How to shake hands with yourself, who flew from the future? Why in your lion can suddenly materialize? How to get into another Universe, visit a time machine and what is “white hole “? This was told by a senior researcher at the laboratory Physics of the Stars of the Main (Pulkovo) Observatory Sergey Krasnikov.
– Sergey Vladilenovich, what is a wormhole?
– There is no strict definition. Such definitions are needed, when you prove some theorems, and there are almost no strict theorems, therefore, mainly limited to figurative concepts, pictures. Imagine we took a ball out of our three-dimensional spaces in one room and the exact same ball was taken out in another room, and the resulting borders of these holes were glued together.
A photo from open sources
So when we in one room step inside this of a former ball that has become a hole, we will emerge in another room – from holes that formed in place of another ball. If we space would not be three-dimensional, but two-dimensional – it would look like a sheet of paper to which a pen is glued. Three-dimensional analogue and its development over time is called the wormhole.
– How do moleholes generally study?
– This is a purely theoretical activity. Wormholes no one never seen, and, in general, there is no certainty that they even exist. Wormhole and began to study, starting from from the question: are there such mechanisms in nature that would guarantee us that such holes in nature do not exist can? These mechanisms were not found, so we can assume that wormholes are a real phenomenon.
– Is it possible, in principle, to see a wormhole?
– Of course. If in a locked room you suddenly have nowhere a man crawls out, then you observe a wormhole. Moleholes like the object of study was invented and promoted by the American theoretical physicist John Wheeler, who wanted to explain with their help, neither as much as electric charges. Let’s explain. Description free electric field in terms of theoretical physics – not a very difficult task.
But to describe the electric charge from the same point of view is very not so easy. An electric charge appears in this sense mysterious thing: some substance, separate from the field, of unknown origin, and it is not clear how to handle it in classical physics. Wheeler’s idea was as follows. Let’s say we have a microscopic wormhole that is pierced by force lines – from one end these lines enter it, and with another – come out.
An outside observer who does not know that these two ends connected by force lines, such an object will perceive as a simple sphere in space, will explore the field around it, and it will look like a field of point charge. Only it will seem to the observer that this is some kind of mysterious substance, which has a charge, etc., and all because he does not know what on in fact, this is a wormhole.
Of course, this is a very elegant idea, and many have tried it. develop, but not particularly advanced, because electrons are, after all, quantum objects, and wormholes at the quantum level naturally, no one can describe. But assuming that the hypothesis is true, then wormholes are more than everyday phenomenon, everything related to electricity will be tied, in ultimately, it is on them.
A photo from open sources
Exotic matter is a classical concept of physics that describes any (usually hypothetical) substance that violates one or several classical conditions, or does not consist of well-known baryons. Such substances may have qualities such as negative energy density or repel rather than attracted by gravity. Exotic matter used in some theories, for example, in the theory of structure molehills. The most famous representative of exotic matter is a vacuum in an area with negative pressure, Casimir effect produced.
– What are wormholes?
– From the point of view of theoretical travels, there are passable and impenetrable moleholes. Impassable are those passing through which collapses, and it happens so fast that to pass from one end to the other no object just does not have time. Of course, the second type of wormhole is the most interesting to study – passable. There is even a beautiful theory that states that we used to be considered supermassive black holes in the centers of galaxies – this is actually the mouth of wormholes. This theory is almost not developed. and, of course, did not find, of course, any confirmation, she rather, it exists as an idea. Its essence is that outside of wormhole you only see that in the center of the galaxy is some spherically symmetrical object, but what is it – a mole hole or a black hole – you cannot say, because are outside this facility.
In fact, they can be distinguished only by one parameter – mass. If the mass turns out to be negative, then this is probably a mole hole, but if the mass is positive, then here you need additional information, because a black hole may also be mole burrow. Negative mass in general is one of the central moments of the whole story with wormholes. Because in order to be passable – the wormhole must be filled with what is called an exotic substance – a substance with would be places at some points the energy density is negative.
At the classical level, no one has ever seen such a substance, but we know for sure that in principle it can exist. Quantum effects that result in the occurrence of such a substance. This is a fairly well-known phenomenon and it is called the Casimir effect. It has been officially registered. AND associated with the existence of a negative energy density, which is very inspiring.
Casimir effect – the effect of mutual attraction conducting uncharged bodies under the influence of quantum fluctuations in vacuum. Most often we are talking about two parallel uncharged mirrored surfaces placed at close range but The Casimir effect also exists with more complex geometries. Cause effect – energy vibrations of a physical vacuum due to the constant birth and disappearance of virtual particles in it. The effect was predicted by the Dutch physicist Hendrick Casimir in 1948, and later confirmed experimentally.
In general, in quantum science, negative energy density is a fairly common thing associated with, for example, Hawking evaporation. If such a density exists, we we can ask the following question: how large is the mass of the black hole (parameter of the gravitational field created by it)? There is a solution to this tasks that apply to black holes – that is, objects with positive mass, but there is a solution applicable for negative masses.
A photo from open sources
If there is enough exotic matter in the wormhole a lot, then outside the mass of this object will be negative. therefore one of the main types of “observations” of wormholes is tracking objects for which it can be assumed that they have negative mass. And if we find such an object, then with pretty with a high degree of probability it will be possible to say that this is a mole Nora.
Mole holes are also divided into intra-world and inter-world. If we will destroy the tunnel between the two mouths of the second type of burrow – we we can see two universes completely unconnected among themselves. Such a wormhole is called interworld. But if we do that the same thing and see that everything is fine – we stayed in the same Of the Universe, then in front of us there is an intramorld wormhole. These two species of wormholes have a lot in common, but there is also an important difference. The fact is that the world-wide wormhole, if it exists, tends to turn into a time machine. Actually, on the background this assumption and the last surge of interest in mole burrows.
In the case of the intra-world wormhole, there are two different ways to look at a neighbor: directly through the tunnel or in a roundabout way. If you start one wormhole mouth to move relative to another then according to the well-known the twins paradox, the second person, returning from a trip, will be younger than the remaining. And on the other hand, when you look through the tunnel – you are both sitting still, from your point view, laboratories, nothing happens to you, your watch synchronized. So you have a theoretical the opportunity to dive into this tunnel and climb out at the moment that the point of view of the external observer precedes the moment when you dived. Adjusted to the appropriate degree of delay will give rise to the possibility of such a circular journey in space-time, when you return to your original place of departure and shake your previous incarnation of the hand.
The twin paradox is a thought experiment by which try to “prove” the inconsistency of a special theory relativity. According to SRT, in terms of “motionless” observers, all processes in moving objects slow down. FROM on the other hand, the principle of relativity declares equality inertial reference systems. Based on this, reasoning leading to an apparent contradiction. For clarity The story of two twin brothers is considered. One of them (traveler) goes on a space flight, and the second (homebody) – remains on Earth. Most often, a “paradox” is formulated in the following way:
In terms of a couch potato, a moving traveler’s watch has slow motion of time, so when they return, they must be behind from the couch potato watch. Conversely, regarding the traveler Earth moved, so the homebody’s clock should lag behind. In fact brothers are equal, therefore, after returning their watch should show one time. However, according to service stations, lagging behind will be the traveler’s watch. In such a violation visible the symmetry of the brothers, and there is a contradiction.
– What is the fundamental difference between a wormhole and a black hole?
– First of all, I must say that there are two types of black holes – those that formed as a result of the collapse of stars, and those that existed originally, arose along with the emergence of The universe. These are two fundamentally different types of black holes. In his time was such a thing as a “white hole”, now it rarely used. The white hole is the same black, but evolving backward in time. In a black hole, substance only flies, and can never escape from there already. From a white hole on the contrary, the substance only flies out, but to get into it in no way not allowed. In fact, this is a very natural thing if we remember that the General Theory of Relativity is symmetrical in time, and, therefore, if there are black holes – white must also exist. Them the totality is a mole hole.
– What is known about the internal structure of wormholes?
– So far, in this sense, models are only being built. On the one hand we we know that the appearance of this exotic matter is possibly detected even experimentally, and still a lot of questions remain. The only wormhole model known to me, more or less consistent with reality – this is a model of initially evaporating (since the beginning of the Universe) of the wormhole. Thereby such a hole remains passable for a long time.
– What exactly are you working on?
– I am engaged in a purely theoretical activity, which can be summarized as the causal structure of space-time – this is the classical Theory of Relativity, sometimes semi-classical (quantum, as you know, does not exist yet).
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In the classical nonrelativistic theory one can come up with strong enough evidence that traveling in time can not be, but in GR there is no such evidence. AND Einstein, when he was just developing his theory, realized this. His was wondering if there was any way such an opportunity to exclude. Then he did not cope with this task, as he himself later and said. And although Einstein created a language to study this issue, the task remained academic. Surge of interest in her happened in the late 1940s when Godel proposed cosmological model containing such closed curves.
But since Gödel always offered something exotic – to This was taken with interest, but without serious scientific consequences. And then, somewhere at the end of the last century, thanks mainly science fiction – for example, the movie “Contact” with Jodie Foster – interest in the theme of time travel with wormholes again reborn. The author of the novel, according to which the script of the film is written, – this is a very famous astronomer, a popularizer of science Karl Sagan.
He approached the matter very seriously and asked his friend, too a very famous relativist, Kip Thorne, see if it is possible everything that is described in the film from the point of view of science. And he published semi-popular magazine article for American physics teachers “Wormhole as an instrument for studying the General Theory of Relativity”, where he considered the possibility of time travel through moles burrows.
But I must say that then in science fiction was popular the idea of traveling through black holes. But he understood that a black hole – the object is absolutely impassable – travel through them impossible, therefore, considered molehills as an opportunity time travel. Although it was known before, but people for some reason, he took his conclusions as a completely fresh thought, and rushed to investigate it. Moreover, the emphasis was on the presumption of that time machines cannot exist, but decided to find out why. And pretty quickly came the understanding that no obvious there is no objection to the existence of such a machine. Since more extensive research has begun, began to appear theories. In general, since then I have been doing this.
Contact is a 1997 science fiction film. Producer – Robert Zemeckis. The main plot: Ellie Arroway (Judy Foster) the whole devoted her life to science, she becomes a participant in the project on the search for extraterrestrial intelligence. All attempts to search for extraterrestrial signals barren, and the future of her project is at stake. Ally is desperate to find support but unexpectedly gets help from an eccentric billionaire Hadden. And here is the result – Ellie picks up the signal. Signal decryption shows that it contains a description technical device. Its purpose is not clear, but inside conceived a place for one person.
After creating and starting the device, Ellie goes to travel through the wormhole system and is probably transferred to planet in a different star system. Waking up there, on the seashore, she meets a representative of another civilization, who chose the image of her deceased father. Looking around, the heroine realizes that this the terrain is recreated by an alien mind in her mind in the image drawing, drawn by her in childhood. An alien tells her that the device allows you to organize a system of interstellar paths communications, and the Earth now becomes a member of the community of civilizations The universe.
Ellie returns to Earth. From the point of view of third parties observers, nothing happened to her after starting the installation, and our body did not leave our planet. Ellie is in a paradoxical situation. Being a scientist, from the point of view of strict science, she does not can confirm your words. One more thing is also becoming clear. circumstance: a camcorder attached to Ellie during travel, didn’t record anything, but the duration of the empty record It was not a few seconds, but 18 hours …
– Is it possible to “make” a molehill?
– Just about this, there is a rigorous scientific result. it due to the fact that there are no exact results on the study of wormholes. There is a theorem proved for a very long time, and it speaks of this. There is such a thing as global hyperbolicity. In this case it doesn’t matter what it means, but the point is that so far since space is globally hyperbolic, the wormhole impossible to create – it can exist in nature, but to make it yourself will not work.
If you succeed in breaking global hyperbolicity, then maybe perhaps you can breed a wormhole. But the fact is that this breaking in itself is so exotic thing so bad studied and obscure that a side result in the form of birth wormhole – this is a relatively trifle compared with itself the fact that you managed to break the global hyperbolicity.
Here is a very famous thing called the “principle strict space censorship, “which says that space always globally hyperbolic. But this, in principle, is nothing more than wish. There is no evidence of fidelity to this principle, there’s just some kind of inner confidence inherent in many people, that space-time should be globally hyperbolic. If it’s so, it’s impossible to create a wormhole – you have to look existing. Meanwhile, severe doubts about the fidelity of the principle space censorship was expressed by the author himself – Roger Penrose, but that’s another story.
– That is, to create a wormhole, some serious energy costs?
“It’s very hard to say something.” The trouble is that when you global hyperbolicity is violated, it is simultaneously violated and predictability is almost the same thing. You can somehow geometrically change the space near you, for example, take a bag and put her in another place. But there are certain limits in whom you can do this, in particular, the limit imposed predictability. For example, sometimes you can say that will happen in 2 seconds, and sometimes not. The brink of what you you may or may not be able to predict just what lies on the global hyperbolicity. If you have space-time globally hyperbolic – you can predict its evolution.
If we assume that at some point it violates the global hyperbolicity – with predictability, everything becomes very bad. Therefore, an amazing thing arises, for example, such that directly here and now a wormhole can materialize through which the lion will jump out. It will be an exotic phenomenon, but it does not will violate any laws of physics. And on the other hand, you you can spend a lot of effort, money and resources to somehow make it easier this process. But the result will still be the same – in both In cases you do not know whether a wormhole will appear or not. IN we can’t do anything with classical physics – he wants to, will arise, will not want – will not arise – quantum science is no hints in this matter has not yet given us.
The principle of “space censorship” was formulated in 1969 Roger Penrose in the following figurative form: “Nature nourishes aversion to naked singularity. “He states that singularities space-time appear in places that, like internal areas of black holes, hidden from observers. This the principle has not yet been proven, and there is reason to doubt it absolute correctness (e.g., collapse of a dust cloud with a large angular momentum leads to a “bare singularity”, but it is unknown whether this solution of the Einstein equations is stable relatively small perturbations of the initial data).
Penrose wording (strong form of cosmic censorship) suggests space-time as a whole is globally hyperbolic.
Stephen Hawking later proposed a different formulation (weak form of space censorship), where only global hyperbolicity of the “future” component of space-time.
Olga Fadeeva
Time Universe Galaxy Time Machine Stephen Hawking Black Hole Einstein
