent job of explaining, well, *the universe* in a way that even I can understand. And that is no mean feat! So hats off to Hawking, may you lay down the phat [mchawking.com] beats for many more years to come!
    • But in those two books, he does an excellent job of explaining, well, *the universe* in a way that even I can understand.

      Several years ago (well, it's probably more like 10 now...ugh) I saw Hawkings give a lecture aimed at the layman to a packed theatre. It was really very impressive -- despite the nature of what he was talking about and his physical limitations, he was engaging, humourous, and very understandable. He's a credit to his field and science in general -- not only through his intellectual ach

  • Well... Duh (Score:5, Funny)

    by SkaterGeek (755048) <killon70@NosPAM.hotmail.com> on Wednesday July 21, 2004 @07:54PM (#9765349)
    Well... Obviously he's going to loose gracefully. Its not like he can get up and start yelling at the other guy. His chair probably doesn't even have an "Angry" voice
  • Fry: Hey! Stephen Hawking! Aren't you that physicist who invented gravity?
    Hawking: Sure. Why not?
    Fry: Let me ask you something. Has anyone ever discovered a hole in nothing with monsters in it? [Hawking's eyes widen in horror.] 'Cause if I'm the first, I want them to call it a "Fry Hole."

    Later:

    Fry: So what do you nerds want?
    Nichols: It's about that rip in space-time that you saw.
    Hawking: I call it a "Hawking Hole."
    Fry: No fair! I saw it first!
    Hawking: Who is The Journal Of Quantum Physics going to believe?

    Interesting note: Apparently Stephen Hawking did provide his voice for that episode.
    • Yeah it's a bit weird that a guy with a computerized voice actually does the guest voices on shows like Futurama and The Simpsons. Of course there was that story a while back about him being worried he'd lose his voice. Apparently his voice-dealy is really old and won't last too long and they can't get a good replacement. All the modern synths are too good!
    • Interesting note: Apparently Stephen Hawking did provide his voice for that episode.

      Sad note: Stephen Hawking hasn't provided HIS voice for anything in many decades.

      Interesting note: Hawking was also featured in an episode of the Simpsons. Groening must be a fan. Who wouldn't be?

      Council: Stephen Hawking!
      Skinner: The world's smartest man!
      Lisa: What are you doing here?
      Hawking: I wanted to see your utopia, but now I see it is
      more of a Fruitopia.
      Skinner: [chuckles] I'm sure what
  • Aww crap! (Score:4, Funny)

    by EmbeddedJanitor (597831) on Wednesday July 21, 2004 @08:05PM (#9765437)
    So now all those aliens that got sucked into black holes in the seventies will be back in future Startrek etc episodes.
  • From the article:


    (This is the formal announcement promised last week.)


    Great! Now they are programming dupes one week in advance...

  • by Anonymous Coward on Wednesday July 21, 2004 @08:07PM (#9765456)
    Oh damn, that means there's gonna be a sequel to Event Horizon... :o(
  • by Hypharse (633766) on Wednesday July 21, 2004 @08:17PM (#9765528)
    From the speech synopsis:
    The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.

    For those grammatically declined I'll explain it to you with an analogy. It's like when you were in high school and used mirrors to peek around the corner into the girl's locker room. The naked chick in the mirror is the APPARANT horizon. The naked chick that kicks the testes back inside your body shortly after DOES NOT EXIST.

    Also, just for laughs (ok...hopefully for mod points too, I admit) Hawking is also a freaking awesome DJ and serial killer on the side. All my Shootin's be driveby's [berkeley.edu]

    Wu's site [berkeley.edu] has other cool stuff to see too. (not a plug, just want to give credit to where the song is downloaded from)

    • "Hawking is also a freaking awesome DJ"

      A DJ is the one that plays the music. The MC is the one that raps. Hawking is the MC.

      Though, it would be interesting to modify his speech computer to control two turntables and a mixer.
  • since my job has disappeared inside a black hole
    and I still don't see any trace of it.
  • A great one knows when he is wrong.
  • Would anyone care to dumb down his point a bit?

    How can this be possible? I thought the whole point of black holes being 'black' was because they had a spherical boundary the crossing thereof would result in an escape velocity greater than C.

    How can something like that only be apparent?

  • MC Hawking [mchawking.com] could not be reached for comment.

    /jk
  • Welcome to good science.
  • by steve buttgereit (644315) on Wednesday July 21, 2004 @08:37PM (#9765670) Homepage
    From the Rueters article pubished by wired...

    For over 200 years, scientists have puzzled over black holes, which form when stars burn all their fuel and collapse, creating a huge gravitational pull.

    Now I'm no scientist, but 200 years of black holes seems like they're giving the issue more duration than history warrants. I thought the concept of a 'black hole' was a consequence of Einstein's relativity work (general, special I can never remember which is which... think it's general).

    Am I wrong and just missed a whole bunch of science history?

    Cheers!
    SCB
    • Black Holes were a theory developed by Professor Hawking, when he realized that objects larger than the Chandresaker Limit not only existed but had no explainable "death".


      (It had been assumed, up until that point, that objects larger than the Limit could not exist, as the maths went crazy with numbers reaching infinity.)


      So, unless Professor Hawking is older than he looks, I think we can safely assume that Black Hole theory is probably more like 60 years old.

    • by John Meacham (1112) on Wednesday July 21, 2004 @09:15PM (#9765894) Homepage
      Black holes were first predicted in 1783 by a geologist named John Mitchell.

      All that was needed to predict something odd would happen at this mass was the concept of escape velocity and that light had a velocity, both of which have been known for quite some time.

      More info can be gotten at:
      http://en.wikipedia.org/wiki/Black_hole
    • by m5brane (322163) on Wednesday July 21, 2004 @09:21PM (#9765926) Homepage
      Yes. You're missing 200 years of Black Hole history.

      The notion of a body whose gravitational force is so strong that not even light can escape was put forward in the late 1700s, first by a British geologist and later by Pierre Laplace. The solution of General Relativity that would come to be recognized as a Black Hole was put forward by Karl Schwarzschild in 1915, only a short time after Einstein had presented his theory of General Relativity. Schwarzschild developed his solution while serving with the German army, on the Russian front. Chandrasekhar's work was initiated in the 1920s. The idea of "Frozen Stars" remained known to physicists, but wasn't the focus of as much attention as it is nowadays. It wasn't until the late 60s and early 70s that they began to attract more attention, and around that time the phrase "Black Hole" appeared.

      A great deal of Hawking's work has been devoted to Black Holes, and he is responsible for a number of significant developments in our understanding of them. In fact, "significant development" doesn't quite do it credit, as some of his ideas were so counter-intuitive (the notion of Black Holes radiating, for one!) as to be totally unexpected. But he definitely did not invent the concept of a Black Hole!

      m5brane
    • by dr. loser (238229) on Wednesday July 21, 2004 @09:25PM (#9765955)
      You're missing something. See, for example, this Brief History of Black Holes [uiuc.edu].

      Once it was clear that light moves at a finite speed, an English geologist, John Michell [wikipedia.org] realized that one could imagine an object with a gravitational escape velocity greater than c. Such an object would appear black. Of course, the term "black hole" didn't appear until much later.

    • The exact theory of a black hole came around Einstein's time, but a physicist in the 1700s-ish theorized that an object could be so heavy even light couldn't get out - even before they realized that gravity does affect light.
  • by HorsePunchKid (306850) <sns@severinghaus.org> on Wednesday July 21, 2004 @09:49PM (#9766082) Homepage
    The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.
    (Quote from the summary in one of the links from the submitter.) That pretty much sums it up to me (IANAP). We studied this in a class I took at UIUC called "The philosophy of space, time, and matter". (No, it wasn't [severinghaus.org] a fluff course.) Basically, from the perspective of someone outside the black hole, the event horizon never actually forms. You see matter spiral in toward the black hole, radiating energy as it falls in (we observe this as x-ray bursts). But you never see the matter actually hit the event horizon! If the universe would last long enough (it won't), you would see that by the time the matter hit the event horizon, the black hole would have evaporated (due to Hawking radiation).

    What Hawking seems to be saying to me is that since the matter never enters the hole from the perspective of an observer outside the hole, the information is never lost. Does this make sense?

  • My take (Score:3, Insightful)

    by Epistax (544591) <epistaxNO@SPAMgmail.com> on Wednesday July 21, 2004 @09:58PM (#9766123) Journal
    This stuff is just awesome to think about. Here's some rambling. If anything makes sense I'd appreciate some feedback.

    I hold that quantum theory is entirely a guess based on possibilities because we currently cannot (and perhaps never can) get true facts on the matter so that real analysis cannot be done. I don't know if anyone has any objections to this but I'm not sure if people realize it.

    Take any level of physics, and only allow yourself to view it from a level above. You can come up with some good guesses as to how things will work which might have a very high degree of accuracy even 100%, but you are really just guessing. A simple example is that modern theory states that any two solid objects can pass through each other without interfering with each other at all-- it's just extremely improbable.
    As a parallel: If you look at any scene in a 2 dimensional perspective you'll see objects passing through each other all the time (behind and in front although to 2d it's the same space). Now if the universe was 2d we could say that everything exists on the same 2d plane and any objects passing through each other is known to be impossible, but we know there's a 3rd dimension so to us it's entirely possible, even though everything in that universe is on the same plane. Well everything in this universe is in the same space, that is, they are all on the same 4th, 5th, 6th etc dimensional coordinates-- but that can just as easily change.

    A 1 dimensional basic has 2 points connected by one line.
    A 2 dimensional basic has 3 points, connected by three lines, encompassing one face.
    A 3 dimensional basic has 4 points, connected by six lines, encompassing four faces, containing one space.
    Guesses? A 4 dimensional basic has (5?) points, connected by (10?) lines, encompassing (5?) faces, containing (3?) spaces, bounding 1 thingy?


    I know I'm not the only person who has tried to mentally vision higher order shapes!
  • Synopsis explained (Score:5, Informative)

    by mike_lynn (463952) on Thursday July 22, 2004 @01:22AM (#9767238)
    ... by someone who doesn't know physics.

    The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.

    The Euclidean path integral is the latest trick in quantum gravity.

    The original problem with quantum gravity was that as you "quantitized" space into discrete units, explaining gravity in terms of particles like 'gravitons' and trying to do the math was possible for simplistic interactions like tree diagrams where time generally flowed one way - but extremely hairy and full of infinities if you started looking at loop diagrams where time can flow both ways.

    So people like Roger Penrose came at it from a different direction, starting off with definining space-time in a quantitized manner (spin networks, quantum foam, whatever you want to call it) which had the side effect that complex examples of spin networks acted a lot like 3-dimensional Euclidean space.

    Once people started talking about space-time like this, math started showing up that helped describe events and the progression of events in this space-time, including the Euclidean path integral which attempts to measure the end result of an interaction of particles in this type of space-time.

    (Good link talking about path integrals and how they were a problem with quantum definition of gravity: http://www.damtp.cam.ac.uk/user/gr/public/qg_qc.ht ml [cam.ac.uk])

    Anyways, it sounds like he's saying: All this new math is great and if the world were a simple place, yeah, black holes would probably have an event horizon and the math to prove it is simple.

    But the world is more complex than you think and doing the math for "the real world" shows that the closer you get to the end result, the less and less predictable the end result will be, even though overall it looks like it has a defined end result (i.e. it looks like it _should_ have an event horizon). In reality it's constantly shifting around - and likely this amount of shifting around is representative of the original information/particle system that went into its formation but you won't be able to trace it backwards and extract what the original information was.

    This will probably tie into time dialation which will make it be: We never get to the end result event horizon that 'should' be there and in the process of never getting there, the black hole will have a nice jiggly event horizon as a result of all that information - but so jiggly we can't tell what went in to it, all we can do is measure the jiggliness.

    What he hasn't explained is how he knows this and the math behind it.

    Crap I'm bored.

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