Talk:Black hole

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Singularity- shouldn't the article have more theories?

It is logical that black holes consist of quarks, other "exotic" non-nuclear plasma, and energy. It is probably baloney that black holes are a singularity, infinitely small, with infinite temperature. Rules of physics still work in a black hole: there is equilibrium and pressure balance. Temperatures would be very high and would start at 200 MeV minimum (for nuclear disintegration and quark production) and go well into the TeV region. Exotic particles would be generated until there is pressure balance. Note that most effective mass might be in the form of photon energy, although these would have a very short mean free path before being absorbed and re-emitted. So most of the mass in our universe, if its in the form of black holes, could be in the form of energy. Note that likely any particle in the black hole, no matter how small, would have almost the same energy as the largest quark, similar to tokamak plasmas where the electron and proton energy is about the same.

Perhaps a black hole could become unstable and explode, but it is more likely that a black hole explosion would occur by instability when 2 black holes of approximate similar mass merge. Evidence for this are in a few galaxies where some enormous explosion fills the whole galaxy. These explosions are centered in the galaxy. And what's in the center of a galaxy?

So a black hole, inside the event horizon, has temperature, pressure, size, shape, probably a strong magnetic field, angular momentum, and effective mass summation, all of which can be described by physics. It is poor logic (Hawkins?) to state a black hole has infinite temperature and no size. - BG —Preceding unsigned comment added by 172.162.170.182 (talk) 01:16, 1 February 2010 (UTC)

Beyond a certain point, it is impossible for degeneracy pressure to support _any_ material, due to relativistic effects. Above a certain finite mass, probably in the neighbourhood of 4 solar masses, your "quark plasma" would have zero radius. You are also overlooking the event horizon, which is unrelated to the type of matter that forms the black hole. If any given amount of mass is compressed within a given radius (the schwarzschild radius), all rays from the future light-cones at any point within that radius point inwards (i.e., in the direction of decreasing radius). Further shrinking is as inevitable as moving forward in time, as there are literally no timelike paths that do not fall further inwards. Result: collapse to a singularity. There are reasons to believe that this picture is modified when the resulting object is sufficiently small (Planck radius), but your argument doesn't touch on this. Instead, you're ignoring the two points I noted above.

Alternatives to black holes that are considered plausible by the scientific community are already mentioned in the article. --Christopher Thomas (talk) 02:28, 1 February 2010 (UTC)

I don’t dispute that energy is contained in the system and light does not escape, but doubt that a black hole's mass-energy structure has zero size or infinite temperature. Light-cones in the outer shell point inwards, except near the center where there is zero or little net gravitational force, just intense pressure (which they add to). The great increase in temperature could provide pressure balance through radiation pressure alone, not even counting for particle pressure or angular momentum. If temperatures were high enough for neutron disintegration, quarks and other particles would form at a temperature of roughly 2000 GK, resulting in a radiation pressure increase of Ten to the 13th power more than a base temperature of 1 GK, which would prevent collapse. Einstein didn’t believe a black hole has zero size. - BG —Preceding unsigned comment added by 172.162.21.153 (talk) 16:00, 23 February 2010 (UTC)

Light cones at all points within the event horizon point inwards. Radiation pressure can't stabilize things, as there is no way for photons to move outwards to apply such pressure on outer layers of your hypothetical ball of plasma! This applies to all methods of transmitting force (force-carrying particles travel at the speed of light or slower). It can be at 1 GK, 1 TK, 1 PK, or the Planck temperature - it still falls inwards.

As for your other statements, the acceleration applied by gravity grow stronger as you move inwards - you'd only get "zero or little net gravitational force" if you were inside a distributed mass, not approaching a pointlike mass. You are correct in noticing that, at the exact center, there is no "inward" direction in which to go; that's part of why this type of situation is called a "singularity" (from mathematical singularity, a "singularity" is a region in which the equations describing a system cease to have well-defined values). At all points besides the exact, geometric center of the hole, the description given by general relativity is well-defined, and has the properties I described above. --Christopher Thomas (talk) 19:57, 23 February 2010 (UTC)

What I was saying is that it is a distributed mass, with a core where light bounces around. Outside the core light heads inwards, the opposite of a conventional star where light heads outwards. I doubt gravity could overcome a force that increases with the fourth power. - BG

You can doubt away all you want, but you might want to leave classical physical intuition behind and actually study GR to understand why what you are saying is flawed. TimothyRias (talk) 16:26, 24 February 2010 (UTC)

Einstein understood GR and didn’t believe a black hole has zero size. —Preceding unsigned comment added by 172.130.31.39 (talk) 17:29, 24 February 2010 (UTC)

He believed that the presence of a singularity in the mathematical description of black holes in GR meant that that description wasn't accurate. That doesn't mean he thought your description was right. Why not look up things that he did propose as alternatives? --Christopher Thomas (talk) 19:55, 24 February 2010 (UTC)

Your proposed structure still fails. Consider a shell of matter of some finite thickness, with a hollow region inside with your photons. At the outer edge of the shell, matter experiences exactly the same gravitational forces as if all of the enclosed mass was a point mass. Per the description above, this means all light-cones on the outermost layer of the shell point inwards, which causes two things to happen. First, the outside edge of the shell contracts as inevitably as moving forward in time (there are no allowable paths that do not result in contraction). Second, the outermost layer of the shell can feel no forces whatsoever from inside itself, because there is no way for force-carrying particles (or any other particles) to propagate outwards towards it. This violates one of the assumptions made by your hypothesis (that the whole structure ends up being stable with a fixed radius), showing that your assumptions are inconsistent (i.e., that it's impossible for a relativistic object to behave in the manner you propose). --Christopher Thomas (talk) 19:53, 24 February 2010 (UTC)

Your statements are logical and I do not have a satisfactory counter arguement at this time. Mathematically everything inside the event horizon should head inwards. Perhaps gravity does not scale linearly, but this smacks of cop-out logic. Perhaps there is a limit to energy density with a given mass. Perhaps radiation pressure overcomes gravitational contraction. We agree on something basic - as the mass contracts, temperature rises. I just think there is something illogical about a singularity. - BG —Preceding unsigned comment added by 172.129.141.65 (talk) 05:46, 28 February 2010 (UTC)

I agree that having the model predict singularities is unsatisfactory. It's usually taken to mean that the model being used is incomplete. Scientists studying the topic still disagree about what an accurate mathematical description of a black hole would be. Some of the proposals are linked from this article. --Christopher Thomas (talk) 08:39, 28 February 2010 (UTC)

One year after the claimed Big Bang the universe was smaller than the Schwarzchild radius, but it did not collapse. How is that explained? - BG —Preceding unsigned comment added by 172.130.18.247 (talk) 14:46, 2 March 2010 (UTC)

This is not a page to discuss black holes or GR. Nor is it a page to educate you in physics or cosmology. Your question is answered by inflation and reheating. TimothyRias (talk) 15:25, 2 March 2010 (UTC)

I'd kind of like to know why the Big Bang was able to expand, and did not collapse under its own gravity. Can that point be covered in the article, or a link provided to an explanation elsewhere. Wikipedia is for educating the masses. When somebody comes here and asks a question like this, it may indicate a gap in the article's coverage. Jehochman ^Brrr 15:34, 2 March 2010 (UTC)

That is a question that should (and is) be answered in the Big Bang article. It basically is the question if the density of the universe is above or below the critical density. If it is above the whole universe would (eventually) collapse in to a singularity known as a Big crunch. The reason that this hasn't happened is that the universe was never (far) above the critical density. (This has to do with inflation and reheating, etc.) But all these questions have only very tangentially to do with black holes (and the only real relation is the formation of GR singularities), they clearly fall beyond the scope of the article. TimothyRias (talk) 10:39, 4 March 2010 (UTC)

Actually, that wasn't the question. The question is how it was possible for the universe to expand, given that when you're sufficiently close to the Big Bang, density should have been high enough for any given region to have a Schwarzschild radius smaller than the observable universe, and so inevitably collapse rather than be able to expand.

The only answer I can think of is that the assumption in the last sentence doesn't hold, and that at any given time space was expanding quickly enough that the "observable universe" was smaller than the Schwarzschild radius of uniformly-distributed matter at that density, but having actual confirmation of that from a source would be nice. --Christopher Thomas (talk) 19:24, 4 March 2010 (UTC)

In the end that is basically what the critical density argument comes down to. The critical density is basically the density at which the Hubble and Schwarzschild radius coincide. With the caveat that you should be careful about what you mean with "radius" in an expanding universe. This indeed means that universe was never "small than the Schwarschild radius" making the original question. Also fundamentally this a question that should be and is adressed in the big bang and FRW metric articles, not in the black hole article. TimothyRias (talk) 20:33, 4 March 2010 (UTC)

If there are forces that can make a black hole expandexplode, then surely there are also forces that can prevent it from compressing to zero size. - BG —Preceding unsigned comment added by 172.129.209.75 (talk) 21:22, 6 March 2010 (UTC)

There also are no forces that can make a black hole expand, so your point is moot. TimothyRias (talk) 23:40, 6 March 2010 (UTC)

Not sure what you mean by forces that "can make a black hole explode". My best guess is that you are referring to evaporation of black holes due to Hawking radiation. But that is a quantum gravitational effect, there are no classical forces involved. (In case you didn't know the concept of "force" does not make sense on the quantum level.) It is quite generally assumed that quantum gravitational effects will also prevent the formation of a singularity. This is mentioned several times in the article. TimothyRias (talk) 15:18, 7 March 2010 (UTC)

I don't think he's referring to that. Near as I can tell, he saw "expansion of space prevents the universe from becoming a black hole" in preceding paragraphs, and jumped on that as a mechanism for his own conjectures about black holes from earlier in this thread.

Short answer is, "no, nothing known can magically make cosmic inflation or other metric expansion of space start within a black hole or within collapsing matter that will become a black hole". Starting within a black hole wouldn't do anything detectable anyways (from the outside, it'll always look like a black hole once it forms; you'll just get a disconnected baby universe inside). --Christopher Thomas (talk) 20:40, 7 March 2010 (UTC)

I think an example of black holes exploding is an explosion that fills the whole galaxy. - BG —Preceding unsigned comment added by 172.162.58.231 (talk) 17:01, 8 March 2010 (UTC)

Where exactly are you getting this? It doesn't seem to be based on any known properties of black holes or of galaxies. If you're talking about quasars, they're very hot accretion discs around very massive black holes. --Christopher Thomas (talk) 17:14, 8 March 2010 (UTC)

2 subjects: (1) Probably my mistake on an explosion filling a galaxy. An old source said M82 looked like it had an explosion that filled the galaxy, and it does look that way. Now its said M82 had an encounter with another galaxy that caused it, so I will read up on it. (2) If "It is quite generally assumed that quantum gravitational effects will also prevent the formation of a singularity.", why does the article say " the singular region has zero volume. It can also be shown that the singular region contains all the mass of the black hole solution." —Preceding unsigned comment added by 172.129.17.73 (talk) 21:23, 11 March 2010 (UTC)

The second statement refers to the description of black holes provided by general relativity. Under general relativity, you can show that all matter inevitably collapses to a region (point, line, or ring) of zero volume containing all of the mass of the hole. General relativity's description is not expected to be exact (though it seems to work very well as an approximation). Quantum gravity is expected to change the picture of what happens near the singularity (in a system where volume is quantized, regions of zero volume probably can't occur). --Christopher Thomas (talk) 22:20, 11 March 2010 (UTC)

The paragraph you are quoting from starts of with the clause "... as described by general relativity ...", in which context does statements can be proven rigorously. The last paragraph of that section discusses that the appearance of singularities in GR singles that the theory is incomplete. Please let us known if you find that last paragraph unclear, and if so what you think is unclear about it. We can then try to fix it. TimothyRias (talk) 08:59, 12 March 2010 (UTC)

Could it be that a black hole/onion displaces the spacetime/aether that was once in its location, thus creating a dense conglomeration of spacetime, exerting enormous inward pressure on the hole/onion, akin to an air bubble displacing water? Because the spacetime has no other place to go it conglomerates on the surface of the hole/onion. —Preceding unsigned comment added by 63.76.208.2 (talk) 16:58, 23 March 2010 (UTC)

Sidis' 1920 views on "black body" stars

Anyone know why William Sidis's 1920 views on "black body" stars (black holes) and "boundary surface" (event horizon) isn't in the history section:?

• The Animate and the Inanimate —Preceding unsigned comment added by 68.23.161.224 (talk) 08:49, 24 February 2010 (UTC)

As far as I can tell, it has had no impact (or real relation) to the developement of the theory of black holes.TimothyRias (talk) 09:38, 8 March 2010 (UTC)

Timothy, I appreciate your reply to the above query (even though I did not ask the question). This type of neutral reply gets the point across without causing unnecessary tension. Steve Quinn (formerly Ti-30X) (talk) 21:00, 8 March 2010 (UTC)

On Black Hole Formation alternate hypothesis.

This discussion has been closed. Please do not modify it.
The following discussion has been closed. Please do not modify it.
Seeing that nothing can travel faster than light, and the newtonian equation of gravity shows that inside of a shell of matter, the gravity is zero for the shell, and only defined by the inside matter of the shell, and under high gravity frame of reference time slows down, and the nature of Black Hole formation under finite energy forces, could it be that Black Holes do not form per-se, but rather Black Onions, where matter starting with a droplet of condensed time dilated state forms and that core grows in miliseconds to compresses all the additional time dilated shells of condensed time dilated mattter about it in similar state, into a long lived metastable state where all of the matter is in a condensed time dilated form against the upper regieme of relativistic forces, or does the matter fall straight past all resistant forces that form white dwarfs and neutron stars, quite certainly, including time dilation on said matter? Such a Black Onion would be a frozen object in time space, never collapsing into a singularity, but slowly radiating its particles starting with light, at the edge of the object with less than infinite relativistic effects due to the temporal near freeze of the collapse and bounce over extended spans of time? LoneRubberDragon (talk) 05:08, 28 February 2010 (UTC) It is a very technical equation set with nearly singular stiff equations, so it is slightly beyond me to answer, and I see little description of such a Black Onion description of the collapsed condensed relativistic state of such an unheard of entity description, based on that fact that matter and energy cannot accelerate matter and energy to the speed of light itself. Almost a chicken and egg problem given that singularity. LoneRubberDragon (talk) 05:08, 28 February 2010 (UTC) As I understand, a distant observer can never see something cross an event horizon. As stuff orbits closer, it redshifts dimmer and time dilates slower. Additionally, inside the ergosphere, frame dragging severely distorts the geometry of space as seen from an external frame of reference. Objects cannot travel a straight line into a rotative black hole (except perhaps at the poles). They get dragged around. Have you looked for sources that hypothesize black holes don't collapse, but rather the event horizon is like a bubble that inflates from the center, and all the mass remains in a shell just above? Have you looked at the gravastar hypothesis? Jehochman Brrr 05:25, 28 February 2010 (UTC) This part I understand well. However, is all of this presuming the existence of a Black Hole to begin with in a good, but potentially false, top-down analysis. An analysis that says, IF we start with mass M compressed to a singularity, THEN all that can be used to determine the Schwarzchild Radius, and other properties of this theoretical object, The Black Hole. However, IF one considers bottom-up the very formation from a star model, does the physics prove Black Hole formation, or does time dilation, entanglement relations, conservation of momentum on the macroscale compared to the time dilation factors that slow matter down and cause an equal and opposite negative gravity effect from entanglement backpropagation and consevation equivalencies, THEN does a Black Ontion form, instead, a highly energetic, but highly time dilated form of frozen superfluid, that slowly escapes out the surface, due to this, OR does the physics Still Show that all the matter will form a singularity. For, all of the equations involved, and factors of inter-frame relativistics to conservation properties and quantum fields of entanglement, and stiff equations, all lead to difficult numerical solutions en-masse, beyond my numerical simulation capabilities. But an extant paper, and not de-facto knowledge of standards and practices, leads me to wonder about this wayward case, that I have never seen an analysis of disproof, like Michaelsom Morley disproved quite smartly and expertly Luminiferous Aether, not knowing if it would be proven or disproven. I do understand the dogma, but not seeing this Black Onion analysis anywhere, leads me to still wonder, about unfinished business. LoneRubberDragon (talk) 03:30, 1 March 2010 (UTC) No a priori assumption of a black hole is required. For example, the collapse of a thin spherical shell of dust can easily be solved analytically in general relativity. Inside the shell spacetime is flat while outside the shell spacetime takes the Schwarzschild metric up to the radius of the sphere. The result is that the dust collapses into a singularity in a finite amount of time as measured by a comoving clock. The analysis can easily be extended to a set of concentric mass shells, with the same result. The analysis becomes much more difficult if you allow other interactions in the matter causing an outward pressure and if you drop the assumption that the initial mass distribution is not spherically symmetric. Nonetheless Hawking and Penrose proved in the 1970's (the Penrose–Hawking singularity theorems) that and mass distribution will collapse to a singularity provided it was dense enough at some point. For their proof they make only very mild assumptions about the nature of the collapsing matter, requiring only that it obeys certain energy conditions.TimothyRias (talk) 10:58, 8 March 2010 (UTC) Gravitational time dilation causes infalling matter to seem to stop from a distant observer's viewpoint, but from the viewpoint of infalling matter, nothing unusual occurs (it feels that it continues to free-fall inwards, passing the horizon in finite "proper time"). It can be thought of as an artifact resulting from the choice of coordinate system used. People did indeed use this interpretation of black holes in the past; they were called "frozen stars", because it seemed that all matter would come to a halt just above the Schwarzschild radius, using the original Schwarzschild description of black holes. Later, when other coordinate systems were applied, it turned out that this was just an artifact of the original coordinate system chosen by Schwarzschild. This is discussed at greater length at Schwarzschild metric. This is good stuff here. But it, too, assumes the top-down model of Black Hole's a priori existence. These models are quite clear, and true in their own frame of reference. But, as before, does the Formation from the initial droplet of superdense, super time dilated matter, surrounded in zero gravity (from newton shells of gravitating matter Surround It) and high collapse pressure state, along with released energies of degenerating matter, passing through electron degenerate white dwarf state, and then neutronic degenerate neutron star matter state, and all of the preceeding observations of effects conservation with time dilation between frames of reference holism and entanglements, produce a Black Onion state of matter that doesn't fall into a singularity, but collides with some energetic big bang like time dilated slowed metastate. And none of this denies that a supermassive Black Onion may exist at the center of the milky way, accreting new matter on it's surface into a similar, near black hole approximation state, and growing in mass, and reradiating itself with photons and neutrinos and such, over extended times, to reach some further state, perhaps Black Hole, or perhaps perfectly temporally frozen and asymptotically non-degenerate singular Hadron Star, or perhaps in Superunification, it all reradiates itself through Superunification chain reactions converted a continual portion of itself, into Black-Onion-escaping forms of radiation, sending all of itself back out to space ... eventually. Too many singular stiff equations for my Dragon Mind to grok completely, but that is what these Dragon Eyes see. LoneRubberDragon (talk) 03:30, 1 March 2010 (UTC) http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation (Newton Shells described, herein) LoneRubberDragon (talk) 03:30, 1 March 2010 (UTC) I will have to research this "Frozen Star" system you describe, to see if I can even penetrate their analysis, and see what they say. This is definitely not a commonly described term, because I have not heard it, from 1971 to 2010. Thank you for the lead on that neologism. I will see if the papers are fruitful on this subject. I do hate forgotten history of some improtance in physics understanding! That's why I still like the Michaelson-Morley experiment. Beautiful physics, even if it found a false. I just hope they are not propaganda articles, but really explain the whole deal down to the roots of equations without missing key physics effects that may have come up in recent years. Your description shows it is a nearly asymptotic system, with errors in original coordinates tipping effects. Could entanglement or other effects do the same backwards, with all effects still not being accounted for? It can still be an open question, if everything isn't known to the n'th degree (pardon the Masonic Reference). LoneRubberDragon (talk) 03:45, 1 March 2010 (UTC) Hehe, reminds me of the movie Dark Star. Great pulp movie from the 1970's, if you can understand it, like the movie Sunshine. These movies scare me as much as Quatermass and The Pit, for the eerieily subtle possible physics considerations of monoliths and entanglement and Colossus/Hal and such. LoneRubberDragon (talk) 03:46, 1 March 2010 (UTC) http://en.wikipedia.org/wiki/Dark_Star_(film) http://en.wikipedia.org/wiki/Sunshine_(2007_film) http://en.wikipedia.org/wiki/Quatermass_and_the_Pit Unfortunately, this Dark Star, is not a Hadron Star that I describe being just Below the limit of the speed of light escape, and asymptotically stuck on the time dilation in a near frozen state. LoneRubberDragon (talk) 03:54, 1 March 2010 (UTC) http://en.wikipedia.org/wiki/Dark_star Wiki (my CAPS bolding) [A dark star is a theoretical object compatible with Newtonian mechanics that, due to its large mass, has a surface escape velocity that EQUALS or EXCEEDS the speed of light. Whether light is affected by gravity under Newtonian mechanics is questionable but if it were, any light emitted at the surface of a dark star would be trapped by the star’s gravity rendering it dark, hence the name.] That's the very numerical problems involved with numerous colliding stiff asymptotic equation solutions. LoneRubberDragon (talk) 03:54, 1 March 2010 (UTC) http://en.wikipedia.org/wiki/Stiff_equation (Sorry, collided with another response (Jehoakim or something), try my talk.) LoneRubberDragon (talk) 03:59, 1 March 2010 (UTC) http://adsabs.harvard.edu/abs/1974IAUS...53..237C LoneRubberDragon (talk) 08:51, 8 March 2010 (UTC) http://articles.adsabs.harvard.edu/full/1974IAUS...53..237C LoneRubberDragon (talk) 08:51, 8 March 2010 (UTC) [secondary conversation on black hole hadron star indistinguishable models of the quantum object.] LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) A "Colossus Joke", that's looking up, Shimon! You have read me somewhere before in time space lines! LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) The reference to XYZT space, is because the baseband universe of mundane matter appears to follow XYZT on the main space of the universe, in your so-called cotangent space. There are small ripples in imaginary time related to quantum physics effects. Of course, in and only in special domains, the conventional notion of XYZ time may show a transformation into a so-called tangent space, as you colorfully or accurately convey, as I cannot yet determine the veracity of what you say, but remember what you have said from somewhere-someone-somewhen else before, perhaps even you. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) Like in the 1970's, people my age and some adult appearing humans, used to speak about black holes, physics, man, and God. As you may read in my delivered LoneRubberDragon.DOC, where I write on black hole formation. The traditional black hole so commonly defined, is a top-down model of a black hole, where a singularity or singularity ring with a geometric light escape velocity sphere or spheroid, is assumed to exist, a-priori, with all the theoretical physics characteristics belived to exist from physics, of that a-priori object, that quantum. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) But what do bottom-up models say about black hole formation? A perfectly round non-rotating star with perfect fusion completion collapse would crash through white dwarf electron degenerate state, neutron star nuclear degenerate state, and then what? Does it collapse into a perfect supersymmetry quantum state, where the star enters into a perfectly balanced hadron star quark degenerate state, akin to the big bang, with a time-dilated matter accreting sphere? Or is the mass-energy-space density against the time dilating sphere size ratio easily large enough to absorb the matter into a singularity from their perspective of infalling matter? LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) You comment about entanglement brings up a terrible question of this state of black hole versus hadron star, too. As the core of a theoretical straight to black hole model dictates, from our perspective, the infalling matter suddenly freezes in time-space on the event horizon, or even for the case of a hadron star, where the escape velocity is slightly less than light, by super symmetry arguments. This infalling matter becomes frozen in time, but newton's law dictates that for every action, there's an equal and opposite reaction. Well, in the core of a nuclear star, every particle has some measure of entanglement history stored in each particle. So, does every entangled atom in the time-dilated black hole, experience a blow back force, because the black hole sudden freeze in classical space, which is in a time dilated core of frozen infalling matter, and cannot express the equal and opposite reaction all of nature expects on the baseband XYZT coordinates of holistic systems? Or perhaps its time freezing state creates a temperature rise in the matter in the hadron star or black hole, commensurate with the time dilation field, in equal and opposite reaction, preventing in supersymmetry, the nature of a nearly frozen bounce in time, that looks like a black hole, but is merely a big bang spehere hadron star? LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) Another interesting property, of a giant hadron star, is that space around it, by definition, looses all sense of time, outside of the reference of the hadron star, since all matter has become absorbed, and the hadron star would experience an odd new state of matter, in supersymmetry, extremely time dilated, and compactly entangled with itself, with zero gravity at the center, and highest density, and mere big bang corraled nearly light escape velocity sphere, virtually indistinguishable from a black hole, a-priori. A place where the in and only in and the mundane matter space, for the most part, are unified. Of course, IF the density of matter is known to produce black holes easily, THEN that mucks up the whole idea, but I have never seen that specific calculation carried out clearly, yet. One commentor on Black Holes in wikipedia, once said that a "dark star" like a hadron star was looked at in 1920, but the calculations were on a hairy edge. Being on a hairy edge shows that the theory may still hold water, with entanglement, advanced analog-digital computers and such, can assist in looking at this so-called hairy edge problem, from the bottom up, as the universe produces such dark stars inferentially from the core of this galaxy, and so forth, evidences of either Black Holes or Hadron Stars. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) Imagine a giant gedanken, where all the matter of a galaxy, by completely artificial means of chaotic decision points, is made to coalesce onto a hadron star. Every new newton shell of matter doesn't contribute to the gravity inside of the shell, only pressure, as newton's shells show zero gravity integrals on their inside. In fact, the initial formation of a black hole, must address the newton's shells issue that at the center of the star, where the pressure is greatest and focus most pronounced of collapse, but also that it is in tensor shifted zero-gravity, of this same high density focus space, dilated from normal space, by the thousands of miles of star matter over its core. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) For a space like your described universe to exist, perhaps there is about 70,000,000,000 universes, all virtually identical, in interaction space, and all highly divergent on separation space, correlating with the 70 billion humans that have existed, both living now, and dead now. However, it flies utterly in the face of one God, outside and within one cosmic space of time and matter. But seeing the world His Lesson Plan Shows, it would explain God's finite bandwidth properties, being only One Being, where God's endless compromises, shatter the illusion, of His Own Integrity. One with infinite powers and continuity, in a One Body and Only One Body world that is created within Himself, of chaos and ill communication as His Master Plan, and The One God with a Broken Body of 70 billions souls, with threats of deaths and destructions terminating nearly all humans in their inner manipulation of a finite power. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) But to call it cotangent space normal and tangent space exception, is to say goodbye normally, in separations. Yes, frequency space is important and compact, but works hand in hand with temporal space of quantums like Laplace Transforms of impulses, toward even random number lists. This is the crux of issues on scatterings created when frequency space and temporal space collide. It is the core of wave and particle duality. It is where scales of the heirarchy of an infinite frequency spectrum cannot touch a delta, or where one DC frequency term can describe the entire list of DC offsets of the universe. It is the crux of reductionism and holism. Of cotangent-tangent space as a whole system. It is the possible flaw of Black Hole research only taking top-down holism assumptions, and not also considering the mirror image of bottom-up reductionist assumptions. And being a time dilated quantum the size of a Black Hole / Hadron Star, both may exist simultaneously at the infinity of a supersymmetry, and Indistinguishable Models of Quantum Physics, in the dark and time dilated form of this object astronomers confirm in implicated observations of black holes by the criteria of existence state beyond neutron star dynamics. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) To be more precise, I claim that freqeuncy spectrums, simply describe many natural systems of structure, as well as Laplacians for impulses, where the language shifts to a compact Laplacian system. And of course, synthetic signals make the most trouble, where neither wave, nor particle, but spirit of living word systems, like computers, and humans, and life, create signals of characters that are none of the above, but are of chaos systems of Lyanupov characteristics. A holy trinity between [wave system particle]. It is complex to describe, as you must obviously have noticed by now. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) But tell me more about this cotangent-tangent space concept. It reminds me of something, from a very long time ago, e.g. 1974, when I was three years old, learning about the prison planet earth cosmos as seen through this american dream of a finite bandwidth God made manifest through the hands of the children of men of the earth over the cosmos, in their pride of lies and finite bandwidth that no-one can deny. LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) "God's Endless Compromises, LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) shatter the illusion, LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) of His Integrity." - LoneRubberDragon LoneRubberDragon (talk) 09:00, 8 March 2010 (UTC) Wikipedia talk pages are for discussions related to improving articles, not for hypothesizing about the subject of an article. If you want to do that, please find a forum somewhere else on the internet. The header of this page has some suggestions. Of course, if there is something that you think is unclear about the current article, please, do ask about, but be concise and to the point. TimothyRias (talk) 09:37, 8 March 2010 (UTC) The formation method of Black Holes themselves are unclear in the article. All hypotheses need to be brought into the article of science. LoneRubberDragon (talk) 09:55, 8 March 2010 (UTC) Is a nuclear war, the only answer to save a NANO-UNIT of memory space, on this site? Are your defenses so close to the edge of criticality, that your system will fail, with a free and open discussion of the pertinent topics on this discussion page. I could zap the entire article, but I hold back, to observe the truth of all pertinent exquations of Black Hole formation, and associated topics, in a hypertext format. LoneRubberDragon (talk) 09:57, 8 March 2010 (UTC) If Timothy Rias, is God over the earth, then so be it, nuclear destruction of your planet, is desirable by humanity. LoneRubberDragon (talk) 09:59, 8 March 2010 (UTC) But you only serve to remind me of pedanitc first grade teachers, who make all dead according to the law, on pertinent data. Blagodurnost! LoneRubberDragon (talk) 09:59, 8 March 2010 (UTC) If improving articles on pertinent data, is hiding and dissembling data, then let us begin? Or should we? I consider your actions hostile on an international scale, and close to God Himself. But earth destruction is the game of man? Not collecting together data for the article, in a unified field of research? Too delicate a system, in my estimation, given your data of criticality of system memory constraints, to store such a small snip of text, Timothy Also-God Rias. LoneRubberDragon (talk) 10:01, 8 March 2010 (UTC) Did you, Timothy Is-God Rias, bring one link, or word, or paper, or discussion, to this very post, of some edification? Just asnwer that. I think you will find the answer is: nyet, Nyet, NYET! LoneRubberDragon (talk) Did I not post useful information for the improvement of "Complete Spatial Randomness", and "SuperResolution" articles on wikipedia? And this is a Discussion Page. If it isn't, what is it for, Your One Mystery Incompleteness Dogma, Only? LoneRubberDragon (talk) 10:21, 8 March 2010 (UTC) Discussion pages on wikipedia are for discussing improvements to an article (see WP:TALK), NOT for discussing the topic of the article in general. You're issues seem to be mainly with (your perception) of the state of Black hole research, not with how this article reflects that state. If you have problems with the actual content and think that it does not accurately reflect the available literature OR think that some of it is unclear. Then please say so and be precise about where you think the article can be improved. (I'm sure it can at many places.) But please leave your own theorizing out of it. Also, if you continue with personal attacks like here above, you are likely to be blocked or banned from wikipedia per WP:TALKNO. TimothyRias (talk) 11:22, 8 March 2010 (UTC) http://adsabs.harvard.edu/abs/1974IAUS...53..237C LoneRubberDragon (talk) 08:51, 8 March 2010 (UTC) http://articles.adsabs.harvard.edu/full/1974IAUS...53..237C LoneRubberDragon (talk) 08:51, 8 March 2010 (UTC) http://en.wikipedia.org/wiki/Gravastar LoneRubberDragon (talk) 09:52, 8 March 2010 (UTC)

Black hole formation

Let's talk about the improvement of the article. I think how the article is written now, causes a misunderstanding of how the formation works. From the viewpoint of the falling observer the collapse of a star happens in finite time, but from the viewpoint of the external observer, the matter is frozen just above the horizon, due to the dilation of the time. For the understanding of black holes it's crucial that the both viewpoints be more emphasized, either in the "Properties and structure" or the "Formation and evolution" section. Currently there is a only a sentence in History/General Relativity section. What do you think? Prot D (talk) 19:46, 14 March 2010 (UTC)

I agree that this issue is somewhat underrepresented at present. I think there are two possible locations to add a paragraph about this in the article: 1) in the event horizon section right after the discussion of gravitational redshift. 2) As a last paragraph of the intro of the formation and evolution section. A third option would be to add it as a footnote somewhere, but that doesn't seem quite right.

Also, does anybody know a reliable modern source that discusses this issue directly? This would be very helpful in providing references for whatever we decide to write. TimothyRias (talk) 09:30, 15 March 2010 (UTC)

I'd be surprised if it wasn't in MTW somewhere. --Christopher Thomas (talk) 17:19, 15 March 2010 (UTC)

I've added a paragraph to the gravitational collapse section with a link to an article by Penrose. Would you have a look to see if it is clear, and check for any mistakes. TimothyRias (talk) 16:38, 18 March 2010 (UTC)

I've tweaked the phrasing a bit. I also added a caveat about most of the energy emission happening early. The energy emission mechanism is mostly thermal emission from hot accreting matter, with some energy invested in polar jets as well, but adding detail about that would have unnecessarily bloated the paragraph. The only other caveat that I can think of is that the last light seen by a distant observer is actually seen in a finite length of time, as past a certain point it's possible to show that there isn't enough energy left to emit a photon of the appropriate temperature, if I'm remembering correctly. I left this out because I don't have a reference for it handy, and it would also have cluttered the paragraph (your description covered all of the points that would be confusing to a layman).

Long story short, looks good, and I made minor tweaks. Thanks for digging up the reference. --Christopher Thomas (talk) 18:02, 18 March 2010 (UTC)

Black hole and singularity

The section singularity descibes the center of a black hole as a point of infinite density. I don’t know much about general theory of relativity . But I think the concepts of black hole and singularity are quite different concepts. After all Pierre Simon Laplace knew nothing about general relativity and infinite densities ; but still he could postulate the black hole.

The Schwarzschild radius is ,

$r_{sc}={\frac {2\cdot G\cdot M}{c^{2}}}$

When the mass of a non rotating black hole is given in terms of its volume and the overall density it can be seen that there are two creterias for an object to be a black hole; the Schwarzschild radius and the critical density.

$\rho \cdot r_{sc}^{2}=C$

Here ρ is the critical density, r_sc is the Schwarzschild radius and C is a constant. (~1.6 10²⁶ SI units) . It is obvious from this relation that, for bigger objects, the critical density for being a black hole decreases. For solar mass the critical density can be as high as 1.85 * 10¹⁹ kg/m³ .But a spherical object with a radius of one light year becomes a black hole with a minute density of 1.8 mgr/m³ . For galactic dimensions the overall density approaches to near vacuum. I find it quite difficult to reconcile the idea of singularity to such low density super big black holes. Nedim Ardoğa (talk) 08:07, 9 March 2010 (UTC)

First note that Laplace's idea (or rather John Michell's idea) of a dark star is somewhat different from a black hole. For example, the dark star idea does not prohibit rocket aided escape, etc. It is somewhat of an (un)lucky coincidence that the radius of a dark star and the Schwarzschild radius coincide exactly, since this prompts people to think that the concepts are the same.

The average "density" of a black hole can indeed be quite low for very mass BHs, however the causal structure imposed by general relativity on the interior of the black hole makes the creation of a singularity inevitable. (This is the essence of the Hawking-Penrose singularity theorems) The formation of the singularity can take a while if the BH is big enough. For example, if you'd take a black hole of the Hubble radius (average density around 1 atomic mass per cubic meter) the actual collapse could take billions of years.

Note that the article does not define a black hole as a singularity, but merely notes that the description of BHs in general relativity necessarily contains a singularity. TimothyRias (talk) 09:12, 9 March 2010 (UTC)

Straw poll: talk page notice

As we've had a few recent extended off-topic threads about peoples' personal ideas about how black holes work, and as this has happend fairly frequently in the past, I floated the idea at WT:PHYS about putting a banner on this page along the lines of the one at the top of Talk:Big Bang. This would direct people towards suitable venues for proposing their own models, while making it clear that this talk page isn't the best venue.

Response at WT:PHYS was positive, so I'm opening a straw poll here to see if implementation should go forward. A draft copy of the Big Bang notice-blurb, tweaked for use with the black hole article, is at Talk:Black_hole/noticeblurb.

Suggestions for suitable forum links are appreciated; I'd like to be able to point users in useful directions, rather than just say "not here".

What are all of your thoughts on this? --Christopher Thomas (talk) 22:52, 10 March 2010 (UTC)

Votes/Comments

• Support addition of such a notice, as long as useful links to other venues are provided (I don't have any). --Christopher Thomas (talk) 22:52, 10 March 2010 (UTC)
• Support don't care what it says, we can tweak it later. --Michael C. Price ^talk 23:13, 10 March 2010 (UTC)
• Support It seems like a useful tool, which would allow the Wikiproject physics editors to have the best use of their valuable time and attention. I certainly don't see this as overkill. Steve Quinn (formerly Ti-30X) (talk) 00:23, 11 March 2010 (UTC)
• Support unpublished personal theories should not clog up the talk page, when there are so many published crank theories already that could better clog up the talk page. 70.29.210.242 (talk) 06:02, 11 March 2010 (UTC)
• Support/comment Such a banner would be useful. I should that there already is a "got a question? Don't ask here" banner at the top of the page. I like your formatting better though. (The old banner does have useful links you can salvage. TimothyRias (talk) 07:00, 11 March 2010 (UTC)

  I noticed the existing banner; I was going to keep it, with the new notice over it, much as with the ones at Talk:Big Bang. Good point re. links; my fallback option would be to tweak the proposed template to say "at any of the links below", but I was hoping for actual pointers towards alternative-physics forums where original material would be welcome, vs. Q&A forums where they'd meet more or less the same response as here. Harvesting the existing links is definitely an option, though! --Christopher Thomas (talk) 07:09, 11 March 2010 (UTC)

  Here is site where original material is welcome and allowed. It is a wiki. Wikinfo. "Wikinfo provides a platform for the meshing of encyclopedic material, original and creative work and public domain material to further education and information." "Wikinfo welcomes editors from Wikipedia and offers much more opportunity to edit freely. Original research and original ideas are welcome."

  Writing an article at Wikinfo is the same as writing an article for Wikipedia except OR and original ideas are acceptable content. The structure and software is either the same or very similar. ----Steve Quinn (formerly Ti-30X) (talk) 07:26, 11 March 2010 (UTC)

• Support - without comment. DVdm (talk) 07:44, 11 March 2010 (UTC)
• Support—I think it is a good idea. There are comparable notices on Talk:Earth about Mostly Harmless as well as the lack of coverage concerning young Earth creationism. It seems to cut down on the unhelpful noise a little. Likewise, some talk pages have notices about recurring themes. The Talk:Evolution page has a FAQ that includes past discussions.—RJH (talk) 17:48, 11 March 2010 (UTC)

Notice added. Links remain a question.

As the overwhelming consensus seems to be in favour of the notice, I added it (with "...at one of the forum links below" as placeholder-directions). If anyone knows where fringe/non-standard black hole theories are usually debated, by all means add a link. I've held off on listing WikiInfo, as that seemed on inspection to a) be fairly low-traffic, and b) be geared more towards non-verified descriptions of mainstream work than fringe work, but that impression could easily be mistaken (and of course I'm not the final arbiter of what goes into the template; I'm just one editor). I hope this is a useful starting point. --Christopher Thomas (talk) 08:15, 12 March 2010 (UTC)

The http://www.physicsforums.com/ site is fairly active. I've posted there before and received useful responses. There seems to be discussion of black holes under the astrophysics section, along with a few unconventional topic headings.—RJH (talk) 16:10, 16 March 2010 (UTC)

Essays by 204.52.246.120

Archived self-published work.
The following discussion has been closed. Please do not modify it.
The newly established Mechanism-Revealed Black Hole Theory Mechanism-Revealed Physics (28/40) & Mechanism-Revealed Black Hole Theory (1/2) The newly established Mechanism-Revealed Black Hole Theory (MRBHT): based on the newly established and verified MRGT (= Mechanism-Revealed Gravitational Theory, P. 445 ~ 514, Ch.4B, reference #1), MRBHT is established (P. 541 ~ 548, 5.5, Ch.5B, reference #1). MRBHT reveals the mechanism and identifies the essence of black holes, thus discovers the fundamental nature of black holes, for the first time in the history of physics and science. The main points of MRBHT include: (i) the mechanism of MRBHT is that the existence of a hugely massive astronomical object reduces the scales of length (space) and time in its vicinity to such an extent that all visible lights become invisible, thus the essence of MRBHT is the tremendous reduction in the scales of length (space) and time. (ii) The ratio of visible light boundary wavelength (Rvlb) is the ratio of lower to upper boundary wavelength of visible light, i.e., Rvlb = 380 nm/760 nm (or 390 nm/780 nm) = 1/2. (iii) Zhao’s black hole radius (RZhao), being determined by satisfying the length scale and time scale equal to Rvlb, is the threshold radius that marks the boundary of a black hole on which entering visible light begins to become invisible, whereas leaving invisible light begins to become visible. Zhao’s black hole radius equation is provided as following (P. 543, reference #1) (but appeared here): The key to understanding of MRBHT: (i) the mechanism thus/and essence of MRBHT is the theoretical core of MRGT, because MRBHT is based MRGT. (ii) As long as you want to know why space and time are variable thus relative in gravitational field, you will readily understand MRBHT, because MRBHT tells the why. (iii) As long as you have known the greatest equation in the history of science, which is Einstein’s famous mass-energy equation (E = mc2 or E0 = mc2), you will easily understand MRBHT, because the law of object’s mass doing work (P. 93 ~ 109, Ch.1A, reference #1), which lays the foundation of MRBHT, also reveals the mechanism behind the greatest equation (P. 114 ~ 118, Ch.1B, reference #1). The fundamentally profound applications of MRBHT: MRBHT is the key to solving the following fundamentally important problems in physics and astronomy, including: the mystery of dark matter (P. 560 ~ 567, 5.7, Ch.5C, reference #1), the mysterious source of gamma ray bursts (P. 567 ~ 574, 5.8, Ch.5C, reference #1), the mysterious source of ultrahigh-energy cosmic rays (P. 574 ~ 577, 5.9, Ch.5C, reference #1), and the famous puzzle of GZK paradox (P. 578 ~ 580, 5.10, Ch.5C, reference #1), as well as the long-standing “black hole information paradox” (P. 580 ~ 582, 5.11.1, Ch.5C, reference #1). Reference #1: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 1(1/2)], ISBN: 978-1-4357-4913-9. Reference #2: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 2(2/2)], ISBN: 978-1-4357-5033-3. Ph.D., Bingcheng Zhao, The author of “From Postulate-Based Modern Physics to Mechanism-Revealed Physics” 1401 NE Merman Dr. Apt. 703, Pullman, WA 99163 USA. Email: bczhao12@gmail.com or bzhao34@yahoo.com or bingcheng.zhao@gmail.com —Preceding unsigned comment added by 204.52.246.120 (talk) 18:26, 18 March 2010 (UTC) Revealing the fundamental nature of Mechanism-Revealed Black Hole Mechanism-Revealed Physics (29/40) & Mechanism-Revealed Black Hole Theory (2/2) Revealing the fundamental nature of black holes with the newly established Mechanism-Revealed Black Hole (MRBHT) (P. 541 ~ 548, 5.5, Ch.5B, reference #1). [*Note, the black holes involved here refer to the black holes revealed and explained with the newly established MRBHT (i.e., mechanism-revealed black holes), for making a distinction from the black holes that are described and interpreted with current postulate-based black hole theory]. MRBHT reveals the following fundamental natures of black holes (P. 544 ~ 548, reference #1). (i) The gravitational scales of space (length) and time increase radially outward from the central region of a black hole — first rapidly then slowly; and in the sequence of inside, on and outside Zhao’s black hole radius (RZhao), the gravitational scales of space (length) and time sequentially undergo the sub-regions of < (1/2), = (1/2) and > (1/2) across the entire region of the black hole. (ii) Black hole bulk density decreases rapidly with the increase in the value of RZhao, and the concept of black hole bulk density demonstrates the mechanistically thus essentially feasible nature of MRBHT. (iii) The constituents of black holes are not essentially unique (i.e., not essentially mysterious), comparing to other ordinary astronomical objects (P. 548, reference #1). (iv) Black holes can emit light, though the lights emitted from and by black holes are invisible within the boundary marked by RZhao. (v) The visible lights that do not vertically travel towards a black hole are deflected away from the black hole (P. 546 ~ 547, reference #1). The equation calculating black hole bulk density is provided as following (P. 546, reference #1)(though not appeared here): The definition of black hole (i.e., mechanism-revealed black hole): a black hole is a region where, due to the existence of a hugely massive astronomical object, the gravitational scales of length (space) and time are reduced to such an extent that all visible lights entering the region become invisible and all lights emitted from and by the black hole are also invisible in the region (P. 547, reference #1). In addition, based on the principle of gravitational light bending embedded on MRGT (= Mechanism-Revealed Gravitational Theory, P. 445 ~ 514, Ch.4B, reference #1), all visible lights not vertically traveling towards a black hole are deflected away from the black hole; more extensively, all visible lights, as long as not traveling towards the center of a black hole, are deflected away from the black hole by the gravitational scale contour lines of space and time in the gravitational field generated by the black hole. Stated plainly, a black hole is the region surrounding a hugely massive astronomical object that makes all visible lights become invisible via hugely reducing the scales of length and time around it. Stated loosely, a black hole is a hugely massive astronomical object that causes all visible lights to become invisible. Reference #1: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 1(1/2)], ISBN: 978-1-4357-4913-9. Reference #2: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 2(2/2)], ISBN: 978-1-4357-5033-3. Ph.D., Bingcheng Zhao, The author of “From Postulate-Based Modern Physics to Mechanism-Revealed Physics” 1401 NE Merman Dr. Apt. 703, Pullman, WA 99163 USA. Email: bczhao12@gmail.com or bzhao34@yahoo.com or bingcheng.zhao@gmail.com —Preceding unsigned comment added by 204.52.246.120 (talk) 18:32, 18 March 2010 (UTC)

Wikipedia is not the place to try to publish or popularize your own ideas. See WP:OR and WP:RS. --Christopher Thomas (talk) 19:02, 18 March 2010 (UTC)

Jehochman's Deletions

Fuzzballs

Jehochman removed this as OR. Fuzzballs are interesting recent work to resolve the singularity within string theory. There are dozens of very good references to this, although the language is suboptimal:

Fuzzballs

Main article: Fuzzball (string theory)

Fuzzballs are theorized by some superstring theory scientists to be the true quantum description of black holes. The theory resolves two intractable problems that classic black holes pose for modern physics:

1. The information paradox wherein the quantum information bound in in‑falling matter and energy entirely disappears into a singularity; that is, the black hole would undergo zero physical change in its composition regardless of the nature of what fell into it.
2. The singularity at the heart of the black hole, where conventional black hole theory says there is infinite spacetime curvature due to an infinitely intense gravitational field from a region of zero volume. Modern physics breaks down when such parameters are infinite and zero.

Fuzzball theory replaces the singularity at the heart of a black hole by positing that the entire region within the black hole’s event horizon is actually a ball of strings, which are advanced as the ultimate building blocks of matter and energy. Strings are thought to be bundles of energy vibrating in complex ways in both the three physical dimensions of space as well as in compact directions—extra dimensions interwoven in the quantum foam (also known as spacetime foam).

Wormholes

Yet again, without shame, he calls this 1940's result of Einstein and Rosen, verified and accepted for decades, original research.

Worm holes

Main article: Wormhole

Diagram of a Schwarzschild wormhole.

General relativity describes the possibility of configurations in which two black holes are connected to each other. Such a configuration is usually called a wormhole. Wormholes have inspired science fiction authors because they offer a means to travel quickly over long distances and even time travel. In practice, such configurations seem completely unfeasible in astrophysics, because no known process seems to allow the formation of such objects.

Reversibility and Information loss

This material was deleted next: I don't know the precise source for this unlike the others, but I do know that it is well accepted material.

Reversibility and information loss

Black holes, however, might violate this rule. The position under classical general relativity is subtle but straightforward: because of the classical no hair theorem, it can never be determined what went into the black hole. However, as seen from the outside, information is never actually destroyed, as matter falling into the black hole takes an infinite time to reach the event horizon.

It should be pointed out that the equations of general relativity in fact obey T-symmetry, and given that the logic above comes from application of (classical) general relativity, one should be suspicious. This is due to the fact that it should not be possible to derive time-reversal-asymmetric conclusions from a time-symmetric theory (Loschmidt's paradox), which is general relativity in this case. Rindler coordinates, which apply near the event horizon for an observer "held" just outside the black hole, are T-symmetric and therefore there should not exist any such thing as an 'irreversible' process. It is possible that the 'paradox' is a result of applying time-asymmetric boundary conditions to the time-symmetric theory, making it a form of Loschmidt's paradox.

Ideas about quantum gravity, on the other hand, suggest that there can only be a limited finite entropy (i.e. a maximum finite amount of information) associated with the space near the horizon; but the change in the entropy of the horizon plus the entropy of the Hawking radiation is always sufficient to take up all of the entropy of matter and energy falling into the black hole.

Many physicists are concerned, however, that this is still not sufficiently well understood. In particular, at a quantum level, is the quantum state of the Hawking radiation uniquely determined by the history of what has fallen into the black hole; and is the history of what has fallen into the black hole uniquely determined by the quantum state of the black hole and the radiation? This is what determinism, and unitarity, would require.

For a long time Stephen Hawking had opposed such ideas, holding to his original 1975 position that the Hawking radiation is entirely thermal and therefore entirely random, containing none of the information held in material the hole has swallowed in the past; this information he reasoned had been lost. However, on 21 July 2004 he presented a new argument, reversing his previous position. On this new calculation, the entropy (and hence information) associated with the black hole escapes in the Hawking radiation itself. However, making sense of it, even in principle, is difficult until the black hole completes its evaporation. Until then it is impossible to relate in a 1:1 way the information in the Hawking radiation (embodied in its detailed internal correlations) to the initial state of the system. Once the black hole evaporates completely, such identification can be made, and unitarity is preserved.

By the time Hawking completed his calculation, it was already very clear from the AdS/CFT correspondence that black holes decay in a unitary way. This is because the fireballs in gauge theories, which are analogous to Hawking radiation, are unquestionably unitary. Hawking's new calculation has not been evaluated by the specialist scientific community, because the methods he uses are unfamiliar and of dubious consistency; but Hawking himself found it sufficiently convincing to pay out on a bet he had made in 1997 with Caltech physicist John Preskill, to considerable media interest.

more info loss

He continues his deletion with this, which I don't know the source for, but is well known folklore:

The loss of information in black holes is puzzling even classically, because general relativity is a Lagrangian theory, which superficially appears to be time reversible and Hamiltonian. But because of the horizon, a black hole is not time reversible: matter can enter but it cannot escape. The time reverse of a classical black hole has been called a white hole, although entropy considerations and quantum mechanics suggest that white holes are just the same as black holes.

The no-hair theorem makes some assumptions about the nature of our universe and the matter it contains, and other assumptions lead to different conclusions. For example, if Magnetic monopoles exist, as predicted by some theories, the magnetic charge would be a fourth parameter for a classical black hole

Taken together, these deletions make a strong case that Jehochman probably should brush up on the literature before making any more edits.Likebox (talk) 23:03, 20 March 2010 (UTC)

I object to your personal attacks. Comment on the article, not the editor. The edits you now complain about happened on November 30, 2009, nearly five months ago, and were discussed at the time. Since then editing has moved on. Why are you complaining now? It looks like you are wikihounding me, and attempting to retaliate for my comments on this thread. I think this comment by you is very telling. Jehochman ^Talk 01:52, 21 March 2010 (UTC)

This isn't personal--- I was actually surprised to find that you were the one behind these ridiculous edits. I was astounded that someone could make these deletions without making the slightest attempt to do the research to see if there are sources. The FA drive should not lead to the article becoming decimated. If you wish to remove good content, place it on the talk page here, or on a related article.

However, I do have to say, this type of editing is not in the best interest of Wikipedia. There is a good chance that if this type of negative editing is tolerated, only this type of negative editing will happen in the future.Likebox (talk) 20:24, 21 March 2010 (UTC)

The removal was done months ago, discussed months ago, and partly-undone months ago. The fact that you are picking up on it right now, immediately after reappearning and joining an AN/I thread involving User:Jehochman, suggests that very little surprise was actually involved on your part, and that it was indeed personal. Please stop turning article and wikiproject pages into political battlegrounds. --Christopher Thomas (talk) 22:07, 21 March 2010 (UTC)

You can believe whatever you like--- I am telling you the truth. I went over articles I contributed to (the ones I remembered), and I saw this one and all my contributions systematically deleted (along with those of others). The only thing I did know (because I read it on some talk page) was that Jehochman was involved in this article, but I didn't realise that it was he who systematically deleted all the stuff.

I put only the deleted contributions of others above. I contributed the intro, which Jehochman also deleted (but it wasn't so great, it was about escape velocity, which is inappropriate, so Ok, but it wasn't OR), and I expanded the list of cases under which the black hole no-hair theorem fails. That list should be restored, it is difficult but possible to source.

More importantly, like infraparticle, large essential chunks of this article is being deleted by someone who has not done the basic reading required to determine what is and what isn't OR. That's borders on outright vandalism in my view, and it is certainly inappropriate to not store the material somewhere accessible.Likebox (talk) 06:24, 22 March 2010 (UTC)

Hmm... Interesting claim... Can you support it? Everybody contributions are being edited and deleted all the time. I think you'll have a hard time proving that a certain editor was specifically tracking down your edits and deleting your contributions. I can try making some stats (with a wiki bot) onto how long your contributions are staying and who has deleted the most. Should be a fun mini project. ;) --Dc987 (talk) 09:22, 22 March 2010 (UTC)

This once again shows the importance of properly sourcing contributions. Although Jehochman was some what loose lipped with the term OR (which I told him at the time), the material he deleted suffered from various other problems. Among which not having any references, but also digressing from the mainline of the article. A single wikipedia article is not enough space to cover everything that has been said about black holes in the literature, as such this article needs to stick to a certain core leaving a lot of technical details to various other articles. (Such Schwarzschild metric and Black hole information loss paradox) Jehochman's deletions gave a good starting point for further improvement of the article. (In which some of the deleted topic were later readded in another form. TimothyRias (talk) 09:03, 22 March 2010 (UTC)

Per the very extensive discussions at WT:PHYS and elsewhere, the onus is on the person who adds material to source it at the time. By failing to do so, you're waiving the right to complain about it being removed. Sure, in an ideal world, someone might come along and source it later, but they are by no means required to do so. --Christopher Thomas (talk) 22:22, 22 March 2010 (UTC)

Of course I don't believe that my contributions were removed on purpose to spite me! I'm not paranoid. I am just saying that the dispute here with Jehochman's edits and the disputes on AN/I with Jehochman's attempts to sanction editors are unrelated. In all honesty: I did note at some point on some talk page that Jehochman was active here, and that might have been a motivation to look at the article again.

The deleted article text should be left here, uncollapsed, because it needs to be replaced in the article or in similar articles. The material that was deleted is all physics folk-knowledge, people should be careful when deleting it.Likebox (talk) 23:20, 22 March 2010 (UTC)

While I agree that all this is not really OR, I do think that a FA article on Black Hole cannot contain too much detail about all these subject (and bringing this article to FA status is the goal behind the recent editing drive). I think the removed detailed explanations can be moved to the more specialized articles for further reading. You could try to keep a summary of the most important points for the general reader here. Count Iblis (talk) 02:16, 21 March 2010 (UTC)

The article was 103K. During this sequence of edits, I and others chopped it down to 84k. This is still too long, and we should be looking to trim additional words from the article by copy editing for conciseness, moving content to related articles or daughter articles, and removing content that is not verified. My edits were done without regard for which editor inserted the content. Frankly, I don't care. Once contributed, content is not owned by anybody and may be edited mercilessly. Jehochman ^Talk 12:56, 22 March 2010 (UTC)

84k is not that long for a physics FA. If you look at other recent physics FA articles like quark, electron or general relativity, you will see that they are respectively 66k, 113k and 163k. This is a complicated subject of very wide scope and thus can be longer than your average FA. Also the article contains a lot of reference. Each ref being about 300 bytes and having nearly 100 references mean that the references alone are around 30k. If this article (with references) can stay below 100k to become FA ready that would already be a great achievement. TimothyRias (talk) 14:36, 22 March 2010 (UTC)

Likebox, you should try see the half filled cup as half full not as half empty. Sure, you did not get everything you want in this article. But there is still room for you put your texts in other articles. If you cannot get the text edited in anywhere on Wikipedia because of oppositions similar to what we saw in case of the infraparticle article, then that would be a problem. But also note that the infraparticle article is in the state you wanted it to be in. So, why not count that as a success?

You correctly noticed there is sometimes a problem on Wikipedia regarding technical texts inappropriately being labeled as OR. You confronted that problem head on in that infraparticle article. Then precisely because you were right about the existence of that problem, that led to some editing disputes on that page. So, you should not make too much of that. Instead, look at the state of the infraparticle after the smoke cleared, as it is now.

On the positive side: If this article becomes a FA, it will appear from time to time on the front page. That may lead to many people also visiting the daughter articles. On those daughter particles there is far more room to put in more technical texts, mathematical appendices etc. etc. Count Iblis (talk) 14:14, 22 March 2010 (UTC)

I am not too unhappy with the article here, so long as there are links to more technical articles elsewhere. I am only trying to make sure that people treat text here with respect. That means that when you delete technical text, store it on the talk page, and try to find a home for it on other articles. The only reason this wasn't done in this case is because the editor that removed the text labelled it OR because of his lack of familiarity with the content.Likebox (talk) 23:20, 22 March 2010 (UTC)

Classification by mass section

Currently the "by mass" subsection of the "classification" section contains a list of black hole "types" by mass with a description of each type. These descriptions contain a lot of information that is redundant with the rest of the article. I propose that we bring back these descriptions back to one sentence each. Any details not already mentioned elsewhere should be integrated in the appropriate sections. Do others agree? TimothyRias (talk) 16:00, 22 March 2010 (UTC)

Expansion of the history section

The history section is currently somewhat incomplete. What topics are missing exactly? Somethings from the top of my hat that should definately be mentioned:

• Developement of Black hole mechanics during golden age of GR.
• Modern results in describing micro states (Strominger, Vafa, Maldacena, etc.)

Any other topics that we are currently missing. TimothyRias (talk) 16:06, 22 March 2010 (UTC)

Can you break it out into a sub-article and leave a summary here? The article is still very long. Jehochman ^Talk 18:38, 22 March 2010 (UTC)

Long, yes. Excessively long? I'm not so sure about that. The threshold for "too long" seems to be about 150k-200k, based on automated notices while editing. I'd worry more about whether or not sections are unnecessarily verbose, rather than absolute size. --Christopher Thomas (talk) 22:16, 22 March 2010 (UTC)

At the good article nomination page, articles greater than 40k are considered long. We frequently do write longer articles, but I think going over 80k is pushing it. Gamma ray burst is only 69k. Jehochman ^Talk 08:26, 23 March 2010 (UTC)

If you take a sensus of the physics top importance FA's you'll find:

• Atom 96k
• Big Bang 77k
• [[Electron] 113k
• General relativity 164k
• Photon 86k
• Star 103k
• Sun 114k

This article is right on track with 83k. Moreover, note that length discussions in GA are always about readable prose, which does not include footnotes, images, references etc. TimothyRias (talk) 09:02, 23 March 2010 (UTC)

This article is not that long, especially for the breadth of the topic. As for splitting the history section to a different article, I think the proper course is to first expand it so that it at least covers all the points. If it turns out that it becomes too overly detailed we can then split it off to a different article and leave a summary style section. As it is however the history section simply doesn't cover all the necessary points. TimothyRias (talk) 08:09, 23 March 2010 (UTC)

The history should mention Eddington's rejection of horizons, and Einstein's. The modern results in describing microstates is the 90s unification of black hole physics and string physics. The charged solutions are important there, so you should mention the Reissner Nordstrom history, and the generalization to p-branes (Gibbons?)

There some very very important recent results that need to be emphasized:

• The Gregory LaFlamme instability: uncharged extended black lines/sheets in higher dimensions tend to fall apart into separate spherical black holes. The instability discovered in the early 90s by Gregory and Laflamme, but in the early part of 2000's some argued (incorrectly--- but that's OR) that null character of the horizon did not allow a long black line to break up into separate black holes. This argument was picked up by Gubser, but I believe it is discredited now (not certain about the sociology--- I only know the argument is incorrect).
• Emparan Reall black holes--- this is from a few years ago--- in higher dimensions, rotating black holes can be rings! The horizon can be like a donut. This is a violation of the no-hair theorem, since the Kerr solution works in any dimension. A condition on horizon topology was recently discovered which links up the work to pure mathematics.
• The Kerr Solution in De Sitter space was recently worked out by Kerr's original method by Gibbons.
• The information problem is solved (although some people don't accept this)

If you want to find all the recent results, go over the gr-qc archive month by month. There are many others.Likebox (talk) 23:35, 22 March 2010 (UTC)

For the so-called "golden age" you want Carter's theorem on local constancy of temperature (surface gravity), there's a proof in the 1979 Einstein centenary symposium. That, along with Hawking's area law and the no-hair theorem, was the foundation of black hole thermodynamics. The Penrose process is already mentioned here.

The Gott time machine is an interesting example, and it involves the 2+1 dimensional analog of the black hole solution, which is the conical defect. There's also a 90's two-d black hole analog which was studied to death.Likebox (talk) 23:47, 22 March 2010 (UTC)

I think for the history section we should not to get too much into recent results. For one there is a lot of nonsense published about black holes, most of which is quickly forgotten. In that sense it is better to stick with things that have proven their worth and are still around after a decade.

As for many of the black holes in higher dimensions results, I think those are best off in a separate black holes in higher dimensions article. There are some excellent lecture notes around (Obers or Reall and Emparan) to start such an article. For this article this will be going to far, and it is probably best to stick with the classical notion of black holes, there is plenty to say about that. TimothyRias (talk) 08:20, 23 March 2010 (UTC)

I don't know any nonsense published about black holes in the professional literature, and accurate technical results that are quickly forgotten take twenty years to be slowly unforgotten. The goal of Wikipedia is to make sure that the material is not quickly forgotten.

If the material can be verified by reading the literature, then it belongs here, although perhaps on a more advanced article. All the stuff I mentioned is well accepted physics, and central to understanding black holes. That is, all except for Horowitz's argument that there is a stable nonuniform neutral black string. Even that argument is well accepted in the narrow sense, in that the proof he gives is technically correct, but leaves loopholes for evasion. The technical literature is not as unreliable as you say, and waiting some decades is not a good way of evaluating. The only reliable way to evaluate technical content is to read it, read the stuff that reference it, and include all the claims and counterclaims in a comprehending way.

Black hole physics has undergone a rapid evolution these last two decades, more rapid than even during the most golden of golden ages. The number of advances since 1995 are greater than all the advances which came before put together. To ignore these advances is counterproductive, and makes Wikipedia into a reactionary force.Likebox (talk) 13:17, 23 March 2010 (UTC)

History suggestion: William Sidis

Should be in history:

The first to clearly predict the existence of black holes, according to the 1979 opinion of American mathematician Buckminster Fuller (among others), was American mathematician William Sidis, who in 1920 explained that in certain regions of negative space “all radiant energy would tend to be absorbed by the stars, which would constitute perfectly black bodies.”

• —Preceding unsigned comment added by 68.23.168.44 (talk) 23:33, 29 March 2010 (UTC)

"In 1925 he published The Animate and the Inanimate, advancing the theory of black holes 15 years before physicists and astronomers warmed to it." (Article: "Good Will Sidis", Harvard Magazine, 1998) —Preceding unsigned comment added by 68.23.168.44 (talk) 00:11, 30 March 2010 (UTC)

As far as I understand, Sidis was not talking about black holes at all. He was talking about hypothetical regions of space in which the second law of thermodynamics would be reversed, a consequence of which would be (according toi him) that stars instead of radiating energy , would absorb all radiation. This does not mean that the stars would be black holes (any more than that ordinary stars are white holes). Note that in a black hole the second law of thermodynamics is not in anyway reversed. TimothyRias (talk) 08:04, 30 March 2010 (UTC)

Wikipedia is not a place to debate or interpret historically established theories. The fact of the matter is that dozens of book references credit Sidis as having predicted the existence of black holes, prior to anyone else, subsequently he should be mentioned in the history section. A basic history is found here:

● Black hole – Encyclopedia of Human Thermodynamics.

Even a simple sentence mention would do, for the sake of others who may be interested in reading his work. —Preceding unsigned comment added by 75.3.116.82 (talk) on 15:31, 30 March 2010

I have yet to see a reliable source that backs up this claim. TimothyRias (talk) 15:35, 30 March 2010 (UTC)

The first reference is the 1979 letter from Buckminster Fuller to editor Gerard Piel of Scientific American:

http://www.sidis.net/Buckyltr.htm

Dozens more can be found on Google books, citing that Sidis first conceived of black holes in 1915, when he was 17, during his stay at the Rice Institute. Prior to this it is well known that Sidis, in 1908 (age 10), had been checking Einstein's work for errors, and thus would have had mass-energy-relativity logic in his head. —Preceding unsigned comment added by 75.3.124.141 (talk) on 08:58, 31 March 2010

None of those are from phycists or other people remotely suspected of understanding what a black hole is. TimothyRias (talk) 12:12, 31 March 2010 (UTC)

Black holes

Black holes are quite a mystery though they are just a theory. Black holes are made by an old dying star that creates an enormous supernova (which happens very rarely). Black holes suck everything that gets to close, even light going approximately 186,282 miles per second can't escape a black hole! There's actually a helpful black hole in the very center of our vast galaxy keeping all our eight planets together. Absolutely no one knows what is inside a black hole, but we do know what happens to something that enters a black hole: first you get extremely squashed and get crushed, and then the temperature gets so hot that you literally boil! You can't see a black hole; the only way to spot one is if you see loads of stars franticly spinning around in a circle. This happens because the black hole is sucking up the dazzling stars.

By Kailo Bouskila, age 8, 31/3/2010 —Preceding unsigned comment added by 188.222.142.226 (talk) 18:51, 31 March 2010 (UTC)

Black hole temperature

Why are black holes "hot"? Shouldn't it be very cold around a black hole? --BrandiAlwaysSmiles (talk) 18:31, 7 April 2010 (UTC)

There are two things that happen near black holes that result in heating. The first is that matter falling towards a black hole forms an accretion disc, a disc-shaped cloud of matter that spirals in. Different parts of the disc are orbiting at different speeds, so there's friction. This causes the gas in the disc to heat up (it ends up converting gravitational potential energy of infalling matter into heat).

The second phenomenon is Hawking radiation given off by the black hole itself. Due to quantum effects described in that article, the black hole's event horizon looks like it has a nonzero temperature. For large holes (stellar-mass and up), this is indeed very cold (but not perfectly cold). For very small holes, however, this can be very hot. As holes give off thermal radiation, they lose mass, growing hotter and giving off even more thermal radiation, until they vanish in a flash of very bright, very hot radiation (as far as our present understanding of black holes goes).

I hope this addresses your question. --Christopher Thomas (talk) 18:57, 7 April 2010 (UTC)

...where "indeed very cold" means "much colder than the cosmic background radiation". ― ___A._di_M. (formerly Army1987) 20:23, 7 April 2010 (UTC)

Main Picture

Am I the only one to notice that the picture looks suspiciously like human eye ?

nirax (talk) 07:52, 18 April 2010 (UTC)