The numerical solution presented in this work seems to indicate that the Hawkins radiation doesn't allow a star to collapse to a black hole. Interesting! While the concept of a black hole formed by the explosive collapse of a dying star is astounding, the possibility that matter from billions of stars can condense into a single super-massive black hole (SMBH) is even more fantastic. Yet we have an observational evidences that at the center of our Galaxy, should present an object Sagittarius A , that is hard to explain without invoking some super-compact super-massive object, such as SMBH. Recent radio interferometric observations show that the radio emission from Sgr A* comes from a region comparable in size to the Schwarzschild radius (2GM/c^2) of 0.1 AU (1.5x10^7 km)! Placing any known concentration of 4x10^6 solar masses within this tiny volume would rapidly condense to a black hole.

The redefinition of the Schwarzschild metrics in the 1970s (Schwarzschild worked c1916) essentially did away with the black hole as an area where no light could escape owing to gravity. Since "Hawking" radiation could escape, there was no more black hole, but a leaking hole.

I think calling it escape is wrong. As far as I remember (I am not pro in this, contrary to Igor who is pro and will correct me) whole radiation happens due fact that particles are born (and die) in vacuum. If two such pair particles happen to be on different sides of black hole horizon and one outside have enough energy it can "escape" :-) As I understand it is greatly simplified explanation.

Okay guys, the thing to remember is how water swirls clockwise going to your shower drain and therefore

It is also true for half of the world :-)

1972 Bekenstein posits an entropy state for black holes, thus redefining what it is. Bekenstein will remain largely uncredited.

1973 Hawking goes to Russia and gets a lot of cool new ideas from the physicists there. Those physicists will remain largely uncredited.

1974 Hawking provides the theory of how the radiation escapes, again redefining the term. After all, if nothing escapes, then something escapes, then that is a huge redefine, and one could argue that there could be a black hole that really is a black hole, not a leaky one, and now there are two basic models.

The simplest (and arguably "not exactly right") explanation is that pairs of particles near the event horizon go in different directions, and that therefore the black hole loses mass (as it should, in some models). However "escape" is still correct, as the mass/radiation has to go somewhere (the information paradox), so it either escapes (Bekenstein-Hawking), or there are other theories. If the particles are created, and then only one is destroyed, that is also a problem. Some ppl use the term "emit" to avoid dealing with the origin of the particles, however the basic idea of the black hole is that "nothing can escape".

However, part of the paradox is that if you define the black hole (and there are different definitions) as a true, hard line where nothing can escape, then one or both of these particles have to created just outside this theoretic radius. If just outside, they are not "escaping" in a literal sense from the inside, but in a theoretical sense. If the radius is a band, rather than a line, it has different properties, and you can adjust the theory to include this transitional area.

According to the theory, and observer outside the event horizon should be able to see or detect the particle that escapes, but not the particle pair that falls back in. However, the basic premise of QM is that you cannot determine the information vis a vis location and momentum, so it is a bit of a wash as to what you might observe.

The theory does not completely resolve the information paradox, as the information of the particle that falls back in may be lost.

However, if the hole is some sort of gravity well, or a Planck star, then it would have different properties. Similarly, there is no reason to believe that all galaxies have the same type of centre.

Getting back to the idea that "black holes cannot exist", this is a typical news grab scenario. But if the math is good, then that's a step forward.

Sabine is a sharp analyst, and her blog is always good.

If somebody says "black holes do not exist" this usually does not mean he denies the existence of huge, extremely dense accumulations of matter. It's mostly the "singularity" aspect of the popular "black hole" model that is highly controversial - the theoretical physics professor whose lectures I heard when I was at the university did not believe the "singularity" aspect, either.

I don't know which alternative model for the dense matter accumulations would be better, but I also don't think a singularity, being a very abstract mathmatical concept not observed anywhere in nature so far, is a very plausible thing to expect existing in reality. I would not be surprised if physicists one day agree on a "black hole" model that does not require the existence of a singularity.

Looking at it from another angle, the argument for white holes would also be in jeopardy. 'A 2011 paper argues that the Big Bang itself is a white hole. It further suggests that the emergence of a white hole, which was named a 'Small Bang', is spontaneous—all the matter is ejected at a single pulse. Thus, unlike black holes, white holes cannot be continuously observed—rather their effect can only be detected around the event itself. '

A new model, developed by Carlo Rovelli and Hal Haggard from Aix-Marseille University called “loop quantum gravity” where gravity and space-time are quantized, woven from tiny-individual loops that can’t be subdivided any further.

As a dying star collapses under its own gravity, it’s surrounded by a boundary called the event horizon: the point of no return, past which nothing can escape the black hole’s gravity. The star will continue to shrink, but eventually it will reach a stage where it can’t get any smaller because the loops cannot compress anymore.

At this point, the loops exert an outward pressure called “quantum bounce,” which transforms the black hole into a white hole. According to the team’s rough estimates, it takes just a few thousandths of a second for a black hole to transform into a white hole. Yet even though the transformation is nearly instantaneous, the researchers say, black holes can still appear to us as lasting billions or trillions of years because their gravity stretches light waves and dilates time.

If that’s the case, then rather than being shrouded by a true, eternal event horizon, black holes would be concealed by a temporary “apparent horizon,” Rovelli says. That’s important, because a true event horizon might violate the laws of physics.