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Can we detect a gravitation field of an object after it failed into a black hole?

Take a simple non-rotating, non-charged black hole and throw a massive object into the black hole:

When the object is outside of the black hole, we can detect the gravitation field of the object.

After the object quickly crossed the event horizon, can we still detect the object's gravitation field?

If yes, does it mean that we (outside of the black hole) can detect how the object fails to the singularity?

If no, how it will look like? Will it be a wave on the event horizon like circular waves on the water? Can we deduce from this wave any information about the state of the object behind the horizon?

Roman Klimenko
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  • We will never see the object fall into the event horizon. Once it hits the event horizon, for any outside observer, the object will appear statonary, as if frozen in time. – Yuzuriha Inori Apr 06 '18 at 09:02
  • Hi romaklimenko. Since you reposted your earlier question I assume you think the question I've linked isn't a duplicate. In that case can you edit your question to explain why the existing question doesn't address it, and I'll reopen this. – John Rennie Apr 06 '18 at 09:07
  • Hi @JohnRennie, sorry for misunderstanding, I believe the current question is the best rephrasing of the problem. The previous actually had two questions: will the object stay forever as a "hill" on top of the horizon. This was answered in the question about the giraffe. But my main concern still: what happens to the object when it crosses the event horizon - will it fail to the center or not?: anyway, its mass will merge somehow with the black hole mass and investigation of how this will happen may show us how the object behaves behind the horizon. This is described in the current question. – Roman Klimenko Apr 06 '18 at 09:35
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    As seen from the outside the object takes an infinite time to reach the horizon, so the observer outside never sees it get inside the black hole. This is covered by How can anything ever fall into a black hole as seen from an outside observer?. – John Rennie Apr 06 '18 at 09:40
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    I like your answer at the linked question @John, but some of the other answers there are rather dubious... – PM 2Ring Apr 06 '18 at 16:33

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