Re: CMBR and neutron stars

Dear Steve Willner:

"Steve Willner" <willner@xxxxxxxxxxxxxxx> wrote in message
news:4304fe09$1@xxxxxxxxxxxxxxxxxxxxxxxxxx
> In article <ruSMe.60916$E95.16488@fed1read01>,
> "N:dlzc D:aol T:com \(dlzc\)" <N: dlzc1 D:cox T:net@xxxxxxxxxx>
> writes:
> SW> I would have guessed that the integrated stellar output
> would
> SW> be greater [than the microwave background]
>
> It now appears that this guess was wrong. The paper I was
> looking
> for was Dwek et al. 1998 (ApJ 508, 106), who detect 16 nW m^-2
> sr^-1
> of "Extragalactic Background Light" in the infrared. Adding in
> other
> spectral regions gives a lower limit of 28 in the same units.
> This
> is a lower limit because there are many wavelengths where the
> EBL has
> not been measured. Models are of course uncertain, but the
> ones Dwek
> et al. use suggest the stellar EBL added over all wavelengths
> should
> be in the range 30 to 90 nW m^-2 sr^-1.
>
> Unless I have done the arithmetic wrong (and someone should
> check!),

If I stand for my doctoral dissertation, be sure that I will have
checked it.

> the microwave background at 2.73 K corresponds to 1000 nW m^-2
> sr^-1.
> (That should be sigma/pi T^4, where sigma is the
> Stefan-Boltzmann
> constant.)
>
> Thus as of today (and barring an error somewhere), it looks as
> though
> stellar light is 3 to 10% of the total radiation in the
> Universe.

.... for a position similar to our own. Stellar light would
likely be lower for a lone BH in deep space, higher (perhaps much
higher) for a BH consuming a companion, or imbedded in the center
of a galaxy.

> SW> ...new stars keep forming.
>
> In article <ruSMe.60916$E95.16488@fed1read01>,
> "N:dlzc D:aol T:com \(dlzc\)" <N: dlzc1 D:cox T:net@xxxxxxxxxx>
> writes:
>> We don't see any new galaxies springing into existence,
>> however.
>
> I'm not sure what you mean by this. We see galaxies at high
> redshift
> that show high rates of star formation. We see star formation
> occurring now in disk galaxies. And existing stars keep
> pouring out
> radiant energy. As I wrote:
>
> SW> Thus the relative contribution from stars increases with
> time.

Actually no, it would not, since the Universe is expanding. The
event horizon is controlled not by geometry, but by the mass
inside. So it would not get larger too...

And "what I meant by this" is that we don't discover entirely new
galaxies where none existed before, say, 10 or 20 years ago. We
are only able to bring new more-distant ones into focus.

>> > SW> If you want
>> > SW> to avoid the medium being optically thick at that epoch,
>> > you
>> > SW> have to show why this extrapolation is wrong.
>> >
>> >> Simple. There was no medium. Coalescence had already
>> >> occurred.
>> >
> SW> "Coalescence" into what?
>>
>> Proto-galaxies, for a start.
>
> How does this keep the Universe from being optically thick?

It doesn't. It presents the inside of an event horizon as an
optically thick surface *also*.

> You
> still have ionized hydrogen; all you have done is make it
> clumpy.

"Allowed" it to be clumpy. not "made".

> In its simplest form, the BB model says the Universe was
> hotter and denser in the past.

No argument, except that hotter appears cooler from here/now.

> At some point in the past, it was hot enough to
> ionize hydrogen and dense enough to be optically thick.

This is the standard definition yes.

> I don't see
> any way around that except "new physics."

No. A "way around it" is that the CMBRM is the inside of the
event horizon, a temperature TBD, and structures exist right up
to it. With "excessive" heavy metals as needed. No "new
physics", just not a single Universe, but one of a "finite
series"... perhaps.

> Adding clumpiness (which
> could be acceptable, depending on what properties you want
> to ascribe to dark matter) might change the exact redshift
> where the Universe becomes optically thick, but I don't see
> how it can change the essential picture.

OK.

> SW> Or that somehow the
> SW> ordinary Saha equation didn't work,
>
>> Note: temperature and density *assumed*, based on the
>> physical model called "standard Big Bang theory". I am
>> not trying to supplant it... I obviously cannot. I could be
>> "right" and still the Universe was filled with a "Universe
>> filling, opaque plasma". But maybe we don't have to
>> have the plasma, to describe what we see.
>
> The point is that an opaque plasma is a clear prediction of
> any model even vaguely close to the BB. I don't see how
> you can get round it without "new physics" or a completely
> different model. Historically, the microwave background
> was one of the earliest predictions of the BB model.

What I seek is a solution-set to GR. It does not necessarily
involve Universe-filling plasma. As you noted the CMBR is quite
a dominant effect on its own, so its contribution to the light
infall of a BH *we* contain... would look much like an opaque
black body radiator. *No* new physics, but no real beginning
either, since our CMBR could perhaps be from the Next Higher
Assembly.

>> A neutron star is the most dense, physcially stable state.
>> Are you so sure?
>
> What does this have to do with event horizons? GR is
> independent of the equation of state of particular types
> of matter.

Since you cut out to what I was responding, let me recall it for
you. "The event horizon is not any sort of physical
singularity." So the statement is that the event horizon is
*inside* the smallest possible physical surface, and is therefore
a *physical* singularity as well. So I guess we get to play with
"what is a singularity"? Or your favorite, "new physics".

Thanks for your time Steve. I will space out my response (if any
required), so that I do not burn too much of your time.

David A. Smith


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