There are three magical “holes” in astronomy, namely black holes, white holes and wormholes. Speaking of these three holes, I have to mention Einstein, because they are all established on the basis of general relativity.
Black hole
I believe many people have heard of black holes. Among the three holes, it is the only celestial body whose real existence has been confirmed. It is a peculiar celestial body in the universe that can swallow almost everything close to it.
In 1915, Einstein proposed the general theory of relativity. The following year German astronomer Karl Schwarzschild predicted that there might be a kind of celestial body with extremely strong gravitational attraction in the universe, which is what we later called black holes. However, it was not until 1970 that humans discovered the first black hole-Cygnus X-1.
General relativity tells us that time and space can be distorted. When a large amount of mass is gathered in a small range of time and space, the space and time are extremely distorted, forming an interface, and even light cannot escape from its horizon. Because black holes not only don’t emit light, they can also swallow light, and humans cannot see its existence from an optical point of view, so it is called a black hole.
According to the quality of black holes, they can be divided into miniature black holes, constant star black holes, intermediate mass black holes and supermassive black holes. Among them, only constant star black holes and supermassive black holes have been observed by scientists. There is a supermassive black hole in the center of the Milky Way.
In addition, according to the angular momentum and charge of the black hole itself, black holes can be divided into non-rotating and non-charged black holes: Schwarzschild black holes; non-rotating charged black holes: RN black holes; rotating non-charged black holes: Kerr black holes; rotating charged black holes : Kerr-Newman black hole.
There is currently no way to directly observe the body of a black hole. At present, it is mainly through observing the accretion disk formed when the black hole swallows matter to indirectly understand the black hole.
White hole
A black hole devours matter and basically only enters but cannot exit, while a white hole is a magical celestial body that only enters but cannot enter. It is generally believed that the matter swallowed by the black hole will be spit out by the white hole. However, the white hole is just an imaginary celestial body that has not yet been discovered.
In 1964, the former Soviet cosmologist Igor Novikov proposed a white hole. Where there is black, there is white. The reason why the concept of white hole is proposed is based on the thinking of symmetry, such as electricity-generating magnetism, magnetism-generating electricity, and electromagnetic symmetry.
A white hole, like a black hole, is also a source of strong gravitation, which can accrete surrounding matter onto the boundary to form an accretion disk. The only difference is that the internal properties of a black hole are different. It can eject matter to the outside world, but cannot absorb any matter and energy from the outside world. These ejected materials collide with the accretion disk around the white hole, which will release huge radiation. Therefore, the white hole theory can be used to explain some high-energy celestial phenomena, such as quasars.
There is also a view that white holes can be transformed from black holes. When a certain change occurs inside the black hole, it may be reversed and become a white hole.
Wormhole
I don’t know if you have heard of the Einstein-Rosen Bridge. The wormhole we call refers to this thing.
In the 1930s, Einstein and Nathan Rosen came up with this concept while studying the gravitational field equation. Wormhole is a narrow tunnel connecting two space-times that may exist in the universe, through which instant space transfer or time travel can be realized. Although the wormhole has not yet been discovered, scientists still have high hopes for it.
Theoretical research shows that even if a wormhole exists, it is unstable, which may be the reason why we still find it. However, scientists believe that if we can use negative energy, we may be able to stabilize the existence of wormholes.
There is a view that a wormhole is a channel connecting two space-times, while a black hole is the entrance of the wormhole, and a white hole is the exit of the wormhole. There are also views that quantum entanglement may be related to wormholes.
Among these three holes, the more peculiar one should be the wormhole, which often appears in science fiction movies. If it really exists, it may really enable humans to achieve interstellar travel. Black holes were once the most peculiar, but they have now revealed their mystery.
