Black holes do not collapse to singularity>

think

Please read this article: Hawking changes his mind about black holes I cant understand, which it says This suggests that black holes do not actually narrow to a singularity at all I cant understand, please explain

Jeebus

That doesn't make any sense to me either. In order to have a black hole they have to overcome neutron degeneracy pressure, which in turn would give you the point or singularity.

Here is the whole part:
Then what do they narrow to? Roger Penrose proved I thought the singularity theorem, which says that a singularity must reside inside every imploding star, and therefore every black hole. Is this an exception and how?

LURCH

I don't know the Euclidian Path Integral technique, but we have discussed this on the Forums before. My eprsonal take has always been that singularities do not form because time dilation prevents them. The final moment of collapse to "0" dimensions takes forever.

Labguy

WHAT?
No "infinitely dense" singularity? How absurd an idea.
Actually, Hawking wrote a paper in 1985 where he renounced infinite density singularities but just didn't explain why very well. I sure hope that Orion1 and I couldn't have been even close to correct when we posted about 6/27/04 on the "Density of a black hole" topic. Part of my 06/27 post was:

Just for fun (really, I don't want to always be an argumentative Labguy) I'll go ahead, totally off subject, and predict today that the concept of either a point singularity or even a planar ring singularity with zero volume will soon be dumped like a hot rock. Either of these, of course, leads to the necessity of a BH with a finite mass but "infinite density" somewhere within. The prediction is meaningless, of course, until and unless you someday remember the "Labguy prediction" when the dumping occurs. I'll also predict that, like Orion1, I will beg-out of this thread and post no more.

The full text of the presentation will tell the story, but I would sure hate for the Labguy's prediction to happen so soon....

think

But if black hole collapses to singularity, then is it 2d, 1d or 0d. Anyway, I cant just imagine any thing existing in Dimensions other than 3D. 0,1,2D are just contained in Mathematics, but how can they exists in real space-time? Its kinda paradox that a star must collapse to a point to form a black hole and also a point cannot exists.

Entropy

I never believed black holes collapsed into points since I learned about string theory.

island

What happens to Guth's inflation if the universe already has volume when a Big Bang occurs?

http://www.geocities.com/naturescience//index.html

sol2

If you have a certain amount of information contained, and you compress this information, it gets very hot. If one wanted to turn the events inside out(the cosmo), what function would have recognzied that such fissionable result would have amounted too, from fusion? New suns born?

Marcus in following raises important points. Why I add here, that this would not be lmited to the cosmo,but to galaxies as well. This would have not deviated from the overall expansion process, but might have made this universe look like swiss cheese

The gif on your site of the Bose Nova?

marcus

I dont grasp the difficulty
AFAIK the standard inflation scenarios work fine starting from
a universe with infinte volume which is infinite in spatial extent

why should the universe NOT already have volume when a Big Bang occurs?

perhaps you would explain or offer a link that explains

marcus

Jeebus, a singularity is a mistake or failure of the theory
a mathematical theorem is not something that is proven about nature or about the world----a theorem is proven in the context of a theoretical framework and it tells something about the abstract framework

Penrose proved in the context of 1915 GR that under some conditions a region where 1915 GR fails to compute must form.
That is, he proved something about General Relativity----that it produces situations where it fails.

This is not a theorem about nature. There are no theorems about nature, only better or worse models.

I cant tell what hawking is up to but it looks like Bojowald is going to try to get rid of the black hole singularity in the LQG context, so why shouldnt Hawking try to do the same thing in the PathIntegral context
LQG and PathIntegral are to some extent allied approaches to quantizing general relativity----they are kindred approaces to Quantum Gravity.

Bojowald got rid of the BigBang singularity in the LQG context and now is getting his toolkit together to try to get rid of the BlackHole singularity in LQG.
It is not unlikely that whatever can be done in LQG can more or less similarly be done in PathIntegral (Hawking's favorite) to the extent that Hawking's approach works at all.

Getting rid of a singularity in Gen Rel simply means to cure a problem in Gen Rel.
One would hope and expect that quantizing Gen Rel will cure problems. So it is not surprising if singularities go away.

Again this is not specifically directed at hawking's talk because we only have hints about it, what I am saying is a more general thing about quantizing Gen Rel curing some singularities.

hope this responds to the question

mc2ise

When Hawking presents his paper with the explanations for what I read here, when and how do we (the public) get to see what he said and read the explanations?

Thanks.

Theothanatologist

From this link:
Here is the summary of his presentation.

Professor Stephen Hawking (Cambridge)

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.

&

"......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."

Olias

My Theory is correct!

So it is now a consequence that the :Blackhole Information Loss equates to a Whitehole information Gain

Stars do NOT create Blackholes..I repeat (like on other forums for what seems like an infinite number of years)..Stars do not create Blackholes...its the OTHER-WAY-AROUND!

I got some great threads just waiting to go online, and some of the questions will go right to the nitty gritty of cosmo, logical, stringtheory.

Here's one for starters, if the Horizon of a Blackhole can interact in TWO-DIRECTIONAL-TIME-ZONES, then the Entropy function (arrow-time) during a Star going critical prior to Supernova Explosions, equates to information being relayed from a Blackhole at a Galaxies core, sending signals to Stars within a said Galaxy, which causes the Star to collapse, its a Quantum Stellar GRAVITATIONAL Collapse Wavefunction!

In some models that have Galactic Shrouds, or Dark Halo's, it is the energy and its Time Symmetric components that are sympathetic to a Stars ability to "create" a Blackhole, and in a reverse of fortune, it is the Entropy Function at the BLACKHOLE-CORE of all Galaxies that is sympathetic to the Creation of Stars by the TWO-WAY information paradox, if ALL, galaxies have Blackholes as a neccessity of a creationary process, then all Stars are WHITE-HOLE reflections of pure and mixed state evolutionary processes.

Hawking Radiation is all around us under the guise of ordinary Sunshine!..and it gets better, the trivial metrics of pure state functions can go either way, what we assume to be a cosmological Big-Bang, is only relevant to a Galaxy and its surrounding shroud, the creation of OUR galaxy is only relevant to its internal observers, who always happen to be looking outwards!..the outside pure state, time-reversed entropy in Einsteins field Equations, stops at a precise moment our Galaxy dissapears, it does not extent to an infinite boundery used in some Major Cosmological models, it fuses with the Compacted Quantum 'E-M' Field , and thus provides a corresponding Cosmological "Correspondance" Limit.

The next big thing is going to be re-interpreting the "correspondence-principle" with respect to Macro Observations? :http://hyperphysics.phy-astr.gsu.edu...tum/hosc6.html


Space and Space-Time have definate seperate paths, the recent work by some, Shahriar Afshar for instance has produced a neat experiment dictating a 'Wave-Particle' similtaineous observation, the outcome of which really hits you for six, if you ask the right questions pertaining to Bohr and Einstein's dissagreements, the answer of which is rooted deep within the E-P-R thought experimnent.

A note on Shahriar Afshar's experiment, one can ask if a particle's trajectory is determined, or corresponds to the Space-time duality at a Quantum microscopic "Limit" is there REALLY a complimentary reasoning, or is it a mathematical consequence, or is it that a Wave-Particle and a Space-Time differ at a dimensional limit?..a particle needs space and time, but a wave does not!..it can blend into a 'SPACE-ONLY' background such as the Electro-Magnetic-Field that permiates far..far away from 4-D space-times.

sol2

Hi there

What makes it diifcult for me, is the consistancy with which we might adopt geometrical modelling for comparison. I see what you are doing, yet here there is a break in your thinking that forces me to question the break in the geometrical consistancy?

You encapsulate the energy to matter and look at the life cycles? Where would you fit your model in?

You have to explain this geometrically?

The entrophy points I have to look at better, if I am to put aside the fusion/fission idea.

Gamma ray bursts speak to this in expeirments of Glast, yet do not go below 2 TEV measures?

Is it just a matter of interpretation?

One last thing here for cosideration brings us back to the bell curve and probabilistic determinations. Greg Egan has a interesting correspondance graphically in the issue of the quantum harmonic oscillator. How would identify such fuzzy spots? Coin flips or orbitals?

Olias

Sol My 'java' plug-in is not working correctly, so forgive me not responding fully here, I have been offline for a number of weeks, but I have been busy doing some certain, 'Un-Certainty' readings !..so for now I will refrain from a decent reply, thanks.

Olias

Sol, I am just going through some Xarchive's in order to update my number of weeks offline, I came across this: http://uk.arxiv.org/PS_cache/gr-qc/pdf/0407/0407077.pdf

and if you recall, I stated that a BH can reflect or scatter particles (posting was in superstringtheory board forum ), and low and behold this paper is interesting:http://uk.arxiv.org/abs/gr-qc/0310008

I was not the first to work along these lines, there is a wealth of obscure papers within pre-print archives, these two papers are interesting though!

Chronos

White holes? Not a very satisfactory answer. You would think they would be very apparent, observationally. Try to resist the quasar explanation.