The impact and development of black holes, a brief introduction to the history of black holes

Chinese name Black Hole.

The foreign name is black hole

Classification of cosmic objects.

Discovered by Karl Schwarzschild in 1916.

Average density = 3mc2 8 gm

Surface temperature t=hc 3 8 kgm

Escape velocity exceeds the speed of light within the horizon.

Albedo 0 main explorers Stephen Hawking Einstein Schwarzschild.

Half-path for Schwarzschild black holes: rs=2gm c2

It is now known that the closest black hole to Earth is 16 light-years away and has little impact on humans.

In general, black holes are considered to be massive stars (celestial bodies greater than times the mass of the Sun) that are unable to maintain nuclear fusion after consuming a certain amount of their own mass, resulting in their own gravitational equilibrium being unable to be maintained, and the gravity is too large to collapse inward to form a black hole.

It's easy to imagine a "black hole" as a "big black hole", but it's not. The so-called "black hole" is such a celestial body: its gravitational field is so strong that not even light can escape.

According to the general theory of relativity, the gravitational field will bend space-time. When a star is large, its gravitational field has little effect on space-time, and light from a point on the star's surface can be emitted in a straight line in any direction. The smaller the radius of a star, the greater its curvature of space-time around it, and the light emitted at certain angles will return to the star's surface along the curved space.

It's easy to imagine a "black hole" as a "big black hole", but it's not. The so-called "black hole" is such a celestial body: its gravitational field is so strong that not even light can escape.

According to the general theory of relativity, the gravitational field will bend space-time. When a star is large, its gravitational field has little effect on space-time, and light from a point on the star's surface can be emitted in a straight line in any direction. The smaller the radius of a star, the greater its curvature of space-time around it, and the light emitted at certain angles will return to the star's surface along the curved space.

A black hole is actually a planet, but it's so dense that objects near it are bound by its gravitational pull (as if people hadn't flown away on Earth). For the earth, flying at the second cosmic speed can escape the earth, but for the black hole, its second cosmic speed is so great that it exceeds the speed of light, so it can't even run out, so the light that comes in is not reflected back, and our eyes can't see anything, just a black patch. Some scientists believe that light is slower than a black hole, so it is sucked in, and when it is faster than a black hole, it can pass through the edge of the black hole.

Of course, the speed of light is already the limit.

Black holes are also celestial bodies in nature because there are different types of black holes, and each type of black hole has a different process of formation. Take a stellar black hole as an example to illustrate the formation process of a black hole.

Stellar black holes are created by the gravitational collapse of a massive enough star after it runs out of fuel for a nuclear fusion reaction.

The stars that can form black holes are all massive stars, and they all go through the stage of the main sequence star first. The first is the black hole formed after the massive star quickly ends its main sequence stage, the original mass of such stars is usually more than 30 times the mass of the sun, and their interior is undergoing violent nuclear fusion reactions, usually from hydrogen fusion to iron in tens of millions or even millions of years, the larger the star becomes a black hole.

When iron begins to be generated in the interior of the star through nuclear fusion, it means that the main sequence stage of the star is over, because the fusion of iron is not to release energy, but to absorb energy, which will cause the radiation pressure inside the star to resist the star's own gravity to disappear, then the huge pressure caused by the star's gravity (gravity) will be squeezed towards the center in an instant, and the center of the star is a sluggish iron core that cannot continue to produce nuclear fusion reactions. When the stellar material hits the iron core, while bringing huge kinetic energy to the core, the material will rush out of the star in the opposite direction at almost the same speed as the impact velocity, and the star will undergo an incomparably incomparable implosion, which is a supernova explosion.

When the supernova explodes, a large number of superheavy elements (elements heavier than iron) are generated, and when the high temperature and pressure in the center reaches a certain level, even neutrons will be crushed, and the entire star core will contract violently, and a black hole will be formed at this moment, which is the most common way of forming black holes in the universe.

According to the law of gravitation, the smaller the radius, the stronger the gravitational pull. A black hole shrinks into a dot, making its surface gravitational pull so strong that even the light around it cannot escape, hence the name "black hole".

In the universe, a star can only eventually evolve into a black hole if the mass of the remaining stellar nucleus after a supernova explosion is greater than 3 times the mass of the Sun (known as the "Oppenheimer-Volkov limit"). The corresponding star has a mass of about 7 times the mass of the Sun.

Black holes are created by the gravitational collapse of a massive enough star after it runs out of fuel for a nuclear fusion reaction and dies.

1. The reason for the formation of a black hole is more like a neutron star, which occurs when a star is about to die**, and the matter in the core is compressed into a dense body, and the internal space and time are compressed at the same time to become a black hole. A black hole is a very dense substance, not only does it have a strong gravitational pull, but the event horizon escapes faster than the speed of light.

2. The cause of the formation of black holes is more similar to the generation process of neutron stars, which occurs when a star is about to die. Stars contract rapidly under the influence of gravity in the universe, and then **, when all the matter in the core is compressed into neutrons, the contraction of the star will also stop immediately. Stars that stop shrinking are compressed into dense stars, and the matter in the core is compressed into dense shapes, compressing the space and time inside the star, thus forming black holes.

A black hole is a high-quality, high-density substance that generates force that can suck anything that comes close to it in.

3. A black hole is a very dense substance, a naturally formed celestial body in the universe, which not only has a strong gravitational force, but also has an event horizon escape speed greater than the speed of light. A black hole is a celestial body with a curvature of space-time that makes it impossible for light to escape, so a black hole is black because it sucks light in. The creation process of a black hole is similar to the creation process of a neutron star, when a star is about to perish, its core will quickly shrink, collapse, and even become strong under the action of its own movement.

When a star is about to die, white dwarfs, neutron stars, and black holes are formed according to the difference in their mass, which are arranged according to the mass of the star from smallest to largest. In other words, not all stars die to form black holes, and only more massive stars become black holes after they die. The death of stars, like their birth, collapses under their own gravity.

This collapse creates new stars at the time of star birth and black holes at death.

We all know that matter is made up of molecules, and molecules are made of atoms, but atoms are not the smallest substances, and there are nuclei in atoms, and there is a substance called neutrons in the nucleus. Yes, matter is like that, layered on top of each other, like matryoshka dolls, small substances are constantly layered to form large substances, and large substances continue to be layered to form new substances. After the death of a star, it will continue to collapse, but to what extent will this collapse stop?

It is only when the matter in the core of the star becomes neutrons that the contraction and collapse stop.

It is precisely because the core becomes such a small substance that the star eventually becomes an extremely dense celestial body. However, due to the extreme mass of some stars, even if their cores become neutrons, this compression process cannot be stopped, just like eating Xuanmai. Because of this continuous compression, the repulsion between the neutrons and the neutrons cannot stop it, so the neutrons eventually turn into powder, and the result of this compression is the formation of a particularly dense matter, which is what we call a black hole.

Scientists are also studying the formation of black holes.

Black holes are typical representatives of various limit states in theoretical physics, and their research has three major significances: 1. The grand unified theory of theoretical physics (the ultimate theory that explains everything in the universe), and 2. Philosophical and religious significance.

3. Practical significance, the study of elementary particles, and the derivation of various civilian products, such as energy, information, and so on.

1. Exploring the existence of black holes can indirectly deduce when and how the universe came into being, and thus we can also understand how the earth came into being after the universe, and with the earth, there were creatures and human beings. And, equally realistically, understanding black holes can also know whether the universe was created because of the big **, whether the evolution of galaxies is affected by the spectacular jets in galaxies, and perhaps most realistically, whether the existence of black holes will affect the survival of humans and organisms on Earth, as well as the ecology and biodiversity of Earth. If so, what ways will science prevent, avoid, or reduce such impacts?

2. Of course, there are more derivative meanings for exploring black holes. Since there are black holes, there may also be white holes in the universe, which proves the existence of white holes, which also indirectly proves the existence of black holes. A white hole is the opposite of a black hole, it is a special cosmic object that only emits energy and does not absorb energy, and the force of the white hole is repulsive, which is the opposite of the attraction of the black hole.

When the ultra-dense matter in the white hole is ejected outward, it will violently collide with the matter around it, releasing a huge amount of energy. It can be inferred that some phenomena such as X-rays, cosmic rays, radio bursts, and radio dual sources may be related to this effect of white holes.

On the other hand, the gravitational waves discovered in 2015 are also derivative of black hole exploration, or the two corroborate each other. This also means that humans can explore the starry sky and complete the puzzle by building blocks.

Step by step, human beings have come to a clear understanding of the universe and the origin of life.

Divide the celestial bodies and analyze their value.

Photographing black holes is a huge problem for humans. Although the two black holes to be photographed are the two largest of the black holes we have discovered, the one closest to the Earth is also 10,000 light-years away, and taking a picture of it is equivalent to taking a picture of a coin on the Sun on Earth, which can be imagined as difficult.

In the face of such a huge challenge, an unimaginable big science project was born: more than 200 scientists around the world reached a major international cooperation program called the Event Horizon Telescope (EHT), and decided to use very long baseline interferometry technology to form a virtual telescope with an aperture the size of the earth from 8 observation points distributed around the world, which achieved unprecedented sensitivity and resolution. Harsh observation sites, including volcanoes in Hawaii and Mexico, Sierra Nevada in Spain, the Atacama Desert in Chile, the South Pole, and more, are finally able to capture the phantom of a black hole.

In fact, the Black Hole Observation Project has involved researchers in almost every field on Earth in varying degrees and in different ways. From Hawaii to Chile in the United States, from the Iberian Peninsula to the ...... AntarcticaMore than 30 research institutes and more than 200 scientists around the world have devoted several years of hard work to work hand in hand to record the dazzling light emitted by the accretion disks and jets around the black hole, so that the supermassive black hole has nowhere to hide and show its "true face".

It is difficult to take pictures, and it is even more difficult to "wash". Radio telescopes cannot directly "see" black holes, but they will collect a lot of data about black holes and use them to describe what black holes look like to scientists. After the observations, the data collected by the various stations will be pooled into two data centers, and after a two-year "wash", the first black hole** in human history will finally be released.

It was the synchronized efforts of the world that allowed humanity to photograph the first-ever black hole**. Scientific exploration is bringing the whole world closer together in unusual ways, not only for the planet, but also for humanity to become a community. As Falck, chairman of the project's scientific committee, said:

It's not easy for different cultures, different institutions, different countries and continents to come together and work together, but it's possible if it's driven by a shared vision and a common dream of seeing a black hole for the first time. ”

Such a project requires the whole world. The appearance of black holes is the result of the common "looking" of human beings. Only when multiple fields and disciplines develop in parallel, transcending countries, eras, and races, and connecting human beings into a whole, can mankind's horizons for exploring the unknown become broader.