The statement in the text is, simply, wrong: black holes were not shown not to exist, it was *claimed* this to be the case. Unfortunately, the claim received a lot of attention-its content much less. But it's the content that's relevant. it's useful to read the technical paper of Hawking and Penrose,

``The Singularities of Gravitational Collapse and   Cosmology'',http://rspa.royalsocietypublishing.org/content/314/1519/529

or the treatise of Christodoulou, 

``The formation of black holes in general relativity'', http://arxiv.org/abs/0805.3880

Is it not the case that singularities arise mathematically as, e.g., 1/r potentials?  So, any reasonable theory on a lattice will be finite.  And why would we think the 1/r potential is meaningful as r->0 where we know that quantum effects come into play.  I see no reason to believe a priori that real singularities exist in nature.  Lots of ideas we use cannot exist in nature, such as plane waves.  None of this means that black holes do not exist.  But I would rather them arise in a fashion that is consistent with QM.   

The last sequences concerning black holes prove only the gravitational theory of black holes presents serious problems and post-modern theoretical physicists are trying solutions ad hoc by targeted adjustments. My viewpoint on the question is the following: never  I believed the gravitational theory of black holes and consequently I have formulated the  " Theory Relativistic of Black Holes" in the 2012 January (see attachment). Anyway the last word on black holes does not regard theoretical physicists but astronomers who make measurements on the field. Only astronomers are able to say us if black holes exist actually. From my viewpoint, if their existence will be confirmed, the question of black holes concerns the most large question of dark matter and there are very little probabilities to solve the question in the order of GR.

Article Relativistic Theory of Black Holes

The statement in the text is, simply, wrong: black holes were not shown not to exist, it was *claimed* this to be the case. Unfortunately, the claim received a lot of attention-its content much less. But it's the content that's relevant. it's useful to read the technical paper of Hawking and Penrose,

``The Singularities of Gravitational Collapse and   Cosmology'',http://rspa.royalsocietypublishing.org/content/314/1519/529

or the treatise of Christodoulou, 

``The formation of black holes in general relativity'', http://arxiv.org/abs/0805.3880

The author of http://phys.org/news/2014-09-black-holes.html seems to be confused by the emission of  radiation in general and Hawking radiation.   The latter is a very specific sort that  occurs after a black hole has been formed. Stars do indeed radiate and lose mass during their final collapse, but that is nothing new. It's called a supernova and we have been investigating those for a very long time. Moreover, stars  lose mass all through their lives (we call that stellar wind). Again, nothing new here and it certainly does not inhibit the formation of black holes

Dear all,

Let's say the singularity of a black hole has some physical indication, but by all means it doesn't represent a real physical description of what's going on in a black hole. The singularities in universe contradicts many facts like the continuity of time and the quantization of energy. So what's the  harm in thinking to solve this problem

The singularities theorems imply the existence of singularities-and the cosmic censorship conjecture that these are hidden by event horizons. These are mathematical statements, under certain assumptions, in classical gravity. I'd recommend, once more, reading Hawing and Penrose's paper-there's no point in repeating it. However it isn't correct that they have anything to do with quantization of energy.

The singularity theorems of Hawking, Penrose and Geroch show that singularities follow from generic initial data in general relativity. Basically, matter clumps up and eventually reaches a density sufficient to drive an infinite solution. The point at which the singularity occurs is not a point of the physical manifold - the theory has broken down there and gives us no information.

There have been efforts to avoid this breakdown, for example by adding terms to the gravitational Lagrangian. My own dissertation was motivated in part by the hope that the second-order corrections to GR from string theory would remove the singularity, but while they changed the strength of the singularity they did not remove it. It is possible that the full string theory would, since as the center of a black hole is reached the high energy will open the 4-dim space-time back into the full 10-dim, "stringy" space.

Whether this is the correct picture or not for what happens at the center, the Schwartzschild solution holds down to minuscule distances, well within the event horizon. Since we understand a great deal about high energy matter from accelerator experiments, we can expect the prediction of GR to hold until very close to the missing point - the singularity. The recent work claiming the instability of black holes might only mean they eventually evaporate. Until clear time scales are established for that calculation, it remains possible that they will exist for arbitrarily long times before evaporating. Considerable effort is going into understanding the exact meaning of the recent result. 

Dear Stam and James

with all respect to your opinions, but I think in reality there is no singularity. Let's look for a while to the universe as a unified unit, if there are any singularities in this unit this means that this unit will be destroyed or becomes  non stable as a whole. At the same time there is a power which is more powerful than the black holes forces which leads to the expansion of the universe as you know the singularity is not found in this force while its assumed to be found in black holes which supposed to have less flux other wise the universe will not be expanded, instead it will shrink at these points. As you well know there is no detection of any shrinkage source that may lead to universe shrinkage at these points.  

I think the more logical assumption is to solve this singularity which I think is not as hard as one may think, but this needs to change some of the assumptions of special and general relativity one of them is assuming the violation of Lorentz symmetry. 

Let me add that Birkhoff's theorem is valid.

However, nonethless it remains true that nothing ever reaches the horizon of a black hole in finite outer time.

Hence unless you happen to know that the universe is already infinitely old, no finished horizon exists anywhere in the cosmos.

Dear Prof. Otto

my point is; the singularities in black holes will make a non isotropy in the expansion of the universe, so the shadow of these points should appear as a non isotropy in the background radiation, which is denied by the experimental results of COBE and Planck experiments.

Gary Lyon Otto is not a 'researcher' worth taking seriously, his article http://phys.org/news/2014-09-black-holes.html is not published in a recognized scientific peer-reviewed journal. It is not known to arXiv or to the SAO/NASA database. Its content is nonsense.

For an alternative theory of gravity (peer-reviewed published) which does not have black hole and big bang singularities see http://arxiv.org/abs/gr-qc/0205035

The very prediction of Hawking radiation is highly dubious and questionable. The formulas themself may be fine, but they require the correctness of QFT for energies up to $10^{1000000}eV$ if one assumes that it will last at least one minute. This problem has been named "trans-Planckian", which is highly misleading, because the differences between the size of the visible universe and Planck length are negligible in comparison with the $10^{-1000000}m$  which become relevant after one minute. 

The question posed is very timely.

The existence of such a theory follows from my recent published work in the European Scientific Journal. But the necessary globally-constant-c version of the field equations is still extant.

Anyone able to write them down already?

Dear Ilja,

Your paper http://arxiv.org/abs/gr-qc/0205035 on a generalization of the Lorentz ether is unfortunately beyond my competence to read. I guess that this is the case for many in  the science community too  (or they just aren't interested), because it has been cited only once (but not discussed)  in a book from 2010 . Quoting your paper on ResearchGate gives less qualified readers the false impression that it is of some importance in contemporary research..

If black holes do not exist then you can move faster than light with your non-singular relativity. Unfortunately, they do exist.

Matts, who care about "contemporary research", which is another word for "string theory"?  Bohm's paper has been ignored for many years, it is in fact only an accident that it was not completely forgotten, but so what?  Today it defines one of the most important interpretations of quantum theory.  I have no problem if this would be the fate of http://arxiv.org/abs/gr-qc/0205035 or the even more important http://arxiv.org/abs/0908.0591 All one needs is that it will not be completely forgotten.  Then, the content speaks for itself. 

It is today when I can recommend to work in such alternative directions only if you are completely indenpendent of state-supported science, if you couldn't care less if working in such a direction will give you another grant or not.  This may be different in 50 years. The content of the papers will remain unchanged in 50 years.  So why should I care? I am independent. 

I think the new change will come from researchers that are out of main stream, at least they have better developed thinking.

The last comments inside this question induce me to do the specification that the contemporary research happens along three directions:

1.  post-modern physics

2.  neoclassical physics

3.  contemporary physics

It is altogether legitimate that every researcher recognizes himself and accepts one of the three directions.

If you follow contemporary physics on arXiv, you find that the spectrum of ideas in the "main stream" is enormous. Some participants on ResearchGate seem to think that most researchers are locked in preconceived ideas. That is not at all true, the problems to be solved are so many and so complicated so they inspire to the utmost intellectual efforts. Professionals are also aware of all the observational constraints and all previously tried solutions. Comments on ResearchGate which refer to some isolated statement by Einstein or Dirac or Hawking testify to the complete ignorance of the commentator.

Scientific community believed that at the heart of every Quasar there in a super massive black hole (BH). Also it is well know that due to very strong magnetic field, there is an ejection of ultra relativistic jets from the magnetic pole of a Quasar.  Here what we need to ask is that, Does a BH has magnetic field? In a paper regarding all the current problem, Prof. Mitra propose a theory that there might be an object called Ethernally Collapse Objects(ECOs) or Magnetic ECOs  other than a BH at the heart of Quasar(see http://www.sciencedirect.com/science/article/pii/S1384107606000923). Also Prof. Mitra suggested that any gravitationally collapse object should emit radiation and there won't be any free fall collapse (see http://journals.aps.org/prd/abstract/10.1103/PhysRevD.74.024010).  Recently we have published a paper suggesting that during the collapse stages of stars, all the masses will converted into radiation. Therefore when the collapse time is infinity the total mass tends to zero and hence no black holes are formed. But if the collapse object possesses a particular luminosity "The Eddington Luminosity", there might form a quasi static super massive star which come under the ECOs/MECOs category that we expect to be the central engine of a Quasar(see http://link.springer.com/article/10.1007/s10509-014-2158-6) .

I can’t see anything particular new in the idea that black holes don’t exist. It’s been well-known for many years that, from the point of view of an external observer, the surface of a collapsing star does not reach the event horizon in a finite time. All discoveries of “black holes” by astronomers are, therefore, observations of the radiation from surfaces of stars whose radius is close to, but always a little greater than their Schwartzschild radius. No actual “naked singularity” ever exists because its radius lies always within the star, where the mathematics of GR in “empty space” that predicts that radius does not apply. What is new to me in the report is the idea that, as the star radiates it loses mass, and the fictitious “singularity” within it continues to shrink along with the star. If that notion is accompanied by detailed calculations the idea is of considerable interest.

I think it is premature, in the context of presently known physics, to worry too much about “the singularity problem in general relativity”. Theories have their limits of applicability. GR becomes inapplicable close to where it predicts a “singularity” (in much the same way that Newtonian physics becomes inapplicable when velocities are close to that of light). To theorise effectively about what happens in those regions would require a consistent unified theory incorporating GR and quantum mechanics. Unfortunately, that theory is unknown.

In the link provided (http://phys.org/news/2014-09-black-holes.html) is the statement “Einstein's theory of gravity predicts the formation of black holes but a fundamental law of quantum theory states that no information from the universe can ever disappear. Efforts to combine these two theories lead to mathematical nonsense, and became known as the information loss paradox.” Let us suppose, for the sake of argument, that a true black holes exists; for example, a Schartzschild-type feature in the geometry of otherwise empty space. The Schwartzschild event horizon, often referred to as a "singularity", is not a mathematical singularity at all – it is analogous to the event horizon that exists behind an accelerating observer in Special Relativity. In that scenario, we don’t think of information “disappearing” and there is no “paradox”. It’s simply that information from beyond the horizon is not accessible to the observer. Why should the Schwartzschild situation be seen as leading to “mathematical nonesense”? Perhaps I’m being naïve…

Dear Ilja:

I looked at your first reference quoted above and am impressed by your ingenuity and fearlessness.

I have published proven evidence that there is no Big Bang and no cosmological origin of the microwave background radiation. The fundamental result which does away with cosmic expansion is the new statistical-mechanical discipline of "Cryodynamics." It applies to attraction-based gases and thus is quite late-born. Its Laws, still incomplete, include the presence of "anti-dissipation" in such gases. The late Ilya Prigogine showed sympathy to the first developments. 

I have also - by a perhaps unfortunate coincidence - an independent published proof that the speed of ight in the vacuum, c,  is a globally valid (and not just an everywhere locally valid) constant of nature. It too is totally unexpected.

The latter result happens to change the properties of black holes. This latter aspect of my findings is maximally unpopular due to the implications it has regarding black holes (as are soon to be attempted to be produced down on earth again). 

The necessity to defend these billion-dollar expenditures is seen to be more important than to predictably gain billions of dollars due to the applicartion of cryodynamics to continuous-fusion reactors. Second, "anti-life" is a beautiful new theoretical prediction of cryodynamics. New theory is a thousand times more fertile than the continued application of old theory. Especially so if the latter is not fully correct.  

I hope that the Chinese Academy of Science will show interest in Cryodynamics in view of its potential technological applicability. 

Take good care, Otto

Otto

Where have you published proven evidence that there is no Big Bang and no cosmological origin of the microwave background radiation?

Eric, what is observed as "black holes" are stars which are massive but small, so that they should be, according to GR, black holes.  What is observed is not their surface, but what happens with infalling matter.  This infalling matter will heavily radiate - which is quite natural and independent of the nature of the "black hole"-candidate itself.  

Ilja ~

I understand your point. Maybe the radiation of infalling matter is greater than that from the surface (which is enormously red-shifted when it reaches us) and/or maybe it has different characteristics that enables astronomers to recognize it (I'm no astrophysicist!). My conclusion that there is no "singularity" is independent of these details

Whether some stars (black hole candidates) have a central singularity or not is beyond our capacity of observations. At best, our observations can approach a singularity, not prove it nor disprove it. Schwarzschild black holes are bona fide mathematical solutions of  GR, and they do have a mathematical singularity at the center, but nobody can assert that they exist or do not exist..

Yes, I agree. Then after it has been confirmed they exist as per numerous and repeated experimental observations, it will need to say if they answer to the gravitational logic or to the relativistic logic.

The gravitational field in the region around a spherically symmetric star is given by the Schwartschild solution – a solution to the empty space field equations. Inside the star those equations do not apply. There is no “singularity” inside the star. We can ask how long it takes for the radius of a collapsing star to become equal to or less than the Schwartzschild radius. A simple calculation gives the answer: from the point of view of an external observer, it takes an infinite time. Astronomers are external observers. Hence a true “black hole” in the sense of a “naked singularity” through which the surface of the star has fallen cannot arise in a finite time. If we accept General Relativity as a true description of gravity, this is what it tells us.

Ironically, gravitation, which causes a burnt-out star to collapse, turns out to be the agency that eventually halts the collapse!

Of course, spherical symmetry is a very special case. There is a lot of literature on “cosmic censorship” that generalizes the idea of “no naked singularities” – but it’s largely speculative.

The signal-to-noise ratio in these blogs is so low to my taste, that I usually refrain from reacting. I'm afraid that this blog is as bad as the rest, yet I am making an exception. There seems to be a misunderstanding.

@Sadeem: the paper in question is taking Hawking radiation into account, but in no way reflects a majority's understanding of what goes on. My point is that Hawking radiation is a very weak quantum effect that can be ignored for astronomical black holes (such as the ones that arise when stars collapse or collide). An observer travelling along with the collapsing matter does not observe Hawking radiation and would see the collapsing matter pass right through the horizon. This is simple math, only disagreed upon by people who don't understand simple math.

So this author succeeded in confusing you (and probably many others) into thinking that black holes do not exist. Many participants in these blogs show their confusion about the horizon - that a horizon wouldn't form in a finite amount of time. Indeed, the horizon refers to an asymptotic state, but it is a state that is reached very quickly in practice. Like when you stir milk in coffee, the colour becomes uniform only after infinite time, formally, but very soon in practice.

You see, physics is a science of observations and models explaining the observations, but neither the observations nor the models are infinitely accurate. What we have is a very accurate model of gravity, but probably not infinitely accurate. According to that model, nothing can stop the collapsing matter of a star. Now since, again according to the model, nothing spectacular happens at a horizon, there is not much reason to doubt this statement.

But you can make different models. My favourite is called "conformal gravity". It boils down to standard GR under practically all circumstances, except that it adds another symmetry: spontaneously broken Weyl symmetry. Since it is very badly broken (yet spontaneously), the symmetry has no consequences practically anywhere, except when a black hole forms. It allows me to transform the picture into another one, one where exactly the thing happens that the paper in question talks about. It's a new kind of relativity if you will, a relativity where different observers disagree about what they think they see. The observer moving in with the collapsing matter disagrees with the observer outside. This is a way of saying that perhaps all are right.

See arXiv:1410.6675, or lectures I presented at Les Houches in 2011 (still not yet available).

Addendum to previous entry: @Eric, physicists are quite aware of the fact that the singularity at the horizon is merely due to the use of bad coordinates - collapsing matter behaves like the polar bear at the North Pole: he may walk across the North Pole without caring much about the fact that the coordinates we use to map the world generate a singularity there.

The singularity people do worry about lies further within the central region, and, though it can be weakened when the black hole carries electric charge or angular momentum, it cannot be removed. 2 points however: 1) you can call that singularity unphysical because it can never be seen by outside observers, so who cares? You could say that it's like a singularity in the complex plane, as soon as you stay put on the real axis, it won't bother you. So, stay at finite time as an outside observer, and the BH’s central  singularity won’t bother you. 2) In my theory of conformal gravity a symmetry transformation can remove the horizon, and the singularity inside. That would be more satisfactory, perhaps. However, that theory of mine has not many followers. Not yet?

Gerard  ~

The central singularity in the Schwartzschild geometry is a "point mass" in an otherwise empty space. It is a mathematical fiction of the same kind as the "point charge" in elementary electostatics. 

"you can call that singularity [ie, the Schwartzschild event horizon, erroneously referred to as a singularity] unphysical because it can never be seen by outside observers, so who cares?"

Astronomers need to care, because they are outside observers.

One can deduce from the mathematics that an "observer" can fall through a Schwartzschild event horizon (if such a thing were to exist in the real world...) in a finite time. So who cares? There are no such observers.

Two much fantasizing gets into these kinds of discussion. Pathological mathematical constructs do not correspond to physical realities.

Dear Prof Gerard t Hooft

Thank you for your valuable participation in this thread. When I asked this question my intention is not for denying the existence of black holes, but for redefining their properties and specially the singularity and the event horizon. I just wanted to bring the attention to this problem which is really needed to be solved if we want to build a real quantum theory of gravity. I know there are black holes in reality but without a singularity and may be with a new definition of the event horizon. I think if we want to solve this issue we must start from special relativity, because the Schwarzschild solution implicitly brings this problem initially from the form of special relativity which already contains this problem in Lorentz factor when the relative velocity reaches the speed of light. I already solved this problem in my new theory and connected it to quantum mechanics. The new form of Lorentz factor contains non singular terms even if the speed of the elementary particle reaches c, because the classical observers in all cases must have certain velocity value due to earth rotation around itself or around the sun or due to their movements or .....etc. One may ask for a while if the problem is relativistic, what the effect of the tiny movement for classical observer may bring with it?

The effect of this tiny velocity is only appeared when we are dealing with velocities so close to speed of light about 299792457.98. The same can be done to general relativity, but I'm afraid there are important modifications needed to be made, but these modifications will simplify the theory and I think it may pave the road towards unification between quantum mechanics and general relativity. The problem is this theory is not fully recognized yet by the scientific community and needs time to persuade the editors with its concepts and I need assistance to develop it further towards quantum gravity theory due to lake of time because GR is not my professional specialization.

Best regards

@Eric, What makes you think that the central singularity is a point mass? The parameter M of a black hole refers to its field at r = infinity. At the center (r=0, which is not where the horizon is) the equations generate a singularity. It's not floating in empty space, it's in a region where the coordinates r and t switch roles: r is timelike and t is spacelike. Observers - or test particles - entering the BH all, regardless their velocity, experience the point r=0 in their (very close) future, where due to the singularity GR ceases to make sense. Please read my previous answers more carefully: outside observers - astronomers - cannot see that singularity. They do see the region asymptotically close to the horizon, r=2GM, which isn't referred to by physicists as a singularity, unless you think that the north pole of planet earth is a singularity. You are the one who's fantasizing. Pathological mathematical constructs? Is the north pole a pathological mathematical construct?

Arno & Gerard ~

The Schwartschild spacetime is an empty space solution. It is a perfectly respectable mathematical entity. What I’m questioning is the extent to which it can be employed to draw conclusions about physics. Undoubtedly, the exterior Schwarzschild solution has provided magnificent contribution to physics. As I see it, the “event horizon” represents a boundary of the space in which physics takes place. It is infinitely distant from any external observer. The “interior” Schwarzschild solution is a mathematical curiosity – fascinating to a mathematician but devoid of implications for physics. The final stage of a collapsing star is a star whose radius is close to, but a little greater than, the Schwartschild radius. There is no event horizon and no central singularity, simply because the interior of a star is not “empty space". There is no “black hole”.

Gerard ~

“[Astronomers] do see the region asymptotically close to the horizon, r=2GM, which isn't referred to by physicists as a singularity, unless you think that the north pole of planet earth is a singularity. You are the one who's fantasizing. Pathological mathematical constructs? Is the north pole a pathological mathematical construct?”

I said that the event horizon is not a singularity! In the usual Schwartzschild coordinate system it happens to coincide with a coordinate singularity, that’s all. The coordinate singularity is removable by choosing a different coordinate system. Nevertheless, the “event horizon” itself is a genuine irremovable anomaly in the geometry, with interesting and curious properties. That’s why I referred to it as “pathological” – a word commonly used by mathematicians to refer to unusual and unexpected mathematical entites.

An observational  proof of the existence of black hole horizons seems not to exist, but for astrophysicists,  galaxies, particularly the active ones, have at their core a black hole.

Several simple theoretical models of stellar collapse  provide a possible final state as a black hole.

In the article cited, apparently taking (negative) Hawking radiation inside the object, the singularity is avoided, but then the outside should ALSO be a Vaidya null radiation metric and not a Schwarzschild as considered in this article.

In the  90´s  Senovilla, Torres  and Fayos proved,  in several articles, that it  is possible a non singular  collapse (NO BLACK HOLE) with a Friedman interior and an outer Vaidya, emitting radiation until the complete evaporation of the star.

Arno, I was not your disapprover, but I still object to your argument.

How could a star be formed by matter and antimatter? Already its formation is an impossibility, and there is no point in speculating about its collapse. Stars die quietly or become supernovae, thereafter neutron stars and possibly black holes. There is no route to introduce antimatter here.

Arno ~

“Don't you notice, dear Charles, that your "singularity is a point mass" is bare nonsense?”

You are taking Charles’s remark out of context. He goes on to say “…I have developed a model of interactions…in which there is no extension of space within the event horizon….”, and concludes: “I see no reason … for thinking that there is any physically meaningful extension of spacetime to the interior of the event horizon.”

Some mathematical concepts are not relevant to physics. The “central singularity” in the Schwartzschild geometry is one of them - a conclusion that can be arrived at whether or not one adopts Charles’s view of QED.

I would want to express a few considerations about  two concepts quoted in the debate: a vacuum and the point-mass.

1. A vacuum is a physical structure characterized by three perfectly known physical parameters: the dielectric constant (=8,86x10-12 F/m), the magnetic permeability (=12,56x10-7 tesla m/ampere) and the mechanical resistance (=0). In TR it represents the physical space. Besides a vacuum is an effective physical medium with insulating properties and it is the natural place, but not the only one, for the propagation of both electromagnetic waves and nanowaves. A vacuum nevertheless in TR does not represent an absolute reference frame and it consequently it is different  from the classic ether. 

2. I agree that point-mass is a mathematical abstraction that allows to consider a physical reality (mass) through a mathematical model (point). The model allows just an easy representation of the large mass by means of a geometrical point of space that coincides with the stationary or moving barycentre of physical mass. It is manifest that the point has zero volume and consequently this model generates always a singularity for any mass. It seems to me that in the gravitational theory of black holes the singularity assumes instead physical reality for which a necessary event horizon must be theorized. The same thing happens with the concept of wave-mass that is a good mathematical model in order to represent elementary masses in some physical situations without forgetting that it too is a mathematical model and the physical reality of elementary masses is the electrodynamic mass. 

With regard to matter and antimatter then the question has been solved by the Principle of Asymmetry.

Dear Arno,

What you have stated clearly and simply is pure nonsense.

The Principle of Asymmetry gives an answer to the question why in nature there is largely matter and little antimatter. If you are interested in, you can see the following attachment:

Article The Principle of Asymmetry in the Elementary Universe

Well Arno, I already told you that there is no route to produce a star containing matter and antimatter. To enter positrons in the argument does not help you: one cannot convert baryons into antibaryons with the help of leptons. Your particle physics is deficient.

Arno,

There is no work cited for you (2005-2014) or Peter Plichta (1980-2014) on arXiv or the SAO/NASA database..

Black holes are rather humoristic for me, and I would rather be interested in the black holes of the brains. What I think is that in the evolution a lot of information is lost and that the first melecules had much more informations as we have for the moment. As reflected in society there is a lot of desintegration, disharmony and misunderstanding for those who preserved the information in their soul. But humor must be tolerated, it is also sane. (Paris)

Dear @Sadeem, black holes do exist and nobody can argue against that; they are a consequence of circular motion that all bodies do follow.

I agree with dear Professor @Arno Gorgels, ""Wahrheit ist nur sich selbst verpflichtet".

 Dear All

I'm not claiming that black holes don't exist; I'm just suggesting solving the singularity problem which does not contradict with black holes but may suggest redefining their properties.

regards

The topic of discussion here (astronomy, not astrology !!) is light years away from medicine or sociology, so I must politely ask nurses and sociologists to stay away, unless some of the other bloggers need their immediate attention...

I try to "read" Demetrios_Christodoulou but it is 594 pages! Can one summarise the tow arguments:

1. BH exists

2. BH do not exists

Arno,

In every reaction inolving leptons and/or baryons the leptonic number is absolutely conserved and the baryonic number is absolutely conserved, you cannot trade one for the other without violating millions of precision experiments. Positrons are NOT at  the core of protons, your invention is pure nonsense.

To whoever downvoted Brenda Jacono’s post ~

That a person working in a completely different field is taking an interest in developments in fundamental physics and attempting to understand is admirable. This should be encouraged – why not reply to her to help her understand instead of simply hiding behind anonymity and downvoting? Seemingly miraculous remissions are a phenomenon related to the relationship between consciousness and the brain and between the brain and the body. The assumption that these questions have nothing to do with physics is unwarranted. Scientists are completely in the dark about what “consciousness” is and how it relates to the physical world. Wigner conjectured that it is involved in what we mean by “observation” in quantum mechanics, and Roger Penrose has speculated that consciousness may be a quantum-mechanical phenomenon taking place in the brain and even suggested that quantum gravity is involved. I’m not saying that I accept these particular speculations, but they are not total nonsense.

Arno,

Black holes accrete matter (baryonic, leptonic, dark matter...) because of gravity.

But I don't know what form matter takes once it has passed inside the horizon, nobody knows. So don't misquote me for having said that BH is about particles when looked upon close. Also, nobody has looked upon them close.

You are, however, wrong in stating that positrons form the core of neutrons, quarks and protons. I'm not going to continue any discussion with you if you repeat this nonsense.

"You are, however, wrong in stating that positrons form the core of neutrons, quarks and protons. I'm not going to continue any discussion with you if you repeat this nonsense."

According to the standard model the positive beta decay of a nucleus involves the conversion of a down quark to an up quark, d → u + e+ + νe. Arno’s idea that leptons (including positrons) contribute to the internal constitution of nucleons may be nonsense. Or it may not. In view of the present state of knowledge of the structure of baryons, this kind of talk is all idle speculation. Let Arno present to us his conceptual model in which "positrons form the core of neutrons, quarks and protons" so that we can consider its merits.

Please present us one and only one unambiguous black hole observation.

Then you can 'attack' Arno's view...

Meanwhile...

Thank you

Arno,

Suppose that indeed positrons form the core of protons. Two questions:

My point is that there is already a vast amount of data from experiments with electrons, so perhaps available data can already exclude your idea.

Marcoen

Arno,

The antiproton is usually considered as the antiparticle of the proton. Assuming the core of protons is formed by positrons, you would then expect that the core of antiproton is formed by the antiparticle of the positron, which is the electron. But apparently this is not true in your framework. So either you hold that the antiproton is not the antiparticle of the proton, or you hold that the electron is not the antiparticle of the positron, or you hold that there is no structural symmetry between an antiproton and a proton. Which one is it?

Marcoen

Arno,

At CERN antiprotons are produced on a regular basis, they have already succeeded in storing them for months. Production of antiprotons is just another day at the office for experimental physicists. I'm interested in your answer to my previous post.

Marcoen

PS: strictly speaking the answer to your question ("how many ...") is an integer, the exact value of which nobody knows.

Arno,

So you do not only deny that antiprotons have been observed, you even deny that they exist. Any physicist would say that you are denying well-established experimental results.

On the other hand you agree that electrons and positrons annihilate. Now according to you, positrons form the core of protons; then why do we not observe annihilations when nuclei of ordinary matter (which contain protons, and thus positrons) are bombarded with a beam of electrons? For example, take an old TV: the images you see are created by bombarding the screen with a beam of electrons with an energy of about 20 KeV. But no annihilations are observed. Doesn't that refute your theory? You have to be honest to yourself, Arno.

I'm afraid I'll have to agree with what Gerard 't Hooft said in an earlier post about the signal-to-noise ratio. My contribution is herewith concluded.

Marcoen

Marcoen ~

The electrons in a cathode-ray tube are not hitting the nuclei of the atoms in the screen. They're not that energetic!

Some unstable elements can undergo a transition to a more stable element by a process in which the nucleus captures one of the inner electons. The basic process is p + e → n + ν.

Just sayin...  (Not implying acceptance of Arno's idea :-)

Eric,

I know electron capture: even then, according to Arno all protons in the unstable nucleus still contain positrons. So why no annihilation upon electron capture?

But the vast majority (>99%) of the atomic nuclei of a TV screen concerns stable matter. The 511 keV photons signalling electron/positron annihilation are not observed.

Marcoen

66 antiprotons? Well, the SPS accelerator at CERN, and the Tevatron at fermilab produced beams of antiprotons colliding against protons. Fermilab reached 1 TeV to observe the top quark and later tried to observe the Higgs particle. Wikipedia mentions that they had 500 trillion collision events, that's a bit more than 66. That may have been the number of antiprotons that CERN managed to stop completely to produce antihydrogen, atoms consisting of an antiproton with a positron circling around it. This way, one can study the antiparticles to check whether their masses and other properties indeed mirror those of ordinary matter precisely. Technically a great achievement.

And what do you mean, Arno, is detecting 66 particles not enough to say that they exist? What kind of science is that?

By the way, Arno, physicists at the beginning of the 20th century did suspect that there are positrons inside protons, but they saw the errors of their ways. In modern physics, we spend about one paragraph to dismiss such concepts. Try to fit the wave function of a positron in the volume of a proton. If you understand the equation - which I don’t expect you to do, you’ll see the problem.