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Why black holes look black to us?

The question might sound weird but my head stuck in it. As we know objects that fall into the black holes seem to remain unchanged in its event horizon due to the nature that lights cannot escape from it. For example, in the below image (image with white astronaut) of the black hole we will see the astronaut remains in its event horizon.

enter image description here

Now, we also know that the black holes are constantly pulling all the interstellar objects & meteors around it, thus if these objects are grabbed by the black hole, we are supposed to see many of these objects remain unchanged on its event horizon surface hence the color of the black hole is not supposed to be black instead the distorted color by the objects (i.e. below image). But still we see its color a pure black in most of the representations and photos.

enter image description here

So why do we see black holes black instead of distorted colors of the space objects?

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Because the light is also redshifted towards infinite wavelengths as the falling object appears to approach the event horizon. The two things go together - the object appears to freeze at the event horizon according to a distant observer, but that means the frequencies of light they emit (according to the same distant observer) tend towards zero.

So if you had a telescope that could see extremely long wavelengths, the object might remain "visible" for just a tiny bit longer.

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When the astronaut is far outside the black hole we can see the astronaut normally.

As the astronaut falls towards the black hole, things get strange. We don't see the astronaut pass the event horizon, instead as the astronaut falls towards the event horizon, he will seem to be time dialated. The clock on his wrist will seem (from our perspective) to run slower (he won't notice this from his perspective, the watch is normal). As he gets closer to the event horizon, light reflected off him will be more and more redshifted. As he gets closer to the event horizon the light will become redshifted to infra-red (at which point he will appear invisible) then microwaves then longer and longer wavelengths carrying less and less energy. He will turn black and invisible to us.

So you can't see the objects that have fallen to the black hole.

From the point of view of the astronaut, he falls down and in a short amount there is a singularity in the equations. It seems that his body is compacted into a single point of infinite density, it seems that general relativity can't yet describe this state, which will require a quantum theory of gravity.

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