Children about the black hole. What are black holes and how are they formed?

The worst place.

There is no more mysterious and frightening object in space than a black hole.
One phrase already evokes unaccountable fear: it paints an image of an all-consuming abyss. Not only ordinary people are shy before her, but astrophysicists are also in awe. "Of all creations human mind: from mythological unicorns and dragons to hydrogen bomb, perhaps the most fantastic is a black hole. A hole in space with very specific edges, into which anything can fall and from which nothing can get out. A hole in which the gravitational force is so strong that even light is captured and trapped within it. A hole that bends space and distorts the flow of time. Like unicorns and dragons, black holes seem more like attributes of science fiction or ancient myths than real objects. However, the laws of physics inevitably imply the existence of black holes. In our Galaxy alone, there are perhaps millions of them,” said the famous scientist, head of the department at the California Institute of Technology (USA), member of the US National Academy of Sciences, member of the NASA Scientific Council, Kip Stephen Thorne, about black holes.
In addition to their fantastic power, black holes have amazing property change space and time within yourself. They first twist into a kind of funnel, and then, having crossed a certain boundary in the depths of the hole, they disintegrate into quanta. Inside the black hole, beyond the edge of this peculiar gravitational abyss, from where there is no exit, amazing physical processes flow and new laws of nature appear.
According to many experts, black holes are the most enormous sources of energy in the Universe. We probably see them in distant quasars, in the exploding cores of galaxies. It is assumed that black holes will become energy sources for humanity in the future.

The end of the world is here.

How do black holes form? According to astrophysicists, most of them arise after the death of large stars. If a star has twice the mass of the Sun, then towards the end of its life the star may explode as a supernova. But if the mass of the material left after the explosion still exceeds two solar masses, then the star should shrink into a tiny dense body, since gravitational forces completely suppress any internal resistance to compression. Scientists believe that it is at this moment that a catastrophic gravitational collapse leads to the emergence of a black hole. They believe that with the end of thermonuclear reactions, the star can no longer be in a stable state. Then for a massive star there remains one inevitable path - the path of general and complete compression, turning it into an invisible black hole.
Why are they invisible?
“The very name “black holes” suggests that this is a class of objects that cannot be seen,” explains the head of the radio astronomy department of the State Astronomical Institute. Sternberg candidate of physical and mathematical sciences Valentin Esipov. - Their gravitational field is so strong that if somehow it was possible to get close to a black hole and direct the beam of the most powerful searchlight away from its surface, then it would be impossible to see this searchlight even from a distance not exceeding the distance from the Earth to the Sun.
Indeed, even if we could concentrate all the light of the Sun in this powerful spotlight, we would not see it, since the light would not be able to overcome the influence of the black hole’s gravitational field on it and leave its surface. That is why such a surface is called the absolute event horizon. It represents the boundary of a black hole. What is hiding there, abroad?

Let's walk to Hell.

The most interesting description The “insides” of the black hole belong to the already mentioned American physicist and astronomer Kip Stephen Thorne. “Imagine yourself as the captain of a large star-class spaceship,” the scientist suggests in his book “Journey Among Black Holes.” - On the instructions of the Geographical Society, you have to explore several black holes located at great distances from each other in interstellar space, and use radio signals to transmit a description of your observations to Earth.

Having been on the road for 4 years and 8 months, your ship slows down in the vicinity of the black hole closest to Earth, called Hades (Hell) and located near the star Vega. The presence of a black hole is noticeable on the television screen: hydrogen atoms scattered in interstellar space are drawn inside by its gravitational field. Everywhere you see their movement: slow away from the hole and increasingly faster as you approach it. It's like the falling water at Niagara Falls, except that the atoms are falling not only from the east, but also from the west, north, south, above and below - everywhere. If you don't do anything, you too will be pulled in.

So, you have to carefully move the starship from a free-fall trajectory into a circular orbit around the black hole (similar to the orbits of artificial satellites orbiting the Earth) so that the centrifugal force of your orbital motion compensates for the gravitational force of the black hole. Feeling safe, you turn on the ship's engines and prepare to explore the black hole.

First of all, through telescopes you observe electromagnetic radiation emitted by falling hydrogen atoms. Far from the black hole, they are so cold that they only emit radio waves. But closer to the hole, where the atoms fall faster, they collide with each other from time to time, heat up to several thousand degrees and begin to emit light. Even closer to the black hole, moving much faster, they heat up to several million degrees due to collisions and emit x-ray radiation.

As you point your telescopes "inward" and continue to approach the black hole, you will "see" gamma rays emitted by hydrogen atoms heated to even higher temperatures. high temperatures. And finally, in the very center you will find the dark disk of the black hole itself.
Your next step is to carefully measure the length of the ship's orbit. This is approximately 1 million km, or half the length of the Moon's orbit around the Earth. Then you look at the distant stars and see that they are moving like you. By observing their apparent movement, you find out that you need 5 minutes. 46 s to complete one revolution around a black hole. This is your “orbital period”.

Knowing its orbital period and the length of its orbit, you can calculate the mass of the Hades (Hell) black hole. It will be 10 times larger than the sun. This is, in essence, the total mass accumulated in a black hole over its entire history and includes the mass of the star, as a result of the collapse of which about 2 billion years ago the black hole was formed, the mass of all interstellar hydrogen drawn into it since its birth, and also the mass of all the asteroids and stray starships that fell on it.

Most interesting are the properties of its surface, or horizon - the boundary due to which anything that falls into the hole cannot return. A boundary beyond which a starship and even any type of radiation cannot escape: radio waves, light, x-rays or gamma rays...
Although you can calculate all the properties of the outside of a black hole from the mass and angular momentum of a black hole, you cannot learn anything about its interior. It may have a disordered structure and be highly asymmetrical. All this will depend on the details of the collapse that resulted in the formation of the black hole, as well as on the characteristics of the subsequent retraction of interstellar hydrogen. So the diameter of the hole simply cannot be calculated.

Once you have these results, you can explore the vicinity of the black hole's horizon...

After saying goodbye to the team, you climb into the descent module and leave the ship, initially remaining in the same circular orbit, continues physicist Thorne. - Then, turning on the rocket engine, brake slightly to slow down your orbital movement. At the same time, you begin to spiral closer to the horizon, moving from one circular orbit to another. Your goal is to enter a circular orbit with a perimeter slightly greater than the length of the horizon. As you move in a spiral, the length of your orbit gradually decreases - from 1 million km to 500 thousand, then to 100 thousand, 90 thousand, 80 thousand. And then something strange begins to happen.

Being in a state of weightlessness, you are suspended in your apparatus, let’s say, with your feet to the black hole, and your head to the orbit of your ship and the stars. But gradually you begin to feel that someone is pulling you down by your legs and up by your head. You realize that the reason is the gravity of the black hole: the legs are closer to the hole than the head, so they are attracted more strongly. The same is true, of course, on Earth, but the difference in the attraction of the legs and head there is negligible, so no one notices it. Moving in an orbit 80 thousand km long above a black hole, you feel this difference quite clearly - the difference in gravity will be 1/8 of the earth's gravity (1/8 g). The centrifugal force caused by your orbital motion will compensate for the pull of the hole at the center point of your body, allowing you to float freely in zero gravity, but your legs will be subject to an excess pull of 1/16 g, while your head will be pulled weakly, and the centrifugal force will pull it up with exactly the same additional acceleration - 1/16 g.
Somewhat puzzled, you continue to move along the twisting spiral, but surprise quickly gives way to concern: as the size of the orbit decreases, the forces stretching you will increase more and more rapidly. With an orbit length of 64 thousand km, the difference will be 1/4 g, at 51 thousand km - 1/2 g, and at 40 thousand km it will reach the full weight of the Earth. Grinding your teeth from the effort, you continue to move in a spiral. With an orbit length of 25 thousand km, the stretching force will be 4 g, i.e. will be four times your weight in terrestrial conditions, and at 16 thousand km - 16 g. You can no longer stand in an upright position. You try to solve this problem by curling up and pulling your legs towards your head, thereby reducing the difference in force. But they are already so large that they will not allow you to bend - they will again stretch you vertically (along the direction radial to the black hole).

No matter what you do, nothing will help. And if the spiral movement continues, your body will not be able to withstand it - it will be torn apart. So, there is no hope of reaching the vicinity of the horizon...
Frustrated, in terrible pain, you stop your descent and transfer the device first into a circular orbit, and then begin to carefully and slowly move along an expanding spiral, moving into increasingly larger circular orbits until you reach the starship.

The story told by Thorne still sounds like science fiction. And it is designed for the time when man will achieve such success in the development of technology and technology that intergalactic flights and the construction of ring worlds around black holes will become a reality. And according to the most optimistic forecasts of futurologists, this will become possible no earlier than in 50 years.

No guys, it's not like that...

It must be admitted that many scientists still deny the existence of black holes. After all, their discovery and study occurs at the tip of the pen. And recently, an even more unexpected suggestion appeared that black holes are not holes at all, but some objects more similar in nature to bubbles of Bose-Einstein condensate (an aggregate state of matter, the basis of which is bosons, cooled to temperatures close to absolute zero). This new hypothesis put forward by researcher Emil Mottola from the Theoretical Division of Los Alamos National Laboratory along with co-author Pavel Mazur from South Carolina State University in the USA.

The researchers' explanation makes a dramatic difference A New Look on the nature of black holes, which appear not as "holes" in space where matter and light inexplicably disappear into the event horizon, but rather as spherical voids surrounded by a special form of matter never before known on Earth. Mazur and Mottola call these objects not black holes, but gravitational stars.

Inside a gravitational star, space and time are reversed, just as in the black hole model.
Mottola and Mazur even suggest that the Universe in which we live may be inner shell giant gravitational star.

>Black holes

What's happened black hole– explanation for children: description with photos, how to find the Universe in space, how stars appear, the death, supermassive black holes of galaxies.

For the little ones parents or At school must explain, what to perceive a black hole as empty place- a grave mistake. On the contrary, an incredible amount of matter is concentrated in it, which is confined in a small space. To explanation for children was more colorful, just imagine if you took a star 10 times more massive than the Sun and tried to squeeze it into an area the size of New York City. Due to this pressure, the gravitational field becomes so strong that no one, not even a light beam, can escape. With the development of technology, NASA is able to learn more and more about these mysterious objects.

Begin explanation for children This is possible because the term “black hole” did not exist until 1967 (introduced by John Wheeler). But before this, for several centuries it was mentioned about the existence of strange objects that, due to their density and massiveness, do not release light. They were even predicted by Albert Einstein in general theory relativity. She proved that when a massive star dies, a small dense core remains. If a star is three times the mass of the sun, then gravity overcomes other forces, and we get a black hole.

Of course it's important explain to the children that researchers are unable to observe these features directly (telescopes only detect light, X-rays and other forms of electromagnetic radiation), so there is no need to wait for a photo of the black hole. But it is possible to calculate their location and even determine their size due to the influence they have on surrounding objects. For example, if it passes through a cloud of interstellar matter, then in the process it will begin to draw matter inward - accretion. The same thing will happen if a star passes nearby. True, a star can explode.

At the moment of attraction, the substance heats up and accelerates, releasing x-rays into space. Recent discoveries have spotted several powerful bursts of gamma rays, demonstrating that the hole is devouring nearby stars. At this moment, they stimulate the growth of some and stop others.

The death of a star is the beginning of a black hole

Most black holes arise from the leftover material of dying large stars (supernova explosions). Smaller stars become dense neutron stars, which lack the massiveness to trap light. If the mass of a star is 3 times greater than that of the Sun, then it becomes a candidate for a black hole. Important explain to the children one oddity. When a star collapses, its surface approaches an imaginary surface (event horizon). Time on the star itself becomes slower than that of the observer. When the surface reaches the event horizon, time freezes and the star can no longer collapse - a frozen, collapsing object.

Larger black holes can appear after a stellar collision. After its launch in December 2004, the NASA telescope was able to detect strong, fleeting flashes of light - gamma rays. Chandra and Hubble then collected data on the event and realized that these flares could be the result of a collision between a black hole and a neutron star, which creates a new black hole.

Although in the process of education children And parents We've already figured it out, but one thing remains a mystery. The holes seem to exist on two different scales. There are many black holes - the remains of massive stars. Typically, they are 10-24 times more massive than the Sun. Scientists constantly see them if an alien star comes critically close. But most black holes exist in isolation and simply cannot be seen. However, judging by the number of stars large enough to be black hole candidates, there must be tens of millions of billions of such black holes in the Milky Way.

There are also supermassive black holes, which are a million or even a billion times larger than our Sun. It is believed that such monsters live in the centers of almost all large galaxies (including ours).

For the little ones it will be interesting to know that for a long time Scientists believed that there was no average size for black holes. But data from Chandra, XMM-Newton and Hubble show that they are there.

It is possible that supermassive black holes arise from a chain reaction caused by the collision of stars in compact clusters. Because of this, a lot of massive stars accumulate, which collapse and produce black holes. These clusters then occupy the galactic center, where the black holes merge and become a supermassive member.

You might already understand that you won't be able to admire the black hole in high quality online because these objects do not release light. But children will be interested in studying photographs and diagrams created based on the contact of black holes and ordinary matter.

How not to get lost in the diversity of the flow of words from little whys? After all, children are extremely curious and want to know everything in the world. It is worthwhile to properly instill in them knowledge and a love of science, so that in the future it will be easier for them to study, and there will be an interest in new knowledge, especially in such amazing things as space!

1. What is astronomy and space?

First of all, it’s worth starting by telling your child what astronomy is. After all, this is where, in essence, the study of stars and space begins.

Astronomy is a science that deals not only with stars, but also studies space and all the particles that move in the Universe. The scope of its study includes changes and transformations that occur with all celestial bodies, space and time.

By the way, the word "space" has Greek roots and means the orderliness and interconnection of everything that is in the Universe.

2. Solar system.

solar system consists of nine planets and one star. All nine planets revolve around a star called the Sun.

The planets have their own names: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. The very first, Venus, is closest to the sun, the last, Pluto, is farthest from the star. Planet Earth, on which we live, is the third.

In addition to the planets in solar system Many satellites, comets, small planets, asteroids, dust and gas also rotate.

3. Galaxy.

Galaxies- are large star systems in which the stars are kept within their boundaries due to gravity.

Scientists believe that there are billions of galaxies. Therefore, the likelihood that there is some kind of life somewhere on other planets and people in this world are not alone is very high.

All galaxies differ from each other in shape. There are only three shapes: elliptical, spiral and irregular.

By the way, our galaxy is called Milky Way. There are also two other large galaxies nearby called Andromeda and Triangulum. Our galaxy is part of a group of 30 other galaxies.

4. Black holes.

A black hole is a region in space-time that has the property of absorbing nearby objects, even those moving at the speed of light.

To explain to a child the effect of a Black Hole, you can compare it to a vacuum cleaner. The principle of operation is approximately the same, with the only difference being that Black holes do not use suction, but gravity to attract cosmic particles to themselves.

The part is affected by gravity before he even has time to see anything. Scientists carried out all the calculations for the simplest spherically symmetric black holes, the radius of which is equal to the Schwarzschild radius. Black holes, formed during the collapse of stars, have more complex characteristics. However, as the authors note, over time they become more and more...

https://www.site/journal/117634

That is approximately 1.6x10-35 meters. Calculations show that on such a scale the formation of microscopic black holes. Let us recall that according to modern ideas, the lifetime of such objects is extremely short - they evaporate in... Hawking. However, the researchers showed that under their hypothesis black holes may be in some stable state. Calculations show that such black holes will have properties similar to elementary particles. In particular, ...

https://www.site/journal/118249

Narrated at a meeting of the American Astronomical Society. black holes Astronomers believe that some supermassive black holes, located in neighboring galaxies, by at least two times, and maybe four times, ... The discovery could change the understanding of how galaxies first form and what role they play in the universe

. Late last month, a team of researchers led by Andrew Fabian, University of Cambridge...

https://www.site/journal/118608 Reach 400 thousand light years. According to researchers, 10-20 percent of all iron in galaxies can be transferred from place to place. black holes . In addition, scientists have established that emissions from a compact object lead to the formation of hole

gas of colossal voids. The sizes of some of them reach 670 thousand light years. Especially for studying...

https://www.site/journal/120495 black holes Currently working in the US, they have proposed a way to create a device whose properties will resemble those of . Such a device should be based on a cylindrical structure, shell and inner part which differ in... absorbed. Authors new job black holes implemented the idea of ​​Russian scientists in practice. To create a microwave

The researchers used metamaterials - special substances that can specifically bend the paths of those passing through them...

https://www.site/journal/121214 black holes Bend, moving in a spiral towards its center - just like , although for completely different reasons. If black hole operates thanks to its colossal force of attraction, a tool invented by Narimanov and Kildishev, ... (Tie Jun Cui) and Qiang Cheng brought it into reality by creating such a simulated “ . In addition, scientists have established that emissions from a compact object lead to the formation of black

", capable of capturing and absorbing microwave radiation. The device is a cylinder consisting of 60 annular layers of porous metamaterials...

https://www.site/journal/121533 black holes That J0005-0006 and J0303-0019 formed shortly after the Big Bang, determining their mass black holes. The more heated dust is in the quasar, the greater the mass black holes(she has a lot of “food” for growth). Masses

J0005-0006 and J0303-0019 turned out to be the smallest of all known quasars in the young Universe. Recently...

https://www.site/journal/124842 black holes Einstein-Rosen. These objects are hypothetical tunnels connecting different regions of space. Poplawski believes that the other end of the wormhole connected to white black holes- a region of space into which nothing can enter). At the same time, conditions arise inside the wormhole that resemble an expanding Universe, similar to the one we observe...

In a new astronomy video lesson, the professor will talk about how black holes are formed and why they are dangerous.

How black holes form

Black holes cannot be touched and you cannot walk through them. Black holes are regions in space-time that form a super-powerful attraction. Attraction bends space and time, which means that inside black hole there are no straight lines, the space is crumpled and intertwined. If a star forms near a black hole, the gravitational forces of the black hole will tear the star apart and it will disappear into the depths of the hole. If something falls into a black hole, it stays there forever. To overcome the powerful attraction of a black hole, it is necessary to develop a speed greater than the speed of light, but this, alas, is impossible. Scientists do not know exactly how supermassive black holes are formed, but with ordinary black holes everything is more or less clear. During the evolution of a star, hydrogen gradually burns out, and accordingly its amount decreases, which leads to the fact that the force of light pressure begins to exceed the force of gravitational compression. The star greatly increases in size and turns into a red giant, which subsequently explodes. After the explosion, compression begins, then the star cools down and becomes not directly visible. But, if the mass of the red giant remnant exceeds the solar mass by 2-2.5 times, then its compression cannot stop, since the gravitational force completely suppresses the resistance to compression, as a result, this remnant is compressed into a dense tiny body, as if closing in on itself. And it is at this moment of gravitational collapse (compression) that black holes are formed. As a result, it turns out that the mass is concentrated in such a small area that even the speed of light is not enough to leave its vicinity. Hence the first part of the name is black, since it can even absorb light. The second part - the hole - means that everything that falls into the region of the black hole becomes forever inaccessible to observation.