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Black Hole Information Loss Paradox Solution Proposed
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."
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?
would be proud.
Welcome to the Panopticon. Used to be a prison, now it's your home.
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.
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.
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
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.
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.
There are 10 kinds of people in this world: those who understand binary, and nine other kinds of people.
Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.
-- http://www.mrc-cbu.cam.ac.uk/~mattd/Cmabrigde/
The unofficial
Achilles vs. the Tortoise all over again?
``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
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..
That's an interesting viewpoint, but I don't think you understand physics.
QM lies at the physical border of observable physics. At the QM boundary, concepts we take for granted such as electrons and the speed of light have different meaning. Humanity has nothing to do with it. At a small scale, the behavior of matter changes.
Here's an analogy:
Let's say Newtonian (ordinary) physics involves sitting on the side of the road and tracking how fast people are driving in their cars. From this perspective, you can get a pretty good idea where the cars are going. But there's still some randomness to it, if some driver changes their mind.
In this analogy, QM would be like sitting inside each car tracking who is having what conversation, who is on their cellphone, whether their hands are on the gearshift or on their girlfriend's boob, etc. It's a whole other level that you can't see from the side of the road.
If you could be inside each car, then you would know. But you can't. That's QM, the individual decision-making of each driver on the road.
Each driver==each electron. Whether you choose to track electrons with free will or with robotics, it's still too small and random to keep track of all the time.
The problem that the study didn't take into account is when somebody has another native tongue (but understands the language the garble is written in) like me. My native tongue has similar words to English, similar spellings yet different meanings to the words. So once you start using combinations of letters that have similar words in the native tongue, people get confused.
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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 from the oven. Or that the magnitude of the electric field near a point charge "grows arbitrarily large" as you get "arbitrarily close" to it. As a mathematician, I love infinity, I really do --- there are infinitely many of them to choose from! But, IMHO, they don't belong in models of the physical universe (apart from simplifying calculations such as integrals over R^3). I don't believe that time is of infinite duration, that space is without bound, or that either one is infinitely subdivisible. Matter and energy are quantized, why not space and time? It has a nice symmetry to it --- a fan favorite for both mathematicians and physicists.
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 chaotic way, mind you) is the central question that people are trying to answer. It's an unsolved problem. Your suggestion would probably get the "right answer" for any real-life measurement we're going to make on black holes anytime soon. But the math may be hinting that there is an underlying physical principle we've been ignoring thus far. This is what has physicists excited: the possibility that this hint may lead to another revolution in our understanding of the universe.
I see where you're coming from. We can't know whether the universe is fundamentally 'supposed' to be time-symmetric or time-asymmetric. So maybe the universe is ruled by equations of the sort you describe. However the really troubling thing is this: all the fundamental equations of physics are time-symmetric. These are the equations that are used to predict and model the existence of black holes. So it's really weird that time-symmetric equations predict the emergence of a time-asymmetric phenomenon. (If you have equations that don't differentiate between left and right, it would be surely astonishing if, after some algebra, the equation had a preference for left or right. Where did the preference come from? You probably made a mistake in your algebra!) The idea of time-symmetry suddenly being broken is tantalizing. It suggests that either we have a hidden assumption in our current models, or that the universe is really able to generate time-asymmetry from time-symmetric forces. Either realization, if proven, would be an important contribution to physics. So I guess it again comes down to physicists not just being uncomfortable with the inelegance of the current formalism, but also hoping that the resolution of this paradox will provide new insights.
Since my background is in chemistry, I also tend to think of the problem in terms of entropy. In which case, to a large extent the emergence of time-asymmetry just amounts to the axiom "the universe started in a low-entropy state" after which statistical mechanics nicely predicts all the phenomena we readily observe. (The viewpoint you describe, where given enough time the universe will simply wander into a low-entropy state, is actually quite compelling.) But that actually makes the black holes all the more tantalizing. Because in statistical mechanics, as you noted, even when you go into high-entropy states, you are not really destroying information. All systems can, in principle, return to previous (even low-entropy) states. (In fact there are equations that allow you to approximate what the 'recurrence time' for a given system will be... where eventually it will return to its initial condition, even if it is a highly-ordered state.) However in a universe with black holes destroying information, this no longer holds true. If you follow the 'information' in such a un