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clipka <ano### [at] anonymous org> wrote:
> I think there's a flaw in here, too: The event horizon itself is subject
> to relativity as well. An observer approaching the black hole in free
> fall will witness the event horizon to "dent in" in front of him, even
> when he himself has already passed the event horizon as witnessed from a
> far-away observer.
I think you have got it completely reversed.
An external observer will never see a falling object crossing the event
horizon. This is because from the external observer's point of view the
time of the falling object slows down as it approaches the event horizon.
The time of the falling object completely stops (from the external
observer's point of view) when it reaches the event horizon (which, in
fact, never happens, as the speed of time approaches zero asymptotically).
So from the external observer's point of view the falling object flattens
into a disc and its time practically stops as it approaches the event
horizon, and it "never" crosses it.
(Of course this is purely under the theoretical assumption that the
external observer could observe the falling object for eternity. This
isn't so in practice because the falling object also red-shifts to black
(again, from the point of view of the external observer) as it approaches
the event horizon, and at some point becomes completely impossible to
observe from the outside.)
The falling object itself experiences no such slowing of time. From its
*own* point of view time continues just normally. It's the time of the rest
of the universe which seems to go haywire.
What the falling object sees as it approaches the event horizon is that
it looks as if the event horizon engulfs the falling object (due to how
light bends near to the event horizon). As the falling object approaches
the event horizon it looks as if the black hole increases in size more
rapidly than the falling speed would dictate. At some altitude (but still
outside of the event horizon) it looks as if the event horizon is a
completely flat plane that takes half of the entire universe (the visible
part of the universe having been "squeezed" to the other half). As it
continues to approach the event horizon, it looks as if the event horizon
bends up, "compressing" the visible universe into an ever-shrinking circle.
Just as the falling object touches the event horizon the circle-shaped
"viewport" of the universe closes and the event horizon seems to completely
surround everything. Then the object passes the event horizon and is now
inside it.
After that it's all weird.
--
- Warp
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