Nothing you said prohibits black holes. Hubble has photos of black holes, not to mention the Chandra X ray telescope.

Your view is so naively that it will be useful for you to read my dialogue http://tpac.theor-phys.org/4200-026 whele almost all such postulates in the form of "arguments" are discussed.

Your arguments aside, Zahid, how do you explain the photographed and well analyzed phenomena that are acting just like black holes? The subject is no longer theory - that was settled in the 90s. And another thing, you contradicted yourself when you said,

"Since all cosmological world time moments are finite, you can not freely take a moment of proper time AFTER infinite wold time, ".

If world time moments are finite then there are no infinite world times. Hello?

In any case, general relativity does predict black holes and black holes are currently being studied. I should know - I study them when I get the chance and wrote a paper about why its impossible to fly into the ones that we usually see. The paper was supported by data acquired from the Hubble and Chandra, so if anyone is naive here, it's you, pal.

You wrote " there are no infinite world times". It is all that I want explain - BH paradigm is based on intuitive postulating the existence of events "after" "infinite world times". As you understand absurdity of this statement and accept GR formulas, you must take as realisable ones only finite world time moments when BHs can not formed since have not enough (world) time.

Anybody who belive that astronomers, who named someone as BH, really "observed" the internal structure of collapsed object, is very very naive man. Papers where authors easily take unrealisable in real world epochs are based not on scientific arguments, but they are sci-fi.

Zahid:

I'm going to take it that since english isn't your first language, that you're using words without knowing their appropriate application. With that in mind, let me just say that you're wrong - black holes are and never were based on intuition - they were discovered first as solutions to certain equations from GR. In 1993, the first large scale astronomical entity was spotted that appeared to be a black hole. Since then, many other objects have been discovered. That fact renders your original statement, moot.

Second, no one knows for certain what happens inside a black hole, we only have mathematical and geometric projections, nonetheless, that lack of certainty does not preclude the existence of black holes.

You mention people believing astronomers and authors of papers, as if that is the only source of information, ignoring that fact that both Hubble and Chandra telescopes have recorded not only evidence of black holes but aspects of their behavior. You don't have to take my word for it, see for yourself -

http://hubblesite.org/search/?query=black+holes&x=0&y=0

http://chandra.harvard.edu/search_results.html?cx=008640298979322525961%3Arpcb8voz8ci&q=black+holes&client=google-coop-np&cof=FORID%3A11

Black holes are real. It's you that has to face the facts. Anything else would be worse than naive. It'd be stupid.

Marshall,

When you say that "they were discovered first as solutions to certain equations from GR" you must remember that they are VACUUM solutions, i.e. give us metrics outside the object's surface. The predicted by the such solution a horizon appears only if a surface radius is less than the gravitational radius of the source.

Internal solutions, i.e. matter solutions, do not contain the horizon and a central singularity.

You also must remember that outside and on the surface of the object there is global simultaneity of events as in classical physics and SR (new property of GR - slowering of proper time intervals - does not change this fact).

If you will analyse these facts of GR, then you will conclude that BH paradigm is based on the intuitive hyphothesis that object's surface can cross its gravitational radius during finite world time interval. In GR this is impossible, while operating by events AFTER infinity (cosmological) world time is absurd in real world.

Dear Marshall, you are completely confused by certain experts in mathematical general relativity, and astrophysicists which are not specialists in general relativity.

The situation in BH investigation just repeats the well-known story about Gaussian distribution in mathematical statistics when theoreticians believed that experimentalists proved that they see such distribution in all data, while practical researchers were sure that theoreticians rigorously proved that the Gaussian distribution is the only consistent distribution in mathematics.

I suspect that you are not a specialist in both GR and astrophysics.

At least you never read the paper by Albert Einstein Ann. Math. (USA) 40, 922 (1939) where he rejected the whole concept of Black Hole (at that time it was horizon and singularity) as absurd in physical reality. Arthur Eddington was also against such physical nonsense as BH.

Also in modern time in professional scientific journals there are acute discussion on the GR solution without Black Holes horizons (see review papers by Abhas Mitra, Stanly Robertson, Anatoly Logunov and many references there).

Accurate astrophysicists call observed compact relativistic objects as BH Candidates and this is correct name, because one needs to perform critical observations to prove one way horizon in the real astrophysical object. Actually there are many observational facts which contradicts the BH existence (magnetic field, surface, bursts).

What is more there are arguments that the physical concept of BH is the consequence of the absence of energy-momentum conservations of the gravity field itself in geometrical gravity theory (see arXiv: 0809.2323 and : 0809.2328). As a result we may conclude that GR is a good theory but it is physically restricted and has limited region of physical applicability in the weak field approximation.

Yuri and Zahid:

Arguing the mathematics about the existence of black holes is moot when we have Hubble photos of them in action. In America, we have a saying - If it walks like a duck and quacks like a duck, it's probably a duck.

Here's NASA's Hubble black hole photo list with explanations - http://search.nasa.gov/search/search.jsp?nasaInclude=black+holes+pictures

The bottom line is that Zahid said the GR prohibits black holes when in fact physicists looking at GR found their possible existence in the equations of GR. Einstein thought that black holes couldn't exist but he was wrong as we have pictures of them in action now. They are any number of objects that aren't called black hole candidates because the observations have been made. Until that happens, yes, they are black holes candidates, but I was talking about the ones that have the total, complete observed behavior - accretion discs, observed devouring of surrounding material, X-ray profiles, galactic jets, and other behavior that meets the requirements for wearing a name tag that says, "Hi! My name is BLACK HOLE".

Arguing the mathematical interpretations is whistling in the wind. The fact remains that there are objects in space acting just like black holes. If they aren't black holes, then what are they?

I really feel sorry for you guys that have to rely on such weak topics to try to stake your reputations on. None of you have addressed any of the physical evidence that I provided before, so I suspect you'll ignore the link I provided this time. And Zahid, your making up terminology to try to make it look like you know what you're talking about doesn't help your cause. No one uses "infinite world times" when talking about black holes. No one, but you...

Dear Marshall, please distinct two cases in social science: first aime is to get money from the taxpayers and second is to perform a real scientific research.

For all your references

http://search.nasa.gov/search/search.jsp?nasaInclude=black+holes+pictures

we have the case 1 just because astronomical images can not prove that one sees a black hole resolution of telescopes too small to see gravitational radius R_g. Only in near future the VLBI observations at millimeter waves will observe such small sizes for the closest BH candidates (e.g. in our Galaxy center).

So now you are in the position of Ptolemaic scientist which see the rotation of the sky and say "Hi! My name is Rotatung Sphere".

Your question "If they aren't black holes, then what are they?" should be addressed to the scientists who develop the physical theory of gravitational interaction, but not to the nice pictures of beautiful astrophysical object. Then you should know that in the scientific literature there is acute discussion on relativistic quantum gravity theory and general relativity is one example of them. All really tested relativistic gravity effects also exists in alternative gravity theories. For example there are relativistic compact objects which has sizes about R_g but it is not a black holes. They have surface, magnetic field, jets and accretion disc, but they are not a black hole which predicted by GR. I already gave you the references.