Which horizon is the border of a black hole. Stephen Hawking "canceled" the horizon of events of black holes. Watch what is "horizon of events" in other dictionaries
Gravity [from crystal spheres to mole-hole nor] Petrov Alexander Nikolaevich
Skyline Events and True Singularity
Zero frequency means there is no signal at all! From under the sphere of radius r. g. Light signals do not leave, gravitational forces do not give them to break out into the outer neighborhood. That is, indeed, this is a sphere where the second cosmic speed becomes equal to the speed of light. Therefore, from under the sphere of radius r. g. It is impossible to spread out no form of matter. Thus, this sphere turns out to be a barrier for which the external observer is unable to look. That is why she got a good name horizon of events, and the object itself began to call black hole.
Term black hole Tastened by the famous American physicist-theorist John Wylegra (1911-2008) one of the students at the conference in 1967. But even earlier, in 1964, Anna Iving was used in the report at the meeting of the American Association for Assistance to Science.
So far, we have considered fixed points of space and observers associated with them. Now let's follow a freely falling body. Let the fall begins from the state of rest from the remote area, where there is almost no curvature, from where we will track its trajectory. In the perception of a remote observer, the story of the fall will be next. First, the movement will not cause surprise. The speed will grow slowly, then faster and faster, quite complying with the law of global. Then, at distances from the center, comparable to the gravitational radius, the increase in the rate of fall will be catastrophic. Here we are also not very surprised, we will explain this by the fact that from the correspondence zone with the gravity of Newton, the object fell into the zone of strong curvature. And at the distances of the share of the gravitational radius from the horizon of events, he, to our amazement, will begin to slow down sharply and everything is slower to approach the horizon of events, and as a result, it will never reach it. But here, too, nothing to be surprised, we recently installed that for a remote observer all processes When the event approaches the horizon, the fall in the body is not an exception.
The effect of the fact that from under the horizon of events does not go outside, we explained the presence of extremely strong gravitational impact. This answer, of course, is correct, since nothing except gravity is not considered. However, it is not constructive, as it does not allow to understand the mechanism of those phenomena, which we just talked about. There is no idea about what is happening under the horizon, and whether something happens at all. On the other hand, we agreed that in the Einstein theory of gravitational forces, as such, there is no. There is curvature space-time. Therefore, let's move step by step to the description within the geometric theory.
We have already seen that the use of a light cone helps to understand many phenomena. In OTO, in curved space-time, has a more meaning of representing it not on the entire diagram, but in the neighborhood of each world point. It will be a local luminous cone formed by tangent to light geodesic at this point. The luminous cone equation has a simple look - the interval is equalized by zero: dS \u003d. 0.
In fig. 8.2 schematically depicts light cones for Schwarzschald geometry. Assuming that the movements occur in radial directions, the diagram is presented in the coordinates r. and t.. These coordinates for a remote observer in its own reference system determine the true distance and time. Therefore, the picture of physical phenomena presented by r. and t, - This is just the picture that the remote observer will perceive. The figure shows that at a considerable removal of the "petals" of the cone are located at an angle of 45 °, that is, as in a flat space-time. Vertical lines correspond to the same fixed (fixed) observers, which we have said recently. As it approaches the black hole, the cone becomes everything already, on the horizon it "sticks out" and turns into one vertical line. Vertical line for a remote observer This means that the light "stopped", its speed has become "zero". This means that on the horizon all the phenomena are frozen. The calculation of the zero geodesic shows that for a remote observer, the light will never reach the horizon.
Fig. 8.2. Space-time Schwarzschald geometry in the coordinates of a remote observer
Partially Such behavior of light cones is associated with the effect of time slowing down when approaching the gravitating center. But, fully his form, as we have already spoken, is determined by the condition dS \u003d. 0, just determines the "visible" light speed for a remote observer: v. c. = c. (1 – r. G. / R.). At a considerable distance from the center speed close to c.As it approaches the center, it decreases, and on the horizon, it really turns to zero. This is directly related to the shape of the light cones in Fig. 8.2. The speed of material particles is always less than the speed of light (the world line of the physical particle, is between the flaps of the light cone), so their "visible" limit speeds are also reduced when moving to the center, and they also never reach the horizon in the coordinates r. and t.. This conclusion confirms our description of free fall to the horizon from the point of view of the remote observer.
Next, continue our mind experiment, now "squeeze" all substance of a spherical object not only before the gravitational radius, but in general, to the "point" r \u003d. 0. That is, all space-time will be considered as a vacuum. Formally, we have the right to do this, since Schwarzshild's decision is just a vacuum. Turn to the expression for the metric. We have noted that on the horizon coefficient g. 00 Ply c. 2 dt. 2 turns to zero, and the coefficient g. 00 Ply dr. 2 becomes infinite. Moreover, there is a feature and in the "point" r \u003d. 0: here, on the contrary, g.becomes equal to "minus infinity", g 11.- equal to zero. Recall that for the "ordinary" body, which was discussed at the beginning of the paragraph, there were no peculiarities. Next, we will discuss the meaning of how features on the horizon, so I. features in the center.
Let's start with the horizon. Recall that in the space of Minkovsky, the physical essences of space and time remain different, despite their relativistic character. This manifests itself in the fact that the time and spatial part are included in the expression for the interval with different signs: the first - with the sign "Plus", the second - with the "minus" sign. This is how it is to solve the Schwarzshild at the removal of the horizon (in the "regular" area of \u200b\u200bspace). Temporary coefficient g. 00 Ply c. 2 dt. 2, indeed, positive, and spatialdetermined by the coefficient g. 11 Ply dr. 2, - negative.
And what will happen under the horizon? There, the situation has changed: in the expression for the interval we must take into account r. < r. G, then the coefficient g. 00 Ply c. 2 dt. 2 becomes negative, and coefficient g. 11 Ply dr. 2 becomes, on the contrary, - positive. And this is how newly we
discussed, means that under the horizon of the coordinate t. becomes spatial and coordinate r - temporary! Now, given this fact, we will construct light cones under the horizon. Because on the coordinate diagram r. and t. Changed the meaning, light cones would be skipped on the side, from the inside on the horizon their target is 180 °, then approaching the center r \u003d. 0, the target decreases. As always, the global line of the real physical particle should be inside the branch of the light cone. Finally, for r \u003d. 0 Petals of cones are finally "sticking out", as shown in Fig. 8.2. The location and shape of the light cones under the horizon are talking about two things. The first, indeed, nor rays of light, nor what material particle can not leave the horizon and the area under it; The second, all particles and light, being under the horizon, will inevitably achieve the origin of the coordinates when r \u003d. 0. Indeed, the melt of the cone is always directed to the line r \u003d. 0.
We see that under the horizon there are no obstacles to the movement of particles, although it looks somewhat unusual. On the other hand, the signals from the outside cannot overcome the horizon. The global lines of light rays and falling particles occurs. It's time to discuss the feature on the horizon. We will try to understand that on the horizon and in its surroundings takes place in reality.
It will be necessary to return to the origins of it and recall that the basic characteristic of space-time is its curvature (curvature), which is determined by the Tensor of the curvature of Riemann. But the calculation of the component of the Riemann tensor on the horizon and does not discover anything unusual in its surrounding. To the horizon on the horizon and under it curvature do not experience No breaks behave quite smoothly, gradually increasing as the center approaches the center. The fact is that the coordinates of the remote observer (and these are the coordinates of the flat space-time), in which the Schwarzshild decision is recorded, are not quite suitable for describing the phenomena in the neighborhood of the horizon. This means that you need to find the coordinates that did not have this defect.
Recall that the true time of each observer for him always has the same current, including very close to the horizon. And maybe on the horizon, why not? Therefore, in the desired coordinates, you can use your own time freely incidental (related) observers as a new temporal coordinate. Such coordinates for Schwarzschild, free from defects on the horizon, proposed in 1938 by Belgian astronomer and mathematician Georges Lemeter (1894-1966). In its concomitant reference system, world lines of particles and light rays stop taking a break on the horizon - they cross it freely. The chart in the coordinates of the lemet is discussed in Appendix 5.
What will observer test, bypassing the horizon? It all depends on the curvature of this horizon. If the black hole is huge, then locally the horizon is quite flat, and the observer does not respond to its intersection. If we reduce the black hole, then at a certain point, the observer will begin to feel the effect of tidal forces. It will begin to "stretch" along the radius and "crimp" from the sides. But these phenomena can begin to reach the horizon, they are not connected with it. The key point is the following. Once under the horizon, the observer has the ability to receive a signal from the outside world, but it does not have the ability to send a signal outward.
Finally, let's discuss the feature in the Center r \u003d. 0. While we got it, conducting a mental experiment. Or maybe such a feature to form in reality? Repeat again for example with the "ordinary" body, which was discussed at the beginning of this chapter. Such an object is described by an internal solution that static does not have features and "stitched" with the external decision of Schwarzschild. The internal solution is obtained taking into account the equation of the state of the body of the body. In this case, the equation of state determines such a pressure that it opposes gravitational compression. That is why the object is static. Is it always possible? Looking forward, where this problem is discussed, say: no, not always. If the mass of the body is equal to or exceeds five solar masses, then does not exist Such a state of substance so that its pressure can withstand gravitational compression. What happens if the body of such a mass is formed, as the rest of the dead star? Clear - the body will begin to shrink. Let's follow these compression, just not from afar (we made sure that the remote observer is not suitable for this), and with the help of an observer planted on the surface of this body. First, the observer, along with the remainder of the star reaches the horizon. Before that, he has a fundamental opportunity to escape on heavy duty rocket, leaving the ill-fated collapsar. But coming to the horizon, he inevitably, along with the remainder of the star "falls" to the center. The fatal word "inevitably" is quite scientifically substantiated, the location of light cones under the horizon speaks unequivocally.
So, indeed, everything can fall into the "Center" r \u003d. 0. But it is possible to say that the result is a feature, it is, in the "point". Strictly speaking, no. The fact is that with such a compression, the density and pressure of the substance reaches the values \u200b\u200bfor which the well-known laws of physics do not work. Most likely, space and time cease to be classic, so in close proximity to the center where everything fell, you can not build the very light cones. So it is wiser to talk about superconducting education in the center, whose physics has not yet been studied.
We will discuss these reservations, however, idealized Spot feature. Again, as in the case of a horizon, we calculate the components of the curvature tensor. But now, unlike the horizon, we get that the curvature appeals to infinity. And this means that such a feature cannot be "eliminated" by moving to other coordinates, as a feature on the horizon. So for r \u003d. 0 We have a feature that is often called true singularity. Further, since it turns out that the entire mass of the object is concentrated in a zero volume, then the density of the substance also addresses infinity. Note that direct r \u003d. 0 on the figure figure 8.2 crossing "Petals" of close light cones. That is, in a straight line r \u003d. 0 No signals apply and particles do not move. Based on this, at the speculative level (without the necessary scientific rigor) singularity r \u003d. 0 can be interpreted as part of the space with a zero volume, infinite density and curvature, on which the flow of time "ends.
From the book InterSELLAR: science for the scene Author Thorn Kip StephenThe chronology of the most important events mentioned in the book VI century. BC. Fales, the founder of Greek philosophy and science, put forward the idea of \u200b\u200bthe "primarylement" at the heart of all the phenomena of nature.v in. BC. Pythagoras established the connection between the string length and the tone height. BC e. Democritus
From the book to be hoking author Hoking JaneThe horizon of events and the curvature of the time when you hear a "black hole", then, most likely, you think not to curvature space, but about how the black hole sucks objects (see Fig. 5.3). Fig. 5.3. Signals that I send after the intersection of the event horizon cannot
From the book of the author12. The horizons of events once a dark windy evening on February 14, 1974, I took Stephen to Oxford to the conference in the Reforda laboratory on the basis of the Atomic Energy Research Center in Haruell. We stayed in Ebington in Coswers House - ancient
How is it possible?
The phrase of Big Weng, used by Fred Hyl (Fred Nooy) in 1950 during his radio interview at the Air Force, was subsequently translated into Russian, it was like a big explosion (in fact the phrase "big explosion" correctly translate only Big Explosion correctly. So the confusion that was missing in English began. Word WANG does not mean the "explosion" itself. It is used in comics to indicate a blow or explosion. It is rather something like "babes" or "boom". The word "explosion" causes quite specific associations, so in connection with a large explosion and questions arise "What exploded?", "Where?", "What?" And the like. In fact, Big Weng is not at all like an explosion. First, the explosion usually occurs in our usual space and is associated with a pressure difference. As a rule, this difference is ensured by a colossal difference in temperature. Its increase is ensured by the rapid release of a large amount of energy due to any chemical or nuclear reaction. The big explosion, unlike the usual, is not associated with any pressure difference. It brought first of all to the birth of the space itself with the substance, and only then to the expansion of the space and the subsequent expansion of the substance. You can not specify the "point" in which it happened. |
Often even professionals (physics, astronomers) to the question: "Is it possible to observe the galaxy, which at the time of radiation by it of light, and at the time of receiving its signal on earth is removed from us faster than light?" - Reply: "Of course it is impossible!" The intrinsiation is triggered, based on the special theory of relativity (STR), which one cosmologist called the "shadows of a hundred". However, this answer is incorrect. It turns out that it is possible. In any cosmological model, the fleet speed is linearly growing up with distance. This is due to one of the most important principles - uniformity of the Universe. Consequently, there is such a distance at which the runoff speed reaches light, and at large distances it becomes superlumous. That imaginary sphere, on which runoff speed is equal to the light, is called a sphere of Hubble.
"How is it possible! - Exclaim the reader. - Is the special theory of relativity are incorrect? " Verne, but there is no contradiction here. Sulfuric speeds are quite real when it comes to the transfer of energy or information from one point of space to another. For example, a sunny bunny can move at any speed, you only need to install the screen by which it runs away. One hundred "prohibits" only the transmission of information and energy with superluminal speed. And to transfer information, you need a signal propagating in space - the expansion of the space itself has nothing to do with it. So in our example about the removable galaxies with the theory of relativity, everything is in perfect order: they are removed with superluminal speed only from the earth's observer, and in relation to the surrounding space, their speed can generally be zero. It's amazing that we can see galaxies flying away from us faster than light. This is possible because the expansion rate of the universe was not constant. If in some period it will decrease and the light will be able to "reach" to our galaxy, then we will see a superlumina source. This example perfectly illustrates that the fate of the photon depends on how the universe behaves during his movement to it. Suppose that at the time of radiation a photon galaxy - the source was removed from us faster than light. Then, although the photon was emitted in our direction, moving along the stretching coordinate grid, it will be removed from us by inflaming the universe. If the expansion rate decreases, it is quite possible that at some point the ruling speed (in the place where the photon is located at this time) will be less than the speed of light. Then the light will begin to approach us and eventually can achieve us. The Galaxy-source itself at the time of "reversal" of light is removed from us still faster than light (because it is much further photon, and the speed grows with distance). At the time of reception of the photon, its speed can also be more light (that is, it will be behind the sphere of Hubble), but it does not prevent her observation.
In the universe, filled with substance (such an universe always paces with a slowdown), you can calculate all these critical parameters. If our world was so, then the galaxies for which the red shift is greater than 1.25, the light emitted now at the moment when their speed was more than the speed of light. The modern sphere of Hubble for the simplest model of the Universe, filled with substance (that is, without the contribution of dark energy), has a radius corresponding to a red displacement, equal to 3. And all the galaxies with a large displacement starting from the moment of radiation to our time are removed from us faster light.
The cosmology speaks about three important surfaces: the horizon of events, the horizon of particles and the sphere of the Hubble. The two past are surfaces in space, and the first - in space - time. With the sphere of Hubble, we have already met, talk now about the horizons. The horizon of particles separates the observed objects from unobservable. Since the universe has a finite age, the light from the distant objects just did not have time to reach us. This horizon is expanding all the time: time is coming, and we "wait" signals from more and more distant galaxies. The horizon of particles is removed, it is like running away from us at a speed that can be more of the speed of light. Thanks to this, we see more and more galaxies.
Note that the modern distance to the "galaxies on the edge of the observed universe" cannot be determined as a product of the speed of light by the age of the universe. In any model of the expanding universe, this distance will be more such a work. And it is quite understandable. Such a distance was the light itself, but the universe had time to expand during this time, so the modern distance to the galaxy is more than the path passed by the light, and at the time of radiation it could be significantly less than this path.
Sources on the horizon of particles have an infinite red displacement. These are the most ancient photons that at least theoretically can now be "see." They were emolred almost at the time of the Big Bang. Then the size of the visible part of the universe was extremely small, and therefore, since then all distances have grown very much. Hence the endless red shift. Of course, in fact, we cannot see photons from the very horizon of particles. The universe during his youth was opaque for radiation. Therefore, photons with red displacement more than 1,000 are not observed. If in the future astronomers learn to register relic neutrinos, it will allow you to look in the first minutes of the life of the universe, corresponding to the red displacement - ZKh10 7. Even more progress can be achieved when detecting relic gravitational waves, coming to "Platform times" (10,43 seconds from the beginning of the explosion). With their help, it will be possible to look into the past as far as it is in principle possible with the help of the laws of nature known for today. Near the initial moment of a large explosion, the overall theory of relativity is already not applicable.
Event horizon is a surface in space - time. Such a horizon arises not in any cosmological model. For example, in the above-mentioned universe of the horizon of events described above - any event from the life of remote galaxies can be seen if you wait long enough. The meaning of the introduction of this horizon is that it separates events that can affect us at least in the future, from those who cannot affect us. Even if the event light signal does not reach us, then the event itself cannot have an impact on us. You can imagine this as the intergalactic broadcast of a football match, which is happening in a distant galaxy, the signal of which we will never get. Why is it possible? There may be several reasons. The simplest is a model with the "end of the world". If the future is limited in time, it is clear that the light from some distant galaxies to reach us simply will not be able. Most modern models do not provide such opportunities. There is, however, the version of the upcoming large gap (Big Rip), but it is not very popular in scientific circles. But there is another option - an extension with acceleration. In this case, some football disorders simply "run away from the light": for them, the expansion rate will be superlumina.
Speaking of the "big universe", it is often believed that the substance is evenly distributed in space. In the first approximation, this is true. However, do not forget about such "disturbances" as the galaxies and their clusters. They are formed from primary density fluctuations. If a ball with a slightly greater density occurs in a uniformly distributed substance, then, without considering the effects associated with the temperature, it can be said that the ball will begin to shrink, and the density of the substance is to grow. In the simplest model of the expanding universe, in which the contribution of dark energy is zero, nothing fundamentally changes. Any density perturbation in such a dust universe (for real gas, and not dust it is necessary that the mass of perturbation exceeds a certain critical value - the so-called weight of jeans) will lead to the fact that the substance "falls" from the extension of the universe and forms a related object. If the contribution of dark energy is not zero, then the density fluctuations from the very beginning should have a value of more critical, otherwise the density contrast will not have time to increase to the desired value, and the substance will not "fall out" from the Hubblovsky flux. Just as the photon energy decreases due to the expansion, the kinetic energy of dust particles will also decrease with time as the universe expands. Because of this, while the fluctuation has not separated completely from the overall expansion of the universe, the process of "collapses" of indignation will go slower than without taking into account expansion. Instead of exponential density growth, its growth will be observed. As soon as the density contrast reaches some critical value, the fluctuation is like "forget" about the expansion of the universe.
Fear of the Black Queen
It turns out that the expanding universe is like something similar to the country of the Black Queen, in which Alice fell in the fairy tale Lewis Carroll "Alice in the Women's Cool." There, to resist the place, it was necessary to run very quickly. Suppose that there is a galaxy, which has a high speed aimed at us. In this case, two effects will contribute to its complete spectral displacement: a cosmological red expansion and a blue displacement due to the Doppler effect due to its own speed. The first question is: how will the distance to the galaxy with zero spectrum displacement? Answer: The galaxy will be removed from us. The second question: imagine the galaxy, the distance to which does not change due to the fact that its own speed has fully compensated for the effect of expansion (this is exactly similar to Alice, running around the country of the Black Queen). The galaxy moves along our drawn coordinate grid at the same speed, from which grid is inflated. What will the spectrum of such a galaxy? Answer: The offset will be blue. That is, lines in the spectrum of such a galaxy will be shifted towards shorter waves.
Such unexpected behavior of the radiation spectrum is due to the fact that there are two physical effects describing in different formulas. For a source, which was located on the Hubble sphere, at the time of radiation in the simplest model of the slowing down universe, the red displacement is 1.25, and the ruling speed is equal to the speed of light. It means to remain at a constant distance from us, the source must have its own speed equal to the speed of light. And to its own (peculiar) speeds, it is necessary to use the formula for the relativistic Doppler effect, which is for speed
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Gravitational linlication at the accumulation of the gala chick. The main contribution to the mass of the cluster makes a mysterious dark substance. The galaxies that are on the sphere of Hubble are removed faster than light. |
Fear of the Black Queen |
Today, cosmology is considered to be accurate science, and the measurement of the space metric is made using laser interferometers and over-conductive gyroscopes. |
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Of course, galaxies cannot have near-light-free. But some quasars and galaxies with active nuclei generate Jets - jets of substances that beat in millions of light years at distances. The rate of substance in such a jet may be close to the speed of light. If the jet is directed to us, then at the expense of the Doppler effect, we can see a blue offset. In addition, the substance should seem to be approaching us. However, in the light of what was written above, the second conclusion is not so obvious. If the source is far enough, then the cosmological expansion will still "take" the substance from us, even if its speed is very close to the light and the jet is visible to us "Missess." Only in cosmology is the emernant absurd at first glance, when the object removing from us has a blue offset. For example, the GB1508 + 5714 quasar having a red displacement of 4.3 is removed from us 1.13 times faster than light. So, the substance of his jet, moving in our side with high self-speed, is removed from us, since the particle speed cannot exceed the speed of light.
The recent discovery of the fact that the Universe is now expanding with acceleration, literally made up the cosmologists. The reasons for such an unusual behavior of our world can be two: either the main "filler" of our universe is not a conventional substance, but an unknown matter with unusual properties (the so-called dark energy), or even more terrible to think!) It is necessary to change the equations of the general theory of relativity. Yes, for some reason, mankind had a chance to live in that short on a cosmological scale period when the slow down expansion was only changed accelerated. All these questions are still very far from their permission, but today it is possible to discuss how the accelerated expansion (if it continues forever) will change our universe and create the horizon of events. It turns out that the life of distant galaxies, starting from the moment they raise a fairly large runoff speed, for us will stop and their future will be unknown to us - the light from a number of events just will never come to us. Over time, in a fairly distant future, all the galaxies that are not included in our local ultra-discharge size of 100 megaparski will hide behind the event horizon: all accelerating expansion "drown" there that correspond to them points on the coordinate grid.
Here, by the way, the difference between the horizon of particles and the horizon of events is clearly visible. Those galaxies that were under the horizon of particles, so under it will remain, the light from them will continue to reach. But the closer the speed of the galaxy becomes the speed of light, the more time you need the light to reach us, and all events in such a galaxy will seem stretched over time. Signally speaking, if you put the hours in such a galaxy, which by the time of its care the horizon of events should show 12 hours of the day, then the terrestrial observers will be visible endlessly slowing down the course of these hours. No matter how much we watched (theoretically, such a galaxy "with a clock" will never disappear from our skyscle), we will never see the arrows of the clock smoothly on the "twelve" - \u200b\u200bthe last turnover it will make an infinitely long for our own clock. After waiting for a long time, we will see what happened in the galaxy (by its o'clock) at 11 h 59 m, at 11 h 59 m 59 with so further. But what happened on her after "noon" will remain hidden from us forever. It is very similar to watching clocks falling in a black hole.
Similarly, perhaps the observer in this distant galaxy also argues. He now sees our galaxy in her past, but at some point in time, our story will become not enough for him, since our signals will no longer reach this galaxy. It is funny that for the generally accepted set of cosmological parameters, such galaxies are in general, not far. Their red bias should be more than 1.8. That is, they can even be within the sphere of Hubble, but to send them a news to them is already late.
These are paradoxical from the point of view of common sense of the phenomenon occur in our universe. Their unusual is due to the fact that the usual concepts of speed, distance and time in cosmology acquire a slightly different meaning. Unfortunately, so far scientists have come to some general opinion about what life our universe lives and that it can happen in principle. After all, even specialists expanding the boundaries of common sense is very difficult.
Sergey Popov, Alexey Toporensky
Albeurt Einstein at one time said: "Common sense is prejudices learned by man under the age of 18." He lived in the era of the formation of a new look at the physical world and had a lot of grounds for distrust with the usual ideas about the properties of objects. As many as three new worlds unfolded before scientists at the beginning of the twentieth century: quantum phenomena, special and general theory of relativity. We have no household intuition, which allows you to feel the specifics of phenomena taking place in these worlds. Common sense, based on our immediate sensations, allows us to understand only the laws of Newtonian mechanics, and it is in micro, mega-and moving with the near-light velocity of the world. Man-made devices come to the rescue, expanding human perception. Accelerators and telescopes, lasers and microscopes, computers and human mind allow us to draw phenomena inaccessible to us, understandable and logical. Only here is the logic and laws that opened by scientists in the study of the depths of the universe were not at all as we used to. |
Moscow, May 27 - RIA Novosti. German and Italian cosmologists say that they managed to find a way to explore what was happening inside the black hole, and understand how her internal structure was arranged, the article published in the magazine PHYSICAL REVIEW Letters.
Black holes arising from the gravitational collapse of massive stars, have such a strong gravity that it cannot be overcome without exceeding the speed of light. No objects or radiation can escape from the border of the effect of a black hole, the so-called event horizon.
What is happening for the "horizon of events" remains the mystery and subject of disputes among physicists. Most scientists believe that we are in principle cannot look inside the black hole and study its structure, as this will lead to extremely unpleasant consequences - in this case, we will not be able to "reconcile" the theory of relativity of Einstein and quantum mechanics. More large disputes causes what it looks like and how the "horizon of events" changes. Scientists call the number of its possible appearance of "entropy", and the individual options for its appearance - microstasses, and argue about whether they can be calculated.
Lorenzo Syndoni (Lorenzo Sindoni) from the Institute of Gravitational Physics in Mülenberg (Germany) and his colleagues from Italy claim that we can still calculate those microstastes that occur at the black hole event horizon using two non-codexal theories describing the behavior of matter on the quantum level - The theory of field groups (GFT) and loop quantum gravity (LQG). Both of these theories cause many questions from physicists, especially those who are supporters of the theory of strings and related crime constructions.
These theories, according to scientists, helped them to calculate how black holes behave from the point of view of thermodynamics, and get the same formulas that were led by Stephen Hawking several decades ago, when describing how entropy generated by a black hole is related to the area The surface of its horizon of events.
Matter inside a black hole, according to the authors of the article, will behave as a special quantum fluid, the behavior of which can be calculated, knowing the properties of one of the quantum particles, of which it is folded. Similar nature of the black hole and the connection between the area of \u200b\u200bits horizon of events and entropy, according to Syndoni, is a serious argument in favor of the so-called "holographic" theories of their device, which says that black holes, and possibly the universe is not three-dimensional, but Two-dimensional objects.
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Equivalence principle ·
World line · Pseudorimanova geometry
| Phenomena |
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| Kepler's task in from · gravitational linlication · Gravitational wave · Hobbating inertial reference systems · Surveillance of geodesic · Horizon of events · Gravitational singularity · Black hole |
| Development of theory |
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| Parametrized Postthtonian Formalism · Kaluzy Type Theories - Klein · Quantum gravity · Alternative theories |
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Horizon of events - Imaginary boundary in space-time, separating those events (space-time points), which can be connected to events on the light-like (isotropic) infinity by light-like geodetic lines (trajectories of light rays), and those events that can not be connected. Since there are usually light-like infinities of this space-time, two: relating to the past and the future, the horizons of events can be two: the horizon of events of the past and horizon of future events. It is simplified that the horizon of the past events shares the events to be changed from infinity and not changeable; And the horizon of the future of the future separates the events that you can find out something, at least in an infinitely distant perspective, from the events that can not be recognized about anything.
The horizon of events is usually three-dimensional hypersurface. Available and sufficient condition for its existence is the spatial-likeness of at least part of the light-like (isotropic) infinity. It should be noted that the horizon of events is the concept integral and nonlocal, as light-like infinity is involved in its definition, that is, all infinitely remote space-time areas. Therefore, in its immediate neighborhood, the horizon of events is not allocated, which represents the problem with numerical calculations in the general theory of relativity. To solve this problem, some close to the properties to the event horizon are proposed, but locally defined concepts: dynamic horizon, trapper surface and apparent horizon (Apparent Horizon).
There is also a concept horizon events of a separate observer. It shares the events that can be combined with the global observer line with light-like (isotropic) geodetic lines, respectively, in the future - the horizon of events of the past, and in the past - horizon of future events, and the events that cannot be done with. For example, a constantly evenly accelerated observer in the Minkowski space has its own horizons of the past and the future (see the Rindler's horizon).
Black Hole Event Horizon
The horizon of the future events is a necessary sign of a black hole as a scientifically confirmed object. The horizon of events of a spherical symmetric black hole is called the Schwarzschald sphere and has a characteristic size, called a gravitational radius.
Being under the horizon of events, any body will only move inside the black hole and will not be able to go back to the external space. C point of view of an observer freely falling into a black hole, light can freely spread both towards a black hole and from her. However, after crossing the event horizon, even the light propagating outside the observer will never be able to go beyond the horizon. The object that came inside the horizon of events, in the end, probably enters the singularity, and before that it is broken due to a high gradient of the strength of the black hole (tidal forces).
Energy may possibly leave the black hole by means of T. N. Radiation of Hawking, which is a quantum effect. If so, the true horizons of events in the strict sense in the crowded objects in our universe are not formed. Nevertheless, since astrophysical chopped objects are very classical systems, the accuracy of their description is sufficient for all conceivable astrophysical applications to the classic black hole model.
Other examples of event horizons
- For an observer moving with a constant eigen-acceleration in the Minkowski space (its speed in the inertial reference system is approaching the speed of light, but does not reach it), there are two horizons of events, the so-called rindler horizons (see Rindler coordinates).
Moreover, for an accelerated observer, there is an analogue of Hoking radiation - ENRU radiation. - The horizon of the future events exists for us in our universe, if the modern cosmological model λcdm is true.
- In acoustics there is also a final interaction propagation rate - the speed of sound, which is why the mathematical apparatus and physical consequences of acoustics and the theory of relativity become similar, and in supersonic fluid or gas streams, analogues of the event horizons are acoustic horizons.
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Excerpt characterizing the horizon of events
- It is impossible not to confess, "Prince Andrei continued," Napoleon as a person is great at the Arkolki Bridge, in the Hospital in Jaffa, where he raises his hand, but ... But there are other acts that hard to justify.Prince Andrei, apparently wanted to soften the awkwardness of Pierre's speech, raised, getting clinging to ride and feeding the sign to his wife.
Suddenly, the prince of Ippolit rose and stopping everyone signs and asking to sit down, spoke:
- AH! Aujourd "Hui On M" A Raconte Une Anecdote Moscovite, Charmante: Il Faut Que Je Vous En Regale. Vous M "Excusez, Vicomte, Il Faut Que Je Raconte en Russe. Autrement on Ne Sentira Pas Le Sel de L" Histoire. [Today I was told the adorable Moscow joke; You need to make them up. Sorry, Viscount, I will tell in Russian, otherwise the whole salt anecdot will disappear.]
And the prince of Ippolit began to speak Russian in Russian, how they say the French who have been told in Russia since the year. All suspended: so lively, strongly demanded the prince of Ippolit attention to its history.
- In Moscou there is one lady, Une Dame. And she is very stingy. She had to have two Valets de Pied [Lacey] for the carriage. And very big growth. It was her taste. And she had a UNE Femme de Chambre [Maid], even great growth. She said…
The prince of Ippolit thought, apparently with difficulty thinking.
"She said ... Yes, she said:" Girl (a la femme de chambre), put on livree [livery] and go with me, for the careta, Faire des Visites. " [Make visits.]
The prince of Ippolit snorted and walked much before his listeners, which made an impression disadvantaged for a narrator. However, many, including the elderly lady and Anna Pavlovna, smiled.
- She went. Strongly became a strong wind. The girl lost his hat, and the hair is broken ...
Here he could not stand more and began to laugh back and through this laughter spoke:
- And the whole world learned ...
Those anecdot and ended. Although it was not clear why he tells him and for which he had to tell himself certainly in Russian, but Anna Pavlovna and others appreciated the secular courtesy of Prince Ippolitis, so nicely ending with the unpleasant and obsertic face of Monsi Pierre. The conversation after a joke crouched into small, minor senses about the future and past the ball, the play, about when and where anyone sees.
Thanking Anna Pavlovna for her Charmante Soiree, [charming evening,] guests began to diverge.
Pierre was awkward. Thick, above ordinary growth, wide, with huge red hands, he, as they say, did not know how to enter the salon and even less skilled out of it, that is, before going out, say something particularly pleasant. In addition, he was scattered. Getting up, he instead of his hat captured a triangular hat with a general plume and kept her, Drejaya Sultan, until the general asked him to return it. But all his absent-way and inability to enter the salon and speaking in it turned out the expression of goodness, simplicity and modesty. Anna Pavlovna turned to him and, with Christian meekness, expressing forgiveness for his rest, nodded him and said:
"I hope to see you still, but I hope that you change your opinions, my dear Monsieur Pierre," she said.
When she told him this, he did not answer anything, just leaned and showed everyone again his smile, who did not say anything, except that: "Opinions opinions, and you see what kind of good and glorious small." And all, and Anna Pavlovna involuntarily felt it.
Prince Andrei went to the front and, substituting the shoulders with a lacquer, who won the raincoat to him, indifferently listened to the chatter of his wife with the prince of the Ippolit, who also came to the front. Prince Ippolit stood near a pretty pregnant princess and stubbornly looked straight on her in Lornet.
"Go, Annette, you are catching up," said the little princess, saying goodbye to Anna Pavlovna. - C "Est Arrete, [Solved," she added quietly.
Anna Pavlovna has already managed to talk with Liza about the matchmaker, which she climbed between Anatola and the slander of a little princess.
"I hope for you, a dear friend," said Anna Pavlovna, too quietly, "you will write to her and tell me, Comment Le Pere Envisagera La Chose. Au Revoir, [How Father will look into business. Goodbye,] - and she left the front.
Prince Ippolit approached the little princess and, closely tilting his face to her, became a half-one to say something to her.
Two lakes, one princess, the other, waiting for it when they ended to talk, stood with the shawl and fining and listened to them, incomprehensible to them, French talking with such persons, as if they understood what was said, but did not want to show it. Princess, as always, said smiling and listened to laughing.
"I am very glad that I didn't go to the Messenger," said Prince Ippolit: "Boredom ... A wonderful evening, is it really beautiful?"
- They say that the ball will be very good, - answered the princess, drawing up a sponge with the toasts. - All beautiful women of society will be there.
- not all, because you will not be there; Not all, "said Prince Ippolit, laughing happily, and grabbing Shawl from Lacey, even pushed him and began to wear it on the princess.
The study of black holes seriously physicists took up not so long ago - although the concept of their existence appeared in the year before last. But the idea of \u200b\u200bpresence somewhere in space such objects seemed so fantastic and unprotected, which was almost uncomply considered. In the new release, the heading "Just about complex" is a story about the history of the opening of the "frozen stars" and what is happening with space and time on the borders of the black hole.
Long story of disbelief
In 1783, the priest from the English village of Tornhill John Mitchell presented his article in the magazine "Philosophical Proceedings of the Royal Society". In it, he wrote that a sufficiently massive and compact star would have such a strong gravitational field that the light could not get away from it - it will be tightened back due to gravitational attraction. Mitchell believed that such objects in space could be very much, but it is impossible to see them - as their light is absorbed by them. Nevertheless, theoretically, their gravitational attraction can be detected. The article did not cause an excitement in the scientific community and passed almost unnoticed.
A few years later, the French scientist Pierre Simon Laplas, unfamiliar with the work of Mitchell, put forward a similar hypothesis. He published it in his work "System of the World", but after the second edition of the theory of the book disappeared - apparently, Laplace decided that he was not worth talking about such a stupid idea.
White dwarfs are obtained from small stars, objects with a density of hundreds of tons per cubic centimeter. In space, they found quite a lot, and our sun will eventually replenish their ranks.
But in the XIX century, scientists could no longer come to mind about invisible stars. The thing is that the Newtonian conviction regarding the fact that the light consists of particles, it came out of fashion. Scientists came to the conclusion that the concept, according to which the light is a wave, better describes the phenomena of the surrounding world. About how gravity acts on the waves was not known, it became, and reasoning about the heavenly objects, "tightening" their own light, I had to forget.
Re-remembered them only in the XX century. In 1916, almost immediately after the publication by Einstein's general theory of relativity, Karl Schwarzschild described the "frozen star", as such objects called, not considering the process of its origin, and in 1939 this missing element was added to Robert Oppenheimer and Hartland Snyder. And only in 1969, the American physicist John Wheeler came up with the term "black hole" (Wieler was generally a romantic, and the term invented by him, "Mute Nora", even more like fantastics).
Postal life stars
The life cycle of the star is like a human - it is born and dying. Initially, a huge cloud of gas (mainly hydrogen) in space begins to shrink under the influence of its own gravity, its molecules are increasingly faced with each other, and their speeds increase. Gas is heated, and at a certain temperature, the reaction of thermonuclear synthesis occurs, as a result of which helium is formed. During the reaction, heat is highlighted and light is emitted. So the star arises. Heat creates an additional pressure that bales the gravitational attraction, and the star ceases to shrink - in a stable state it can exist more than a million years. But sooner or later, the reserves of the reactive hydrogen have a star, and it begins to cool and shrink.
There is a comparison with human life ends, because the further fate of the luminaire depends on its mass. White dwarfs are obtained from small stars, objects with a density of hundreds of tons per cubic centimeter. In space, they found quite a lot, and our sun will eventually replenish their ranks. Neutron stars are formed from larger luminaires. Their size is much less than that of white dwarfs, but the density is hundreds of millions of tons per cubic centimeter.
And finally, if the mass of the star is large enough, the resulting neutron star under the influence of gravity is compressed and stronger and stronger until it becomes a black hole.
No exit
One of the most important achievements of Einstein was the discovery of the nature of gravity. The scientist showed that it is, in fact, is the curvature of space. Under the influence of massive objects, it is "presented" as the stretched elastic fabric to which the heavy item was laid. Continuing this comparison, it can be said that the sun can be represented in the same way in the form of a heavy ball, and the Earth, being a much smaller ball, is not attracted to him, but only rotates in the resulting funnel (with the only difference that the real ball Over time, I would roll down).
In the same black hole, the curvature of space-time becomes infinite - such a state of physics is called singularity, and there is no space or there is no space in our understanding.
You can also imagine the birth of a black hole - the ball on the stretched elastic fabric is becoming more small and dense, and the fabric becomes more stronger under his weight, until he finally becomes so small that she just closes him and he disappears from sight . Approximately this is happening in reality: the space-time around the star is coagulated, and it disappears from the Universe, leaving in it only a strongly curved area of \u200b\u200bspace-time. In the same black hole, the curvature of space-time becomes infinite - such a state of physics is called singularity, and there is no space or there is no space in our understanding.
Due to what is happening the curvature of the rays of light, coming from the star, change their trajectories. If you imagine these rays as a cones, the top of which is the stars, and the "sole" is a circle of diverging light, then we can say that in the process of the collapse, these cones are gradually increasingly leaked inwards, to the star. An observer looking to this process will seem that the glow is becoming more dull and red (this is because the red light has the greatest wavelength). In the end, curvature (that is, the gravitational field) will become so strong that no beam of light can get out. According to the theory of relativity, nothing can move faster than light, and this means that from now on, nothing can get out of this gravitational field. This area of \u200b\u200bspace, from which there is no exit, and is called a black hole. Her border is determined by the trajectory of those light rays that the first to lose the opportunity to go out. It is called the horizon of black hole events - just like, looking out of the window, we do not see what is behind the horizon and the conditional observer cannot understand what is happening inside the boundaries of the invisible dead star.
In fact, everything is wrong
The belief that nothing can leave the black hole, was unshakable until the 70s of the XX century. And in 1974, Stephen Hoking suggested that black holes as a result of quantum processes emit a variety of elementary particles, mainly photons. In the 2010s, various groups of scientists in the laboratory confirmed its assumption. At the same time, in the nature of such radiation, it was not yet discovered, as, however, the black holes themselves - the Nobel Prize for their discovery is still waiting for his lucky one.
