*December 24, 2012 19:48*

In the middle of the year in the physics community interested in research in the field of black holes (BH), there was some confusion. The site appeared arXiv work that literally threatens the creation of the paradox is not the weakest of your Schrödinger cats and Maxwell's demon. In general, supported by many scholars in the belief that the information is in contact with the black hole does not go away and have a major dilemma.

Imagine that the two particles — let's call them Alice and Bob — fly around the usual black hole. Alice, being caught by the black hole gravity, crossed the event horizon of the latter. And then suddenly it turns out that between **Alice** and Bob existed quantum entanglement. Under it, a few simplifying understood the relationships between two different particles (Alice and Bob) to theoretically unlimited long distance, and such a relationship, in which their parameters are related to each particular moment. Accordingly, the information on the state of Alice's on the horizon the BH will be available to Bob, and Bob on the parameters it can understand and outsider. And here begins the most important thing: if, as most physicists prefer to think, the information is not lost in the black **hole** (after getting there with the matter surrounding the black hole of the world) and it can be restored to the Hawking radiation emitted by the hole, then there is a contradiction between the quantum entanglement and Alice Bob and quantum entanglement BH and its immediate surroundings. Bob, it seems equally strongly coupled quantum immediately and with Alice, and with the "third party", which physicists call Carrie. However, quantum mechanics forbids equally strong quantum entanglement between more than two particles: quantum entanglement "monogamous" or Bob can not be in the same strongly coupled together at once, and with Alice, and with Carrie.

And that's not all. What happens if Bob is not just a particle and a bystander and compare the information it receives from the Hawking radiation (from Kerry) and the quantum coupled with it Alice? "It will be a disaster — says physicist Rafael Busse (Raphael Bousso) University of California, Berkeley (USA). — Because Bob, an external observer sees the same information in the Hawking radiation, and if they can talk about it [with Alice, quantum coupled with Bob], there will be a quantum copying is strictly forbidden in quantum mechanics. "

Following the publication of the said group of scientists led by Ahmed Almeyri (Ahmed Almheiri) University of California, Santa Barbara (USA) came a wave of comments (only some of them), the contents of which are quite predictable: the group Almeyri (aka AMPS) that- there too clever by half. Despite the unanimous critical impulse, opponents soon had to admit that in the framework of known physical laws proposed paradox clearly exists. If not, then some of these laws are wrong.

Traditionally, according to general relativity, is that if something or someone falls into a big black hole, the action script "No problem» (No Drama): at the event horizon of gravity is weak, and Alice, be it man, not tear apart . Although the fall deep into the black hole in the end it comes to a singularity, and its gravity will pull, gradually "spagettiziruya."

If proposed by Mr. Almeyri and colleagues option is true, at the entrance to the black hole (exactly at the event horizon) should be a firewall that prevents the ingress of quantum coupled with Bob Alice further into the black hole. What a strange phrase means physically, is not yet clear. Presumably, this can be a state of singularity, contrary to our concept of the black hole, is located right at the event horizon and immediately destroys any feed the horizon object, including Alice, along with all its quantum entanglement.

Obviously, we have a kind of new EPR paradox: if the "fire wall" at the entrance to the **black hole** is, or the general theory of relativity, or our understanding of **quantum** mechanics is lame. Outputs of the paradox is not much. It can be assumed that the **information** falling into the **black** hole is actually destroyed. Indeed, it is unclear as to Hawking radiation emitted from the black hole just swallowed like BSE, can restore the information contained in the encyclopedia. But then you have to say goodbye to the unitary **principle** — a cornerstone of modern physics. In other words, the principle that the sum of the probabilities of events that can happen to a quantum system is always one. The reader will, we believe, suspects that a violation of the principle of quantum mechanics makes the whole thing very shaky, and the option that physicists do not like.

However, some physicists still thought about that possibility. Although we do not know what will happen with quantum mechanics, without the principle of unitary, "this does not mean that nothing like it can be done — believes the famous physicist John Phillip Preskill of the California Institute of Technology (USA). — Look in the mirror and ask yourself: Do I put my life for unitary? "

The prospect is certainly frightening. There are alternatives: the revision of the principle of equivalence of gravity and inertia. According to him, if the inertial and gravitational masses are equal, it is impossible to distinguish which force acting on a given body — gravity or inertia. This principle makes it possible to the above scenario, "No problem", it was he who comes into conflict with the principle of unitarity in a scenario with "fire wall." According to the conclusions of the seminar held at Stanford University, or unitary, or the principle of equivalence, or the concept of the same physical laws and outside the black hole inside her to reconsider — but which of these three principles put under the ax, while none of the fifty participating in the discussion of physicists do not know: