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RECENT POSTS IN THIS TOPIC

Sergey Fedosin: on 10/4/12 at 9:23am UTC, wrote If you do not understand why your rating dropped down. As I found ratings...

Hoang Hai: on 9/19/12 at 14:20pm UTC, wrote Dear Very interesting to see your essay. Perhaps all of us are convinced...

Steve Dufourny: on 9/17/12 at 11:31am UTC, wrote bad band known , the names are known , kill me band of comics , you have...

Gurcharn Sandhu: on 9/9/12 at 13:05pm UTC, wrote Dear Johann, I have read your essay and I appreciate your novel viewpoint....

Armin Nikkhah Shirazi: on 8/26/12 at 3:17am UTC, wrote Hi Johann, My essay was just posted yesterday, and it presents a certain...

Michael James Goodband: on 8/6/12 at 14:39pm UTC, wrote Dear Johann I am impressed with the results you give in your essay. I...

Avtar Singh: on 7/11/12 at 21:42pm UTC, wrote Dear Johann Weiser: I enjoyed reading your paper, especially how to avoid...

Thomas Ray: on 7/6/12 at 14:05pm UTC, wrote Johann, Thanks for a delightfully informative essay. I think it is highly...


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FQXi FORUM
July 19, 2019

CATEGORY: Questioning the Foundations Essay Contest (2012) [back]
TOPIC: The Gravitational Collapse Does Not Lead to a Singularity by Johann Weiser [refresh]
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Author Johann Weiser wrote on Jun. 26, 2012 @ 16:09 GMT
Essay Abstract

It is well known and generally accepted, that the temperature of matter in thermal equilibrium in curved space time is proportional to the inverse square root of the tt-component of the metric. During a gravitational collapse, the ordinary matter radius of the star approaches the corresponding Schwarzschild radius. Thereby the value of this metric component on the surface of the star is approaching zero and correspondingly the temperature on the surface rises quite sharply. Therefore the matter on the surface can no longer be modeled as an ideal fluid or as a degenerated Fermi gas. Instead, above some critical temperature, it behaves like an ideal gas. Pressure is rising proportional to the temperature and therefore the matter is pressed away from the surface of the star, which on the other side changes the metric. A equilibrium state is emerging. Some numerical calculations using Mathematica have been carried out and thereby for simplicity a pure ideal gas model has been used. The calculated functions for pressure , energy density, particle density as well as the spherically symmetric metric are shown. In such a model, matter is distributed on a spherical shell, the radius of which is the Schwarzschild radius. The ring is thicker for high temperatures of the matter and thinner for low temperature matter.

Author Bio

I received the PhD in theoretical physics in 1984 at the Technical University of Vienna. Afterwards I was working for quite a long time in information technology, but remained in contact with physics. Since about two years my interest in physics is growing again.

Download Essay PDF File

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Armin Nikkhah Shirazi wrote on Jun. 28, 2012 @ 06:40 GMT
Dear Johann,

I find your idea intriguing and have a couple of questions:

1. It seems that the mechanism you outline in your paper could help understand the microscopic degrees underlying thermodynamic phenomena like entropy and temperature at event horizons, but on the other hand usually these are considered within the context of the vacuum solution i.e. zero energy-momentum tensor whereas in your model you require a non-zero energy-momentum tensor. Can you reconcile these, or is your model not applicable to finding out more about the nature of the microscopic degrees of freedom underlying thermodynamic phenomena in standard vacuum solutions?

2. As there have recently been some condensed matter models that capture by analogy some aspects of black holes, do you think that you can come up with a condensed matter analogue through which you can make testable predictions?

All the best,

Armin

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Author Johann Weiser replied on Jun. 29, 2012 @ 13:12 GMT
Hi Armin,

ad microscopic states:

In fact I describe completely the microscopic states of the black holes (actually only for ideal gas particles), and can from these derive all macroscopic variables. I cannot give explicit formulas - I can only calculate the data numerically. In my opinion the model is not applicable to standard vacuum solutions. I consider it as an alternative concept (or even a counter - concept) to standard vacuum solutions. In the chapter titled "intuitive example" I argue, that a gravitational collapse through the Schwarzschild radius is unphysical and impossible and therefore the same is the case for vacuum solutions.

Ad condensed matter analogues:

Up to now I read about these experiments only in some popular physics websites. I did not have these in mind in connection with my model. I think, this is an interesting idea, which may bear some fruits in the future. It might be that not only vacuum solutions can be modeled, but also my non-vacuum solutions. I would like to read a bit more about these experiments. Do you have some list of names (with which I can search in arxiv.org) or a list of websites, regarding this topic?

Ad predictions in general:

I was a bit cautious in my document regarding predictions, however there are a few basic predictions of the model. They concern the black holes directly (and not models), so here I give them to some extent: There is a smooth transition from neutron stars to black holes, black holes are in fact neutron stars with a "hole" (a rather empty space) in the middle and with a heavily changed metric. Black holes have a temperature (e.g. 1 billion Kelvin) and they therefore emit light corresponding to a black body radiator having that temperature. They get their energy for radiation from their thermal energy and also as gravitational binding energy via a slow contraction. The black body radiation follows quite naturally from the model - standard vacuum solutions have some problems with a plausible explanation.

Many thanks for your interesting comments, and please, if easily available, provide some info about condensed matter analogues.

Johann

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Armin Nikkhah Shirazi replied on Jul. 1, 2012 @ 02:49 GMT
Hi Johann,

Actually, when I wrote my comment above, I was thinking of an article I read in Scientific American many years ago. The authors were Ted Jacobson and Renaud Parentani. Parentani has several papers on arxiv which look at Hawking Radiation through the lens of acoustic analogues. This is of course not exactly the same topic as yours, but perhaps it seems close enough that your approach might offer some new insights on this as well.

I wonder whether it is possible to extract a prediction from your idea in the following manner: We are fairly certain that at the center of our galaxy there is a supermassive black hole, but because of interstellar dust we are limited in observing radiation coming from it only at certain wavelengths. If it in fact radiates like a black body, then might it not possible to fit the radiation we do observe to a characteristic curve, and from there predict certain other properties which can be checked independently? Or perhaps going the other way around, from properties we reasonably believe it has (such as Mass=4M solar masses) construct a black body curve and see whether it fits the observed regions of its radiation spectrum?

All the best,

Armin

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Author Johann Weiser replied on Jul. 6, 2012 @ 10:26 GMT
Hello Armin,

Regarding your second paragraph: That is completely right, I fully agree. However I do not know, whether currently available data of centers of galaxies are consistent with such a black body radiation.

Thanks for your interest,

Johann

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Author Johann Weiser wrote on Jun. 29, 2012 @ 13:26 GMT
In case that anyone wants to have a close look to my calculations, I provide them here as attachments: I use package "GREAT" (download from Wolfram) for some basic general relativity calculations, which must be loaded first. Then I have a a notebook file, it contains my calculations as a package. First the package must be loaded by clicking into the code and pressing "shift-enter". Function "test3" creates the examples I have used in the document, function "exampleCalculations" contains some more high-, medium- and low- temperature examples and also some description of parameters and "test1" is my test function, where I change parameters (variables in the function) as needed.

Johann

attachments: GREAT.m, RadialEquation5.nb

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Thomas Howard Ray wrote on Jul. 6, 2012 @ 14:05 GMT
Johann,

Thanks for a delightfully informative essay. I think it is highly nontrivial that avoiding the "naked" singularity (at any scale) is essential for any future quantum theory of gravity compatible with relativity, and you explained it well. Eliminate the boundary conditions, and I think you'll find that everything else holds for arbitrarily small black holes; i.e., all functions nondegenerate near the singularity.

Hope you get a chance to visit my essay, which deals with the same essential subject in a different way. Best wishes.

Tom

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Avtar Singh wrote on Jul. 11, 2012 @ 21:42 GMT
Dear Johann Weiser:

I enjoyed reading your paper, especially how to avoid black hole singularity that is also described in detail based on the Gravity Nullification Model (GNM) described in my posted paper, From Absurd to Elegant Universe, and my book, The Hidden Factor: An Approach for Resolving Paradoxes of Science, cosmology, and Universal Reality.

Black holes that radiate away more mass than the mass falling in via gravitational pull from outside are expected to shrink and vanish completely due to the spontaneous evaporation or conversion of mass to energy. Hawking forwarded quantum arguments to show that the radiation is similar to the black body radiation governed by thermal effects. However, without a theory of quantum gravity, it is impossible to analyze the detailed thermodynamic state of a black hole. A new Gravity Nullification model (GNM) is proposed to describe the missing (hidden variable) physics of the spontaneous conversion of mass to energy. This is integrated into a simplified form of general relativity to provide a GNM based Universe Expansion (GNMUE) model, which eliminates black hole singularity and predicts both the observed linear Hubble expansion in the nearby universe and the accelerating expansion in the distant universe.

The mechanism of spontaneous mass-energy conversion entails the Hawking radiation or emitted Luminous Radiant Energy (LRE) as mathematically described in Chapter 5, equation 5-50 (see attached pdf), in my book [15]. The LRE is equal to the total gravitational energy minus the rotational kinetic energy in the overall GNMUE model. This model of radiated energy is vindicated by the close predictions by GNMUE of the observed visible size of a galaxy by GNMUE as depicted in Figure 5-22 (attached pdf).

Sincerely,

Avtar Singh

attachments: Response_to_Johann_WeiserAttach_71112.pdf

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Michael James Goodband wrote on Aug. 6, 2012 @ 14:39 GMT
Dear Johann

I am impressed with the results you give in your essay. I didn't think it would have been possible to get a metric solution without a physical singularity by such an approach in GR. I note the upturn in the time component of the metric at small radius, do you think that this is real or just a computational artefact? It would seem to make more sense if it were just an artefact of the approximation inherent to the computation.

I consider the hypothetical scenario of a black hole being a physical S^2 surface with a thickness given by compactified particle dimensions such that the interior is devoid of space in http://www.mjgoodband.co.uk/papers/QFT_KKv2.pdf (section 3). This gives the same sort of scenario of a hollow mass shell. The interesting thing is to perform simple thermodynamic analysis for the case that the surface contains wave modes. The radius of the sphere provides a long wavelength cut off which forces only harmonic modes, and the diameter of the assumed compactified particle dimensions provides a short wavelength cut off - the character of these dimensions is irrelevant, only the cut off effect matters. When the sphere shrinks some of these wave modes will be excluded, which gives radiation being emitted from the sphere into the surrounding space with energy density proportional to T^4 and T inversely proportional to the radius - as for a black hole. The entropy for the restricted number of harmonic modes within the surface can be calculated as S=kA/d^2 where d is the diameter of the assumed compactified dimensions. If the radius of the particle dimensions is the Planck length, this would give the expression for the entropy of a black hole, but in this case it is derived without touching Quantum Theory. I then give a scenario in a Kaluza-Klein theory where such black holes would occur with a hollow space inside in which space itself does not exist.

Your numerical solutions and my scenario of a compactified sphere seem to provide unexpected support for a common conclusion: there is no physical singularity inside a black hole, it is instead a hollow sphere where the mass lies at or just outside the event horizon.

All the best,

Michael

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Steve Dufourny replied on Sep. 17, 2012 @ 11:31 GMT
bad band known , the names are known , kill me band of comics , you have played, we are going to play now. Soon I will go in Holland just to smoke a joint in a coffee shop. Gooeidag meneers. Mijn naam is Steve Dufourny, Ik ben een Jedi.

Tot ziens !!!Johan,Brendan, Tom, Mickael, Don,Jonathan,Verlinde,Gerard,Lawrence,Joy,lisi.....a goodband they say.

Steve

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Armin Nikkhah Shirazi wrote on Aug. 26, 2012 @ 03:17 GMT
Hi Johann,

My essay was just posted yesterday, and it presents a certain way of thinking about the relationship between quantum theory and general relativity in way that I have not seen anywhere else. In particular, it imposes a certain boundary on the domain of validity of general relativity which at this time has not been subjected to experiment yet.

As someone who is very knowledgeable on GR, you may well be in a good position to provide useful constructive feedback and criticism, and if you find the time to take a look at my work and provide such, I would be grateful.

Armin

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Gurcharn Singh Sandhu wrote on Sep. 9, 2012 @ 13:05 GMT
Dear Johann,

I have read your essay and I appreciate your novel viewpoint. Even though our views regarding the curved space time are different but I agree on the main thrust of your argument. All authors in this contest have presented their viewpoints in different styles. In the grand maze of the unknown it is important to consider all possible alternatives and different viewpoints for...

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Hoang cao Hai wrote on Sep. 19, 2012 @ 14:20 GMT
Dear

Very interesting to see your essay.

Perhaps all of us are convinced that: the choice of yourself is right!That of course is reasonable.

So may be we should work together to let's the consider clearly defined for the basis foundations theoretical as the most challenging with intellectual of all of us.

Why we do not try to start with a real challenge is very close and are the focus of interest of the human science: it is a matter of mass and grain Higg boson of the standard model.

Knowledge and belief reasoning of you will to express an opinion on this matter:

You have think that: the Mass is the expression of the impact force to material - so no impact force, we do not feel the Higg boson - similar to the case of no weight outside the Earth's atmosphere.

Does there need to be a particle with mass for everything have volume? If so, then why the mass of everything change when moving from the Earth to the Moon? Higg boson is lighter by the Moon's gravity is weaker than of Earth?

The LHC particle accelerator used to "Smashed" until "Ejected" Higg boson, but why only when the "Smashed" can see it,and when off then not see it ?

Can be "locked" Higg particles? so when "released" if we do not force to it by any the Force, how to know that it is "out" or not?

You are should be boldly to give a definition of weight that you think is right for us to enjoy, or oppose my opinion.

Because in the process of research, the value of "failure" or "success" is the similar with science. The purpose of a correct theory be must is without any a wrong point ?

Glad to see from you comments soon,because still have too many of the same problems.

Regard !

Hải.Caohoàng of THE INCORRECT ASSUMPTIONS AND A CORRECT THEORY

August 23, 2012 - 11:51 GMT on this essay contest.

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Sergey G Fedosin wrote on Oct. 4, 2012 @ 09:23 GMT
If you do not understand why your rating dropped down. As I found ratings in the contest are calculated in the next way. Suppose your rating is
and
was the quantity of people which gave you ratings. Then you have
of points. After it anyone give you
of points so you have
of points and
is the common quantity of the people which gave you ratings. At the same time you will have
of points. From here, if you want to be R2 > R1 there must be:
or
or
In other words if you want to increase rating of anyone you must give him more points
then the participant`s rating
was at the moment you rated him. From here it is seen that in the contest are special rules for ratings. And from here there are misunderstanding of some participants what is happened with their ratings. Moreover since community ratings are hided some participants do not sure how increase ratings of others and gives them maximum 10 points. But in the case the scale from 1 to 10 of points do not work, and some essays are overestimated and some essays are drop down. In my opinion it is a bad problem with this Contest rating process. I hope the FQXI community will change the rating process.

Sergey Fedosin

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