A black hole is a region of space-time that nothing, not even light, can leave because of the very strong gravity.
- Is space travel possible through black holes?
- What will happen to objects falling into a black hole, including spaceships, or will gravitational forces tear the ship apart?
- Can we hope that after flying through the hole, the ship will reappear from some other black hole? Perhaps they will move into their own newborn universe, which will arise from our region of the universe?
- How to find a black hole if even light cannot escape from it?
In the center of our Galaxy, a huge black hole was discovered - Sagittarius A, presumably, which is the center around which the Milky Way revolves.
The mass of this supermassive black hole is a million times the mass of our Sun. Near it, a star was found that revolves around a black hole at a speed equal to about 2% of the speed of light, that is, faster than the average electron revolves around a nucleus in an atom.
According to some scientists, black holes are the pinnacle of the evolution of the mind, and esotericists believe that Sagittarius A is God.
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If dust clouds did not cover the center of the galaxy from us, then every night from Earth we would observe a huge fireball in the constellation Sagittarius, which would eclipse the Moon and would be the brightest object in the night sky.
The black hole in the center of the Galaxy has a mass of about 2.5 million solar masses, its radius is about 0.1 of the radius of the orbit of Mercury. This is not the most massive black hole by galactic standards; quasars may contain black holes of several billion solar masses.
The next galactic black hole closest to us is located in the center of the Andromeda galaxy, the galaxy closest to Earth, its mass is 30 million solar masses.
All black holes found in space are spinning rapidly; some rotate at about 1.6 million km / h, as calculated by the Hubble Space Telescope.
In the very center, you can see a flat, rounded core, the dimensions of which are often about a light year across. There is a black hole inside this core.
The "unusualness" of black holes is due to the fact that they have no surface, but there is a so-called "event horizon" - the outer boundary of a black hole, from under which nothing can get back into our Universe.
What is the nature of the appearance of black holes - a region of space-time, from where nothing can fly into infinity?
By producing nuclear fuel, the star can no longer maintain internal pressure, and under the influence of its own gravity it begins to contract. As the star shrinks, the force of gravity on its surface becomes greater. When the radius decreases to 30 km, the speed required for separation will reach the speed of light - 300,000 km / s, after which no light emitted by the star can go to infinity, but will be attracted back by the gravitational field. As a result, a region of space-time is formed around the collapsed star, which nothing can leave. This area is the black hole.
According to the general theory of relativity, in the distant past, there should have been a state of the Universe with infinite density - the Big Bang, which can be considered the beginning of time. If the Universe contracts again, then in the future another state of infinite density should await it - the "big collapse", which will become the end of time. Even if the universe as a whole does not contract, singularities should arise in its limited regions, which will lead to the formation of black holes.
So far, two types of black holes have been discovered. The first type is star-scale black holes. When such holes are formed, gravity destroys the dying star and it explodes inward. Type II black holes are much easier to spot. They are galactic in scale, lurking in the very center of huge galaxies and quasars, and their mass ranges from millions to billions of solar masses.
Scientists don't know what's going on inside the black hole. For the equations of general relativity, there are solutions that allow you to fall into a black hole and exit somewhere else out of the white hole.
Stephen Hawking believes that a white hole is a reversible black hole, an object from which you can exit, but which cannot be entered.
The white hole could be somewhere else in the universe. This would provide an opportunity for fast intergalactic travel. However, these journeys may be too fast. If travel through black holes were possible, then nothing would prevent us from going back before we left.
Astrophysicists believe that black holes are corridors of time. A gravitational field forms around the black hole, in which objects reach the speed of light. Inside black holes, time and space stop functioning and change places, with the result that travel through space becomes travel through time.
For an astronaut who falls into a black hole and falls into a singularity, time is running out. According to his own clock, the falling astronaut reaches the singularity in a finite time. However, in relation to the outside world, his clock runs slower and slower, and, accordingly, it seems to the astronaut that events in the outer world are proceeding faster and faster. As a result, during the fall, he manages to see in an accelerated mode the entire future of the Universe, even if it is infinite.
Albert Einstein explained the possibility of the existence of space-time "portals" in the depths of black holes. Physicists call these portals wormholes because they create a shorter alternate path between two points. These portals are also sometimes called portals or “gates” to other dimensions. Someday they may become a means of travel between different dimensions.
According to one of the hypotheses, “primitive” black holes are the remains of the universe that existed more than 13 billion years ago - before the Big Bang. Scientists believe that these holes may have survived, survive the Big Bang and the formation of a new universe. A "primitive" black hole with a mass of a billion tons (the mass of Mount Fuji), about the size of a proton, would have a temperature of about 120 billion degrees Kelvin, which corresponds to an energy of several tens of millions of electron volts.
The number of black holes in the universe may be two to three times greater than previously thought. Scientists believe that life can exist in them. With the help of the orbiting space telescopes Spitzer and Chandra, astronomers have discovered an unusual space region, where several hundred black holes are located at a relatively small distance from each other. This region is located at a distance of several billion light years from the solar system.
One of the hypotheses of the "end of the world", which is prophesied not only by science fiction writers, but also by scientists - our planet can be swallowed up by a black hole. A supermassive black hole in the center of our Galaxy was discovered due to the disappearance of interstellar matter in it. Could a black hole engulf the solar system? It is unlikely, because it is located very far away.
Stephen Hawking believes that the energy of the universe does not drain irrevocably. Sooner or later, the process of absorption of matter by "black holes" may stop, and then the reverse process will begin - the release of energy and matter outside. Perhaps, starting from this moment, time will flow backward? Perhaps in the future, humanity will be able to see black holes and look into the center of the Milky Way?
“Black holes can become passages at any time. If we had to jump into a black hole, it is assumed that we would appear in another part of the universe and in a different time era … Black holes can be the gateway to Wonderland. But are there Alice and the white rabbits there? - Carl Sagan
Valentina Zhitanskaya