George replied to David:

Is the "photon historical record" of infalling light through
the event horizon isothermal?

No, it has the spectrum of whatever stars and
external objects produced it only severely
blue shifted (depending on the motion of the
infalling observer as you said).

I'd expect a free-falling observer to see infalling
light redshifted. The longer the time since crossing
the horizon, the greater the redshift. An observer
slowing his downward acceleration sufficiently would
see infalling light blueshifted.

-- Jeff, in Minneapolis

Dear George Dishman:

"George Dishman" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox
wrote in message news:yxdKe.308849$Qo.131840@fed1read01...
Dear George Dishman:

"George Dishman" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox
wrote in message news:wTpJe.286569$Qo.235834@fed1read01...
Dear George Dishman:

"George Dishman" wrote in message
...
...
If we were on the inside of an event horizon, we could
not see beyond that

That is not correct. Light does not pass out
across the horizon but it does fall in.

But (outer) space becomes (inner) timelike.

This is the area I'm less sure about but I think
that is an artefact of the Schwarzchild coordinates
and it get resolved using Kruskal but please check
that, I could easily be wrong.

Probably not. The answers I find I cannot yet understand.
URL:http://xxx.lanl.gov/abs/astro-ph/9905144
URL:http://xxx.lanl.gov/abs/gr-qc/0406109
Kruskal does not appear to do away with timelike...

I might be thinking of Eddington-Finkelstein Coordinates

http://scholar.uwinnipeg.ca/courses/...lack_Holes.htm

However, you might find this site interesting:

http://www.etsu.edu/physics/plntrm/relat/blackhl.htm

Follow the "next" link at the bottom. This is the
contents page:

http://www.etsu.edu/physics/plntrm/relat/relatabs.htm

Will do.

URL:http://xxx.lanl.gov/abs/astro-ph/9904162
... but this "fellow" seem to say that the singularity is
*coincident* with "just inside the event horizon". Which
would be true for the container Universe... just don't
know how the paper fared in peer review.

When I see "We insist that our derivation is
straightforward and there is no scope for any
ambiguity ... ", I get very suspicious. Why
is he having to have a little rant in a simple
abstract?

Agreed, because it continues to be discussed for long after 1999.
I just didn't want to load one side of the "teeter-totter"... but
provide some sort of balance.

So any light that falls in loses any correlation to
frequency, or momentum. Only energy would be conserved,
right?

No, have you looked at Andrew Hamilton's animations?

http://casa.colorado.edu/~ajsh/schw.shtml

External objects end up sweeping an arc across the sky. Other
objects in other places do the same. Definitely NOT specular
images. And this is a non-rotating BH, which adds yet another
twist (literally) to the infalling light. And note that in
the simulation, the external-Universe stars don't change
color.

The point is that you can see them, there is nothing
at the event horizon but vacuum. It isn't a physical
barrier but just a location.

You can't "see them". They are no longer point sources, but area
sources. "Like" the CMBRM.

This paragraph and image show the view of external
objects from 0.35 Schwarzschild radii:

http://casa.colorado.edu/~ajsh/singu...tml#distortion

The blue, orange and green shapes are the other
stars in his hypothetical double binary system.

Yes. Unfortunately, if outer-r becomes timelike, the entire
history of the container Universe is written on the inner Big
Bang... at least until the contained Universe evaporates.
Anything that ever (outer-time) infalls, arrvies at the inner
"Big Bang".

I don't believe that is physical though, just
an artificial peculiarity of the coordinates
Schwarzschild used.

Kruskal still has it timelike. It is not a peculiarity, but a
requirement.

Andrew Hamilton's pages
would take such effects into account.

Perhaps. Not doubting the abilities, just questioning what a
"Universe full of stars" would look like.

True but the point was simply that you would
still receive photons from outside.

Still receive photons is not at issue. Are they specular?
No. Are they diffuse? Yes and no. Is the
surfaceo-of-last-emission transparent?

What surface?

The surface of the star that originally emitted the light.

There is no material to emit at
the event horizon, it is a location and all
matter is passing it at the speed of light
as determined by an observer at infinity (I
think!).

Not quite. It is a location in *time*, and all matter (and
energy) propagate from there. And I understand that you are
uncomfortable with this.

The kinetic velocities obtained in the new internal space will
likely only be sufficient to conserve energy and momentum.

No. Is the "photon historical record" of infalling light
through the event horizon isothermal?

No, it has the spectrum of whatever stars and
external objects produced it only severely
blue shifted (depending on the motion of the
infalling observer as you said).

*Integrated over time*. Is the integral light history of our
Universe from formation of a BH, until it evaporates, isothermal?
I think it is *to a close approximation*.

The classical surface of last emission is not within the
Universe inside the event horizon. The closest "place"
in this Universe is "just inside the event horizon". You
can't see beyond it. It is opaque, if you accept my
"abomination" of the word. We won't get specular images
from before the CMBRM... either way.

Well it is certainly opaque around 379,000 years
because we have the photos ;-) I'm not aware of
any other "classical surface of last emission"
though.

This is my quest. I wonder if the "structures" were already
formed (coalescence not a problem), the Universe-filling gas,
wasn't Universe filling (the non-issue of absoprtion spectra
disappears), and the CMBRM is a/the "photographic record"
of our container Universe.

Go back far enough, to the end of the inflationary
period IIRC, and what now constitutes the observable
universe was the size of a grapefruit. There wouldn't
be much space for light to get through at that density.

Note I am not entirely diagreeing. I wonder whether
primordial black holes could have grown rapidly in
such a high density environment that they existed
before the mix became transparent and were the
seeds of what are now galactic clusters. I think we
may lewarn a lot when we can detect Pop III SNe but
we will have to wait for at least the next generation
of telescopes to come on line.

No one currently believes the Universe started out "the size of a
grapefruit", unless they also posit "c_BB c_now". You "helped
establish" the CMBRM was many tens of million light years thick,
only ~300,000 years after the BB, based on the (lack of) spectra.
You can't get that big from a point (essentially) in that time.
Or am I misunderstanding again?

I think you are being misled by the coordinate
feature of the Schwarzschild solution. Perhaps
after looking at Andrew's site, you could
reformulate the question.

I can't.

I think you have above.

Bjoern tried to help me "get it", but the ground is rocky, and
crops will not (yet) grow. I'm not dead yet, so maybe there
is hope.

The simple answer is that GR says there was no
container and the density was far too high to
see through it anyway when you go back far
enough. The "surface of last scattering" is
a feature of the gas _in_ the universe and
a black hole has nothing equivalent.

GR *does* allow description of a container, but it is a
description you are not comfortable with. The inside of the
event horizon is the only spatial location in the newly minted
space from which the light could have come, so is therefore
opaque. And you are reciting the established/accepted source of
the CMBR, that does not obviate an alternate choice of sources
*fully in compliance with GR*. GR doesn't require that the CMBRM
be Universe filling gas, unless gas is the source. The source
could be a container Universe, depending on the answer to my
question to Tom. Even so, it could be a way to resolve the age
of the Universe that contains us, since only certain light
profiles could result in what we see.

Or not.

The mix is not assumed, it is observed in
primitive stars and other ways.

It isn't the mix, George. It is the distribution.

Yes, I follow your question now.

From nearly patternless to fully coalesced in less than 1 Gy.
A universal *smooth* distribution can't coalesce under the
effects of gravity. So we started out pretty lumpy (which we
are still working on resolving).

Our theories of galactic formation have a long
way to go. The roles of dark matter and super-
massive black holes are far from being fully
understood so watch this space.

;) Always do! And I do try and understand.

It also
predicted from nucleosynthesis as the best
fit to other measurements as I said below.
Check the bands in the diagram at the bottom

http://www.astro.ucla.edu/~wright/BBNS.html

You are right we assume that is the source,
but at a high enough temperature you get a
black body from any mix. Why do you think
this is a problem?

As I have said, my "hypothesis" allows for structures
to be found right up to the CMBRM, even for heavier
elements to be present from the "get go". And since
infalling light is not fatally blue shifted for those that are
"falling towards the singularity", the CMBRM is not
necessary to have protected us from the "fires of
creation".

I don't follow, if we were falling towards a
singularity, the universe would be shrinking.

No. The outer r becomes inner t. The outer Universe "expects
us" to become more and more dense. We have internal-space that
is orthogonal to our time. This space is defined by c and time.
The speed of light (as expected by the outer Universe) is an
inverse function of density. As we approach a singularity (from
outer reconing), c approaches 0 (as the outer Universe expects,
not as we would observe), and space becomes larger and larger.
Viola! Expansion. The problem is the "discontinuity" that
occurs at the event horizon, and the confusion between inner and
outer coordinates that results. But that is just a description
problem (eg: non-standard verbage is required).

I also don't agree with the infalling light being
necessarily fatal.

I wasn't really saying that earlier.

I wasn't sure what you meant by:

I
can't be sure what we would have seen had it not
existed, but then we wouldn't be here to see anything.

... perhaps that there would be no matter for us to be
comprised of...

Yes, that was it. What the universe would look like
if it contained no matter whatsoever is moot!

This is where I diverge with Bjoern. He believes you can have a
Universe without matter. But Einstein suggests that spacetime is
the product of all mass-energy in the Universe (if I understand
correctly). This means no mass/energy provides null spacetime.

Given a Universe, you have mass/energy. Given mass/energy, you
have spacetime.

That was my point, even after crossing the
event horizon, you would still be able to
see the part of the universe you had left
hence the horizon cannot be opaque.

There is no part of the external Universe that extends into
the internal Universe. What you see, perhaps, is all the
positions and all the intensities of all the stars, and the
container Universe's CMBR, spread across 2 pi
steradians... for all time. Neglecting expansion, which
only serves to red shift the panopoly. It *is* opaque, it is
NOT specular. You cannot see before the Big Bang, even
without a CMBRM.

But you would in what you describe, you would
be seeing "all the stars" in the container
Universe, the horizon would only be a location
in the vacuum.

Only as a plenum. The "off ramp" is all you can see, with the
CMBR as the "sound of car horns" on a freeway to which we are but
a side road.

Structures can infall into large black holes and survive...
probably not gravitationally bound ones, but who knows. Maybe
the nature of the early Universe actually tells us how steep the
off ramp is (namely something about how many of the four forces
yield to the curvature of the event horizon).

David A. Smith

Dear George Dishman:

"George Dishman" wrote in message
...
....
Probably not. The answers I find I cannot yet understand.
URL:http://xxx.lanl.gov/abs/astro-ph/9905144
URL:http://xxx.lanl.gov/abs/gr-qc/0406109
Kruskal does not appear to do away with timelike...

I might be thinking of Eddington-Finkelstein Coordinates

http://scholar.uwinnipeg.ca/courses/...lack_Holes.htm

They still have an inner time coordinate v, that is a blend of
outer time and outer space (specifically r). It only helps to
describe the inner in terms the outer can "comprehend". And it
blends two orthogonal axes to do it.

However, you might find this site interesting:

http://www.etsu.edu/physics/plntrm/relat/blackhl.htm

.... only for r r_B (the surface of the mass). When, in this
Universe, did the quarks making up your protons and neutrons and
your electrons *not* exist? If mass existed right up to the Big
Bang, this coordinate definition sounds like it is invalid.

Follow the "next" link at the bottom. This is the
contents page:

http://www.etsu.edu/physics/plntrm/relat/relatabs.htm

Good stuff! Thanks!

David A. Smith

Dear Jeff Root:

"Jeff Root" wrote in message
ups.com...
George replied to David:

Is the "photon historical record" of infalling light through
the event horizon isothermal?

No, it has the spectrum of whatever stars and
external objects produced it only severely
blue shifted (depending on the motion of the
infalling observer as you said).

I'd expect a free-falling observer to see infalling
light redshifted. The longer the time since crossing
the horizon, the greater the redshift. An observer
slowing his downward acceleration sufficiently would
see infalling light blueshifted.

True with expansion. As to how you would reverse time to "slow
your downward acceleration"...

David A. Smith

David wrote to George:

the CMBRM was many tens of million light years thick

I ripped that out of context, and I'm not at all certain I know
what you meant, but about ten years ago I asked an astronomer
who specializes in IR light from plasmas and gases (nebulae,
galactic jets, and the like) what the optical depth (thickness)
of the CMBR was, and he said it was about 100 parsecs.
That is, all the light we see in the CMBR is from a shell only
100 parsecs (300 light-yers) thick.

-- Jeff, in Minneapolis

David replied to Jeff:

I'd expect a free-falling observer to see infalling
light redshifted. The longer the time since crossing
the horizon, the greater the redshift. An observer
slowing his downward acceleration sufficiently would
see infalling light blueshifted.

True with expansion. As to how you would reverse time to "slow
your downward acceleration"...

Expansion? Are you referring to the fact that everything falling
into a black hole gets stretched out? Of course, it also gets
squeezed in on the sides. An explorer free-falling into a very
large black hole would not see anything change at the instant
he crossed the event horizon. As he fell in farther and farther
the tide would pull his socks down and make his hair stand on
end. Eventually it would pull his feet and head off of his body.

It wouldn't be necessary to reverse time to slow acceleration.
A rocket would still work, although I don't know what direction
you would aim it, and of course it wouldn't do much good for
very long.

-- Jeff, in Minneapolis

Dear Jeff Root:

"Jeff Root" wrote in message
ups.com...
David wrote to George:

the CMBRM was many tens of million light years thick

I ripped that out of context, and I'm not at all certain I know
what you meant, but about ten years ago I asked an astronomer
who specializes in IR light from plasmas and gases (nebulae,
galactic jets, and the like) what the optical depth (thickness)
of the CMBR was, and he said it was about 100 parsecs.
That is, all the light we see in the CMBR is from a shell only
100 parsecs (300 light-yers) thick.

That is significantly smaller than what was arrived at here in
sci.astro, in Jan 2003 (thread Olber's paradox). Tens of million
light years was the number then. Maybe new information has come
to light? ;)

David A. Smith

Dear Jeff Root:

"Jeff Root" wrote in message
ups.com...
David replied to Jeff:

I'd expect a free-falling observer to see infalling
light redshifted. The longer the time since crossing
the horizon, the greater the redshift. An observer
slowing his downward acceleration sufficiently would
see infalling light blueshifted.

True with expansion. As to how you would reverse
time to "slow your downward acceleration"...

Expansion? Are you referring to the fact that everything
falling into a black hole gets stretched out?

No. I am referring to the solution to a Black Hole using Kruskal
coordinates in GR. As you propagate towards the singularity
(outer Universe), inner space gets larger, just like Universal
expansion.

Of course, it also gets
squeezed in on the sides. An explorer free-falling into a very
large black hole would not see anything change at the instant
he crossed the event horizon.

Not locally, no. But what he would see of the outer Universe
would be distorted before he arrived at the event horizon, and
would only distort more.

As he fell in farther and farther
the tide would pull his socks down and make his hair stand on
end. Eventually it would pull his feet and head off of his
body.

Not likely, if a new Universe is formed inside (Kruskal and GR),
and your infall direction becomes propagating along your time
axis.

It wouldn't be necessary to reverse time to slow acceleration.
A rocket would still work, although I don't know what direction
you would aim it, and of course it wouldn't do much good for
very long.

It wouldn't work, since you can't stop time for the Universe at
large.

David A. Smith

"Jeff Root" wrote in message
ups.com...
George replied to David:

Is the "photon historical record" of infalling light through
the event horizon isothermal?

No, it has the spectrum of whatever stars and
external objects produced it only severely
blue shifted (depending on the motion of the
infalling observer as you said).

[Note the parenthetical qualification.]

I'd expect a free-falling observer to see infalling
light redshifted.

A free-falling observer should see red-shift
behind and ahead but blue-shift on all sides,
a side-effect of 'spaghettification'.

My point however was that it would be a
shifted view of the original spectrum,
there is no mechanism to thermalise what
would be seen.

The longer the time since crossing
the horizon, the greater the redshift. An observer
slowing his downward acceleration sufficiently would
see infalling light blueshifted.

That's what I meant, the closest achievable
to hovering just inside the event horizon
which is impossible of course.

George

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:AvzKe.6008$E95.4317@fed1read01...
Dear George Dishman:

"George Dishman" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:yxdKe.308849$Qo.131840@fed1read01...
Dear George Dishman:

"George Dishman" wrote in message
...
....
... have you looked at Andrew Hamilton's animations?

http://casa.colorado.edu/~ajsh/schw.shtml

External objects end up sweeping an arc across the sky. Other objects
in other places do the same. Definitely NOT specular images. And this
is a non-rotating BH, which adds yet another twist (literally) to the
infalling light. And note that in the simulation, the external-Universe
stars don't change color.

The point is that you can see them, there is nothing
at the event horizon but vacuum. It isn't a physical
barrier but just a location.

You can't "see them". They are no longer point sources, but area sources.

Why? Those on Andrew's page are nearby and start
as areas (just as we see the Sun) and are then
distorted. Distant point sources would surely
remain as points, wouldn't they?

"Like" the CMBRM.

....
Yes. Unfortunately, if outer-r becomes timelike, the entire history of
the container Universe is written on the inner Big Bang... at least
until the contained Universe evaporates. Anything that ever (outer-time)
infalls, arrvies at the inner "Big Bang".

I don't believe that is physical though, just
an artificial peculiarity of the coordinates
Schwarzschild used.

Kruskal still has it timelike. It is not a peculiarity, but a
requirement.

Of course, but isn't the time axis contiguous
through the horizon? It was the switch between
spatial and temporal that I thought was the
artefact.

Andrew Hamilton's pages
would take such effects into account.

Perhaps. Not doubting the abilities, just questioning what a "Universe
full of stars" would look like.

Go out in your back yard one night ;-)

Serously though, why would you expect to see
anything different?

True but the point was simply that you would
still receive photons from outside.

Still receive photons is not at issue. Are they specular?
No. Are they diffuse? Yes and no. Is the
surfaceo-of-last-emission transparent?

What surface?

The surface of the star that originally emitted the light.

Someone well outside the event horizon would see
a sky not unlike our own (perhaps brighter if
the were in the core of a galaxy). Someone
infalling just inside the horizon would see the
same but squished into a smaller fraction of the
sky with the rest looking devoid of sources. You
seem to be saying the whole sky would be
illuminated but it should be more like looking
through a pinhole lens above you.

There is no material to emit at
the event horizon, it is a location and all
matter is passing it at the speed of light
as determined by an observer at infinity (I
think!).

Not quite. It is a location in *time*, and all matter (and energy)
propagate from there. And I understand that you are uncomfortable with
this.

I am uncomfortable with the idea that there is
a physical exchange of axes because I have read
many times that it was never real, just a problem
with the coordinates, but I can't find useful
references and I may be mistaken about which
coordinates had and resolved the problem.

The kinetic velocities obtained in the new internal space will likely only
be sufficient to conserve energy and momentum.

Velocity relative to what? Relative to an
observer outside the horizon, it is greater
than the speed of light (I think).

No. Is the "photon historical record" of infalling light through the
event horizon isothermal?

No, it has the spectrum of whatever stars and
external objects produced it only severely
blue shifted (depending on the motion of the
infalling observer as you said).

*Integrated over time*.

Why? We only see what is on our past light cone.

Is the integral light history of our Universe from formation of a BH,
until it evaporates, isothermal? I think it is *to a close approximation*.

....
Note I am not entirely diagreeing. I wonder whether
primordial black holes could have grown rapidly in
such a high density environment that they existed
before the mix became transparent and were the
seeds of what are now galactic clusters. I think we
may lewarn a lot when we can detect Pop III SNe but
we will have to wait for at least the next generation
of telescopes to come on line.

No one currently believes the Universe started out "the size of a
grapefruit",

Put "grapefruit inflation cosmology" into Google
and you will get about 600 hits ;-) It is the
conventional view at the moment I believe.

http://zebu.uoregon.edu/~imamura/123...lecture-7.html

"During inflation, the Universe increases in size by
a huge factor -- perhaps by as much as a factor of
10^(10^12)!!! Some models say that the size of the
current Universe increased from 10^-50 centimeters
to roughly the size of a grapefruit during inflation."

The lecture seems contradictory on the period of
inflation, saying it started at the end of the
era from 10^-43s to 10^-35s and ending at the
start of the next period. Anyway, the use of a
grapefruit to illustrate the size wasn't my idea!

unless they also posit "c_BB c_now". You "helped establish" the CMBRM
was many tens of million light years thick, only ~300,000 years after the
BB, based on the (lack of) spectra. You can't get that big from a point
(essentially) in that time. Or am I misunderstanding again?

You are misunderstanding something but this
has moved on so I'll reply to a later post.

The simple answer is that GR says there was no
container and the density was far too high to
see through it anyway when you go back far
enough. The "surface of last scattering" is
a feature of the gas _in_ the universe and
a black hole has nothing equivalent.

GR *does* allow description of a container,

It does allow it for a black hole but not for the
big bang AIUI. The big bang is closer to a white
hole in GR.

but it is a description you are not comfortable with.

No it was your switching of teporal and spatial
axes that I doubt.

The inside of the event horizon is the only spatial location in the newly
minted space from which the light could have come, so is therefore opaque.
And you are reciting the established/accepted source of the CMBR, that
does not obviate an alternate choice of sources *fully in compliance with
GR*.

GR says the event horizon is just a place in the
vacuum so it allows light to pass inwards freely.
Light could also pass outwards execpt that any
source inside is moving away from an external
observer faster than the speed of light so it
cannot reach them, the light falls inwards even
if emitted in an outwards direction. I am saying
that the horizon isn't opaque and I don't know
why you are suggesting it would be.

GR doesn't require that the CMBRM be Universe filling gas, unless gas is
the source.

GR doesn't provide a source for the CMBR of any
kind, you need matter to produce it.

The source could be a container Universe, depending on the answer to my
question to Tom.

If there were a container then the source could
be the matter in the container universe in which
case the light would have falling in through the
horizon. That is quite different to saying it was
the horizon that produced the light or that the
horizon is opaque and could in some way thermalise
the spectrum of the stars in the container.

Even so, it could be a way to resolve the age of the Universe that
contains us, since only certain light profiles could result in what we
see.

Or not.

I'm not sure what you are trying to resolve, the
age appears to be 13.7 billion years.

As I have said, my "hypothesis" allows for structures
to be found right up to the CMBRM, even for heavier
elements to be present from the "get go". And since
infalling light is not fatally blue shifted for those that are "falling
towards the singularity", the CMBRM is not
necessary to have protected us from the "fires of
creation".

I don't follow, if we were falling towards a
singularity, the universe would be shrinking.

No. The outer r becomes inner t.

I don't accept that, I believe it was found to be
an artefact of the maths only. I will be happy if
you can show me to be wrong though.

The outer Universe "expects us" to become more and more dense. We have
internal-space that is orthogonal to our time. This space is defined by c
and time. The speed of light (as expected by the outer Universe) is an
inverse function of density. As we approach a singularity (from outer
reconing), c approaches 0 (as the outer Universe expects,

Pardon? c is invariant in GR locally. The outer
universe sees increasing time dialtion but that
doesn't change c. I'm realy not following what
you are saying here at all.

not as we would observe), and space becomes larger and larger. Viola!
Expansion. The problem is the "discontinuity" that occurs at the event
horizon, and the confusion between inner and outer coordinates that
results. But that is just a description problem (eg: non-standard verbage
is required).

Or better coordinates!

I also don't agree with the infalling light being necessarily fatal.

I wasn't really saying that earlier.

I wasn't sure what you meant by:

I
can't be sure what we would have seen had it not
existed, but then we wouldn't be here to see anything.

... perhaps that there would be no matter for us to be comprised of...

Yes, that was it. What the universe would look like
if it contained no matter whatsoever is moot!

This is where I diverge with Bjoern. He believes you can have a Universe
without matter.

You can solve the equations for that condition,
but we wouldn't be in it.

But Einstein suggests that spacetime is the product of all mass-energy in
the Universe (if I understand correctly). This means no mass/energy
provides null spacetime.

It is partly philosophical, what does it mean
to calculate the trajectory of a test paticle
in a universe devoid of particles ;-)

Given a Universe, you have mass/energy. Given mass/energy, you have
spacetime.

That seems more relevant to our situation.

That was my point, even after crossing the
event horizon, you would still be able to
see the part of the universe you had left
hence the horizon cannot be opaque.

There is no part of the external Universe that extends into
the internal Universe. What you see, perhaps, is all the
positions and all the intensities of all the stars, and the
container Universe's CMBR, spread across 2 pi
steradians... for all time. Neglecting expansion, which
only serves to red shift the panopoly. It *is* opaque, it is
NOT specular. You cannot see before the Big Bang, even
without a CMBRM.

But you would in what you describe, you would
be seeing "all the stars" in the container
Universe, the horizon would only be a location
in the vacuum.

Only as a plenum. The "off ramp" is all you can see, with the CMBR as the
"sound of car horns" on a freeway to which we are but a side road.

It would have to be seeing the lights of cars
coming down the off ramp. Even from a great
distance where the individual lights cannot
be distinguished, the integrated spectrum
would be a blend of many thermal curves but
at different temperatures (types of bulbs)
and that mix wouldn't be thermal itself.

Structures can infall into large black holes and survive... probably not
gravitationally bound ones, but who knows. Maybe the nature of the early
Universe actually tells us how steep the off ramp is (namely something
about how many of the four forces yield to the curvature of the event
horizon).

for a very large black hole, the acceleration
at the horizon is negligible. I believe a human
in a spacesuit could easily survive crossing the
horizon of a super-massive BH with nothing more
than a spacesuit.

George