The black holes

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Yes,the black holes are really black, because the light waves from it are not reflected in any way, and the object itself does not emit light.The gravitational field becomes so strong during the formation of this cosmic object, that even the rays of light can not escape beyond its limits. And as a result, the area in which the star was previously brightly shining becomes absolutely black.

But it can be seen only on the background of bright glowing objects, for example, during the passage of the star-satellite. In other cases, we see not the hole, but only traces of the absorbed mass, the so-called accretion disk which glows quite brightly. This effect can be seen in the movie «interstellar» by Christopher Nolan.

Astronomers looking for black holes in outer space by the ratio of mass and luminosity. A big blank, black space with a minimal amount of light around usually indicates the presence of a black hole a large mass.

By the way,  the name the object was not immediately. The term was invented by the American physicist John Wheeler, who simply decided that the past is the name «dark star» does not fully reflect the essence of the phenomenon. For the first time the name «black hole» mentioned in the journal Physical Review, initially, the term was considered quite obscene, but then caught on in the scientific community.

black holes
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