"Dozens of countries are in chaos, and this guy is going to take advantage of it. ”

On a luxury passenger ship heading to the East China Sea, Ye Wuji sat leisurely on a seat near the side of the ship on the deck of the third floor, enjoying the scenery on the sea while reading the newspaper in his hand.

When he returned to the Navy Headquarters with Kuzan and the others, except for the beginning when someone came to interrogate, no one came to disturb him, until two days ago he received an order from the Navy Headquarters to let him go to the Navy Division in the Four Seas, because because of his special situation, he could choose any Navy branch in the Four Seas at will.

The navy has a very large number of divisions in the four seas, and there are nearly 100 divisions in the East China Sea alone, and the top officer of each division is generally a colonel.

The divisions of the four seas do not have a unified person in charge, and they are all directly under the headquarters of the Navy.

Since it was a choice, Ye Wuji of course chose a place he was very familiar with for the first time, Rogue Town, a place close to the entrance of the Great Passage of the East China Sea.

At the same time, Ye Wuji's military rank was finally changed and he became a lieutenant colonel of the Navy Headquarters.

After being appointed, Ye Wuji immediately went to take office, and I have to say that the treatment of the navy is still good, and the expenses of this trip to the East China Sea can be fully reimbursed.

A black hole is a singularity with infinite density, infinite curvature of space-time, infinitely small volume, and infinite heat in the center, and a part of the surrounding empty celestial region, which is not visible within the scope of this celestial region. According to Albert Einstein's theory of relativity, when a dying star collapses, it will gather into a point where it will become a black hole, swallowing all light and any matter in the adjacent cosmic region.

The creation of a black hole is similar to that of a neutron star: when a star is preparing to perish, its core rapidly shrinks, collapses, and explodes under the force of its own gravity. When all the matter in the core turns into neutrons, the contraction process immediately stops, and it is compressed into a dense star, which also compresses the space and time inside. But in the case of black holes, the mass of the star's core is so large that the contraction process goes on endlessly, and even the repulsion between neutrons cannot be stopped. The neutrons themselves are crushed into powder by the attraction of the squeezing gravity itself, leaving behind a material that is unimaginably dense. The gravitational pull due to the high quality is such that any object that comes close to it will be sucked into it. [5]

It can also be simply understood as: usually stars initially contain only hydrogen, and the hydrogen nuclei inside the star collide with each other all the time and fuse. Due to the massive mass of stars, the energy produced by fusion competes with the gravitational pull of the stars to maintain the stability of the star structure. As a result of the fusion of hydrogen nuclei, a new element, helium, is produced, and then the helium atoms are also involved in fusion, changing their structure to form lithium. By analogy, according to the order of the periodic table, beryllium, boron, carbon, nitrogen, etc., will be formed in turn, until iron is formed, and the star will collapse. This is due to the fact that iron is quite stable, and the energy released when participating in fusion is less than the required energy, so the fusion stops, and iron exists inside the star, causing the star to not have enough energy to compete with the gravitational pull of the massive star, which causes the star to collapse and eventually form a black hole. It is called "black" because it generates a gravitational pull that makes it impossible for the light around it to escape. Like neutron stars, black holes evolve from stars that are tens or even hundreds of times more massive than the Sun.

When a star ages, its thermonuclear reaction has depleted the center of fuel, and the energy generated by the center is running out. In this way, it no longer has enough strength to carry the enormous weight of the shell. So under the weight of the shell, the core begins to collapse, and matter will march inexorably towards the central point, until finally a star with a near-infinitesimal volume and almost infinite density will be formed. And when its radius shrinks to a certain point (it must be smaller than the Schwarzschild radius), the mass-induced distortion of space-time makes it impossible for even light to shoot outward – and the "black hole" is born.

Accretion

Black holes stretch, tear and devour stars

Black holes stretch, tear and devour stars

Black holes are usually discovered because they collect the surrounding gas to produce radiation, a process known as accretion. The efficiency of radiant heat energy from high-temperature gases can seriously affect the geometrical and kinetic properties of accretion flows. Thin disks with higher radiation efficiency and thick disks with lower radiation efficiency have been observed. As accretion gases approach the central black hole, the radiation they produce rotates the black hole and acts as a flow of the central extended material system. Accretion is one of the most prevalent processes in astrophysics, and it is precisely because of accretion that many common structures around us are formed. In the early days of the universe, galaxies were formed when gas flowed towards the center of the gravitational potential well created by dark matter. Even today, stars are formed by gas clouds that collapse and fragment under their own gravitational pull, and then accretion of surrounding gas. Planets, including the Earth, are also formed around newly formed stars through the accumulation of gas and rocks. When the central object is a black hole, accretion takes on its most spectacular side. In addition to accreting matter, black holes also radiate particles outward through the process of Hawking evaporation. [6]

evaporate

Since the density of the black hole is extremely large, according to the formula we can know the density = mass/volume, in order to make the black hole infinite density and the mass of the black hole unchanged, then it means that the volume of the black hole should be infinitely small, so that it can become a black hole. A black hole is a death star formed after the "extinction" of some stars, and it is extremely massive and extremely small. According to Hawking's theory, in quantum physics, there is a phenomenon called the "tunnel effect", that is, although the field strength distribution of a particle is as strong as possible in the place with low energy, even in the place where the energy is quite high, the field strength will still be distributed.

Hawking also proved that every black hole has a certain temperature, and that the temperature is inversely proportional to the mass of the black hole. In other words, large black holes have low temperatures and weak evaporation, while small black holes have high temperatures and strong evaporation, similar to violent eruptions. A black hole the mass of the sun will evaporate in about 1x10^66 years, and a black hole the mass of an asteroid will evaporate in 1x10^-21 seconds. [1]

destroy

Black holes emit dazzling light, shrink in size, and even explode, ejecting objects and emitting dazzling light. When British physicist Stephen William Hawking made this prediction in 1974, the entire scientific community was shaken.

Hawking's theory is a leap of inspiration-governed thinking, combining general relativity and quantum theory, and he discovered that the gravitational field around a black hole releases energy while consuming both the energy and mass of the black hole.

Stars are swallowed by black holes

Stars are swallowed by black holes

Suppose a pair of particles will be created at any time and place, and the created particles are positive particles and antiparticles, and if this creation process occurs near the black hole, two particles will be annihilated, and one particle will be sucked into the black hole. "A particle is sucked into a black hole" situation: a pair of particles created near the black hole, one of the antiparticles will be sucked into the black hole, and the positive particles will escape, because energy cannot be created out of thin air, we let the antiparticles carry negative energy, the positive particles carry positive energy, and all the motion processes of the antiparticles can be regarded as the opposite motion process of a positive particle, such as an antiparticle being sucked into the black hole can be regarded as a positive particle escaping from the black hole. In this case, a particle carrying positive energy from the black hole escapes, i.e., the total energy of the black hole is less, and Einstein's mass-energy equation E=mc^2 shows that the loss of energy leads to the loss of mass.

As the mass of the black hole gets smaller and smaller, its temperature gets higher and higher. Thus, when a black hole loses mass, its temperature and emissivity increase, and therefore its mass loss is faster. This "Hawking radiation" is negligible for most black holes, as large black holes radiate more slowly, while small black holes radiate energy at extremely high rates until the black hole explodes.

Presentation editing

A black hole with a strong gravitational pull.

A black hole with a strong gravitational pull.

According to British media reports, a new theory suggests that the way black holes die may have been carried out in the way of transformation into white holes. Theoretically, a white hole behaves like the opposite of a black hole – a black hole is constantly devouring matter, while a white hole is constantly ejecting matter. The discovery was first reported by a British magazine website and was based on the obscure theory of quantum gravity. [7]

The space-time distortion of stars changes the path of light from what it would have been without a star. The light is slightly deflected inward near the star's surface, a phenomenon that can be seen when looking at the light emitted by distant stars during a solar eclipse. When the star collapses inward, the space-time distortion caused by its mass becomes stronger, and the light is deflected inward more strongly, making it more difficult for photons to escape from the star. To an observer from a distance, the light becomes dimmer and redder. Finally, when the star shrinks to a critical radius (Schwarzschild radius), its mass causes space-time to distort so strongly that the light is deflected inward so strongly that it can't escape. In this way, if the light can't escape, everything else can't escape, and it will be pulled back. That is, there is a collection of events or a region of space-time from which it is impossible for light or anything to escape to reach an observer in the distance, and such a region is called a black hole. Its boundary is called the event horizon, and it coincides with the trajectory of light rays that just can't escape from the black hole.

Compared to other celestial bodies, black holes are very special. It cannot be directly observed, and scientists can only speculate about its internal structure. What makes black holes hide themselves is the curved space-time. According to the general theory of relativity, space-time bends under the action of a gravitational field. At this point, the light is still traveling along the shortest path between any two points, but it is relatively bent. When passing through a dense celestial body, space-time will bend and the light will deviate from its original direction.

Black hole image

Pictures of black holes (35 photos)

On Earth, the distortion of space-time is minimal due to the small effect of the gravitational field. And around black holes, this distortion of space-time is very large. In this way, even if the light emitted by a star blocked by a black hole will fall into the black hole and disappear, another part of the light will pass through the curved space around the black hole and reach the Earth. Observing the starry sky on the back side of a black hole as if the black hole didn't exist is the stealth of the black hole.

What's even more interesting is that some stars not only emit light energy towards Earth that reaches Earth, but also light emitted in other directions can be refracted by the strong gravitational pull of a nearby black hole to reach Earth. In this way, we can see not only the "face" of the star, but also its "side" and even "back", which is the "gravitational lensing" effect in the universe.

This infrared image captures the central part of the galaxy where we live, where all the stars of the galaxy orbit around a supermassive black hole that may exist at the galactic core. According to Space Network, a new study shows that the largest black hole in the universe may have begun to grow rapidly earlier than scientists originally estimated and is still accelerating.

A team of astronomers from Tel Aviv University in Israel found that the first rapid growth period of the largest mass black hole in the universe occurred when the universe was about 1.2 billion years old, instead of 20~4 billion years as previously thought. Astronomers estimate the age of the universe to be about 13.82 billion years.

At the same time, the study also found that the oldest and most massive black holes in the universe also have very rapid growth. Details of this discovery were published in the journal Astrophysical Sinica.

If the black hole is large enough, the astronaut will begin to perceive that the gravitational force pulling his feet is stronger than the gravitational force pulling his head, and this attraction will drag him down mercilessly, and the gravitational difference will quickly increase and tear him apart (stretch the line), and eventually his body will be disintegrated and fall into the infinitely dense core of the black hole.

Matter outside the black hole can also be "spitted" outward by thermal radiation. This quantum mechanical phenomenon is known as Hawking radiation.

On September 25, 2014 (Beijing time), the Physicists Organization Network reported that in the new study, Mersini-Horton described a completely new approach. Both she and Hawking agree that Hawking radiation is produced when stars collapse due to their own gravitational pull. But Mersinier-Houghton believes that the mass of the star is also constantly lost after this radiation is emitted. Because of this, when these stars collapse, it is impossible to reach the mass density necessary for the formation of black holes. She believes that dying stars, after their last expansion, will explode and then die, with singularities never forming and black hole event horizons not appearing. There simply is no such thing as a black hole.

In fact, as early as the beginning of this year, Hawking pointed out through a paper that black holes do not exist in classical theory, and he admitted that his initial understanding of the horizon was flawed, and proposed a new "gray hole" theory. The theory is that matter and energy are trapped in a black hole for a period of time before being released back into the universe.

The definition of a black hole has come to be accepted after a long period of speculation. However, Hawking published an article denying the existence of black holes at the beginning of this year, and instead proposed the "gray hole" theory, which caused a lot of waves in the physics community. Now, Mersini Horton's blunt statement that "there is no such thing as a black hole" is undoubtedly another bombshell – even though Mersini Horton is nowhere near as well known as Hawking. Of course, it is not so easy to overturn the existing theories on your own, and more convincing evidence is needed to support them. [9]

Classification features edited

Physical property division

According to the physical properties of the black hole itself, mass, angular momentum, charge division, black holes can be divided into five categories.

A black hole that does not rotate and does not carry an electric charge: its space-time structure was discovered by Schwarzschild in 1916 and is called a Schwarzschild black hole.

Non-rotating charged black holes: called R-N black holes. The spatiotemporal structure was developed by Reissner and Nordstrom in 1916-1918.

Rotating uncharged black hole: Called a Kerr black hole. The structure of space-time was found by Kerr in 1963.

Black holes in general: Called Kerr-Newman black holes. The structure of space-time was developed by Newman in 1965.