Now scientists have analyzed that there is no black hole in the universe, which needs further proof, but we can have different opinions academically.
First, explain the image of a black hole:
Black holes have great gravity, and even light will be attracted by them. There is a huge gravitational field hidden in the black hole. This gravitational field is so big that nothing, even light, can escape from the palm of the black hole. Black holes don't let anything in their boundaries be seen by the outside world, which is why such objects are called "black holes". We can't observe it through the reflection of light, and we can only indirectly understand the black hole through the objects around us that are affected by it. It is speculated that a black hole is the remnant of a dead star or an explosive air mass, which was produced when a special massive Supergiant star collapsed.
Explain from a physical point of view:
A black hole is actually a planet (similar to a planet), but its density is very, very high. Objects close to it will be bound by its gravity (just like people on earth will not fly away), and no matter how fast they use it, they can't escape. For the earth, flying at the speed of the second universe (1 1.2km/s) can escape from the earth, but for a black hole, its third cosmic velocity is too big to exceed the speed of light, so even the light can't run out, so the incoming light is not reflected, and our eyes can't see anything except black.
Because black holes are invisible, people have always questioned whether black holes really exist. If they really exist, where are they?
The process of a black hole is similar to that of a neutron star. The core of a star shrinks rapidly and explodes violently under its own weight. When all the substances in the core become neutrons, the contraction process stops immediately and is compressed into a dense planet. But in the case of a black hole, because the mass of the star core is so great that the contraction process goes on endlessly, the neutron itself is ground into powder under the attraction of the squeezing gravity itself, and the rest is the matter with unimaginable density. Anything near it will be sucked in, and the black hole will become like a vacuum cleaner.
In order to understand the dynamics of black holes and how they prevent everything inside from escaping from the boundary, we need to discuss general relativity. General relativity is Einstein's theory of gravity, which is applicable to planets, stars and black holes. This theory put forward by Einstein in 19 16 shows how space and time are distorted by the existence of massive objects. In short, general relativity says that matter will bend space, and the bending of space will in turn affect the motion of objects passing through space.
Let's see how Einstein's model works. First of all, consider that time (the three dimensions of space are length, width and height) is the fourth dimension in the real world (although it is difficult to draw another direction other than the usual three directions, you can try to imagine it). Secondly, consider that time and space is the bed surface of a huge taut spring bed for gymnastics performance.
Einstein's theory holds that mass bends time and space. We might as well put a big stone on the bed surface of the spring bed to illustrate this scene: the weight of the stone makes the tight bed surface sink a little. Although the surface of the spring bed is basically flat, its center is still slightly concave. If more stones are placed in the center of the spring bed, it will have a greater effect and make the bed surface sink more. In fact, the more stones there are, the more the spring bed surface bends.
Similarly, massive objects in the universe will distort the structure of the universe. Just as 10 stone can bend the spring bed better than 1 stone, celestial bodies with much greater mass than the sun can bend space better than celestial bodies with mass equal to or less than one sun.
If a tennis ball rolls on a tight spring bed, it will move in a straight line. On the contrary, if it passes through a concave place, its path is arc. Similarly, celestial bodies will continue to move in a straight line when crossing the flat area of time and space, while celestial bodies crossing the curved area will move in a curved trajectory.
Now let's look at the influence of black holes on the surrounding space-time areas. Imagine putting a very heavy stone on a spring bed to represent a very dense black hole. Stones will naturally have a great influence on the bed surface, which will not only bend and sink its surface, but also cause the bed surface to break. A similar situation can also happen in the universe. If there is a black hole in the universe, the cosmic structure there will be torn apart. The rupture of this spatiotemporal structure is called singularity or spatiotemporal singularity.
Now let's see why nothing can escape from a black hole. Just as a tennis ball rolls over a spring bed and falls into a deep hole formed by a big stone, an object passing through a black hole will be caught by its gravity trap. Moreover, saving unlucky objects requires infinite energy.
As we have said, nothing can enter a black hole and escape from it. But scientists believe that black holes will slowly release energy. Hawking, a famous British physicist, proved in 1974 that a black hole has a non-zero temperature, and the temperature is higher than its surroundings. According to the principle of physics, all objects whose temperature is higher than the surrounding environment will release heat, and black holes are no exception. A black hole will emit millions of trillion years of energy, and the energy released by a black hole is called Hawking radiation. When a black hole dissipates all its energy, it will disappear.
Black holes between time and space slow down time, make space elastic, and devour everything that passes through it. 1969, American physicist John Artie Wheeler named this insatiable space "black hole".
We all know that black holes can't reflect light, so we are worried? T: Which hospital is it? Make a copy of 5? ⒐? What's the title? What happened to the bed? Litigation eggplant? 乽 Mü? What is Ye's tomb? What happened? What's wrong with vinegar? Take off the crowbar? ⒚ ⒚ ⒚ ⒚ ⒚ ⒚ ⒚ ⒚ ⒚? Hey?
Hawking pointed out that the radioactive material source of black holes is a kind of solid particles, which are produced in pairs in space and do not follow the usual physical laws. Moreover, after these particles collide, some will disappear into the vast space. Generally speaking, we may not have a chance to see these particles before they disappear.
Hawking also pointed out that when black holes are produced, real particles will appear in pairs accordingly. One of the real particles will be sucked into the black hole, the other will escape, and a bunch of escaped real particles will look like photons. For the observer, seeing the escaping real particles is like seeing the light from a black hole.
So to quote Hawking, "A black hole is not as black as it is supposed to be", it actually emits many photons.
According to Einstein's law of conservation of energy and mass. When an object loses energy, it also loses mass. Black holes also obey the law of conservation of energy and mass. When a black hole loses energy, it doesn't exist. Hawking predicted that the moment the black hole disappeared, there would be a violent explosion, releasing the energy equivalent to millions of hydrogen bombs.
But don't look up with anticipation, thinking that you will see the fireworks show. In fact, after the black hole explodes, the energy released is very large, which is likely to be harmful to the body. Moreover, the energy release time is also very long, some of which will exceed 10 billion years to 20 billion years, which is longer than the history of our universe, and it will take trillions of years for the energy to dissipate completely.
It is easy to imagine a "black hole" as a "big black hole", but it is not. The so-called "black hole" is such a celestial body: its gravitational field is so strong that even light cannot escape.
According to the general theory of relativity, the gravitational field will bend space-time. When the star is large, its gravitational field has little influence on time and space, and the light emitted from a certain point on the surface of the star can be emitted in any direction in a straight line. The smaller the radius of the star, the greater the bending effect on the surrounding space-time, and the light emitted at some angles will return to the surface of the star along the curved space.
When the radius of a star is less than a certain value (called "schwarzschild radius" in astronomy), it will even capture the light emitted from the vertical plane. At this time, the star becomes a black hole. To say it is "black" means that once anything falls in, it can't escape, including light. In fact, black holes are really invisible, which we will talk about later.
So, how are black holes formed? In fact, like white dwarfs and neutron stars, black holes probably evolved from stars.
When a star ages, its thermonuclear reaction has exhausted the fuel (hydrogen) in the center, and the energy generated by the center is running out. In this way, it no longer has enough strength to bear the huge weight of the shell. Therefore, under the heavy pressure of the shell, the core began to collapse, until finally a small and dense star was formed, which could balance the pressure again.
Stars with smaller mass mainly evolve into white dwarfs, while stars with larger mass may form neutron stars. According to scientists' calculations, the total mass of neutron stars cannot be more than three times that of the sun. If it exceeds this value, there will be no force to compete with its own gravity, which will lead to another big collapse.
This time, according to scientists' guesses, matter will move relentlessly towards the center point until it becomes a small volume and tends to be very dense. When its radius shrinks to a certain extent (it must be smaller than that of schwarzschild radius), as we mentioned above, the huge gravity makes it impossible to shoot out even light, thus cutting off all the connections between the star and the outside world-a "black hole" is born.
Compared with other celestial bodies, black holes are too special. For example, a black hole is invisible, so people can't directly observe it, and even scientists can only make various guesses about its internal structure. So how does a black hole hide itself? The answer is-bending space. As we all know, light travels in a straight line. This is a basic common sense. But according to the general theory of relativity, space will bend under the action of gravitational field. At this time, although the light still propagates along the shortest distance between any two points, it is not a straight line, but a curve. Figuratively speaking, it seems that light should go straight ahead, but strong gravity pulls it away from its original direction.
On earth, because the gravitational field is very small, this bending is very small. Around the black hole, this space deformation is very large. In this way, even if the light emitted by the star is blocked by the black hole, although part of it will fall into the black hole and disappear, the other part will bypass the black hole in the curved space and reach the earth. So we can easily observe the starry sky on the back of the black hole, just as the black hole does not exist. This is the invisibility of black holes.
More interestingly, some stars not only send light energy directly to the earth, but also send light in other directions, which may be refracted by the strong gravity of nearby black holes and reach the earth. In this way, we can see not only the "face" of this star, but also its side and even its back!
"Black hole" is undoubtedly one of the most challenging and exciting astronomical theories in this century. Many scientists are trying to uncover its mystery, and new theories are constantly put forward. However, these latest achievements in contemporary astrophysics cannot be explained clearly here in a few words. Interested friends can refer to special works.
Black holes can be divided into two categories according to their composition. One is a dark energy black hole and the other is a physical black hole. Dark energy black holes are mainly composed of huge dark energy rotating at high speed, and there is no huge mass inside. Huge dark energy rotates at a speed close to the speed of light, and a huge negative pressure is generated inside to devour objects, thus forming a black hole. See "Cosmic Black Hole Theory" for details. Dark energy black holes are the basis of galaxy formation, as well as galaxy clusters and galaxy clusters. Physical black holes are formed by the collapse of one or more celestial bodies, and their mass is huge. When the mass of a physical black hole is equal to or greater than that of a galaxy, we call it a strange black hole. Dark energy black holes are very big, and can be as big as the solar system. But physical black holes are small and can be turned into singularities.
adhesion
Translation by Ramesh narayan and Eliot Quartal
Black holes are usually found because they gather around gas to produce radiation. This process is called accretion. The efficiency of high temperature gas radiating heat energy will seriously affect the geometric and dynamic characteristics of accretion flow. At present, thin disks with high radiation efficiency and thick disks with low radiation efficiency have been observed When accretion gases approach the central black hole, their radiation is extremely sensitive to the rotation of the black hole and the existence of the horizon. The photometric and spectral analysis of accretion black holes provides strong evidence for the existence of rotating black holes and horizons. The numerical simulation also shows that relativistic jets often appear in accretion black holes, some of which are driven by the rotation of black holes.
Astrophysicists use the word "accretion" to describe the flow of matter to a central gravitational body or a central expanding material system. Accretion is one of the most common processes in astrophysics, and it is precisely because of accretion that many common structures around us are formed. In the early universe, galaxies were formed when gas flowed to the center of gravitational potential well caused by dark matter. Even today, stars are still formed by the collapse and fragmentation of gas clouds under their own gravity, and then accreted by the surrounding gas. Planets, including the earth, are also formed by the accumulation of gas and rocks around newly formed stars. But when the central celestial body is a black hole, accretion will show its most spectacular side.
However, black holes do not absorb everything. They also emit protons outward.
Explosive black hole
Black holes will glow, shrink in size and even explode. When British physicist Stephen Hawking made this language in 1974, the whole scientific community was shocked. Black holes were once thought to be the ultimate destination of the universe: nothing can escape from them. They devour gas and stars, and their mass increases, so the volume of holes will only increase. Hawking's theory is an inspiration-led thinking leap. He combined general relativity with quantum theory. He found that the gravitational field around the black hole releases energy and consumes the energy and mass of the black hole. This "Hawking radiation" is negligible for most black holes, while small black holes radiate energy at a very high speed until the black hole explodes.
Wonderful shrinking black hole
When a particle escapes from a black hole without repaying the borrowed energy, the black hole will lose the same amount of energy from its gravitational field. Einstein's formula E = MC 2 shows that the loss of energy will lead to the loss of mass. So black holes will become lighter and smaller.
Boil until destruction.
All black holes will evaporate, but big black holes boil very slowly, and their radiation is very weak, so it is difficult to be detected. But as the black hole becomes smaller, this process will accelerate and eventually get out of control. When the black hole becomes insignificant, the gravity will become steeper, producing more escaping particles, and the more energy and mass will be plundered from the black hole. Black holes are becoming more and more trivial, which makes the evaporation speed faster and faster, and the surrounding gas field becomes brighter and hotter. When the temperature reaches 10 15℃, the black hole will be destroyed in the explosion.
Articles about black holes:
Since ancient times, human beings have always dreamed of flying into the blue sky, but no one knows that there is a huge black space outside the blue sky. There is light, water and life in this space. Our beautiful earth is one of them. Although the universe is so colorful, it is also dangerous here. Asteroids, red giants, supernova explosions, black holes ...
A black hole, as its name implies, is an invisible substance with super attraction. Ever since Einstein and Hawking deduced the existence of this substance through speculation and theory, scientists have been exploring and seeking to avoid the destruction of our planet.
Maybe you will ask, what is the relationship between black holes and the destruction of the earth? Let me tell you something, it has a lot to do with it. You'll understand when you get to know him.
A black hole is actually a mass of matter with great gravity (no matter with greater gravity has been found so far), forming a deep well. It is formed by the constant collapse of a star with great mass and density. When the material core inside a star is extremely unstable, an isolated point called "singularity" will be formed (see Einstein's general theory of relativity for details). He will inhale everything that enters the horizon, and nothing can escape from it (including light). He has no specific shape, so he can't tell. He can only judge the existence of the surrounding planets according to their directions. Maybe you will cry out in horror because of its mystery, but there is no need to worry too much. Although it is very attractive, it is also an important evidence to judge its status. Even if it had an impact on the material very close to the earth, we still had enough time to save it, because its "official boundary" was still far away from us at that time. And most stars will become neutron stars or white dwarfs when they collapse. But that doesn't mean we can relax our vigilance (who knows if we will be inhaled next moment? ), which is one of the reasons why humans study it.
We have learned about his terrible attraction, but no one knows what it will look like if inhaled. In this regard, scholars and scientists are also unable to agree and have different opinions. Some people think that the substance he inhaled will be destroyed. Others think that black holes are the gateway to another universe. We don't know what will happen after being inhaled. Maybe only those inhaled substances can understand it!
The black hole is just one of Qian Qian's 10,000 mysteries, but we don't know how long it will take to explore a small part of it. The strength of one generation is limited, but the strength of a million generations will surely succeed. I believe that in the near future, we and our descendants will fully explore the mysteries of black holes and the whole universe.
Stars, white dwarfs, neutron stars, quarks and black holes are five kinds of stars with equal density in turn. Of course, stars are the lowest density, and black holes are the ultimate form of matter. BIGBANG will happen after the black hole, and the energy will enter a new cycle after it is released.
In addition, black holes refer to places where e-mails are lost or newsgroup announcements disappear in the network.