Drunk on Black Holes

[decraig]

 

the black hole (as in, event horizon) doesn't require a central singularity. They both emerge from the same theory; but that is believed to be incomplete under the extreme conditions near the singularity (theory of quantum gravity required, probably).

 

There is at least one theory that describes black holes (with event horizon) without a central singularity: http://researchnews.osu.edu/archive/fuzzball.htm

 

This also claims to address the information paradox.

 

So, what? First, your quoted article has nothing to say about a central singularity. And so what if it did? You seem to be drifting off topic. This article was about string theory, of all things. Generate a sufficiently complex theory among the many string theories and you can explain anything you want.

 

If the information paradox is in your interest Strange, which is what this article is about, you might look into research on how information might remain encoded in the surface structure of black holes, instead.

 

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For others: It is not correct to dismiss the event horizon because it is only a coordinate singularity. The event horizon is central to the issues I have presented in the opening post, rather than any hypothetical central singularity, be it physical or not.

 

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For all of you following this thread:

 

Please forgive me for the outburst. Despite my combative nature, I will endevor to act in a gentlemanly manner. Polite and encouraging and supportive. (All good things!)

Not for fear of moderators, but because I am ashamed of what I see when I later read my own ranting posts.

Edited November 23, 2013 by decraig

[Strange]

 

So, what? First, your quoted article has nothing to say about a central singularity. And so what if it did? You seem to be drifting off topic.

 

Sorry. I thought one of your objections to the standard black model was the existence of singularities. I was just pointing out that there are a number of other approaches that avoid a singularity (which isn't surprising, because I doubt anyone thinks the singularity is a physical reality).

 

 

If the information paradox is in your interest Strange, which is what this article is about, you might look into research on how information might remain encoded in the surface structure of black holes, instead.

 

Again, just pointing out that there are alternative explanations. There is a lot of interesting research in this are. The extreme conditions of black holes are a good place to develop the relationships between GR and QM.

 

http://arxiv.org/pdf/1306.0533v2.pdf

http://www.nature.com/news/astrophysics-fire-in-the-hole-1.12726

http://www.scientificamerican.com/article.cfm?id=black-hole-firewalls-confound-theoretical-physicists

 

But if you are only interested in discussing the one paper on incipient black holes, I will wander off and leave you to it....

[ajb]

For others: It is not correct to dismiss the event horizon because it is only a coordinate singularity. The event horizon is central to the issues I have presented in the opening post, rather than any hypothetical central singularity, be it physical or not.

The event horizon is a very important concept. No-one here as dismissed it, but we have pointed out to you that the aparant singular nature at the event horizon for a Schwarzschild black hole is a coordinate singularity.

[decraig]

1) Can even a single particle of light classically cross the event horizon?

 

Under what seem the most ideal circumstances we might use the Schwarzschild metric where the particle is moving radially inward.

 

The reduced Schwarzschild metric is

 

[math]c^2d\tau^2=(1-r_s/r)c^2dt^2 - dr^2/(1-r_s/r)[/math].

 

The particle follows a null geodesic;

 

[math]d\tau^2=0[/math].

 

[math]0=(1-r_s/r)c^2dt^2 - dr^2/(1-r_s/r)[/math]

 

Therefore the coordinate velocity is

 

[math]v=dr/dt=c(1-r_s/r)[/math].

 

Sanity check: at large r, [math]dr/dt \rightarrow c[/math] as expected.

 

How long does it take the particle to reach r_s from some finite R, where [math]R>r_s [/math]?

 

[math]dt= (1/v)dr[/math]

 

Integrating both sides, [math]T = \int_{R}^{r_s} \frac{1}{c(1-r/r_s)} dr[/math].

 

At [math]r=r_s[/math] the integral diverges to infinity.

 

For an observer outside the event horizon, with coordinate time t¢,

 

[math]dt'/dt[/math] remains in finite ratio.*

 

Therefore [math]\int dt'[/math] also diverges to infinity.

 

The particle never crosses the event horizon in the coordinates of an outside observer.

 

-----------------------------------

 

2) Now we want to make a Schwarzschild black hole. Consider that all of the energy is within the Schwarzschild radius but for one particle of light. We can define this radius would the particle be in the interior.

 

Again, the amount of time required for the particle to reach [math]r_s[/math] diverges.

It appears that, classically, we cannot make a Schwarzschild black hole.

 

 

* There is at least one condition to be met for this to be true. The observer in the primed coordinate system cannot be in a state of accelerated motion such that an event horizon develops. Normally we can say that an event that transpires in one coordinate system also transpires in another. But introducing coordinate singularities make exception.

Edited November 23, 2013 by decraig

[ajb]

The particle never crosses the event horizon in the coordinates of an outside observer.

Right, as far as a distant observer is concerned he never observes an in falling observer crossing the event horizon. It takes an infinite amount of time for the in falling observer to reach the event horizon as measured by a distant observer.

 

But as far as the in falling observer is concerned he will cross the event horizon after some finite duration.

[decraig]

Right, as far as a distant observer is concerned he never observes an in falling observer crossing the event horizon. It takes an infinite amount of time for the in falling observer to reach the event horizon as measured by a distant observer.

 

But as far as the in falling observer is concerned he will cross the event horizon after some finite duration.

 

Yes, of course true for a test particle with an idealized black hole having time-like Killing fields.

 

Not true under less idealized circumstances, where we would include a radiating black hole with shrinking [math]r_s[/math].

I addressed this in post#1, item 4.

 

We could modify the Schwarzschild solution to have [math]r_s[/math] a function time, though I didn't think at the time that such detail was a necessary addition to the logical argument. It would be an exponential decay rate. The model would make the point better evident.

 

However, I'm somewhat mystified by the statement. I used the in falling test particle to set up the machinery for point #2 of my last post, #29.

Edited November 24, 2013 by decraig

[Bill Angel]

Right, as far as a distant observer is concerned he never observes an in falling observer crossing the event horizon. It takes an infinite amount of time for the in falling observer to reach the event horizon as measured by a distant observer.

 

But as far as the in falling observer is concerned he will cross the event horizon after some finite duration.

The discrepancy in observations could be more dramatic than that. The person entering the back hole observes himself just falling in uneventfully, but the observer watching him from outside the event horizon observes him being incinerated near the event horizon by Hawking radiation. Such is the assertion made by Brian Greene in his book "The Hidden Reality".

[ajb]

The discrepancy in observations could be more dramatic than that. The person entering the back hole observes himself just falling in uneventfully, but the observer watching him from outside the event horizon observes him being incinerated near the event horizon by Hawking radiation. Such is the assertion made by Brian Greene in his book "The Hidden Reality".

There is much debate about so called firewalls, I have not kept up with this though.

[hoola]

if the information within strings in a black hole is retrievable, does this mean that the strings are information, and not mere carriers of information? That is, the "strings" are composed of a non-material sets of numbers, of certain algorithms by which describe differing material objects. As I understand black holes having the property of reducing material substance to it's smallest component, wouldn't this smallest component be the information that describes that substance, as I understand John Wheeler's "information is the foundation of everything". To me, this would imply that the material that fell into the black hole is gone, with nothing left but the descriptions of those particles. And does this description retrieval imply that black holes are essentially a recording device? Would this also mean that light falling into a black hole could be retrieved, and we could orbit a black hole and access the light information so as to see everything that happened near the black hole since it's formation, like a backwards-running movie?

[decraig]

The scientific consensus don't agree with you, the standard black hole model is a well established part of mainstream physics.

 

 

So you claim. Reference me an article addressing

black hole formation.

 

You are the one making extraordinary claims. Not I.

The discrepancy in observations could be more dramatic than that. The person entering the back hole observes himself just falling in uneventfully, but the observer watching him from outside the event horizon observes him being incinerated near the event horizon by Hawking radiation. Such is the assertion made by Brian Greene in his book "The Hidden Reality".

 

And there is more. According to current theory of dark energy, the very atoms of an infalling observer, and even his nuclei will be torn apart by dark energy infinitely sooner than he will enter the black hole.

 

Now, I'm not real big on dark energy, and consider it might be a failure of general relativity, but if you are a standard thinker then you could be comforted to know that the consensus of physicists must concede that nothing will ever cross the event horizon but thru spacelike displacements according to the point of view of an external stationary observer such as us on Earth.

 

I'm try to be concise, but "spacelike displacement" in this context means information travels faster than light. This is no small thing, and our consensus of experts would say this in not a element of established physics.

 

This is difficult to explain. (I've been trying to get it across for over 34! posts back.) The accepted foundations of physics preclude existence of black holes. These three accepted beliefs are incompatible.

 

In other words you cannot claim that all three of the following are true because claiming two of them will preclude the remainder: 1) The universe expands at an accelerated rate (dark energy), 2) Information propagates at less than the speed of light, and 3) Black holes exist.

Edited December 20, 2013 by decraig

[ajb]

So you claim. Reference me an article addressing

black hole formation.

Penrose, R. (1965). "Gravitational Collapse and Space-Time Singularities". Physical Review Letters 14 (3): 57.

 

Hawking, S. W.; Penrose, R. The singularities of gravitational collapse and cosmology.

Proc. Roy. Soc. London Ser. A 314 1970 529–548.

[decraig]

Penrose, R. (1965). "Gravitational Collapse and Space-Time Singularities". Physical Review Letters 14 (3): 57.

 

Hawking, S. W.; Penrose, R. The singularities of gravitational collapse and cosmology.

Proc. Roy. Soc. London Ser. A 314 1970 529–548.

I don't have access. Please post the relevant information. It is legal to do so if properly attributed.

 

I have supplemented my post #35. Read the last line. How do you address it?

Edited December 20, 2013 by decraig

[ajb]

I have supplemented my post #35. Read the last line. How do you address it?

I don't see how all three are related.

 

The expansion of the Universe is a global thing, local gravitational fields can overcome this and so we can have black holes.

[decraig]

I don't see how all three are related.

 

The expansion of the Universe is a global thing, local gravitational fields can overcome this and so we can have black why

no problem. Give it a day or a week or more, and get back to me. This is not an easy thing to consider.

 

 

You piss me off ajb, but I respect you all the more because you want to know if my crazy rantings, in your understanding, are really crazy after all. I don't think you are the pedantic thinker expected of you in the context of this forum. Send me a private email if this is so.

 

btw, I'm too poor to subscribe to the professional journals.

 

By the way, I love your icon/pic. We take so often take ourselves too seriously. I do. Will you send me a private message? I don't know how.

Edited December 20, 2013 by decraig

[ajb]

I think your mistake is in confusing what a distant observer can see and what the in falling observer will see. It is true that distant observers will not see an object pass the event horizon, any signals the in falling observer can send will become more and more red shifted and the signal will become weaker and weaker. In any finite duration as measured by the distant observer the in falling observer will not be seen to cross the event horizon. It looks like he never reaches the black hole. It takes forever to fall in if we just look at the paths of light rays sent by the in falling object!

 

But this is not the same as the local proper time as our in falling observer see it. For him it takes a finite amount of time to fall in. Also if he were sat on the surface of a collapsing star he we see the singularity form in finite time.

You piss me off ajb, but I respect you all the more because you want to know if my crazy rantings, in your understanding, are really crazy after all.

I am not sure if that was meant as a compliment!

 

 

btw, I'm too poor to subscribe the the professional journals.

This can be an issue, but less so today as we have the arXiv for newer works.

 

What you can sometimes do is contact the authors and they can send you an off print of the paper. Maybe in this case this won't work, but for less famous papers you can do it.

 

The other option is to get to a university library. The rules here may well depend on place to place, but generally they allow guests. You could from there photocopy the paper, which is usually okay as the paper is for private educational purposes.

Edited December 20, 2013 by ajb

[decraig]

Yes. This is exactly the problem.

 

What does an infalling observer perceive vs. the exteranal observers perception. In the common perception an event that occurs to one observer is an event that occurs to any other observer. Usually this is the case. But this not universally true. but coordinates in which the black hole disappears from existence (Rindlard horizon) are beyond the kin of you'll, and plays no part in this argument.

 

You must consider the transfinite ratios of things.

[hoola]

As time slows in the trajectory of an object falling into a black hole to an outside observer, the redshift makes the object disappear, but if somehow you were able to still see it, the object continues to fall in a slowing finite manner....not stopping completely, and would continue to fall in it's trajectory for the duration of the universe's existence... and that the object would "see" itself, fall right in...in an increasingly rapid finite manner.....isn't this the ultimate example of time dilation?

[decraig]

As time slows in the trajectory of an object falling into a black hole to an outside observer, the redshift makes the object disappear, but if somehow you were able to still see it, the object continues to fall in a slowing finite manner....not stopping completely, [bold added] and would continue to fall in it's trajectory for the duration of the universe's existence... and that the object would "see" itself, fall right in...in an increasingly rapid finite manner.....isn't this the ultimate example of time dilation?

No, not stopping completely. See my post #29.

 

Maybe you're getting the idea. We are comparing things of transfinite ratio. This is, after all, why these things are called singularities. In one inertial frame an event has a single spatial and temporal coordinate. In another, there are an infinitude of coordinates. If we were mathematicians we would say that the coordinate systems are not one-to-one.

Edited December 20, 2013 by decraig

[hoola]

when you say "in one inertial frame an event has a single spatial and temporal coordinate" ...by this do you mean when it appears to stop from the perspective of an outside observer? and when you say..."in another, there are an infinitude of coordinates"...by this do mean to say; as from the perspective of the object as it is rushing toward the singularity ? thanks, edd

[hypervalent_iodine]

G00d grief!!!!!!!!!!!!!!!!!!!!!

 

I should never have started this frikin thread.

 

Those who have an piss ant's education in relativity beyond the special theory, raise your hands.

 

Those who don't, but are in love with black holes, can count themselves among the faithful, unthinking followers of authority

!

Moderator Note

I realise that this is a month late, but this is totally unacceptable. If you can't post here without being insulting, then don't post at all or be prepared for a suspension.

 

Secondly, you are responsible for providing evidence for your claims (not anyone else, since black holes are an accepted model in physics) and you are responsible for demonstrating how they are linked and you need to do so without waving off criticisms by insulting the intelligence of the people who take the time to reply. In fact, the rules dictate that you have to do this, so please rectify this or the thread will be closed.

[decraig]

In following quoted article, Penrose examines the collapse of matter toward an r=2m event horizon.

 

Rodger Penrose,

Gravitational Collapse and Space-Time Singularities

Physical Review Letters, Volume 14, #3

 

“Before examining the asymmetrical case, consider a spherically symmetrical matter
distribution of finite radius in C³ which collapses symmetrically. […] Note that an exterior observer will always see matter outside r =2m, the collapse through r =2m to the singularity at r =0 being invisible to him.

After the matter has contracted within r =2m, a spacelike sphere S² can be found in the empty region surrounding the matter.[…]”

 

 

In the first paragraph Penrose recognizes that matter will not collapse to the event horizon in finite time in the coordinate system of an exterior observer. In the second paragraph he goes on to examine this collapse, anyway, in a coordinate system where the metric is well behaved, then continues onward to examine the interior solution.

 

In this article my objections to transfinite time of collapse are unaddressed. It sees to be either glossed-over or not recognized in going from one paragraph to the next. No references to previous work were made to fill this void.

 

A similar examination of a 1970s Hawking-Penrose article was equally disappointing.

Edited December 22, 2013 by decraig

[decraig]

G00d grief!!!!!!!!!!!!!!!!!!!!!

 

I should never have started this frikin thread.

 

Those who have an piss ant's education in relativity beyond the special theory, raise your hands.

 

Those who don't, but are in love with black holes, can count themselves among the faithful, unthinking followers of authority.

 

 

 

 

Do you really want to understand the mathematical underpinnings of general relatvity?

No one will care.

Is this the naked singularity requiring infinite energy density, or have you got something meaninful?

 

This is a very good point Airbrush. I've wondered also.

 

If you could instruct me how black holes could produce jets, and not incipients produce jets, I would appreciate it

 

 

A

Sorry Airbush,and...i think someone else. too. I can be a horrible person. I have not excuse.

If you read this, please forgive; there is nothing wrong with you, only me.

 

 

In explanation, (no excuse),I become over impassioned. It is my failing

Edited December 22, 2013 by decraig

[decraig]

The following lists some most recent articles as submitted to the arXivs concerning the formation of black holes.

 

First, there is a central issue to be addressed here. It is a common misunderstanding and drives the objections to my speculations. General relativity is not Newtonian gravity.

 

1) Gravity hinders or inhibits or prevents the formation of black holes.

 

Specifically this is the time-time term of the stress-energy tensor (See the Wiki). Welcome to the 21st century.

 

2) What mighty allow formation of an event horizon? Jumping energy over a boundary in finite time per an external observer. The issue is unresolved, with contradictory conclusions among researchers probing vairous applications of quantum mechanics.

 

 

To the best of my knowledge the current state of affairs concerning black hole formation, and therefore existence, is subsumed in the following:

"A clear advantage of the present approach is that the action for the system

greatly simplifies in the interesting limit of an incipient black hole and raises

the hope that a solution, even to the notorious back-reaction problem, may

be within reach."

This is a quote from my second reference, below.

 

What did this say? Nobody knows boy and girls. Nobody knows if there is a physical mechanism of formation.

As I said above, these are objects of extraordinary claim. And possess heuristic problems as well.

 

(I claim hypervalent Iodine that Steven Hawking and Suskin are arguing over the shade of invisible pink polka-dot unicorns Steven says are hiding in his basement. See the following references.

 

You claim "...since black holes are an accepted model in physics..." This lazy nature may be good enough for cosmologists and those who do not research black holes, but is not at all evident among those that actually do.)

 

arXiv:1307.5861 [pdf, ps, other]

Icezones instead of firewalls: extended entanglement beyond the event horizon and unitary evaporation of a black hole

John Hutchinson, Dejan Stojkovic

Comments: 10 pages, 4 figures. v2: construction of icezone density matrix, 12 pages

Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc) 2013

 

arXiv:0711.0006 [pdf, ps, other]
Schrodinger Picture of Quantum Gravitational Collapse
Tanmay Vachaspati
Comments: 9 pages, 1 figure. Matches published version
Journal-ref: Class.Quant.Grav.26:215007,2009
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Theory (hep-th)

arXiv:gr-qc/0701096 [pdf, ps, other]
Quantum Radiation from Quantum Gravitational Collapse
Tanmay Vachaspati, Dejan Stojkovic
Comments: accepted for publication in Phys. Lett. B
Journal-ref: Phys.Lett.B663:107-110,2008
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Theory (hep-th)

arXiv:0806.0628 [pdf, ps, other]
Hawking radiation as seen by an infalling observer
Eric Greenwood, Dejan Stojkovic
Comments: Added analysis of the Hawking-like radiation as seen by an observer in Eddington-Finkelstein coordinates. Accepted for publication in JHEP
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Theory (hep-th) 2008

 

arXiv:gr-qc/0609024 [pdf, ps, other]

Observation of Incipient Black Holes and the Information Loss Problem

Tanmay Vachaspati, Dejan Stojkovic, Lawrence M. Krauss

Comments: 15 pages; 9 figures. Changes made in response to referee's comments and to clarify arguments, in particular to describe clearly that the results represent observations made by an asymptotic observer. Accepted for publication in Phys. Rev. D

Journal-ref: Phys.Rev.D76:024005,2007

Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

 

 

arXiv:hep-ph/0505026 [pdf, ps, other]

Holes in the walls: primordial black holes as a solution to the cosmological domain wall problem

Dejan Stojkovic, Katherine Freese, Glenn D. Starkman

Comments: References added; Published in Phys. Rev. D

Journal-ref: Phys.Rev. D72 (2005) 045012

Subjects: High Energy Physics - Phenomenology (hep-ph); Astrophysics (astro-ph); General Relativity and Quantum Cosmology (gr-qc)

 

arXiv:gr-qc/0604072 [pdf, ps, other]
Information-preserving black holes still do not preserve baryon number and other effective global quantum numbers
Dejan Stojkovic, Glen D. Starkman, Fred C. Adams
Comments: Honorable Mention on Gravity Essay Competition 2005; Published in the special Essay issue of Int.J.Mod.Phys
Journal-ref: Int.J.Mod.Phys. D14 (2005) 2293-2300
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Theory (hep-th)

Edited December 29, 2013 by decraig

[imatfaal]

Could you be more specific concerning where you believe those articles aid your argument? Most of this thread has been objecting to the concept of black holes through a classical argument (which I believe was flawed but nonetheless) with a few mentions of the information paradox. However, these articles - not exactly representative of the subject, basically by two researchers and various colleagues - are firstly not dismissive of the general notion of black holes as you seem to be, secondly are all trying to breach the as yet impassable division between the semi-classical approximations of black hole formation and a full quantum gravity explanation, and thirdly do not address the existence of black holes but rather probe the possibilities of their formation and the fact that we cannot at present provide a route of unitary transformation from infalling matter to a blackhole.

 

The GR basis of black holes Penrose/Hawking calculations has been shown above in the articles referenced by AJB - and there are regions of the universe within which there is such amount of mass within such a volume that we believe a blackhole per accepted these ideas is the only plausible explanation. We cannot go there to check - and frankly 'seeing is believing' went out of vogue in physics a few centuries ago - and other than that, the central volumes of spiral galaxies have all the predicted characteristics of black holes and continue to pass every test.

 

The fact that we cannot provide a method of formation that obeys the unitary rules of quantum mechanics would be intensely worrying if we had a functioning theory of quantum gravity - but we don't! The simplicity yet extreme conditions dictated by GR in the vicinity of a black hole may well be the clues required to get that theory - but you cannot use the absence of a pathway in an incomplete theory to throw away the mathematical formalism within GR and the observational evidence of black holes

 

 

[decraig]

I don't know what to tell you. I've been over, and over this material.

 

I posted these articles on the current state of research, that I know of. If you know of others, I would be pleased to know.

 

But how these researchers 'feel' their research should evolve doesn't argue well with me.

 

[...]- but you cannot use the absence of a pathway in an incomplete theory to throw away the mathematical formalism within GR and the observational evidence of black holes

 

 

Where have I thrown away the mathematical formalism of GR?? I know of no supportive observational evidence that can distinguish a black hole from an incipient black hole. Do you have supportive documents?

Edited January 2, 2014 by decraig