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Sunday, October 27, 2019

Theories of Black Holes

Theories of Black Holes Zhiting Liu The Black Hole The first impression of a black hole may be heard like a dark and a very horrible hole. It was a big planet that you cannot ignore. It is the object that have a very strong gravitational, even the light cannot escape. When the Schwarzschild radius of the star is tiny, even the light vertical emitting to the surface also cannot escape (Schwarzschild). Then the star becomes a black hole. We said, Black, the fact is that it is like a bottomless pit of the universe, when the matter has been absorbing by black hole, it looks like cannot escape. Due to the light cannot escape a black hole, we cannot directly observe the black hole. Only by measuring the impact on the surrounding objects to speculate indirectly to its existence. In other words, although the black hole is black, but it is essentially still a star. As we classify the stars, the black hole also has many categories. It can be composed into dark energy black holes and physics black hole. If divided by physical properties, it can be: not rotating and uncharged black hole; not rotating charged black hole; uncharged rotating black hole; general black hole and the binary black hole (Wikipedia). So the black hole is composed by what? For this problem, contemporary scholars have different views. First of all, the most common and most easy to accept that a black hole is a tiny hole. It was the remains of the star, when the star was collapse. That is to say; the composition of the black hole is as same as the general stars. In recent years, however, the people who have hold different views they put forward the new ideas. They believe that the black hole is actually a large celestial bodies are composed in a particular state of the substance in the collapse process, it gradually condense to form a black hole, the same process is like the w ater into ice. This explanation provides a new idea for the study of quantum gravity theory, and the quantum theory of gravity is possible to make the Einsteins general theory of relativity and quantum mechanics in together (David). So how this amazing celestial black hole formed. In fact, the process of produces a black hole is as similar as produces the neutron star; the core of the star shrink rapidly under its weight, the in a violent blast. When all the substances in the core have become neutrons, the process of contraction would stops immediately then it be compressed into a dense planet (Wikipedia). However, in the case of a black hole, the core of a massive star is too big, it make the process of contraction on endlessly, neutron was crushed into a powder by its own gravitational attraction squeeze, and the remaining is a high-density material . The black hole like a vacuum, all of the objects will be sucked into it when close to it. Moreover, so, after the contraction it formation a new black hole. It also can be understood, the general stellar initially only hydrogen elements, hydrogen atoms inside stars collide moment, fission, and fusion. Because of the large stellar mass, fission and fusion energy contend with stellar gravity, in order to maintain the structure stability of the star. Because fission and fusion, hydrogen atoms eventually change the internal structure of the rupture and form a new element the element helium. Then, the helium atom is also involved in fission and fusion, change the structure, generate to lithium element. By the same method, from order of the periodic table, it will be generated by a beryllium, boron, carbon, nitrogen and other elements (Hawking). Until generated to iron element, the star will collapse. Because iron is fairly stable it cannot participate fission or fusion, however the iron is present in the interior of stellar, it will resulting the interior energy of stellar cannot contend with the stellar gravity of large stellar mass, it cau sing the star collapses, and forming a black hole (Hawking). In fact, black hole is as same as white dwarfs and neutron stars, it may also evolve by a star that are 30 times bigger than the sun. It works like, when the star is aging; its thermonuclear reaction has run out of the center fuel (hydrogen), the energy generated by the center is running out too. Thus, it does not have enough strength to bear the weight of a huge shell. Therefore, under the weight of the shell, the core began to collapse. Finally, it becomes a small and high-density stars which can re-balance the pressure (Hawking). Some of the small mass stars evolve into white dwarfs, and more massive stars are likely to form a neutron star. According to the scientists calculations, the total mass of the neutron star cannot be three times greater than the suns mass. If this value is exceeded, then there are no force can compete with its gravity, and thus lead to another Big Crunch. According to scientists suspect that in this kind of collapse, the material will march inexorably toward the center, until it becomes a small size, but have a great density. And when it once the radius of the contraction to a certain degree (must be less than the Schwarzschild radius), in such a high density, the great gravity makes even the light cannot be emitted outward, it cutting off all contact with the outside of the star and black hole was born. As scientists calculated, an object has the speed as 7.9 kilometers per second; it cannot pull by the Earths gravity, it will move like a circle. At this rate, called the first cosmic speed. If it will not go to other planets, at least have the speed of 11.2km/s, and this rate called the second cosmic velocity. This result is calculate by the size of the Earths mass and radius. It means if an object wants escape from the ground, at least to have the enough speed. However, for the other celestial body, the escape speed is not necessarily needed as big as in the earth. Quality objects that are big and have small radius, it will be more difficult to get rid of gravity, and the speed of escape need be more quickly (Khatri, Poudel, Gautam). According to this reasoning, we can think maybe there is a celestial body, it have a great quality and tiny radius, the escape speed of that celestial body areas bigger as the speed of light. In other words, the light also pull by its gravitational, cannot run out the surface. Since the light cannot run out, we cannot see and then talk about it, so it is a black. As we know the fastest speed in the universe is light, since light cannot come out from these objects, any other substance will never expect to run out. Everything like falling into a bottomless pit, such a celestial body, and people call it a black hole. In conclusion, that’s all I search and know about the black hole, when I find these information, it show me a new area that I never touched. It’s really different and mystery. I believe people will find the rule of the black in the future, and it will give us the new technology and knowledge. Reference page The New New Math of String Theory Phys.org.David Pescovitz. Web. 1 Dec. 2014 http://phys.org/news70021180.html>. â€Å"Black Hole† Wikipedia. Web. Physical Properties Part â€Å"ÃÅ"ber das Gravitationsfeld eines Massenpunktes nach der Einstein’schen Theorie.† Reimer, Berlin 1916, S. 189 ff. (Sitzungsberichte der Kà ¶niglich-Preussischen Akademie der Wissenschaften; 1916) â€Å"A Brief History of Time† Hawking, Stephen (1988). Bantam Books â€Å"Principles of Physics† Khatri, Poudel, Gautam, M.K., P.R., A.K. Kathmandu: Ayam Publication. 2010: 170, 171 â€Å"Neutron star† Wikipedia. Web. Introduction of Neutron star.

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