When the black hole First, let's describe this object. Black holes in the galaxy
A star can turn into a black hole by the end of its life. During this transformation, the star is compressed very strongly, while its mass is conserved. The star turns into a small but very heavy ball. If we assume that our planet Earth becomes a black hole, then its diameter in this state will be only 9 millimeters. But the Earth will not be able to turn into a black hole, because completely different reactions take place in the core of planets, not the same as in stars.
So strong compression and the compaction of the star comes from the fact that under the influence of thermal nuclear reactions in the center of the star, its force of attraction greatly increases and begins to attract the surface of the star to its center. Gradually, the rate at which the star contracts increases and eventually begins to exceed the speed of light. When a star reaches this state, it ceases to glow, because particles of light - quanta - cannot overcome the force of attraction. A star in this state ceases to emit light, it remains "inside" the gravitational radius - the boundary within which all objects are attracted to the surface of the star. Astronomers call this boundary the event horizon. And beyond this boundary, the force of attraction black hole decreases. Since light particles cannot overcome the gravitational boundary of a star, a black hole can only be detected using instruments, for example, if for some unknown reason a spaceship or another body - a comet or an asteroid - starts to change its trajectory, then most likely it came under the influence of the gravitational forces of a black hole . A controlled space object in such a situation must urgently turn on all the engines and leave the zone of dangerous attraction, and if there is not enough power, then it will inevitably be swallowed up by a black hole.
If the Sun could turn into a black hole, then the planets solar system would be inside the gravitational radius of the Sun and it would attract and absorb them. Luckily for us, this won't happen. only very large, massive stars can turn into a black hole. The sun is too small for that. In the process of evolution, the Sun will most likely become an extinct black dwarf. Other black holes that are already in space are not dangerous for our planet and earthly spacecraft - they are too far from us.
In the popular series "The Big Bang Theory", which you can watch, you will not learn the secrets of the creation of the Universe or the causes of black holes in space. The main characters are passionate about science and work in the department of physics at the university. They constantly get into various ridiculous situations that are fun to watch.
Black holes have always been one of the most interesting objects of observation for scientists. Being the largest objects in the Universe, they are at the same time inaccessible and completely inaccessible to humanity. It will be a long time before we learn about the processes that occur near the "point of no return". What is a black hole in terms of science?
Let's talk about the facts that nevertheless became known to researchers as a result of lengthy work..
1. Black holes are not actually black.
Since black holes radiate electromagnetic waves, they may not look black, but rather quite colorful. And it looks very impressive.
2. Black holes don't suck in matter.
Among ordinary mortals, there is a stereotype that a black hole is a huge vacuum cleaner that pulls the surrounding space into itself. Let's not be dummies and try to figure out what it really is.
In general, (without going into the complexity quantum physics and astronomical research) a black hole can be represented as a cosmic object with a greatly overestimated gravitational field. For example, if there were a black hole of the same size in place of the Sun, then ... nothing would happen, and our planet would continue to rotate in the same orbit. Black holes "absorb" only parts of the matter of stars in the form of a stellar wind inherent in any star.
3. Black holes can spawn new universes
Of course, this fact sounds like something out of science fiction, especially since there is no evidence for the existence of other universes. Nevertheless, such theories are being studied quite closely by scientists.
If to speak plain language, then if at least one physical constant in our world changed by a small amount, we would lose the possibility of existence. The singularity of black holes cancels the usual laws of physics and can (at least in theory) give rise to a new universe that differs in one way or another from ours.
4. Black holes evaporate over time
As mentioned earlier, black holes absorb stellar wind. In addition, they slowly but surely evaporate, that is, they give up their mass to the surrounding space, and then disappear altogether. This phenomenon was discovered in 1974 and named Hawking radiation, in honor of Stephen Hawking, who made this discovery to the world. 
5. The answer to the question “what is a black hole” was predicted by Karl Schwarzschild
As you know, the author of the theory of relativity associated with - Albert Einstein. But the scientist did not pay due attention to the study of celestial bodies, although his theory could and moreover predicted the existence of black holes. Thus, Karl Schwarzschild became the first scientist to apply general theory relativity to justify the existence of a "point of no return". 
Interestingly, this happened in 1915, just after Einstein published his general theory of relativity. It was then that the term "Schwarzschild radius" appeared - roughly speaking, this is the amount of force with which it is necessary to compress an object so that it turns into a black hole. However, this is not an easy task. Let's see why.
The fact is that in theory any body can become a black hole, but under the influence of a certain degree of compression on it. For example, a peanut fruit could become a black hole if it had the mass of the planet Earth ...
Interesting fact: Black holes are the only cosmic bodies of their kind that have the ability to attract light by gravity.
6. Black holes warp space around them.
Imagine the entire space of the universe in the form of a vinyl record. If you put a hot object on it, it will change its shape. The same thing happens with black holes. Their ultimate mass attracts everything, including rays of light, due to which the space around them curves.
7. Black holes limit the number of stars in the universe
.... After all, if the stars are lit -
Does that mean anyone needs it?
V.V. Mayakovsky
Usually fully formed stars are a cloud of cooled gases. The radiation from black holes does not allow gas clouds to cool, and therefore prevents the formation of stars.
8. Black holes are the most advanced power plants.
Black holes produce more energy than the Sun and other stars. The reason for this is the matter around it. When matter crosses the event horizon high speed, it heats up in the orbit of a black hole to the limit high temperature. This phenomenon is called blackbody radiation.
Interesting fact: In the process of nuclear fusion, 0.7% of matter becomes energy. Near a black hole, 10% of matter turns into energy!
9. What happens if you fall into a black hole?
Black holes "stretch" the bodies that are next to them. As a result of this process, objects begin to resemble spaghetti (there is even a special term - "spaghetti" =).
Although this fact may seem comical, it has its own explanation. This happens thanks to physical principle attraction forces. Let's take the human body as an example. While on the ground, our legs are closer to the center of the Earth than our head, so they are attracted more strongly. On the surface of a black hole, the legs are attracted to the center of the black hole much faster, and therefore top part the body simply does not keep up with them. Conclusion: spaghettification!
10. Theoretically, any object can become a black hole
And even the sun. The only thing that keeps the sun from turning into absolutely black body is the force of gravity. In the center of a black hole, it is many times stronger than in the center of the Sun. In this case, if our luminary were compressed to four kilometers in diameter, it could well become a black hole (due to the large mass).
But that's in theory. In practice, it is known that black holes appear only as a result of the collapse of super-large stars, exceeding the mass of the Sun by 25-30 times.
11. Black holes slow down time near them.
The main thesis of this fact is that as we approach the event horizon, time slows down. This phenomenon can be illustrated using the "twin paradox", which is often used to explain the provisions of the theory of relativity.
The main idea is that one of the twin brothers flies into space, while the other remains on Earth. Returning home, the twin discovers that his brother has aged more than he, because when moving at a speed close to the speed of light, time begins to go slower. 
A black hole is a special region in space. This is a kind of accumulation of black matter, capable of drawing in and absorbing other objects of space. The phenomenon of black holes is still not . All available data are just theories and assumptions of scientific astronomers.
The name "black hole" was introduced by the scientist J.A. Wheeler in 1968 at Princeton University.
There is a theory that black holes are stars, but unusual, like neutron ones. A black hole is - - because it has a very high luminosity density and sends absolutely no radiation. Therefore, it is invisible neither in infrared, nor in x-rays, nor in radio rays.
This situation French astronomer P. Laplace still 150 years before black holes. According to his arguments, if it has a density equal to the density of the Earth, and a diameter exceeding the diameter of the Sun by 250 times, then it does not allow the rays of light to propagate through the Universe due to its gravity, and therefore remains invisible. Thus, it is assumed that black holes are the most powerful radiating objects in the universe, but they do not have a solid surface.
Properties of black holes
All alleged properties of black holes are based on the theory of relativity, derived in the 20th century by A. Einstein. Any traditional approach to the study of this phenomenon does not provide any convincing explanation for the phenomenon of black holes.
The main property of a black hole is the ability to bend time and space. Any moving object that has fallen into its gravitational field will inevitably be drawn inward, because. in this case, a dense gravitational vortex, a kind of funnel, appears around the object. At the same time, the concept of time is also transformed. Scientists, by calculation, still tend to conclude that black holes are not celestial bodies in the conventional sense. These are really some kind of holes, wormholes in time and space, capable of changing and compacting it.
Black hole - enclosed area space into which matter is compressed and from which nothing can escape, not even light.
According to the calculations of astronomers, with the powerful gravitational field that exists inside black holes, not a single object can remain unharmed. It will instantly be torn into billions of pieces before it even gets inside. However, this does not exclude the possibility of exchanging particles and information with their help. And if a black hole has a mass at least a billion times greater than the mass of the Sun (supermassive), then it is theoretically possible for objects to move through it without being torn apart by gravity.
Of course, these are only theories, because the research of scientists is still too far from understanding what processes and possibilities hide black holes. It is possible that something similar could happen in the future.
You must have seen sci-fi movies, where the heroes, traveling in space, end up in another universe? Most often, mysterious cosmic black holes become the door to another world. It turns out that there is some truth in these stories. So scientists say.
When the very center of a star, its core, runs out of fuel, all its particles become very heavy. And then, the whole planet collapses into the center of itself. This causes a powerful shock wave that breaks the outer, still burning, shell of the star and it explodes in a blinding flash. One teaspoon of a small extinct star weighs several billion tons. Such a star is called neutron. And if a star is twenty to thirty times larger than our sun, its destruction leads to the formation of the strangest phenomenon in the universe - black hole.
The attraction in a black hole is so strong that it captures planets, gases, and even light. Black holes are invisible, they can only be found by a huge funnel of cosmic bodies flying into it. Only around some holes a bright glow is formed. After all, the rotation speed is very high, particles of celestial bodies heat up to millions of degrees and glow brightly
cosmic black hole attracts all objects, twisting them in a spiral. When approaching a black hole, objects begin to accelerate and stretch out like huge spaghetti. The force of attraction gradually grows and at some point becomes so monstrous that nothing can overcome it. This boundary is called the event horizon. Any event that happens behind it will remain invisible forever.
Scientists suggest that black holes can create tunnels in space - " wormholes". If you get into it, you can go through space and find yourself in another Universe, where there is an opposite white hole. Maybe someday this secret will be revealed on powerful spaceships people will travel in other dimensions.
The boundless Universe is full of secrets, riddles and paradoxes. Although modern science made a huge leap forward in space exploration, much in this endless 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 such objects, the existence of which we can only guess. 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 atomic scientists have been struggling with this issue for more than a dozen years. What is a black hole in space? What is the nature of such objects?
Talking about black holes in simple terms
To imagine what a black hole looks like, it is enough to see the tail of a train leaving the tunnel. The signal lights on the last car as the train deepens into the tunnel will decrease in size until they completely disappear from view. In other words, these are objects where, due to the monstrous attraction, even light disappears. Elementary particles, electrons, protons and photons are not able to overcome the invisible barrier, they fall into the black abyss of nothingness, therefore such a hole in space was called black. There is not the slightest bright spot inside it, solid blackness and infinity. What lies on the other side of a black hole is unknown.
This space vacuum cleaner has a colossal force of attraction and is able to absorb an entire galaxy with all clusters and superclusters of stars, with nebulae and dark matter to boot. How is this possible? It remains only to guess. The laws of physics known to us in this case are cracking at the seams and do not provide an explanation for the ongoing processes. The essence of the paradox lies in the fact that in a given section of the Universe, the gravitational interaction of bodies is determined by their mass. The process of absorption by one object of another is not affected by their quality and quantitative composition. Particles, having reached a critical amount in a certain area, enter another level of interaction, where gravitational forces become forces of attraction. The body, object, substance or matter under the influence of gravity begins to shrink, reaching a colossal density.
Approximately such 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 called neutrons. The density of this substance is enormous. A particle of matter the size of a piece of refined sugar has a weight of billions of tons. Here it would be appropriate to recall the general theory of relativity, where space and time are continuous quantities. Therefore, 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 itself change, twisting into a space-time funnel. Reaching the bottom of this funnel, any matter decays into quanta. What is on the other side of the black hole, this giant hole? Perhaps there is another other space where other laws operate and time flows in the opposite direction.
In the context of the theory of relativity, the theory of a black hole is as follows. The point in space, where gravitational forces have compressed any matter to microscopic dimensions, has a colossal force of attraction, the magnitude of which increases to infinity. A wrinkle of time appears, and space is curved, closing in one point. Objects swallowed by the black hole are unable to resist the force of retraction of this monstrous vacuum cleaner on their own. Even the speed of light possessed by quanta does not allow elementary particles to overcome the force of attraction. Any body that gets to such a point ceases to be a material object, merging with the space-time bubble.
Black holes in terms of science
If you ask yourself, how do black holes form? There will be no single answer. There are a lot of paradoxes and contradictions in the Universe that cannot be explained from the point of view of science. 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 ongoing processes by 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 is scientific name— gravitational collapse. The term "black hole" first appeared in the scientific community in 1968, when the American astronomer and physicist John Wheeler tried to explain the state of stellar collapse. According to his theory, in place of a massive star that has undergone gravitational collapse, a spatial and temporal gap appears, in which an ever-growing compression acts. Everything that the star consisted of goes inside itself.
Such an explanation allows us to conclude that the nature of black holes is in no way related to the processes occurring in the Universe. Everything that happens inside this object does not affect the surrounding space in any way 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 form 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. A curious fact is that black holes can appear at any point in outer space, where they are created for this. ideal conditions. Such a wrinkle of time and space levels out the huge speeds with which the stars rotate and move in the space of the galaxy. Time in a black hole flows in another dimension. Within this region, no laws of gravity can be interpreted from the point of view 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 others space objects, which are affected by gravitational fields. The whole picture of the struggle for life and death takes place on the border of a black hole, which is covered by a membrane. This imaginary surface of the funnel is called the "event horizon". Everything that we see up to this limit is tangible and material.
Scenarios for the formation of black holes
Developing the theory of John Wheeler, we can conclude that the mystery of black holes is 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 from the tight grip of gravity. There is a limit to the size to which a star can shrink to give 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 circumstantial evidence for the presence of black holes in a dozen x-ray binary stars. An X-ray star, pulsar or burster does 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, makes it possible to trace the formation of these curious objects.
Based on research and theoretical assumptions, there are four scenarios for the formation of black stars in science today:
- 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;
- the formation of quantum black holes.
The first scenario is the most realistic, but the number of black stars with which we are familiar 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 prime example- a supermassive black hole Sagittarius A *, sheltered in the center of our galaxy. The mass of this object is 3.7 solar masses. The mechanism of this script is similar to the script gravitational collapse with the only difference being that it is not the star that undergoes the collapse, 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 breaks up into quanta, forming a black hole. However, this theory is questionable, since Columbia University astronomers recently identified satellites of the Sagittarius A* black hole. They turned out to be a lot of small black holes, which probably formed in a different way.
The third scenario is more theoretical and is related to the existence of the Big Bang theory. At the time of the formation of the Universe, part of the matter and gravitational fields fluctuated. In other words, the processes took a different path, not related to the known processes of quantum mechanics and nuclear physics.
The last scenario is focused on physics nuclear explosion. In clumps of matter, in the process of 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, how fast do they grow? The dimensions 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 luminary has a radius of 3 km. The average density of a black hole formed in the place of a star with a mass of 10⁸ solar masses will be close to the density of water. The radius of such formation will be 300 million kilometers.
It is likely that such giant black holes are located in the center of galaxies. To date, 50 galaxies are known, in the center of which there are huge time and space 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 possesses.
As for small holes, these are mini-objects, the radius of which reaches negligible values, only 10¯¹² cm. The mass of such a crumb is 10¹⁴g. Similar formations arose at the time of the Big Bang, but over time increased in size and today flaunt in outer space as monsters. The conditions under which the formation of small black holes took place, scientists today are trying to recreate in terrestrial conditions. For these purposes, experiments are carried out in electron colliders, through which elementary particles accelerate 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 a matter of time. Another thing is whether such an achievement of human science will turn into a catastrophe for us and for our planet. By artificially creating a black hole, we can open Pandora's box.
Recent observations of other galaxies have allowed scientists to discover black holes whose dimensions exceed all conceivable expectations and assumptions. The evolution that occurs with such objects makes it possible to better understand why the mass of black holes grows, what is its real limit. Scientists have come to the conclusion that all known black holes have grown to their real sizes within 13-14 billion years. The difference in size is due to the density of the surrounding space. If a black hole has enough food within reach of the forces of gravity, it grows by leaps and bounds, reaching a mass of hundreds and thousands of solar masses. Hence and giant size such objects located at the center of galaxies. A massive cluster of stars, huge masses of interstellar gas are abundant food for growth. When galaxies merge, black holes can merge together, forming 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, the mass of which 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 is still unknown. There is approximately one such object per galaxy. The study of X-ray stars made it possible to find two average 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. Another 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 a 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, scientific world worries about the place and role of the black hole in the fate of the Milky Way galaxy and, in particular, in the fate of the planet Earth. The fold of time and space that exists in the center milky way, gradually absorbs all existing objects around. Millions of stars and trillions of tons of interstellar gas have already been absorbed into the black hole. Over time, the turn will reach the arms of Cygnus and Sagittarius, in which the solar system is located, having traveled a distance of 27 thousand light years.
The other nearest supermassive black hole is in the central part of the Andromeda galaxy. This is about 2.5 million light years from us. Probably, before the time when our object Sagittarius A * absorbs its own galaxy, we should expect a merger of two neighboring galaxies. Accordingly, there will be a merger of two supermassive black holes into one, terrible and monstrous in size.
A completely different matter is small black holes. To absorb the planet Earth, a black hole with a radius of a couple of centimeters is enough. The problem is that, by nature, a black hole is a completely faceless object. No radiation or radiation comes from her womb, so it is quite difficult to notice such a mysterious object. Only with close range you can detect the curvature of the background light, which indicates that in this region of the universe there is a hole in space.
To date, scientists have determined that the closest black hole to Earth is V616 Monocerotis. The monster is located 3000 light years from our system. In terms of size, this is a large formation, its mass is 9-13 solar masses. Another nearby object that threatens our world is the black hole Gygnus X-1. With this monster we are separated by a distance of 6000 light years. The black holes revealed in our neighborhood are part of a binary system, i.e. exist in close proximity to a star that feeds an insatiable object.
Conclusion
The existence in space of such mysterious and mysterious objects as black holes, of course, makes us be on our guard. However, everything that happens to black holes happens quite rarely, given the age of the universe and huge 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 of the kind, neither the distortion of space, nor the fold of time, appeared near the solar system. Probably, there are no suitable conditions for this. That part of the Milky Way, in which the Sun star system resides, is a calm and stable section of space.
Scientists admit the idea that the appearance of black holes is not accidental. Such objects play the role of orderlies in the Universe, destroying the excess of 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 certain stage may cease to exist. It is no longer a secret to anyone that such objects are the most 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 radiates energy, losing its mass. In his assumptions, the scientist was guided by the theory of relativity, where all processes are interconnected with each other. Nothing just disappears without appearing somewhere else. Any matter can be transformed into another substance, while one type of energy goes to another energy level. This may be the case with black holes, which are a transitional portal from one state to another.
If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.