what is the black hole in the universe?

the black hole is a kind of celestial body that exists in cosmic space in modern general theory of relativity.

the gravity of the black hole is so large that the escape speed in the horizon is greater than the speed of light.in 1916, the german astronomer karl schwarzschild(1873~ 1916) calculated a vacuum solution of the einstein gravitational field equation, which showed that if a large amount of material was concentrated in space, will produce a strange phenomenon, that is, there is an interface around the particle-"horizon"once into the interface, even if the light can not escape.this"incredible celestial body"by the american physicist john archie boulder wheeler(johnarchibaldwheeler) named"black hole".

the black hole is a space-time curvature that can not escape from its horizon celestial bodies".(electromagnetic wave) also escape.the black hole can not be directly observed, but it can be known indirectly by its existence and quality, and observe its impact on other things.

the information of the existence of a black hole can be obtained by releasing the"edge message"of the gamma ray by the high temperature before the object is sucked in.it is inferred that the existence of a black hole can also be obtained by indirectly observing the position of the star or the interstellar cloud of the orbit and the quality of the black hole is an infinite density of the center, the infinite height of the space-time curvature, the infinite singularity of the infinite and the surrounding area , this area is not visible within the scope.