Hawking Solves Black Hole Mystery

[Labguy]

Labguy, sometimes I don't get jokes----are you really 100 years old this year?

But somehow you got this impulse to tell us you were born in 1904, the year after Kitty Hawk. We celebrated your 100th birthday at PF and I wrote you a congratulatory post which you probably didnt read.

I know some people live past 100 and remain very sharpwitted so I have to believe you were not pulling our electronic legs.

No, actually I don't type worth a *%#@ and only noticed last week that I was 100 years old. So, I changed (1905, I think) to 1975. You won't believe how long it takes me to type even a short post; two-fingered.

I don't usually like to post sarcastic comments, but it does get my feathers ruffled when someone (other threads) flat-out calls me an idiot when I have doubts about point singularities of infinite density, or when I state that a black hole can emit pairs of real particles by methods other than "Hawking radiation". They can and do, period.

You come across as a curmudgeon, perhaps, but more like a curmudgeon in early retirement.

I don't know what one of those is. (?)

If I had to guess, I'd say born in the Depression years 1932-1940.

Cripes, I'm not that old. Also, my name actually isn't "Labguy" any more than bozo is bozo or jcsd is jcsd, etc. If you're Marcus then I'm Stephen, that's a real name. But, like holly says, back to black holes.

_____________________
Stephen Sherrod
(There are about 12 of us scattered around the US)

 

[marcus]

OK people want to talk about black holes.

I will toss in a two-bit opinion that may be relevant to the present media play.

Unitarity

It is like singularity
(the word has a technical meaning that doesn't jibe with what it sounds like and this has caused public misunderstanding and turmoil for years)
A singularity is a region where a model breaks down and fails to compute or computes nonsense like infinities. A singularity does not have to be a single isolated point---the model can break down over a whole region.
But it sounds like the bad place should be a single isolated point.


The Black Hole Information Paradox could also be called
"the Unitarity of quantum mechanics paradox"

Unitary sounds like universal or unified or whole or united but it doesn't mean that. It is a mathematical terms meaning "distance preserving" which is applied to the time-evolution operator in conventional quantum mechanics. And even the idea "distance -preserving" is misleading. What it comes down to is that the time-evolution operator in conventional quantum theory preserves virgin unmixed states of the system, whatever the system is.

In conventional quantum theory the time evolution operator preserves information because it preserves pure crisp quantum states.
These are states with definite quantum numbers describing them that have not been mooshed or averaged together with other states so that it is part this and part that. It is a hard idea and maybesomeone else will help.

If a state is pure and crisp then by conventional QM it will always be so if you just let time pass-----even 10⁶⁰ years will not cause one hair to turn gray. Shakespeare probably wrote a sonnet about it.

But people have found a case, involving a black hole, where it does not seem to work.

Shhhh! Maybe there are many many cases where this "unitarity" of time-evolution does not work. maybe it is actually an unrealistic assumption built into conventional quantum theory. Heresy!

The BH info paradox excites physicists basically not because of black holes but because it threatens one of the all-time most fundamental assumptions of Quantum Theory------which for many physicists is like threatening Mother.

But they will mostly not admit that. Your physicist in the street will say that the paradox shows there must be something wrong with our understanding of black holes.

they must, somehow, not destroy information but instead somehow "let it out" in a kind of burp after they eat something

or by "teleportation" or in a little *pop* that happens 10^60 years later when they evaporate. So people are busy imagining burp mechanisms by which the info can be restored to the world at large at least by the time the black hole evaporates and is no more.

this is a way of saving Mother Unitarity

 

[marcus]

I don't usually like to post sarcastic comments, but it does get my feathers ruffled when someone (other threads) flat-out calls me an idiot when I have doubts about point singularities of infinite density, ]

I hope holly will join me in roundly admonishing whoever called Labguy idiot, which he most especially is not.

Also congratulations on being 29 years old and not 100, as was heretofore supposed.

Also you seem to have been prophetic about doing away with the BH singularity. Bojowald (who did away with the BigBang singularity by quantizing the equation that governs it) is getting set to look at black holes, and I would expect that he will quantize the model we have of them and there will turn out to be something interesting quantum business down where the singularity used to be.

the density, I would hazard a guess like yours Labguy, may well not be infinite down in the Planck scale guts of the thing.

Or maybe Bojowald will fail and someone else succeed. At all events infinities are meant to be done away with by improving the model

 

[holly]

I KNEW the yardstick would work. Now we ALL feel better.

Except for me. I thought that the BH really were going to "burp" the information back out, as marcus so pithily put it. Isn't that what Dr. Hawking says now? And we can catch the information? But marcus is thinking that's not it, so now it doesn't seem so hopeful. Or maybe I don't understand what marcus says. I thought we had a good chance to see some of the past happenings as they go by. I had my heart set on seeing some of the stories of Genesis.

I hope no one is calling Labguy an idiot. I still have the yardstick handy.

(sol2, the dogs weren't hurt by the ruler. They couldn't calm themselves, didn't know their place. The vet let them know he was top dog and that everything was safe and okay. These were just dogs boarding, no time to train them. No one seems to care I was whopped also. Hmph.)

How can the BH stuff be proven? Is it proven by math or by some experiment? Are enough people working on it?

 

[marcus]

I KNEW the yardstick would work. Now we ALL feel better.

Except for me. I thought that the BH really were going to "burp" the information back out, as marcus so pithily put it. Isn't that what Dr. Hawking says now?

yes dammit holly, but with all (well-earned) respect due to hawking
he could be wrong

indeed he has found a burp mechanism

but this is the free marketplace of ideas and people may not buy it

other eminent physicists (e.g. leonard susskind, maldacena) have invented burp mechanisms and tried to market them and people have not bought

another possible view of the paradox is that a burp is not needed
because by the time the black hole evaporates the information
it ate might simply have died or faded away naturally

maybe the paradox is telling us that information is not everlasting
and crisp new quantum states do not last forever


at present this little squabble is among mathematicians and the like,
and it is resolvable by more or less theoretical means (without experiment)
if I understand the issues rightly. Also I suspect
they probably didnt need to have made such a ruckus about it

As for great poetry, we know it lives forever anyway. just
dont let your books get rained on and keep them from falling into black holes

 

[sol2]

(sol2, the dogs weren't hurt by the ruler. They couldn't calm themselves, didn't know their place. The vet let them know he was top dog and that everything was safe and okay. These were just dogs boarding, no time to train them. No one seems to care I was whopped also. Hmph.)

You have to look at the whole picture. From chaos(dogs barkng to the bell) You would have thought Pavlov was a Tibetan Om my goodness




One of the ways I tried to approach it was looking at http://wc0.worldcrossing.com/WebX?14@65.ORaxciqPmmj.0@.1dde6b71 .

Well at the same time you are looking at the collapse you must also envison other dynamcis going on, much like what Heisenbergs saw in the use of the collapsing sphere. In his case, we are talking about the bomb.

So far(sonolumnence) it might be consistant up to a point of...did the universe really begin from a black hole? Then how would we have understood somebody unrolling their cuffs? Or turning inside/out(klein bottle). You have to watch the whole process, like watching the Bose Nova.

Along side of this subject, Bubble eversions and geometrodynamics.

 

[bozo the clown]

The black hole is a storage point for a mind boggling amount of energy that upon critical mass then releases that energy in one gigantic explosion. Our only knowledge of such occurence is the big bang.
Thats a common sense opinion on black holes.

 

[turbo]

Black hole burp

I can't wait to see what Mr. Hawking has come up with this time! As I posted earlier on another thread, I often think what a black hole would look like if its event horizon collapsed for some reason. I don't know what reason there could be, but what if black holes are not simple mass-dumps? They are, after all, unobservable in our universe except for their effects. They create a "pinch" in space-time (singularity) and presumably they develop very luminous accretion disks as material from our visible universe falls into them.

The material in a black hole is not visible to us, and it may not be constrained by the "rules" we make up to match our perception of the black hole. We say that the black hole must be a singularity, because that's the characteristic we perceive/predict based on the rules in our universe. A "black hole" may well exist as something other than a singularity in its own universe, however, and instead of being a monolithic "nothing" it may have its own complex dynamics. If those dynamics cause its relationship to our observable universe to change, who is to say that we might not see a black hole's event horizon collapse or shrink, from our viewpoint?

If this should happen, would we see a VERY luminous small body, not unlike a quasar? Would not the light emitted from such a compact super-dense region be heavily redshifted? I'm very interested in high-redshift objects, and in quasars in particular, since their luminosity is far greater than we can possibly account for (if they are at the cosmological distances implied by their redshifts).

 

[sol2]

One would have to understandhttp://universe.gsfc.nasa.gov/images/lifecycles/cycles.jpg

Think about shell fractures that preceed black hole formations?

 

[berty]

If Hawking new theory of black holes states that they don't have a well defined event horizon, how does this affect the gravitational tidal force gradient? Will light still orbit in parallel at the boundary, or is there no longer a distinct boundary?

If as he says information is eventually released from black holes, what form is it likely to take? And is it likely that a sufficiently technologically advanced intelligent species (if one still exists) would be capable of deciphering it?

 

[marcus]

Will light still orbit in parallel at the boundary, or is there no longer a distinct boundary?

the radius at which light is predicted to orbit a Schwarzschild black hole is
3GM/c²

the radius of the event horizon (whether it exists or not) is 2GM/c²

light is not supposed to skim parallel along the surface of the event horizon

it is supposed to do that outside, 50 percent further away

I cannot imagine that anything Stephen hawking or anyone else says next week is going to change scientific opinion about light going in circles around a black hole at that 3GM distance.

no one can know the future, but at this point I feel utterly confident that next week light will still circle black holes at the same distance as always and whatever else may trouble us at least we don't have to worry about that one

 

[sol2]

scratch scratch...hmmmm...maybe we are stripping the photon?

 

[turbo]

One would have to understandhttp://universe.gsfc.nasa.gov/images/lifecycles/cycles.jpg

Think about shell fractures that preceed black hole formations?

There are a couple of ??s in that diagram. First of all is the big multicolored bang at the top left, and another is the one-way nature of black holes near the right-hand side. We have a magical (here it began-don't ask why) in the former and another unknowable (oops, it's gone forever) singularity situation in the latter. Why do we cling to such concepts?

We humans tend to think of our universe as having a beginning, a middle, and an end because WE do. We also tend to think of our gods as bigger, more powerful, versions of ourselves. We may need to look at cosmology a little less anthropologically before some of these things make sense to us. It may be that we should take another look at an infinite universe with continuous creation and destruction. The Indian goddess Kali is a good example, in some of her aspects simultaneously giving birth and killing. I don't want to get too metaphysical, but it seems like many folks approach cosmology and religion in a similar fashion, and I want to point out that what we *want* to believe is not exactly how the universe is constructed.

 

[Devilin]

turbo-1 The universe isn't infinite, starting from the big bang traveling at the speed of light, its has a definable size, the universe also has a beginning, the big bang, a middle, the bit between the big bang and the big END, and the end of the universe, in approximately ( somebody correct my bad interpretation of the mathematics) 10 to the power of 32 years, about lunch time, the Half Life of Proton's , the universe runs out of energy and dies, arrrrr, clump. it's worse than that, its dead Jim



The rest of you near due wells
OI what about my field's of maggots ?

 

[Labguy]

turbo-1 The universe isn't infinite, starting from the big bang traveling at the speed of light, its has a definable size, the universe also has a beginning, the big bang, a middle, the bit between the big bang and the big END, and the end of the universe, in approximately ( somebody correct my bad interpretation of the mathematics) 10 to the power of 32 years, about lunch time, the Half Life of Proton's , the universe runs out of energy and dies, arrrrr, clump. it's worse than that, its dead Jim



The rest of you near due wells
OI what about my field's of maggots ?

Maybe. Linde has been thinking about that lately:

http://www.newscientist.com/news/news.jsp?id=ns99992759

 

[sol2]

There are a couple of ??s in that diagram. First of all is the big multicolored bang at the top left, and another is the one-way nature of black holes near the right-hand side. We have a magical (here it began-don't ask why) in the former and another unknowable (oops, it's gone forever) singularity situation in the latter. Why do we cling to such concepts?

To your question, one just has to look at the http://www-glast.sonoma.edu/index.html Let it load and look at the ways in which we can look at the universe.

 

[Chronos]

Apologies to Marcus. I got a little cross there and vented on you. Professor Hawking is a remarkable man. Despite infirmities that would have sucked most people into a 'black hole' of despair, he has accomplished more than most fully functional humans have ever attempted. It ruffles me when unfair criticisms are raised about his work. He can even change his mind without making excuses [a rare trait in scientists]. Your rebuttal of my diatribe was elegant. So back to black holes...

No one seems to talk much about the Planck density in black hole theory. I don't understand that. Applying the Planck mass and Planck volume seems to solve the whole singularity problem. A black hole, while incredibly dense, still occupies a finite volume, hence it has a finite density. I have this notion that physical reality is limited by mathematical boundaries and vice-versa. If this is not true [examples would be appreciated], I need to rethink everything I thought I knew about physics.

 

[MadIce]

Articles of Ohio State University

Gokul congratulations for various things! Like being in the physics department at Ohio State 3 doors down from Mathur and so forth!
I will keep an eye out for your papers----or, if you are not too modest to self-promote, please give a link to some of your research.

In the other thread ("PF member solves BH info paradox") where we were also discussing this, you mentioned Mathur's efforts in that direction.

In that thread, I remember giving two arXiv links to Samir Mathur papers:

http://arxiv.org/gr-qc/0007011
Resolving the black hole information paradox
Samir D. Mathur

http://arxiv.org/hep-th/0205192
A proposal to resolve the black hole information paradox
Samir D. Mathur

The first one is the one you mentioned. In the second one the title seems more tentative. Since you know Mathur, does he currently feel that he has resolved the paradox? And if so, would that be restricted to a string theory context somehow, or valid generally?

Here is link to that thread "PF member solves BH paradox"
https://www.physicsforums.com/showthread.php?p=246672#post246672

I think the wonderful thing about a good paradox is that it keeps on being paradoxical until some fundamental notions change. Do you think so, and would this apply to BH info paradox?

I suspect that BH info paradox will persist until there is a change in some fundamental notion, like time or black hole or something equally basic.

I suspect it will not be resolved merely within the context of some established model, but it will force some change in the model.

must stress, of course, that this is a humble personal opinion. Best wishes to you and colleague Samir.

The Ohio State University claims that...

Samir Mathur and his colleagues have derived an extensive set of equations that strongly suggest that the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.

The finding suggests that black holes are not smooth, featureless entities as scientists have long thought.

Instead, they are stringy “fuzzballs.”

You can find the full article here: http://researchnews.osu.edu/archive/fuzzball.htm

The paper in the March 1 issue of the journal Nuclear Physics B mentioned in the above article is available at: http://arxiv.org/abs/hep-th/0311092

More publications:

http://arxiv.org/abs/gr-qc/0007011
http://arxiv.org/abs/hep-th/0205192
http://arxiv.org/abs/hep-th/0401115
http://arxiv.org/abs/hep-th/0405017
http://arxiv.org/abs/hep-th/0406103

 

[Devilin]

Maybe. Linde has been thinking about that lately:

http://www.newscientist.com/news/news.jsp?id=ns99992759

Dark energy. pahh, dark matter, pif & nonsense, if you can't work it out conjure up some, dark energy fairy's with magic dark fairy dust to, sort it out for you,

And over look the totally obvious,

The universe, is nice and warm, and although its a vacuum it isn't a complete vacuum, positive energy and all that, blar blar blar, anyway because the universe isn't a complete vacuum, putting it in a complete vacuum, would make it expand at an accelerated rate, once gravity started to lose its grip, i.e. we're expanding into a total vacuum, probably a dead universe, at a guess,
Somebody call new scientist, and give me a banana

 

[marcus]

The Ohio State University claims that...
...
...

You can find the full article here: http://researchnews.osu.edu/archive/fuzzball.htm

The paper in the March 1 issue of the journal Nuclear Physics B mentioned in the above article is available at: http://arxiv.org/abs/hep-th/0311092...

...

Out of respect for Samir Mathur and the scientific content of his paper, we should probably try to assess what it actually says (and not necessarily how the OSU "Research News" reporter named Pamela Gorder interprets it for the public)

MadIce, thanks for the links!
this answers at least one of the questions i asked in my post
"Is the result limited to a string theory context?"

the abstract for Nuclear Physics B article helps to clear this up.


the result is for certain of the "extremal" black holes of string theory----these are not the black holes of General Relativity which GR-theorists and astronomers usually talk about, but instead are hypothetical structures assumed to be so highly charged electrically and/or spinning so fast that they only barely fall short of disassembling.

there is no testable string theory, so of course one cannot be sure that results derived within a string context have anything to do with nature, but if the brand of string theory used by Mathur were ever brought to a verifiable point and found to serve as a model for reality, then the result would apply to "extremal" black holes rather than to those objects which astronomers think they are observing these days and call black holes, or which GR-theorists such as Hawking and friends normally theorize about.
the "extremal" black hole is a mental construct which is rather special to string theory and not really current elsewhere AFAIK.

Here is the abstract of the Nuclear Physics paper you kindly and helpfully provided:

"It has been found that the states of the 2-charge extremal D1-D5 system are given by smooth geometries that have no singularity and no horizon individually, but a `horizon' does arise after `coarse-graining'. To see how this concept extends to the 3-charge extremal system, we construct a perturbation on the D1-D5 geometry that carries one unit of momentum charge $P$. The perturbation is found to be regular everywhere and normalizable, so we conclude that at least this state of the 3-charge system behaves like the 2-charge states. The solution is constructed by matching (to several orders) solutions in the inner and outer regions of the geometry. We conjecture the general form of `hair' expected for the 3-charge system, and the nature of the interior of black holes in general."

the operative word at the conclusion is "conjecture" and it is conjectured that the inside of a general black hole (not the type or types special to string theory but presumeably the usual kinds other people talk about)
is, as Pam Gorder puts it in her research-publicity article

"...a giant tangle of strings that fills a black hole from its core to its surface"

---------
each of us has to make of this what he or she will
but the message does not seem to address the main problem at the heart of the BH Information Paradox, which is "how does the information get out before the BH evaporates?"

Samir is conjecturing a form in which the information that falls into the hole may continue to exist. But that is not what bothers people. the information could exist in various ways. What causes the paradox is the expectation that the hole will evaporate---so then where is the information?

OK it fell into the hole and Samir Mathur has encoded it in a gigantic tangle of strings. But a trillion years later the hole has evaporated by emitting Hawking radiation for a trillion years. How did the information get out? Or did it unravel somehow from the "gigantic tangle of strings" where it was encoded, and die, while it was waiting inside the hole? Or was there some trick method which allowed it to escape?

String theory, indeed conventional quantum theory in general, does not allow information to die. Time evolution is "unitary" ----math jargon meaning in this case information-preserving.

It does not appear that postulating a gigantic tangle of strings inside the hole, which is made to encode the information, addresses the heart of the paradox.

However there may be other Samir Mathur papers which treat the question everyone is asking which is how does the info escape. Apparently
Leonard Susskind, another string theorist, conjectured a kind of "teleportation" in the 1990s that would get it out. Various people have apparently conjectured various mechanisms. Somewhat like Houdini Escape-Stunt trick doors that allow Houdini to get out of the lock and chains and box submerged in the swimming pool, before he suffocates or drowns.

Anyway it is all very interesting. I think you would agree that we owe it to Samir Mathur to try to get some notion of what he actually is claiming to have proved. And in some other paper he may have conjectured a Houdini Escape mechanism---which would be fascinating to know about----so I hope you will kindly pass along some links about that if you find any.


Reply to Devilin. Devilin the satirical way you ended your last post made me break out laughing. I can easily imagine a theorist saying just that upon finishing his latest brilliant research paper.
"Somebody call New Scientist, and give me a banana."

 

[marcus]

A more relevant Samir Mathur paper?

I was checking out other Samir mathur papers and saw this.

"It will be interesting to address dynamical questions with the above picture. It is possible that infalling matter falls straight through the ‘fuzzball’ towards r = 0 (as if it were falling through a conventional horizon), but over the Hawking evaporation time information is transferred to the ‘light fractional modes’ and into the radiation."

No mechanism is proposed for how matter plummeting to the center of the hole should give up its information to the "giant tangle of strings" or whatever dwells in the hole.

but it is "possible" that it some how does transfer its information to the fuzzball or whatever dwelleth in the hole.

Now how might such information be transferred out thru the event horizon and percolate into the Hawking radiation witnessed by the outsider world?

"... we have argued that bound states swell upto a size of order the horizon radius; thus the interior of the horizon is not just ‘empty space with a central singularity’. This makes it possible for radiation from the hole to pick up information from the ‘hair’ and avoid the information paradox."

Again it is suggested to be possible for Hawking radiation leaving the hole to have "picked up"---perhaps the idea is "to be infected by" as one picks up a flu germ---information encoded in the tangle that dwells in the hole.
I guess the possibility is shown by proximity---because the tangle extends out to the horizon where the radiation is. But again no mechanism.

The above quotes are from the conclusions of

"Where are the states of a black hole?"
Samir D. Mathur
7 pages
http://arxiv.org/hep-th/0401115

Abstract: "We argue that bound states of branes have a size that is of the same order as the horizon radius of the corresponding black hole. Thus the interior of a black hole is not `empty space with a central singularity', and Hawking radiation can pick up information from the degrees of freedom of the hole."

My comment:
As yet no mechanism for the info to seep out thru the event horizon and be transcribed into the Hawking radiation.
Hawking radiation is usually considered on theoretical grounds to be "thermal" which means it doesn't carry information----thermal blackbody radiation is the nondescript generic glow corresponding to a given temperature.

thanks to MadIce for calling attention to Mathur's interesting work
I hope everyone checks it out and sees what it actually says.
Salutes to Mathur for ingeniously proposing some string theory getaway
routes---though as yet without means for the information to travel them.
I remain skeptical as to anyone actually having resolved the Info Paradox, at least in the way Mathur and others appear to want it resolved

 

[turbo]

To your question, one just has to look at the http://www-glast.sonoma.edu/index.html Let it load and look at the ways in which we can look at the universe.

That's a nice page, and yes, I know that we can see our observable universe in LOTS of wavelengths. That was not my point, though.

The theories relating to the Big Bang are generally agreed to be consistent with observations to a remarkable degree of accuracy, BUT this has been accomplished by invoking all kinds of things that cannot be observed or measured, except by testing for self-consistency within the various flavors of cosmological theory. All our physics falls apart near the BB singularity, and we need to invoke inflation, dark matter and dark energy to explain the current state of the (presumed) accelerating expansion of the universe, etc, etc. The constant tweaking and refining necessary to hold standard BB theory together troubles me. It seems that as our grasp of the nature of the universe improves, we should be able to do away with some of these band-aids, and not have to apply more and more of them.

Observational astronomers keep discovering older and older quasars and very massive luminous galaxies (at least if they are at the cosmological distances implied by their redshifts), which leads us inescapably to the conclusion that either the very early universe was much more highly ordered than we can account for with the current standard heirarchical model OR perhaps there may be other causes for the high redshift observed in these objects, so that high redshift does not perfectly equate to distance and age. When the monster binocular telescope comes on line, I predict that astronomers will discover objects that are even more highly redshifted than the ones currently known. When that day comes, we are going to have to take a hard look at the 13.7Gy age of the universe. I hope it will prompt some fresh re-assessments and not just a new layer of band-aids.