An elementary question for the black hole experts

On Jun 15, 5:28 pm, Tom Roberts wrote:

The horizon is not directly observable by any observer. The horizon is NOT any
sort of physical object or place; it is merely an abstract geometrical locus
that is the outermost closed, trapped surface. Observers outside the horizon can
deduce where the horizon is located by measuring orbits or other properties of
the gravitation near the black hole, or possibly by observing the behavior of an
infalling object. Once an observer is inside the horizon, there is no way she
can measure the speed or distance of the horizon, as no infalling object or
light ray that crosses the horizon after she does can ever catch up with her.

When infalling matter approaches and enters the horizon, the horizon expands
with the local speed of light, but this is not a null geodesic -- any null
geodesic at the original position of the horizon will not expand, but rather
fall inward and intersect the singularity.

Since there is no mathematics describing the inside of a Schwarzschild
black hole, your assumption is just as good as anyone else’s. shrug

My theoretical context is GR. That is really the only context
in which "black hole" makes sense.

The Schwarzschild black hole can never be observed by distant
observers due to the infinite gravitational time dilation at the event
horizon. shrug

I'm pretty sure all the above
statements are true for any sort of black hole, but I can only
prove them for a Schwarzschild black hole, spherically symmetric
infalling matter, and an observer of negligible mass.

Thus, a black hole cannot ever form to distant observers. To a local
observer, this is a different story. shrug

Since the propagating speed of gravitational effect is c under the
concept of GR, it is subject to gravitational time dilation. Thus,
its effect will vanish outside of the event horizon. To distant
observers, a Schwarzschild black hole after it is formed would cease
to exist since its gravitational effect stops right at the horizon.
shrug

This is what the Schwarzschild black holes say under GR. shrug