Astronomers and cosmologists in the United States have followed the behavior of one million of the largest black holes and have concluded that stars fall through entirely and that they have an event horizon predicted by Einstein's theory of relativity, according to an article published in the journal MNRAS.
“We did not try to find out what form the event horizon has, whether it is solid, or, as colleagues believe, looks like a fluffy 'skein' of thread. We were just trying to find the first evidence that he really exists. Our observations show that all or nearly all black holes have an event horizon, and that matter actually disappears from the observable universe the moment it crosses it. The theory of relativity has successfully passed the next test,”said Ramesh Narayan from Harvard University (USA).
Point or hole?
The theory of relativity predicts that so-called singularities can exist in the Universe - points with an infinitely high density and any mass. The well-known black holes are a special case of singularity.
Such objects, in accordance with the Penrose-Hawking principle of "cosmic censorship", cannot be seen, since they will be separated from the rest of the Universe by the event horizon. In other words, the singularity is located inside an imaginary sphere, from which even light cannot escape due to the super-strong attraction of the black hole. The implementation of this principle is extremely important for physics, since the discovery of a "naked singularity", at least in theoretical form, would mean that all modern physical science is wrong.
More recently, theoretical physicists have suggested that black holes do not have to be a singularity. At the point where the singularity should be located, there may be a superdense object, not isolated from the surrounding Universe, but invisible to us, or a "wormhole" - a tunnel connecting two different spaces. This idea is today causing great controversy among cosmologists and astronomers, since evidence in favor of its existence, or refutation of this idea has not yet been found.
Narayan and his colleagues have found an ingenious way to test whether an event horizon exists in black holes by observing how the largest black holes, located in the centers of galaxies, “eat up” stars approaching them.
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Singularity clarification
Scientists drew attention to the fact that the consequences of the convergence of a star and a black hole in the presence and absence of an event horizon will be noticeably different. If it is present, the star will disappear without a trace, "falling" into a singularity smaller than an atom, and in its absence, the star will collide with a superdense object that forms the basis of a black hole.
As a result of this collision, the matter of the luminary will "smear" on this object, it will cease to be invisible to us and give rise to an outbreak that will last for decades and whose brightness will change in a unique way, unlike how supernovae or "normal" black ejections occur. holes. Accordingly, by observing a sufficiently large number of galaxies, we will be able to understand whether supermassive black holes exist without an event horizon if their brightness rises sharply and they become visible.
Trying to find traces of such "flares", scientists analyzed images of more than a million galaxies with especially large supermassive black holes in the immediate vicinity of the Earth, which were received by the automated Pan-STARRS telescope in Hawaii over the past four years.
Narayan and his colleagues have not recorded a single such outbreak, which means two things - that the largest black holes have an event horizon and that the stars are "swallowed" by them entirely, disappearing forever and without a trace from the visible universe. Scientists believe that smaller black holes in the centers of galaxies and their smaller "cousins" of stellar mass behave in a similar way.
This is supported by the fact that Pan-STARRS should have recorded at least ten such temporary flares on the surface of "black holes" if theories about the formation of such superdense objects were correct. In the near future, Narayan and his colleagues will test their findings at the LSST survey telescope under construction in Chile, which will be able to track a much larger number of galaxies than the Hawaiian observatory.