Black hole in space, what's inside. What is a black hole. What's in a black hole

Black holes are one of the strangest phenomena in the Universe. In any case, at this stage of human development. This is an object with infinite mass and density, and therefore attraction, beyond which even light cannot escape - therefore the hole is black. A supermassive black hole can suck in an entire galaxy without choking, and beyond the event horizon, normal physics begins to screech and twist into a knot. On the other hand, black holes can become potential transition “holes” from one node of space to another. The question is, how close can we get to a black hole, and will there be consequences?

They take over everything they encounter. From subatomic particles to stars, solids, gases, liquids and even light, everything that falls into them is lost. And just like that, black holes capture the popular imagination. Thinking about space since humans first saw the points of light gracing the night sky has led the mind to imagine things that cannot be seen here on Earth. And black holes expand the imagination more than any other wonder of astronomy.

In order for a black hole to form, it is necessary to compress a body to a certain critical density so that the radius of the compressed body is equal to its gravitational radius. The value of this critical density is inversely proportional to the square of the black hole's mass.

For a typical stellar mass black hole ( M=10M sun) gravitational radius is 30 km, and the critical density is 2·10 14 g/cm 3, that is, two hundred million tons per cubic centimeter. This density is very high compared to the average density of the Earth (5.5 g/cm3), it is equal to the density of the substance of the atomic nucleus.

For a black hole at the galactic core ( M=10 10 M sun) gravitational radius is 3·10 15 cm = 200 AU, which is five times the distance from the Sun to Pluto (1 astronomical unit - the average distance from the Earth to the Sun - is equal to 150 million km or 1.5·10 13 cm). The critical density in this case is equal to 0.2·10 –3 g/cm 3 , which is several times less than the density of air, equal to 1.3·10 –3 g/cm 3 (!).

For the Earth ( M=3·10 –6 M sun), the gravitational radius is close to 9 mm, and the corresponding critical density is monstrously high: ρ cr = 2·10 27 g/cm 3, which is 13 orders of magnitude higher than the density of the atomic nucleus.

If we take some imaginary spherical press and compress the Earth, maintaining its mass, then when we reduce the radius of the Earth (6370 km) by four times, its second escape velocity will double and become equal to 22.4 km/s. If we compress the Earth so that its radius becomes approximately 9 mm, then the second cosmic velocity will take on a value equal to the speed of light c= 300000 km/s.

Further, a press will not be needed - the Earth, compressed to such a size, will already compress itself. In the end, a black hole will form in place of the Earth, the radius of the event horizon of which will be close to 9 mm (if we neglect the rotation of the resulting black hole). In real conditions, of course, there is no super-powerful press - gravity “works”. This is why black holes can only form when the interiors of very massive stars collapse, in which gravity is strong enough to compress matter to a critical density.

Evolution of stars

Black holes form at the final stages of the evolution of massive stars. In the depths of ordinary stars, thermonuclear reactions occur, enormous energy is released and a high temperature is maintained (tens and hundreds of millions of degrees). Gravitational forces tend to compress the star, and the pressure forces of hot gas and radiation resist this compression. Therefore, the star is in hydrostatic equilibrium.

In addition, a star can exist in thermal equilibrium, when the energy release due to thermonuclear reactions at its center is exactly equal to the power emitted by the star from the surface. As the star contracts and expands, the thermal equilibrium is disrupted. If the star is stationary, then its equilibrium is established in such a way that the negative potential energy of the star (the energy of gravitational compression) in absolute value is always twice the thermal energy. Because of this, the star has an amazing property - negative heat capacity. Ordinary bodies have a positive heat capacity: a heated piece of iron, cooling down, that is, losing energy, lowers its temperature. For a star, the opposite is true: the more energy it loses in the form of radiation, the higher the temperature at its center becomes.

This strange, at first glance, feature has a simple explanation: the star, as it radiates, slowly contracts. During compression, potential energy is converted into kinetic energy of falling layers of the star, and its interior heats up. Moreover, the thermal energy acquired by the star as a result of compression is twice as much as the energy lost in the form of radiation. As a result, the temperature of the star’s interior increases, and continuous thermonuclear synthesis of chemical elements occurs. For example, the reaction of converting hydrogen into helium in the current Sun occurs at a temperature of 15 million degrees. When, after 4 billion years, in the center of the Sun, all hydrogen turns into helium, for the further synthesis of carbon atoms from helium atoms, a significantly higher temperature will be required, about 100 million degrees (the electrical charge of helium nuclei is twice that of hydrogen nuclei, and to bring the nuclei closer together helium at a distance of 10–13 cm requires a much higher temperature). It is precisely this temperature that will be ensured due to the negative heat capacity of the Sun by the time the thermonuclear reaction of converting helium into carbon is ignited in its depths.

White dwarfs

If the mass of the star is small, so that the mass of its core affected by thermonuclear transformations is less than 1.4 M sun, the thermonuclear fusion of chemical elements may cease due to the so-called degeneracy of the electron gas in the star's core. In particular, the pressure of a degenerate gas depends on density, but does not depend on temperature, since the energy of quantum motions of electrons is much greater than the energy of their thermal motion.

The high pressure of the degenerate electron gas effectively counteracts the forces of gravitational compression. Since pressure does not depend on temperature, the loss of energy by a star in the form of radiation does not lead to compression of its core. Consequently, gravitational energy is not released as additional heat. Therefore, the temperature in the evolving degenerate core does not increase, which leads to the interruption of the chain of thermonuclear reactions.

The outer hydrogen shell, unaffected by thermonuclear reactions, separates from the star's core and forms a planetary nebula, glowing in the emission lines of hydrogen, helium and other elements. The central compact and relatively hot core of an evolved low-mass star is a white dwarf - an object with a radius on the order of the Earth's radius (~10 4 km), a mass of less than 1.4 M sun and an average density of about a ton per cubic centimeter. White dwarfs are observed in large numbers. Their total number in the Galaxy reaches 10 10, that is, about 10% of the total mass of the observable matter of the Galaxy.

Thermonuclear burning in a degenerate white dwarf can be unstable and lead to a nuclear explosion of a sufficiently massive white dwarf with a mass close to the so-called Chandrasekhar limit (1.4 M sun). Such explosions look like Type I supernovae, which have no hydrogen lines in their spectrum, but only lines of helium, carbon, oxygen and other heavy elements.

Neutron stars

If the star’s core is degenerate, then as its mass approaches the limit of 1.4 M sun, the usual degeneracy of the electron gas in the nucleus is replaced by the so-called relativistic degeneracy.

The quantum motions of degenerate electrons become so fast that their speeds approach the speed of light. In this case, the elasticity of the gas decreases, its ability to counteract the forces of gravity decreases, and the star experiences gravitational collapse. During collapse, electrons are captured by protons, and neutronization of the substance occurs. This leads to the formation of a neutron star from a massive degenerate core.

If the initial mass of the star's core exceeds 1.4 M sun, then a high temperature is reached in the core, and electron degeneration does not occur throughout its evolution. In this case, negative heat capacity works: as the star loses energy in the form of radiation, the temperature in its depths increases, and there is a continuous chain of thermonuclear reactions converting hydrogen into helium, helium into carbon, carbon into oxygen, and so on, up to the elements of the iron group. The reaction of thermonuclear fusion of nuclei of elements heavier than iron no longer occurs with the release, but with the absorption of energy. Therefore, if the mass of the star's core, consisting mainly of iron group elements, exceeds the Chandrasekhar limit of 1.4 M sun , but less than the so-called Oppenheimer–Volkov limit ~3 M sun, then at the end of the nuclear evolution of the star, gravitational collapse of the core occurs, as a result of which the outer hydrogen shell of the star is shed, which is observed as a type II supernova explosion, in the spectrum of which powerful hydrogen lines are observed.

The collapse of the iron core leads to the formation of a neutron star.

When the massive core of a star that has reached a late stage of evolution is compressed, the temperature rises to gigantic values ​​of the order of a billion degrees, when the nuclei of atoms begin to break apart into neutrons and protons. Protons absorb electrons and turn into neutrons, emitting neutrinos. Neutrons, according to the quantum mechanical Pauli principle, with strong compression begin to effectively repel each other.

When the mass of the collapsing core is less than 3 M sun, neutron speeds are significantly less than the speed of light and the elasticity of matter due to the effective repulsion of neutrons can balance the gravitational forces and lead to the formation of a stable neutron star.

The possibility of the existence of neutron stars was first predicted in 1932 by the outstanding Soviet physicist Landau immediately after the discovery of the neutron in laboratory experiments. The radius of a neutron star is close to 10 km, its average density is hundreds of millions of tons per cubic centimeter.

When the mass of the collapsing stellar core is greater than 3 M sun, then, according to existing ideas, the resulting neutron star, cooling, collapses into a black hole. The collapse of a neutron star into a black hole is also facilitated by the reverse fall of part of the star's shell, ejected during a supernova explosion.

A neutron star typically rotates rapidly because the normal star that gave birth to it can have significant angular momentum. When a star's core collapses into a neutron star, the characteristic dimensions of the star decrease from R= 10 5 –10 6 km to R≈ 10 km. As the size of a star decreases, its moment of inertia decreases. To maintain angular momentum, the speed of axial rotation must increase sharply. For example, if the Sun, rotating with a period of about a month, is compressed to the size of a neutron star, then the rotation period will decrease to 10 -3 seconds.

Single neutron stars with a strong magnetic field manifest themselves as radio pulsars - sources of strictly periodic pulses of radio emission that arise when the energy of the rapid rotation of a neutron star is converted into directed radio emission. In binary systems, accreting neutron stars exhibit the phenomenon of X-ray pulsar and type 1 X-ray burster.

One cannot expect strictly periodic pulsations of radiation from a black hole, since the black hole has no observable surface and no magnetic field. As physicists often say, black holes do not have “hair” - all fields and all inhomogeneities near the event horizon are emitted when the black hole is formed from collapsing matter in the form of a stream of gravitational waves. As a result, the resulting black hole has only three characteristics: mass, angular momentum and electric charge. All individual properties of the collapsing substance are forgotten during the formation of a black hole: for example, black holes formed from iron and from water have, other things being equal, the same characteristics.

As predicted by the General Theory of Relativity (GR), stars whose iron core masses at the end of their evolution exceed 3 M sun, experience unlimited compression (relativistic collapse) with the formation of a black hole. This is explained by the fact that in general relativity the gravitational forces tending to compress a star are determined by the energy density, and at the enormous densities of matter achieved during the compression of such a massive star core, the main contribution to the energy density is no longer made by the rest energy of the particles, but by the energy of their movement and interaction . It turns out that in general relativity the pressure of a substance at very high densities seems to “weigh” itself: the greater the pressure, the greater the energy density and, consequently, the greater the gravitational forces tending to compress the substance. In addition, under strong gravitational fields, the effects of space-time curvature become fundamentally important, which also contributes to the unlimited compression of the star’s core and its transformation into a black hole (Fig. 3).

In conclusion, we note that black holes formed in our era (for example, the black hole in the Cygnus X-1 system), strictly speaking, are not one hundred percent black holes, since due to relativistic time dilation for a distant observer, their event horizons still have not formed. The surfaces of such collapsing stars appear to an observer on Earth as frozen, endlessly approaching their event horizons.

In order for black holes from such collapsing objects to finally form, we must wait the entire infinitely long time of the existence of our Universe. It should be emphasized, however, that already in the first seconds of relativistic collapse, the surface of the collapsing star for an observer from Earth approaches very close to the event horizon, and all processes on this surface slow down infinitely.

Black holes are the only cosmic bodies capable of attracting light by gravity. They are also the largest objects in the Universe. We are unlikely to know what happens near their event horizon (known as the “point of no return”) anytime soon. These are the most mysterious places in our world, about which, despite decades of research, very little is still known. This article contains 10 facts that can be called the most intriguing.

Black holes do not suck matter into themselves

Many people imagine a black hole as a kind of “space vacuum cleaner”, drawing in the surrounding space. In fact, black holes are ordinary space objects that have an exceptionally strong gravitational field.

If a black hole of the same size arose in the place of the Sun, the Earth would not be pulled in, it would rotate in the same orbit as it does today. Stars located next to black holes lose part of their mass in the form of stellar wind (this happens during the existence of any star) and black holes absorb only this matter.

The existence of black holes was predicted by Karl Schwarzschild

Karl Schwarzschild was the first to use Einstein's general theory of relativity to prove the existence of a “point of no return.” Einstein himself did not think about black holes, although his theory predicts their existence.

Schwarzschild made his proposal in 1915, immediately after Einstein published his general theory of relativity. At that time, the term “Schwarzschild radius” arose - this is a value that shows how much you would have to compress an object for it to become a black hole.

Theoretically, anything can become a black hole if compressed enough. The denser the object, the stronger the gravitational field it creates. For example, the Earth would become a black hole if it had the mass of an object the size of a peanut.

Black holes can give birth to new universes

The idea that black holes can give birth to new universes seems absurd (especially since we are still not sure about the existence of other universes). Nevertheless, such theories are actively being developed by scientists.

A very simplified version of one of these theories is as follows. Our world has extremely favorable conditions for the emergence of life in it. If any of the physical constants changed even a little, we would not be in this world. The singularity of black holes overrides the normal laws of physics and could (at least in theory) give rise to a new universe that will be different from ours.

Black holes can turn you (and anything else) into spaghetti

Black holes stretch objects that are near them. These items begin to resemble spaghetti (there is even a special term - “spaghettification”).

This happens due to the way gravity works. At the moment, your legs are closer to the center of the Earth than your head, so they are attracted more strongly. On the surface of a black hole, the difference in gravity begins to work against you. The legs are attracted to the center of the black hole faster and faster, so that the upper half of the body cannot keep up with them. Result: spaghettification!

Black holes evaporate over time

Black holes not only absorb stellar wind, but also evaporate. This phenomenon was discovered in 1974 and was called Hawking radiation (after Stephen Hawking, who made the discovery).

Over time, the black hole can release all its mass into the surrounding space along with this radiation and disappear.

Black holes slow down time near them

As you approach the event horizon, time slows down. To understand why this happens, we need to look at the “twin paradox,” a thought experiment often used to illustrate the basic principles of Einstein's theory of general relativity.

One of the twin brothers remains on Earth, and the second flies off on a space journey, moving at the speed of light. Returning to Earth, the twin discovers that his brother has aged more than he has because time moves slower when traveling near the speed of light.

As you approach the event horizon of a black hole, you will move at such a high speed that time will slow down for you.

Black holes are the most advanced energy systems

Black holes generate energy better than the Sun and other stars. This is due to the matter orbiting around them. Crossing the event horizon at enormous speed, matter in the black hole's orbit heats up to extremely high temperatures. This is called black body radiation.

For comparison, nuclear fusion converts 0.7% of matter into energy. Near a black hole, 10% of matter becomes energy!

Black holes bend the space around them

Space can be thought of as a stretched rubber plate with lines drawn on it. If you put an object on the record, it will change its shape. Black holes work the same way. Their extreme mass attracts everything, including light (the rays of which, to continue the analogy, could be called lines on a plate).

Black holes limit the number of stars in the Universe

Stars arise from gas clouds. For star formation to begin, the cloud must cool.

The radiation from black bodies prevents gas clouds from cooling and prevents stars from appearing.

Theoretically, any object can become a black hole

The only difference between our Sun and a black hole is the force of gravity. At the center of a black hole it is much stronger than at the center of a star. If our Sun were compressed to about five kilometers in diameter, it could be a black hole.

Theoretically, anything can become a black hole. In practice, we know that black holes arise only as a result of the collapse of huge stars that exceed the Sun in mass by 20-30 times.

Most people have a vague or incorrect idea of ​​what black holes are. Meanwhile, these are such global and powerful objects of the Universe, in comparison with which our Planet and our entire life are nothing.

Essence

This is a cosmic object with such enormous gravity that it absorbs everything that falls within its boundaries. Essentially, a black hole is an object that does not even let out light and bends space-time. Even time moves slower near black holes.

In fact, the existence of black holes is just a theory (and a little practice). Scientists have assumptions and practical experience, but have not yet been able to closely study black holes. Therefore, all objects that fit this description are conventionally called black holes. Black holes have been little studied, and therefore many questions remain unresolved.

Any black hole has an event horizon - that boundary after which nothing can escape. Moreover, the closer an object is to a black hole, the slower it moves.

Education

There are several types and methods of formation of black holes:
- the formation of black holes as a result of the formation of the Universe. Such black holes appeared immediately after the Big Bang.
- dying stars. When a star loses its energy and thermonuclear reactions stop, the star begins to shrink. Depending on the degree of compression, neutron stars, white dwarfs and, in fact, black holes are distinguished.
- obtained through experiment. For example, a quantum black hole can be created in a collider.

Versions

Many scientists are inclined to believe that black holes eject all the absorbed matter elsewhere. Those. there must be “white holes” that operate on a different principle. If you can get into a black hole, but cannot get out, then, on the contrary, you cannot get into a white hole. The main argument of scientists is the sharp and powerful bursts of energy recorded in space.

Proponents of string theory generally created their own model of a black hole, which does not destroy information. Their theory is called "Fuzzball" - it allows us to answer questions related to the singularity and the disappearance of information.

What is singularity and disappearance of information? A singularity is a point in space characterized by infinite pressure and density. Many people are confused by the fact of singularity, because physicists cannot work with infinite numbers. Many are sure that there is a singularity in a black hole, but its properties are described very superficially.

In simple terms, all problems and misunderstandings arise from the relationship between quantum mechanics and gravity. So far, scientists cannot create a theory that unites them. And that is why problems arise with a black hole. After all, a black hole seems to destroy information, but at the same time the foundations of quantum mechanics are violated. Although quite recently S. Hawking seemed to have resolved this issue, stating that information in black holes is not destroyed after all.

Stereotypes

Firstly, black holes cannot exist indefinitely. And all thanks to Hawking evaporation. Therefore, there is no need to think that black holes will sooner or later swallow the Universe.

Secondly, our Sun will not become a black hole. Since the mass of our star will not be enough. Our sun is more likely to turn into a white dwarf (and that’s not a fact).

Thirdly, the Large Hadron Collider will not destroy our Earth by creating a black hole. Even if they deliberately create a black hole and “release” it, then due to its small size, it will consume our planet for a very, very long time.

Fourthly, you don’t need to think that a black hole is a “hole” in space. A black hole is a spherical object. Hence the majority of opinions that black holes lead to a parallel Universe. However, this fact has not yet been proven.

Fifthly, a black hole has no color. It is detected either by X-ray radiation or against the background of other galaxies and stars (lens effect).

Due to the fact that people often confuse black holes with wormholes (which actually exist), these concepts are not distinguished among ordinary people. A wormhole really allows you to move in space and time, but so far only in theory.

Complex things in simple terms

It is difficult to describe such a phenomenon as a black hole in simple language. If you consider yourself a techie versed in the exact sciences, then I advise you to read the works of scientists directly. If you want to learn more about this phenomenon, then read the works of Stephen Hawking. He did a lot for science, and especially in the field of black holes. The evaporation of black holes is named after him. He is a supporter of the pedagogical approach, and therefore all his works will be understandable even to the average person.

Books:
- “Black Holes and Young Universes” 1993.
- “The World in a Nutshell 2001.”
- “The Brief History of the Universe 2005”.

I especially want to recommend his popular science films, which will tell you in clear language not only about black holes, but also about the Universe in general:
- “Stephen Hawking's Universe” - a series of 6 episodes.
- “Deep into the Universe with Stephen Hawking” - a series of 3 episodes.
All these films have been translated into Russian and are often shown on Discovery channels.

Thank you for your attention!

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The boundless Universe is full of secrets, riddles and paradoxes. Despite the fact that modern science has made a huge leap forward in space exploration, much in this vast world remains incomprehensible to the human worldview. We know a lot about stars, nebulae, clusters and planets. However, in the vastness of the Universe there are objects whose existence we can only guess about. For example, we know very little about black holes. Basic information and knowledge about the nature of black holes is based on assumptions and conjectures. Astrophysicists and nuclear scientists have been struggling with this issue for decades. What is a black hole in space? What is the nature of such objects?

Speaking about black holes in simple terms

To imagine what a black hole looks like, just see the tail of a train going into a tunnel. The signal lights on the last car will decrease in size as the train deepens into the tunnel until they completely disappear from view. In other words, these are objects where, due to monstrous gravity, even light disappears. Elementary particles, electrons, protons and photons are unable to overcome the invisible barrier and fall into the black abyss of nothingness, which is why such a hole in space is called black. There is not the slightest light area inside it, complete blackness and infinity. What is on the other side of the black hole is unknown.

This space vacuum cleaner has a colossal gravitational force and is able to absorb an entire galaxy with all the clusters and superclusters of stars, with nebulae and dark matter to boot. How is this possible? We can only guess. The laws of physics known to us in this case are bursting at the seams and do not provide an explanation for the processes taking place. The essence of the paradox is that in a given part of the Universe the gravitational interaction of bodies is determined by their mass. The process of absorption by one object of another is not influenced by their qualitative and quantitative composition. Particles, having reached a critical number in a certain area, enter another level of interaction, where gravitational forces become forces of attraction. A body, object, substance or matter begins to compress under the influence of gravity, reaching colossal density.

Approximately similar processes occur during the formation of a neutron star, where stellar matter is compressed in volume under the influence of internal gravity. Free electrons combine with protons to form electrically neutral particles - neutrons. The density of this substance is enormous. A particle of matter the size of a piece of refined sugar weighs billions of tons. Here it would be appropriate to recall the general theory of relativity, where space and time are continuous quantities. Consequently, the compression process cannot be stopped halfway and therefore has no limit.

Potentially, a black hole looks like a hole in which there may be a transition from one part of space to another. At the same time, the properties of space and time themselves change, twisting into a space-time funnel. Reaching the bottom of this funnel, any matter disintegrates into quanta. What is on the other side of the black hole, this giant hole? Perhaps there is another space out there where other laws apply and time flows in the opposite direction.

In the context of the theory of relativity, the theory of a black hole looks like this. The point in space where gravitational forces have compressed any matter to microscopic sizes has a colossal force of attraction, the magnitude of which increases to infinity. A fold of time appears, and space bends, closing at one point. Objects swallowed up by a black hole are not able to independently withstand the pulling force of this monstrous vacuum cleaner. Even the speed of light, which quanta possess, does not allow elementary particles to overcome the force of gravity. Any body that gets to such a point ceases to be a material object, merging with a space-time bubble.

Black holes from a scientific point of view

If you ask yourself, how do black holes form? There will be no clear answer. There are quite a lot of paradoxes and contradictions in the Universe that cannot be explained from a scientific point of view. Einstein's theory of relativity allows only a theoretical explanation of the nature of such objects, but quantum mechanics and physics are silent in this case.

Trying to explain the processes occurring with the laws of physics, the picture will look like this. An object formed as a result of colossal gravitational compression of a massive or supermassive cosmic body. This process has a scientific name - gravitational collapse. The term “black hole” was first heard in the scientific community in 1968, when American astronomer and physicist John Wheeler tried to explain the state of stellar collapse. According to his theory, in the place of a massive star that has undergone gravitational collapse, a spatial and temporal gap appears, in which an ever-increasing compression operates. Everything that the star was made of goes inside itself.

This explanation allows us to conclude that the nature of black holes is in no way connected with the processes occurring in the Universe. Everything that happens inside this object is not reflected in any way on the surrounding space with one “BUT”. The gravitational force of a black hole is so strong that it bends space, causing galaxies to rotate around black holes. Accordingly, the reason why galaxies take the shape of spirals becomes clear. How long it will take for the huge Milky Way galaxy to disappear into the abyss of a supermassive black hole is unknown. An interesting fact is that black holes can appear anywhere in outer space, where ideal conditions are created for this. Such a fold of time and space neutralizes the enormous speeds with which stars rotate and move through the space of the galaxy. Time in a black hole flows in another dimension. Within this region, no laws of gravity can be interpreted in terms of physics. This state is called a black hole singularity.

Black holes do not show any external identification signs; their existence can be judged by the behavior of other space objects that are affected by gravitational fields. The whole picture of a life-and-death struggle takes place on the border of a black hole, which is covered with a membrane. This imaginary funnel surface is called the “event horizon.” Everything we see up to this border is tangible and material.

Black hole formation scenarios

Developing the theory of John Wheeler, we can conclude that the mystery of black holes is most likely not in the process of its formation. The formation of a black hole occurs as a result of the collapse of a neutron star. Moreover, the mass of such an object should exceed the mass of the Sun by three or more times. The neutron star shrinks until its own light is no longer able to escape the tight embrace of gravity. There is a limit to the size to which a star can shrink, giving birth to a black hole. This radius is called the gravitational radius. Massive stars at the final stage of their development should have a gravitational radius of several kilometers.

Today, scientists have obtained indirect evidence of the presence of black holes in a dozen X-ray binary stars. X-ray stars, pulsars or bursters do not have a solid surface. In addition, their mass is greater than the mass of three Suns. The current state of outer space in the constellation Cygnus - the X-ray star Cygnus X-1, allows us to trace the process of formation of these curious objects.

Based on research and theoretical assumptions, today in science there are four scenarios for the formation of black stars:

• gravitational collapse of a massive star at the final stage of its evolution;
• collapse of the central region of the galaxy;
• the formation of black holes during the Big Bang;
• formation of quantum black holes.

The first scenario is the most realistic, but the number of black stars we are familiar with today exceeds the number of known neutron stars. And the age of the Universe is not so great that such a number of massive stars could go through the full process of evolution.

The second scenario has the right to life, and there is a striking example of this - the supermassive black hole Sagittarius A*, nestled in the center of our galaxy. The mass of this object is 3.7 solar masses. The mechanism of this scenario is similar to the gravitational collapse scenario, with the only difference that it is not the star that collapses, but the interstellar gas. Under the influence of gravitational forces, the gas is compressed to a critical mass and density. At a critical moment, matter disintegrates into quanta, forming a black hole. However, this theory is in doubt, as recently astronomers at Columbia University identified satellites of the black hole Sagittarius A*. They turned out to be many small black holes, which were probably formed in a different way.

The third scenario is more theoretical and is associated with the existence of the Big Bang theory. At the moment of the formation of the Universe, part of the matter and gravitational fields underwent fluctuations. In other words, the processes took a different path, unrelated to the known processes of quantum mechanics and nuclear physics.

The last scenario focuses on the physics of a nuclear explosion. In clumps of matter, during nuclear reactions under the influence of gravitational forces, an explosion occurs, in the place of which a black hole is formed. Matter explodes inward, absorbing all particles.

Existence and evolution of black holes

Having a rough idea of ​​the nature of such strange space objects, something else is interesting. What are the true sizes of black holes and how fast do they grow? The sizes of black holes are determined by their gravitational radius. For black holes, the radius of the black hole is determined by its mass and is called the Schwarzschild radius. For example, if an object has a mass equal to the mass of our planet, then the Schwarzschild radius in this case is 9 mm. Our main star has a radius of 3 km. The average density of a black hole formed in place of a star with a mass of 10⁸ solar masses will be close to the density of water. The radius of such a formation will be 300 million kilometers.

It is likely that such giant black holes are located at the center of galaxies. To date, 50 galaxies are known, in the center of which there are huge temporal and spatial wells. The mass of such giants is billions of the mass of the Sun. One can only imagine what a colossal and monstrous force of attraction such a hole has.

As for small holes, these are mini-objects, the radius of which reaches negligible values, only 10¯¹² cm. The mass of such crumbs is 10¹⁴g. Such formations arose at the time of the Big Bang, but over time they increased in size and today flaunt in outer space as monsters. Scientists are now trying to recreate the conditions under which small black holes formed in terrestrial conditions. For these purposes, experiments are carried out in electron colliders, through which elementary particles are accelerated to the speed of light. The first experiments made it possible to obtain quark-gluon plasma in laboratory conditions - matter that existed at the dawn of the formation of the Universe. Such experiments allow us to hope that a black hole on Earth is just a matter of time. Another thing is whether such an achievement of human science will not turn into a disaster for us and for our planet. By creating an artificial black hole, we can open Pandora's box.

Recent observations of other galaxies have allowed scientists to discover black holes whose dimensions exceed all imaginable expectations and assumptions. The evolution that occurs with such objects allows us to better understand why the mass of black holes grows and what its real limit is. Scientists have concluded that all known black holes grew to their actual size within 13-14 billion years. The difference in size is explained by the density of the surrounding space. If a black hole has enough food within the reach of its gravitational forces, it grows by leaps and bounds, reaching a mass of hundreds or thousands of solar masses. Hence the gigantic size of such objects located in the center of galaxies. A massive cluster of stars, huge masses of interstellar gas provide abundant food for growth. When galaxies merge, black holes can merge together to form a new supermassive object.

Judging by the analysis of evolutionary processes, it is customary to distinguish two classes of black holes:

• objects with a mass 10 times the solar mass;
• massive objects whose mass is hundreds of thousands, billions of solar masses.

There are black holes with an average intermediate mass equal to 100-10 thousand solar masses, but their nature still remains unknown. There is approximately one such object per galaxy. The study of X-ray stars made it possible to find two medium-mass black holes at a distance of 12 million light years in the M82 galaxy. The mass of one object varies in the range of 200-800 solar masses. The other object is much larger and has a mass of 10-40 thousand solar masses. The fate of such objects is interesting. They are located near star clusters, gradually being attracted to the supermassive black hole located in the central part of the galaxy.

Our planet and black holes

Despite the search for clues about the nature of black holes, the scientific world is concerned about the place and role of the black hole in the fate of the Milky Way galaxy and, in particular, in the fate of planet Earth. The fold of time and space that exists in the center of the Milky Way gradually absorbs all existing objects around it. Millions of stars and trillions of tons of interstellar gas have already been swallowed up in the black hole. Over time, the turn will come to the Cygnus and Sagittarius arms, in which the Solar system is located, covering a distance of 27 thousand light years.

The other closest supermassive black hole is located in the central part of the Andromeda galaxy. It is about 2.5 million light years from us. Probably, before our object Sagittarius A* engulfs its own galaxy, we should expect a merger of two neighboring galaxies. Accordingly, two supermassive black holes will merge into one, terrible and monstrous in size.

Small black holes are a completely different matter. To swallow planet Earth, a black hole with a radius of a couple of centimeters is enough. The problem is that, by its nature, a black hole is a completely faceless object. No radiation or radiation emanates from its belly, so it is quite difficult to notice such a mysterious object. Only at close range can you detect the bending of the background light, which indicates that there is a hole in space in this region of the Universe.

To date, scientists have determined that the closest black hole to Earth is the object V616 Monocerotis. The monster is located 3000 light years from our system. This is a large formation in size, its mass is 9-13 solar masses. Another nearby object that poses a threat to our world is the black hole Gygnus X-1. We are separated from this monster by a distance of 6000 light years. The black holes discovered in our neighborhood are part of a binary system, i.e. exist in close proximity to the star feeding the insatiable object.

Conclusion

The existence of such mysterious and mysterious objects in space as black holes certainly forces us to be on our guard. However, everything that happens to black holes happens quite rarely, given the age of the Universe and the vast distances. For 4.5 billion years, the solar system has been at rest, existing according to the laws known to us. During this time, nothing like this, neither a distortion of space nor a fold of time, appeared near the Solar System. There are probably no suitable conditions for this. The part of the Milky Way in which the Sun star system resides is a calm and stable area of ​​space.

Scientists admit that the appearance of black holes is not accidental. Such objects play the role of orderlies in the Universe, destroying excess cosmic bodies. As for the fate of the monsters themselves, their evolution has not yet been fully studied. There is a version that black holes are not eternal and at a certain stage may cease to exist. It is no longer a secret that such objects represent powerful sources of energy. What kind of energy it is and how it is measured is another matter.

Through the efforts of Stephen Hawking, science was presented with the theory that a black hole still emits energy while losing its mass. In his assumptions, the scientist was guided by the theory of relativity, where all processes are interrelated with each other. Nothing just disappears without appearing somewhere else. Any matter can be transformed into another substance, with one type of energy moving to another energy level. This may be the case with black holes, which are a transition portal from one state to another.

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