Dear Tom Roberts:

"Tom Roberts" wrote in message
. ..
N:dlzc D:aol T:com (dlzc) wrote:
Dear Tom Roberts:
"Tom Roberts" wrote in message
...
N:dlzc D:aol T:com (dlzc) wrote:
The CMBR appears to have a perfect blackbody emission
curve, at least from what is left after passing through
intergalactic and interstellar "stuff". Normal matter does
not produce the kind of emission curve that the CMBR
produces (apparently).

Sure it does, as long as it is black.

I find no reference that supports this claim, Tom.

Look in elementary textbooks on thermodynamics and/or
quantum mechanics. You'll have a difficult time finding a
reference for 1+1=2 also.

Thanks for your efforts, Tom. Bilge provided the missing (for
me) piece with the plasma, excited beyond the absorption/emission
energies.

Any black object will emit a black body spectrum.
And virtually all astronomical objects are very close
to black (with some absorbtion/emission lines added
-- ignore them). That's why the black body model is
so useful.

I have always imagined the thermal emissions of normal
matter as the typical material "emission bands", smeared
by thermal velocities (gamma factor from individual atomic
motions). Neutrons don't have emission bands. I
suppose their "atmospheres" do... iron.

There is more to it that that. You are just considering atomic
emission for atoms that to not ionize. But in many materials
there are free electrons (i.e. electrons not bound to any
particular atom), and for hot enough objects some/most
atoms will ionize -- both of these contribute a continuous
spectrum. The combination of all of the radiation from a black
object reproduces the blackbody spectrum because
of the thermodynamics of the situation.

Tom, I am given to understand that the CMBR was
produced by an opaque "medium" (CMBRM).

Yes. In the early universe no atom could remain an atom
very long because the high temperature gave other particles
enough kinetic energy so a simple collision often/usually
would ionize the atom. So between a few seconds and
~300k years after the big bang the universe was filled with a
charged plasma consisting primarily of electrons
and protons. When the temperature had been reduced
enough so most collisions did not have enough K.E. to
ionize the atoms the electromagnetic attraction between
protons and electrons quickly caused them to form
hydrogen atoms. The charged plasma was essentially
opaque to all types of EM radiation (hence it was black),
but the hydrogen is transparent to most EM radiation.
So in a short time the radiation emitted by the plasma could
suddenly propagate over large distances. It is
remnants of this radiation we see as the CMBR.

But the CMBR is free of the absorption bands of "cooler"
hydrogen. Let's pretend a timeline, with "CMBRM stops glowing"
at 300,000 pBB (post-Big Bang). What about this Universe
filling, formerly opticaly dense, hydrogen at 301,000 pBB? Does
this mean that it all coalesced to "structures" in
next-to-no-time?

I am further given to understand that the CMBR shows an
intensity vs. frequency curve that
is NOT reproducable by hydrogen at 3000 K "locally".

Right. Because it was not generated by hydrogen, it was
generated by the charged plasma, and modified by
transmisstion through the subsequent universe....

The CMBRM filed the early Universe. The CMBRM emitted
blackbody radiation. The radiation was not absorbed by the
same Universe-filling hydrogen because...

Because hydrogen is transparent to most of the CMBR
radiation. The CMBR was emitted as a continuous blackbody
spectrum ~3000 K; hydrogen can only absorb discrete lines
from it, and the large redshift and Doppler shifting of the
hydrogen in the early universe smeared out the bands so much
they are not prominent (or perhaps not apparent at all,
I don't know).

Not detectable at all.

At some point the CMBR had redshifted enough so it could
not be absorbed at all by hydrogen, and since then the
universe has been transparent to it (except for isolated
objects we call stars).

Let me ask a related question. The CMBRM has been described as
opaque and isothermal. Presumably "opaque" could be defined as
no emissions detectable from beyond a certain place (watch my
terms). So let me ask this question about the Universe that
contains ours... It would be certainly opaque, since we cannot
see beyond the Big Bang, but would the container Universe appear
isothermal? Rather than the CMBRM being some intermediate matter
state on *this* side of the Big Bang, could it simply be
infalling light?

I gave you a couple of "days off" so hopefully I don't elicit an
ulcer on your part...

David A. Smith

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:tfUHe.236624$Qo.33184@fed1read01...
Dear Tom Roberts:

"Tom Roberts" wrote in message
. ..
N:dlzc D:aol T:com (dlzc) wrote:
....
Tom, I am given to understand that the CMBR was
produced by an opaque "medium" (CMBRM).

Yes. In the early universe no atom could remain an atom
very long because the high temperature gave other particles
enough kinetic energy so a simple collision often/usually
would ionize the atom. So between a few seconds and
~300k years after the big bang the universe was filled with a charged
plasma consisting primarily of electrons
and protons. When the temperature had been reduced
enough so most collisions did not have enough K.E. to
ionize the atoms the electromagnetic attraction between
protons and electrons quickly caused them to form
hydrogen atoms. The charged plasma was essentially
opaque to all types of EM radiation (hence it was black),
but the hydrogen is transparent to most EM radiation.
So in a short time the radiation emitted by the plasma could suddenly
propagate over large distances. It is
remnants of this radiation we see as the CMBR.

But the CMBR is free of the absorption bands of "cooler" hydrogen. Let's
pretend a timeline, with "CMBRM stops glowing" at 300,000 pBB (post-Big
Bang). What about this Universe filling, formerly opticaly dense,
hydrogen at 301,000 pBB? Does this mean that it all coalesced to
"structures" in next-to-no-time?

No, it was still hot, though slightly cooler, and
still ubiquitous and pretty much homogenous but
instead of being a hot dense opaque plasma, it
was a hot dense transparent non-ionised gas. To
get a picture in your mind, watch this video of
the Landolt reaction and imagine it happening in
reverse:

http://video.uni-regensburg.de:8080/...lt_Reaction.rm

At some point the CMBR had redshifted enough so it could
not be absorbed at all by hydrogen, and since then the
universe has been transparent to it (except for isolated
objects we call stars).

Let me ask a related question. The CMBRM has been described as opaque and
isothermal. Presumably "opaque" could be defined as no emissions
detectable from beyond a certain place (watch my terms).

"a certain place" may give the wrong impression
although obviously we are "here". It is perhaps
better to consider opaque in this case in terms
of the mean free path of a photon being greater
than the time from emission to the time of
complete transparency multiplied by the speed of
light regardless of where the photon is emitted
since the CMBRM was almost homogenous throughout
the universe.

So let me ask this question about the Universe that contains ours...

There is no "Universe that contains ours" in the
Big Bang model so it is not meaningful to ask the
question.

George

Dear George Dishman:

"George Dishman" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox
wrote in message news:tfUHe.236624$Qo.33184@fed1read01...
Dear Tom Roberts:

"Tom Roberts" wrote in message
. ..
N:dlzc D:aol T:com (dlzc) wrote:
...
Tom, I am given to understand that the CMBR was
produced by an opaque "medium" (CMBRM).

Yes. In the early universe no atom could remain an atom
very long because the high temperature gave other particles
enough kinetic energy so a simple collision often/usually
would ionize the atom. So between a few seconds and
~300k years after the big bang the universe was filled with a
charged plasma consisting primarily of electrons
and protons. When the temperature had been reduced
enough so most collisions did not have enough K.E. to
ionize the atoms the electromagnetic attraction between
protons and electrons quickly caused them to form
hydrogen atoms. The charged plasma was essentially
opaque to all types of EM radiation (hence it was black),
but the hydrogen is transparent to most EM radiation.
So in a short time the radiation emitted by the plasma
could suddenly propagate over large distances. It is
remnants of this radiation we see as the CMBR.

But the CMBR is free of the absorption bands of
"cooler" hydrogen. Let's pretend a timeline, with
"CMBRM stops glowing" at 300,000 pBB (post-Big Bang). What
about this Universe filling, formerly
opticaly dense, hydrogen at 301,000 pBB? Does this
mean that it all coalesced to "structures" in
next-to-no-time?

No, it was still hot, though slightly cooler, and
still ubiquitous and pretty much homogenous but
instead of being a hot dense opaque plasma, it
was a hot dense transparent non-ionised gas. To
get a picture in your mind, watch this video of
the Landolt reaction and imagine it happening in
reverse:

http://video.uni-regensburg.de:8080/...lt_Reaction.rm

I don't have the applet required to play it. I found another
site that had it in Quicktime. Hydrogen absorbs light. We find
its signature everywhere we look, when we look at point sources.
But we don't find it with the CMBR. And it has been exposed
longer, assuming the Universe filling gas didn't coalesce.

At some point the CMBR had redshifted enough so it could
not be absorbed at all by hydrogen, and since then the
universe has been transparent to it (except for isolated
objects we call stars).

Let me ask a related question. The CMBRM has been
described as opaque and isothermal. Presumably "opaque"
could be defined as no emissions detectable from beyond a
certain place (watch my terms).

"a certain place" may give the wrong impression
although obviously we are "here".

We can't see beyond the CMBRM, so it is opaque. If we were on
the inside of an event horizon, we could not see beyond that
Universe's Big Bang, and see specular images of the container
Universe. The Big Bang (aka. the inside of an event horizon) is
opaque *without* invoking space-filling hydrogen plasma.

It is perhaps
better to consider opaque in this case in terms
of the mean free path of a photon being greater
than the time from emission to the time of
complete transparency multiplied by the speed of
light regardless of where the photon is emitted
since the CMBRM was almost homogenous throughout
the universe.

So let me ask this question about the Universe that contains
ours...

There is no "Universe that contains ours" in the
Big Bang model so it is not meaningful to ask the
question.

The Schwarzchild solution to GR for a black hole, describes
another Universe inside the black hole, with internal time
starting where external space leaves off. Since the Big Bang
model is commonly dressed in the clothes of GR, are you sure
'There is no "Universe that contains ours" in the Big Bang model
so it is not meaningful to ask the question'?

You say imagine the Landolt reaction in reverse... imagine that
our Big Bang is the inside of the event horizon of the (probably
really big) black hole that contains our Universe.

So sure are you?

David A. Smith

N:dlzc D:aol T:com (dlzc) wrote:

Dear Tom Roberts:

"Tom Roberts" wrote in message

. ..
Yes. In the early universe no atom could remain an atom
very long because the high temperature gave other particles
enough kinetic energy so a simple collision often/usually
would ionize the atom. So between a few seconds and
~300k years after the big bang the universe was filled with a
charged plasma consisting primarily of electrons
and protons. When the temperature had been reduced
enough so most collisions did not have enough K.E. to
ionize the atoms the electromagnetic attraction between
protons and electrons quickly caused them to form
hydrogen atoms. The charged plasma was essentially
opaque to all types of EM radiation (hence it was black),
but the hydrogen is transparent to most EM radiation.
So in a short time the radiation emitted by the plasma could
suddenly propagate over large distances. It is
remnants of this radiation we see as the CMBR.

But the CMBR is free of the absorption bands of "cooler"
hydrogen. Let's pretend a timeline, with "CMBRM stops glowing"
at 300,000 pBB (post-Big Bang). What about this Universe
filling, formerly opticaly dense, hydrogen at 301,000 pBB? Does
this mean that it all coalesced to "structures" in
next-to-no-time?

Not at all. At Z~1000 the 3000K background glow was isotropic and the
distance to the surface of last scattering correspondingly shorter. The
distance to the surface of last scattering for H-alpha and other
wavelengths where neutral hydrogen can absorb (and re-emit) will be
different and second order effects may make for a slight change in the
BB radiation intensity at those wavelengths, but to first order every
neutral hydrogen atom is surrounded by an isotropic black body emitter
at 3000K.

Each hydrogen atom that absorbs an H-alpha photon will enventually
re-emit it in some other direction. The radiation field stays isotropic
- to first order all the neutral hydrogen in that era does is to make
the universe more opaque at certain resonant frequencies.

Because hydrogen is transparent to most of the CMBR
radiation. The CMBR was emitted as a continuous blackbody
spectrum ~3000 K; hydrogen can only absorb discrete lines
from it, and the large redshift and Doppler shifting of the
hydrogen in the early universe smeared out the bands so much
they are not prominent (or perhaps not apparent at all,
I don't know).

Not detectable at all.

Beyond experimental limits. I think your problem is that you are not
imagining the situation correctly. The universe is bathed in an
isotropic radiation field from the big bang. It is now a tiny 3K
background but at Z~1000 it was 3000K (and still isotropic).

Let me ask a related question. The CMBRM has been described as
opaque and isothermal. Presumably "opaque" could be defined as
no emissions detectable from beyond a certain place (watch my
terms). So let me ask this question about the Universe that
contains ours... It would be certainly opaque, since we cannot
see beyond the Big Bang, but would the container Universe appear
isothermal? Rather than the CMBRM being some intermediate matter
state on *this* side of the Big Bang, could it simply be
infalling light?

The observable horizon is moving away from us at the speed of light. The
challenge for cosmology is to explain why our patch of universe is so
isotropic. Alan Guth's inflation is one possible solution:

http://nedwww.ipac.caltech.edu/level..._contents.html

You need to think more carefully about how absorbtion lines arise in a
continuum spectrum. Energy is always conserved.

Regards,
Martin Brown

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:jNbJe.275166$Qo.182521@fed1read01...

I don't have the applet required to play it. I found another site that
had it in Quicktime.

It used Real Player but as long as you got
the idea, a bulk material can switch from
opaque to transparent.

Hydrogen absorbs light.

Hydrogen also emits light. By the laws of
thermodynamics, there must be a precise
relationship between the two.

We find its signature everywhere we look, when we look at point sources.
But we don't find it with the CMBR. And it has been exposed longer,
assuming the Universe filling gas didn't coalesce.

If the gas is in equilibrium, the energy
absorbed must be balanced by that emitted.
It is therefore exactly at the crossover
between producing absorption and emission
lines. Given the slight anisotropy, perhaps
it will be possible some time soon to detect
a line redshifted down but it has taken
sensitive space-borne missions just to
measure the anisotropy in broad bands so
looking for individual lines would require
another step up in design.

At some point the CMBR had redshifted enough so it could
not be absorbed at all by hydrogen, and since then the
universe has been transparent to it (except for isolated
objects we call stars).

Let me ask a related question. The CMBRM has been
described as opaque and isothermal. Presumably "opaque"
could be defined as no emissions detectable from beyond a
certain place (watch my terms).

"a certain place" may give the wrong impression
although obviously we are "here".

We can't see beyond the CMBRM, so it is opaque.

That is correct, it rapidly absorbs any light
that passes through it.

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. If
you could hover just inside the event horizon
you would be bombarded by high energy photons
falling in.

Universe's Big Bang, and see specular images of the container Universe.
The Big Bang (aka. the inside of an event horizon) is opaque *without*
invoking space-filling hydrogen plasma.

The event horizon is not opaque, light passes
through it without being absorbed.

It is perhaps
better to consider opaque in this case in terms
of the mean free path of a photon being greater
than the time from emission to the time of
complete transparency multiplied by the speed of
light regardless of where the photon is emitted
since the CMBRM was almost homogenous throughout
the universe.

So let me ask this question about the Universe that contains ours...

There is no "Universe that contains ours" in the
Big Bang model so it is not meaningful to ask the
question.

The Schwarzchild solution to GR for a black hole, describes another
Universe inside the black hole, with internal time starting where external
space leaves off.

I'm not sure about that, it seems to depend on
the coordinate system you use but I know too
little of GR to comment sensibly.

Since the Big Bang model is commonly dressed in the clothes of GR, are you
sure 'There is no "Universe that contains ours" in the Big Bang model so
it is not meaningful to ask the question'?

I am fairly sure that the picture of the event
horizon of a black hole to which you are
referring is related to an isolated mass in a
lower density environment while the big bang
scenario has uniform density throughout. You
can get a similar effect I believe in a uniform
density regime:

http://scienceworld.wolfram.com/phys...ntDensity.html

but in this case it would be more like the
horizon that is expected to be produced by
cosmic acceleration and is a limitation on
visibility _within_ the universe.

However, that needn't mean our universe isn't
embedded in something different. The idea I
find most understandable to illustrate the
possibility is that of Alan Guth where he
talks of multiple universes embedded in
'false vacuum' which is in a permanent state
of inflation. That is not exclusive though,
just indicative of the feasibility.

You say imagine the Landolt reaction in reverse...

Purely to suggest the change from opaque to
transparent could be due to a phase change in
the hydrogen/helium mix (plasma to gas) rather
than requiring the material to coalesce into
structures leaving vacuum between as you were
suggesting. That could come later.

imagine that our Big Bang is the inside of the event horizon of the
(probably really big) black hole that contains our Universe.

So sure are you?

I am sure that the H/He mix was present because
we see the radiation from it in the form of the
CMBR, it is predicted by nucleosynthesis and we
can see the mix in primeval stars. I can be sure
it was opaque for over 300k years from lab
experiments and WMAP. I can't be sure what we
would have seen had it not existed, but then we
wouldn't be here to see anything. Beyond that,
I would just point you at the faq entry and say
that I wouldn't presume to be any more sure than
Philip Gibbs, and since it is 8 years old,
perhaps even that might be slightly outdated.

http://math.ucr.edu/home/baez/physic.../universe.html

George

Dear George Dishman:

"George Dishman" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox
wrote in message news:jNbJe.275166$Qo.182521@fed1read01...

I don't have the applet required to play it. I found another
site that had it in Quicktime.

It used Real Player but as long as you got
the idea, a bulk material can switch from
opaque to transparent.

The "bromate clock" does this too, but the symbolism would invoke
the "constant creation" and "recycling Universe" crowds... ;)

Hydrogen absorbs light.

Hydrogen also emits light. By the laws of
thermodynamics, there must be a precise
relationship between the two.

Yes, I finally got it. Only the "vector part of the momentum"
will be altered, since the momentum of the "intervening" hydrogen
(indicating *its* temperature) will average out to no net
contribution. I think.

We find its signature everywhere we look, when we look at
point sources. But we don't find it with the CMBR. And it
has been exposed longer, assuming the Universe filling
gas didn't coalesce.

If the gas is in equilibrium, the energy
absorbed must be balanced by that emitted.
It is therefore exactly at the crossover
between producing absorption and emission
lines. Given the slight anisotropy, perhaps
it will be possible some time soon to detect
a line redshifted down but it has taken
sensitive space-borne missions just to
measure the anisotropy in broad bands so
looking for individual lines would require
another step up in design.

I'm always up for sharper tools.

At some point the CMBR had redshifted enough so
it could not be absorbed at all by hydrogen, and
since then the universe has been transparent to it
(except for isolated objects we call stars).

Let me ask a related question. The CMBRM has
been described as opaque and isothermal. Presumably
"opaque" could be defined as no emissions detectable
from beyond a certain place (watch my terms).

"a certain place" may give the wrong impression
although obviously we are "here".

We can't see beyond the CMBRM, so it is opaque.

That is correct, it rapidly absorbs any light
that passes through it.

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

If
you could hover just inside the event horizon
you would be bombarded by high energy photons
falling in.

I don't agree, and I can't quite tell you why that is.
Ultimately I think it is because you cannot hover just inside the
event horizon, since to do so would be to stop time. So if you
infall at a rate of 1 second per second, the light should be
received at finite energy, since your "motion along the time
axis" is also closely correlated to c.

My question to Tom is would this also achieve the appearance of
being isothermal? The entire history of our container Universe
(up until the point we evaporated) is written on/into the event
horizon. Given what we know/expect of Universal temperature, and
size of the Universe at that temeprature, I think this also would
provide a very nice blackbody curve.

Universe's Big Bang, and see specular images of the container
Universe. The Big Bang (aka. the inside of an event horizon)
is
opaque *without* invoking space-filling hydrogen plasma.

The event horizon is not opaque, light passes
through it without being absorbed.

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.

It is perhaps
better to consider opaque in this case in terms
of the mean free path of a photon being greater
than the time from emission to the time of
complete transparency multiplied by the speed of
light regardless of where the photon is emitted
since the CMBRM was almost homogenous throughout
the universe.

So let me ask this question about the Universe that
contains ours...

There is no "Universe that contains ours" in the
Big Bang model so it is not meaningful to ask the
question.

The Schwarzchild solution to GR for a black hole,
describes another Universe inside the black hole, with
internal time starting where external space leaves off.

I'm not sure about that, it seems to depend on
the coordinate system you use but I know too
little of GR to comment sensibly.

You are no more God than I am. You have tried on the hat more
than once, in an effort to help me (and those that might someday
have these or related questions). For that I thank you. Some
questions are so poorly worded that they cannot be understood,
and some questions just cannot be answered. I'm thinking I've
formulated the former, but you never know. ;)

Since the Big Bang model is commonly dressed in the clothes
of GR, are you sure 'There is no "Universe that contains ours"
in
the Big Bang model so it is not meaningful to ask the
question'?

I am fairly sure that the picture of the event
horizon of a black hole to which you are
referring is related to an isolated mass in a
lower density environment while the big bang
scenario has uniform density throughout. You
can get a similar effect I believe in a uniform
density regime:

http://scienceworld.wolfram.com/phys...ntDensity.html

but in this case it would be more like the
horizon that is expected to be produced by
cosmic acceleration and is a limitation on
visibility _within_ the universe.

However, that needn't mean our universe isn't
embedded in something different. The idea I
find most understandable to illustrate the
possibility is that of Alan Guth where he
talks of multiple universes embedded in
'false vacuum' which is in a permanent state
of inflation. That is not exclusive though,
just indicative of the feasibility.

You say imagine the Landolt reaction in reverse...

Purely to suggest the change from opaque to
transparent could be due to a phase change in
the hydrogen/helium mix (plasma to gas) rather
than requiring the material to coalesce into
structures leaving vacuum between as you were
suggesting. That could come later.

imagine that our Big Bang is the inside of the event horizon
of the (probably really big) black hole that contains our
Universe.

So sure are you?

I am sure that the H/He mix was present because
we see the radiation from it in the form of the
CMBR,

This is not conclusive, but *assumed*. That is the crux of my
problem. It is a perfect blackbody radiator, with some hint of
structure (variable intensity) written in/on it. The Universe
should have been mostly hydrogen and helium. Therefore the CMBRM
must be mostly hydrogen and helium. A logical chain, just not
one I am fond of.

it is predicted by nucleosynthesis and we
can see the mix in primeval stars. I can be sure
it was opaque for over 300k years from lab
experiments and WMAP. I can't be sure what we
would have seen had it not existed, but then we
wouldn't be here to see anything.

I don't agree with "lab experiments" since we cannot generate an
opaque plasma in the lab. I also don't agree with the infalling
light being necessarily fatal. If Joe were to don a spacesuit,
and fall into the BH at the center of the Milky Way, would the
infalling light kill him? No. If other stuff didn't kill him
(with differential orbital velocity) he'd just see infalling
light that became more and more distorted (non-specular).

Beyond that,
I would just point you at the faq entry and say
that I wouldn't presume to be any more sure than
Philip Gibbs, and since it is 8 years old,
perhaps even that might be slightly outdated.

http://math.ucr.edu/home/baez/physic.../universe.html

Thanks George. I hope you have/had a great Sunday.

David A. Smith

Dear Martin Brown:

"Martin Brown" wrote in
message ...
N:dlzc D:aol T:com (dlzc) wrote:
....
Let me ask a related question. The CMBRM has been described
as opaque and isothermal. Presumably "opaque" could be
defined as no emissions detectable from beyond a certain place
(watch my terms). So let me ask this question about the
Universe that contains ours... It would be certainly opaque,
since
we cannot see beyond the Big Bang, but would the container
Universe appear isothermal? Rather than the CMBRM being
some intermediate matter state on *this* side of the Big Bang,
could it simply be infalling light?

The observable horizon is moving away from us at the speed of
light. The challenge for cosmology is to explain why our patch
of universe is so isotropic. Alan Guth's inflation is one
possible
solution:

http://nedwww.ipac.caltech.edu/level..._contents.html

You need to think more carefully about how absorbtion lines
arise in a continuum spectrum. Energy is always conserved.

Not always is energy conserved in GR, but I understand your
point. I did finally "get it". And my question also provides an
isotropic Universe, since we "infell" from such a Universe.
Perhaps. Cake batter always gets more uniform with each
"folding".

Now I made myself hungry! ;)

Have a good Sunday.

David A. Smith

"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.

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

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.

If
you could hover just inside the event horizon
you would be bombarded by high energy photons
falling in.

I don't agree, and I can't quite tell you why that is. Ultimately I think
it is because you cannot hover just inside the event horizon, since to do
so would be to stop time.

Indeed, I was glossing over that.

So if you infall at a rate of 1 second per second, the light should be
received at finite energy, since your "motion along the time axis" is also
closely correlated to c.

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

snip question to Tom

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.

The Schwarzchild solution to GR for a black hole,
describes another Universe inside the black hole, with
internal time starting where external space leaves off.

I'm not sure about that, it seems to depend on
the coordinate system you use but I know too
little of GR to comment sensibly.

You are no more God than I am. You have tried on the hat more than once,
in an effort to help me (and those that might someday have these or
related questions). For that I thank you. Some questions are so poorly
worded that they cannot be understood, and some questions just cannot be
answered. I'm thinking I've formulated the former, but you never know.
;)

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 am sure that the H/He mix was present because
we see the radiation from it in the form of the
CMBR,

This is not conclusive, but *assumed*. That is the crux of my problem.

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

It is a perfect blackbody radiator, with some hint of structure (variable
intensity) written in/on it. The Universe should have been mostly
hydrogen and helium. Therefore the CMBRM must be mostly hydrogen and
helium. A logical chain, just not one I am fond of.

it is predicted by nucleosynthesis and we
can see the mix in primeval stars. I can be sure
it was opaque for over 300k years from lab
experiments and WMAP. I can't be sure what we
would have seen had it not existed, but then we
wouldn't be here to see anything.

I don't agree with "lab experiments" since we cannot generate an opaque
plasma in the lab.

No but we can measure the cross section of the
particles and calulate the depth need for the
plasma to be opaque.

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

I wasn't really saying that earlier.

If Joe were to don a spacesuit, and fall into the BH at the center of the
Milky Way, would the infalling light kill him? No. If other stuff didn't
kill him (with differential orbital velocity) he'd just see infalling
light that became more and more distorted (non-specular).

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.

George

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...

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.

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.

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".

If
you could hover just inside the event horizon
you would be bombarded by high energy photons
falling in.

I don't agree, and I can't quite tell you why that is.
Ultimately I think it is because you cannot hover just
inside the event horizon, since to do so would be to
stop time.

Indeed, I was glossing over that.

So if you infall at a rate of 1 second per second, the
light should be received at finite energy, since your
"motion along the time axis" is also closely correlated
to c.

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

snip question to Tom

It may not have an answer that I can understand.

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.

The Schwarzchild solution to GR for a black hole,
describes another Universe inside the black hole, with
internal time starting where external space leaves off.

I'm not sure about that, it seems to depend on
the coordinate system you use but I know too
little of GR to comment sensibly.

You are no more God than I am. You have tried on the hat
more than once, in an effort to help me (and those that
might someday have these or related questions). For that
I thank you. Some questions are so poorly worded that
they cannot be understood, and some questions just
cannot be answered. I'm thinking I've formulated the former,
but you never know. ;)

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. 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.

...
I am sure that the H/He mix was present because
we see the radiation from it in the form of the
CMBR,

This is not conclusive, but *assumed*. That is the
crux of my problem.

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

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

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".

It is a perfect blackbody radiator, with some hint of
structure
(variable intensity) written in/on it. The Universe should
have
been mostly hydrogen and helium. Therefore the CMBRM
must be mostly hydrogen and helium. A logical chain, just
not one I am fond of.

it is predicted by nucleosynthesis and we can see the
mix in primeval stars. I can be sure it was opaque for
over 300k years from lab experiments and WMAP. I
can't be sure what we would have seen had it not
existed, but then we wouldn't be here to see anything.

I don't agree with "lab experiments" since we cannot
generate an opaque plasma in the lab.

No but we can measure the cross section of the
particles and calulate the depth need for the
plasma to be opaque.

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...

If Joe were to don a spacesuit, and fall into the BH at the
center of the Milky Way, would the infalling light kill him?
No. If other stuff didn't kill him (with differential orbital
velocity)
he'd just see infalling light that became more and more
distorted
(non-specular).

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.

And if we can...

David A. Smith

"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

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?

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.

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

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? 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!).

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).

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.

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.

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.

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.

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!

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.

George