Black hole questions

Folks,

I have a few questions about black holes which I am unable to find a
solution from books or the internet. They may be due to my
misunderstanding of GR. Any comment or pointer is highly appreciated.

1. When a heavy object, say a neutron star, approaches a black hole,
will the black hole be moved by the gravity of the former? If so, how
long does it take for the change of the black hole's gravity to reach
the object?

It seems to me that since it takes inifinite time for light both to
reach and escape from the event horizon, and that gravity travels at
the same speed as light, we can never observe the acceleration of a
black hole caused by another object's gravity.

2. When an object falls straight into a black hole, its thickness will
approach zero as it nears the event horizon due to relativistic
contraction. From the object's frame of reference, will the event
horizon appear elongated, flat or the same (spherical)?

From a distant observer's frame of reference, the thickness of the
object will be less than the size of an atom nucleus before it crosses
the event horizon. From the object's frame of reference, does an atom
nucleus appear thicker or the same? Or has GR broken down already?

3. When a heavy object touches a black hole's event horizon, the
space-time curvature of that point will be reduced by the gravity of
the former, and thus it is no longer part of the event horizon. Will
the event horizon be dented, broken, or enlarged?

Many TIAs.

Wai Wong
.

Relevant Pages

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  • Re: A BLACK HOLE MYTH GETS BUSTED:
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    ... a black hole, will the black hole be moved by the gravity ... neutron star, similar to how the neutron star moves towards it. ... Infalling light reaches the event horizon in finite time. ...
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