View Full Version : Hawking Solves Black Hole Mystery
russ_watters
Jul15-04, 11:37 PM
http://www.newscientist.com/news/news.jsp?id=ns99996151
The explanation will have to wait until next week though when he presents his findings at a black hole conference.
http://www.newscientist.com/news/news.jsp?id=ns99996151
The explanation will have to wait until next week though when he presents his findings at a black hole conference.
Hi Russ,
I started a thread about this a while back (2 July) and we had a fairly
wide ranging discussion which readers of this thread might want to check out:
http://www.physicsforums.com/showthread.php?t=33553
Somewhere in that thread there is Hawking's brief summary of the talk he plans to give, and a link to the whole program of the conference, listing all the plenary talks. It is the 17th triennial conference on General Relativity and Gravity (abbr. GR17) and by no means restricted to black holes!
John Baez and Roger Penrose will be talking. sounds pretty good
Devilin
Jul16-04, 12:26 AM
Apparently its taken him 30 years to find the answer :surprise:
He should have asked me, took about 3 minutes to work it out :biggrin:
And the answer is ----------------------------Magnetic fields,
Anybody care to do the mathematics, :confused:
russ_watters
Jul16-04, 07:33 AM
Hi Russ,
I started a thread about this a while back (2 July) and we had a fairly
wide ranging discussion which readers of this thread might want to check out: D'oh - sorry.
Gokul43201
Jul16-04, 07:52 AM
I don't think that title is fair. Most of the work was done by other people.
If he were not so humble, I'm sure Mathur (whose office is 3 doors down from mine) could claim to have solved the paradox.
Has anyone observed, recorded effects of Hawking radiation or shown
any evidence that it exists yet?, i think his theory is just a mathematical
pinprick, in the BH saga.
I dont know how much BH science theory ,matches "known",
things, with a high degree of certainty, maybe someone could
give the latest news?
Can Hawking bring any new thinking into BH science, i dare say
he will produce a nice mathematical solution, but with no real world
way of knowing if he is right.
I don't think that title is fair. Most of the work was done by other people.
If he were not so humble, I'm sure Mathur (whose office is 3 doors down from mine) could claim to have solved the paradox.
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"
http://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.
... i think his theory is just a mathematical
pinprick, in the BH saga...
wolram, I think you may have read Hawking's brief summary his paper which is posted at the Dublin GR17 site
It says something like "Event Horizons don't really exist"
the earlier so-called "semiclassical" analysis of BH
which Hawking and others did (back in 1970s, a lot of if)
assumes that the event horizon is a meaningful surface and it looks
at processes occurring around the event horizon
now the abstract of his talk is saying, in effect, "what we used to think of as an event horizon never really forms"
I dont want to sound either like a fan or a detractor of him
but his abstract promises to propose a basic change in how to look at black holes. If he comes thru on that, then maybe you will be satisfied.
Because that would tend to confirm what you just said, that the work up til now has been more of a semiclassical pinprick
or a semiclassical stab-in-the-BH-dark
that somehow didnt quite connect with the hole reality
the other aspect is Sir Stephen's showmanship
the abstract may have some blurb character
(rather than being just dry objective summary of what he will say)
in Dublin they must be talking about GR17 like it was a football match
or a new brand of beer
Here's the link to the GR17 programme
here is the webpage for the GR17 conference:
http://www.dcu.ie/~nolanb/gr17.htm
Here's Hawking's abstract taken from that GR17 site:
"- The information paradox for black holes
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."
bozo the clown
Jul16-04, 11:42 AM
Was wondering if any of hawking's work has actually been proven. Is it not true that you can do magic with maths ?
Was wondering if any of hawking's work has actually been proven. Is it not true that you can do magic with maths ?
I feel that it is very important to be discussing the work of Stephen Hawking with someone named Bozo the Clown
and therefore I am replying in haste to your question.
what you can do or not do with maths is a side issue
in fact someone at Cambridge was posting (I think on sci.physics.research) and saying that he had attended a seminar Hawking gave about this very work this summer, and that it was not even mathematically convincing.
there would not be any experimental backing, that is a given
the issue is not experimental evidence but mathematical rigor and consistency
in effect he said that even in that department it was a bit sketchy and he guessed it would not convince a lot of people that the paradox really was resolved
but who knows? we can just wait and see
quartodeciman
Jul16-04, 12:24 PM
Steven* Hawking is truly the successor to Albert* Einstein in terms of the power of fame. Everyone gasps when they promise to reveal something new. Also, it is a super big bonus to be able to argue convincingly against them. Who else can hold the presses like this.
*May we start calling them Steve and Al?
*May we start calling them Steve and Al?
Please not to call Albert Einstein Al
otherwise I have no concern
According to this article: http://www.cnn.com/2004/TECH/science/07/15/hawking.holes.reut/index.html
Is the "Way Out" simply a way to resolve the apparent paradox between quantum theory and physics at a larger level, or is it a hypothetical means to travel out of this universe, into others, as some versions of quantum theory imply is possible? Or is it a little bit of both? Or does anybody have any clue?
Devilin
Jul16-04, 04:03 PM
Maybe, I've missed something, maybe you've missed something,
let me see if this works, a black hole, is a gravitational dent in space time, and probably lots of other stuff, as well, but that's a different kettle of black holes, anyway a black hole, is a gravitational dent in space time, undoubtedly emitting a massive magnetic field, although matter, including light, and radiation are drawn towards the gravitational dent, the magnetic field would be unaffected, because the particles that make up a magnetic field, let's call them maggots, are unaffected by gravity particles
Now the supposed paradox that everything enters a black hole but nothing leaves, isn't really a paradox, because a black hole in a field of maggots will lose information through the maggots wouldn't it?
Devilin
Jul16-04, 06:50 PM
According to this article: http://www.cnn.com/2004/TECH/science/07/15/hawking.holes.reut/index.html
Is the "Way Out" simply a way to resolve the apparent paradox between quantum theory and physics at a larger level, or is it a hypothetical means to travel out of this universe, into others, as some versions of quantum theory imply is possible? Or is it a little bit of both? Or does anybody have any clue?
The theory combining classical, and quantum physics, the unifying theory, or the theory of everything,
Although this was difficult, it took me almost a week, I've gone and done it, the answer is relatively simple excuse the pune, although what has alluded me so far, is putting it into words, i.e. turning an idea into simple text
A way of very very roughly describing it is , its all about scale, and probability
lvlastermind
Jul16-04, 07:07 PM
http://www.newscientist.com/news/news.jsp?id=ns99996151
The explanation will have to wait until next week though when he presents his findings at a black hole conference.
Im getting nervous waiting for the answer
bozo the clown
Jul16-04, 08:24 PM
If Hawking presents a mathematical model for the the vast amount of hot air he produces then he will have his first proven working theory.
The guy is overated not in the same league as Einstien and Feynman
I think he should concentrate his efforsts on writing sci-fi novels, a more useful contribution to society.
..ok I know im prob gonna get plastered !
The guy is overated not in the same league as Einstien and Feynman
..ok I know im prob gonna get plastered !
on the contrary, you should be awarded a medal
Popular science idols can easily confuse more people than they inform
and their popularity can have to do with other things besides how enlightening their schtick actually is.
about hawking, Bozo the Clown said it so I dont have to.
thanks
Chronos
Jul17-04, 01:32 AM
That was cold. Apparently the contributions Hawking made to solving field equations, predicting 'Hawking Radiation', and otherwise proposing workable solutions to black hole theory are just a bunch of populist bunk. I also suppose that means Roger Penrose's contributions to string theory, is merely his way of apologizing for collaborating with Hawking.
History will, no doubt, recognize the contributions of Bozo and Marcus to the evolution of modern theory.
Apologies. That really got to me. Hawking is controversial, in some respects. But, he has brilliant insights and is a better scientist than most of us could ever hope to be. But thanks for the other insight, Marcus. I thought the title 'Physics Expert' meant you had peer recognition.
So publish your papers. I will lamely critique them.
bozo the clown
Jul17-04, 02:06 AM
I heard Hawking and Penrose went on a balloon flight, after enjoying the scenery and shortly before they were due to land they started talking black holes strings etc ... , anyways they started ascending rapidly but it didn't take long for these imaginitive physicists to realise that when they kept their mouths closed they were able to land the balloon.
...
History will, no doubt, recognize the contributions of Bozo and Marcus to the evolution of modern theory.
...
We are not talking about historical contributions to science (both Hawking and Penrose, not to mention Feynmann and Einstein) have made splendid contributions!
I dont spend time ranking great men of science but I guess I probably consider Penrose as one of the most creative mathematicians of our time. I can't tell how seriously to take Hawking's current contributions but his insights of the 1970s are among the most important in the theoretical physics of the second half of the 20th.
I dont see how you, Chronos, can have gotten so confused about what I was saying. I admire these men as scientist and mathematician and esteem their very real contributions.
What we were talking about is Hawking as popular science idol.
In that capacity I do not think he has done science or the public any good.
His popular books have tended to confuse people.
His image resonates with a distorted popular misconception of what scientists are like.
Because he is good "copy" the media and journalists make a big buzz around Hawking at every opportunity. And I have the impression he encourages this.
There have been other Science Celebrities who, IMO, performed that role wonderfully well. Feynmann was great BOTH in reality as a scientist and as a mythical science-figure in the public eye. Carl Sagan was a wonderful science celebrity.
These men were not mere short-sighted self-promoters and they used their visibility and media-presence to teach deep valuable lessons to the public about what science is about.
Einstein was a great Popular Idol, as well as being great in the real scientist department.
In my respectful opinion how a science idol uses his or her prominence to give a face to science is important and some people have used their celebrity status well and others have used it selfishly and destructively.
You raised the issue of Sir Roger Penrose. As far as I know he is not a Media Magnet---but I could be mistaken. I never got the impression that he was confusing the public or particularly looking for media attention. So if you are criticising me for being disrespectful of Penrose you are not reading my posts or else you are grossly distorting the situation. I am currently trying to call attention to the Friday 23 July public lecture by Penrose called "Fashion Faith and Fantasy in Theoretical Physics". he is quite a wonderful guy IMHO and the lecture (of which I've heard an online previous version) is a wonderful lecture for general audience.
I heard Hawking and Penrose went on a balloon flight, after enjoying the scenery and shortly before they were due to land they started talking black holes strings etc ... , anyways they started ascending rapidly but it didn't take long for these imaginitive physicists to realise that when they kept their mouths closed they were able to land the balloon.Get real, OZOB! What's with the Hawking/Penrose bashing? It's an old joke with different names thrown in. Sour grapes maybe? Read Chronos' post above and try as he suggests; I'll read your posts before dismissing them as garbage... :zzz:
I'm not real big on Bible studies, but like one of the 13 Commandments says; "Thou shalt not envy."
NOTE to PF Mentors:
Don't delete it yet today, sometimes we have to disagree in public for our own mental stability.
________________________________
Labguy;
Open-minded, congenial physics idiot.
...
________________________________
Labguy;
Open-minded, congenial physics idiot.
Labguy, sometimes I dont get jokes----are you really 100 years old this year?
You come across as a curmudgeon, perhaps, but more like a curmudgeon in early retirement.
If I had to guess, I'd say born in the Depression years 1932-1940.
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.
Bozo,
Gadzooks! Is Penrose also guilty of being a great Hot Air Puffer?
I thought he was a delightful guy with lots of original thoughts who writes books on stuff besides mathematics---but I didnt think of him as an attention-getter. Did I miss something?
We should dust off the old word "pietist" people who think it is very important to be pious all the time are pietists. It is hard to spell. Is there a better word?
Sycophant?
those who worship the outer garments, to show how reverent they are.
what's the word for it.
Is it okay to post this here?
Didn't Dr. Hawking presented some amazing thoughts yesterday, saying that BH, unlike he previously thought, do end up parting with what went into them? That's what I got from the remarks, that they reveal the past and even the future. Certainly the past, I'm sure on that part. I guess it streams out of them. What I'm excited about is if so, maybe we could capture it and get some more information on Biblical times. That part has me about in a swoon.
BTW, I don't think Dr. Hawking is a media hound. My ex "knows" him. Dr. Hawking keeps quiet about much of his life. He has a troubled life; even looks like someone is trying to harm him, someone close to him. Maybe some posters from Britain could add to that. It isn't covered much here. But he keeps quiet about it.
Is it okay to post this here?
.
Indeed, it seems like an ideal place to post it. I think you holly have very good sense about human nature and people. So if you think Dr Hawking is not a media hound then I have to say that you may be right and I wrong about that. So I will lay down that particular banner or placard and let someone else wave it if they want.
Also, holly, do you think Labguy is really 100 years old or was he kidding?
I trust your judgement in this more than my own.
Rats, it seems that Labguy has gone and edited his Public Profile so that he is no longer 100 years old, but is a young whipper-snapper.
No one will believe Labguy is under 30, even I can see that is a ruse.
Human psychology evidently has its own version of a black hole: Everything that gets sucked in eventually gets spewed out, many times on the wrong people.
And usually nice-natured people, if they hang around with not-so-nice people, sometimes get pulled into darkness, too. A little tip to all: Anger, snideness, mocking, hate: All are just fear dressed in different mouldering rags. I'll take my fear unadorned and urge you to find the strength to do the same.
All this flaming on this thread; it's disgusting. When I used to work for a veterinarian, all the dogs we were boarding would get to snarling and howling and barfing and running in circles and generally wild in their cages. I recall trying to understand that they were all hurting, lonely, upset, being nice to them, soothing. They kept at it. The vet walked in, and being a practical man, took a yardstick and ran it up and down the chainlink of the cages. Up and down, zzzzzrrrr, clang, on and on. Then he let himself into the dog run and started to lay about with the yardstick. Everyone got a slap on the butt with it. They all calmed down. He hit me a few times as well, and the stick broke. Aw, don't tell me about animal abuse. The whop on the rear helped them. Helped me. I wish I had a yardstick right about now; I'd whop you guys good and you'd all feel better afterwards. Man, these physics types, so quarrelsome. So scared that maybe their vaunted intelligence isn't so grand. Then what do they have to be proud of?
Shut up everyone and talk about black holes now.
The black holes: I never did think it made sense that nothing could get out, or only a little get out. That doesn't seem to go with the rest of the world.
edit, can't spell 2day
bozo the clown
Jul17-04, 12:32 PM
im just kiddin around I pretty much agree with what Marcus was saying.
In regards to the vet and the measure ruler.
Pavlovian response by ruler dragging on the cage? Yet I do not believe this man was smart enough(warm enough) to speak to the animals in another way.
Should of rang bell, and gave each a treat? Repetivenss of the bell and treat and soon, just the bell will silent? :smile: Introduce new treat in words of kindness and the bell and kindness form, and then soon, the bell becomes kindness :smile:
Anyway back to blackholes
im just kiddin around I pretty much agree with what Marcus was saying.
dont worry bozo,
holly was correcting my manners, not yours,
I can tell this from some of the things she said
Labguy, sometimes I dont 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)
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 doesnt 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 doesnt 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
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
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?
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 :smile:
(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. :smile: From chaos(dogs barkng to the bell) You would have thought Pavlov was a Tibetan Om my goodness :smile:
One of the ways I tried to approach it was looking at sonoluminence (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 blackhole? 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
Jul17-04, 04:15 PM
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.
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).
One would have to understand Life Cycle of Energy and Matter (http://universe.gsfc.nasa.gov/images/lifecycles/cycles.jpg)
Think about shell fractures that preceed blackhole formations?
If Hawkings 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?
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 dont have to worry about that one
:smile:
scratch scratch........hmmmm........maybe we are stripping the photon? :smile:
One would have to understand Life Cycle of Energy and Matter (http://universe.gsfc.nasa.gov/images/lifecycles/cycles.jpg)
Think about shell fractures that preceed blackhole 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
Jul17-04, 08:41 PM
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 ?
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
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 Window on the Universe (http://www-glast.sonoma.edu/index.html) Let it load and look at the ways in which we can look at the universe.
Chronos
Jul18-04, 01:46 AM
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.
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"
http://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
Jul18-04, 05:15 AM
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, :yuck:
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
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."
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 transfered 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 doesnt 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
To your question, one just has to look at the Window on the Universe (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.
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