Re: Light inside a black hole?

Dear George Dishman:

George Dishman wrote:
N:dlzc D:aol T:com (dlzc) wrote:
"George Dishman" <george@xxxxxxxxxxxxxxxxx> wrote in message
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"dlzc" <dlzc1@xxxxxxx> wrote in message
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Dear Jeff Root:

Jeff Root wrote:
...
My understanding of a black hole event horizon is
that its location depends on the location and
motion of the observer.

Agreed. Just like a horizon moves away from you
as you move towards it.

David, that is one reason why I have doubts about the
physicality of the transposition of space and time
coordinates.

George, the physicality of length contraction and time
dilation in SR can never be answered.

In what way David? There is obviously the question
of whether the geometry is "truly" Riemann or it is
an emergent property but I don't see any problem
with the "physicality" of it other than the usual
semantic problem that some people include
geometric effects in "physical" while other draw a
distinction.

I was referring to the ongoing (eternal) struggle between relativists
and "Lorentz aetherists". Nature does not allow instantaneous
signalling, so the Lorentz aether cannot yield to measurement. "Does
the moving rod really contract, or is it an artifact of measurement?"
It thought that was germaine to the question of "physicality"

I don't expect this to be any
simpler.

I don't think the physics of BHs is "simple" in any
way, and it is certainly a lot harder than SR, but
that doesn't mean that the answer isn't know by
people somewhat marter than I.

I wouldn't put a lot of money on anyone having the one-and-only answer.
Just one that is consistent with their knowledge and beliefs.

The other is that I suspect any real BH
must have a non-zero angular momentum and in the
Kerr solution the coordinates revert before the
singularity.

You are on pretty solid ground there. Seems there was a post
here just a couple of days ago that pulsars got their spin not
from conservation of angular momentum (with "pre-formation
momentum"), but from shedding their outer layers... if BHs were
formed in some sort of "shock wave" in dense matter...

Regardless of their formation, suppose you had that
most elusive of objects, a non-rotating BH, say 1km in
radius. Then one atom falls into it but on an approach
trajectory that would miss the exact centre by just
1mm if projected as a straight line from the path a light
year away. Once the atom merges with the hole, the
hole has a non-zero angular momentum. I think the
Schwarzschild solution must be seen as purely
hypothetical. Even the electrical charge would have a
noise component (thermal ?) as positive and negative
ions fall in at random times even though the mean
(DC) might stay close to zero.

Agreed.

David A. Smith

.

Relevant Pages

  • Re: Light inside a black hole?
    ... the physicality of length contraction and time dilation ... from conservation of angular momentum (with "pre-formation ... Then one atom falls into it but on an approach ... Once the atom merges with the hole, ...
    (sci.astro)
  • Re: Light inside a black hole?
    ... the physicality of length contraction and time dilation ... Kerr solution the coordinates revert before the ... from conservation of angular momentum (with "pre-formation ...
    (sci.astro)
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