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From the perspective of a faraway observer watching an object fall into a black hole, they will see the object approach the black hole's horizon at a slower and slower rate until eventually "flattening out" against the event horizon. This would resemble a 2d circle, where an object falls in, say, from the right side and flattens into the circumference, creating a sort of "shell".

But what about an object that falls into a black hole from directly in front of an observer? Not from the side, striking the circumference of a 2d circle, to use the same representation, but directly ahead, landing within the area of the circle where a black hole is, conventionally, totally dark.

Why is it that the object falling into the black hole from the side from the perspective of someone faraway flattens into a sort of shell, illuminating the circumference of the black hole, while an object falling directly into the black hole (while I understand similarly fades via red-shift and likewise would "flatten out") does not leave a similar "shell" observable to the outside observer? I would think that whatever glow/shell an object joining the event horizon would contribute, thus giving a sort of halo effect to the black hole, would be uniform throughout the black hole.

Why, then, is the black hole dark everywhere but the circumference when the entire surface of the black hole is undergoing the same accumulation of radiating "shells". Should not the whole black hole similarly radiate some uniform glow?

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    $\begingroup$ Your description is unclear and the title makes no sense. A horizon is not a 2D circle, but a 3D sphere. Any falling object falls toward the horizon the same way, so the distinction in your title is incorrect. “… flattens into the circumference, creating a sort of ‘shell’” - It doesn’t. It flattens radially, but doesn’t expand in other directions. “illuminating the circumference” - There is no “illumination”. Where did you get this idea? You are asking why something happens, but it doesn’t happen. You simply have a wrong information or wrong interpretation, but no actual question. $\endgroup$
    – safesphere
    Commented Nov 20 at 3:28
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    $\begingroup$ Why, then, is the black hole dark everywhere but the circumference…” - The circumference of a black hole itself is dark just like any other part. You may see the light of distant stars around the circumference, but it doesn’t come from the black hole of from the objects falling to the horizon. Your question is based on a wrong premise. $\endgroup$
    – safesphere
    Commented Nov 20 at 3:43

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