Ned Wright's TBBNH Page (B1)

Joseph Lazio wrote in message
...
"g" == greywolf42 writes:

"The size of the cloud of gas and galaxies in this picture is
limited by the condition that during the collapse phase the
gravitational potential energy per unit mass, phi, cannot exceed
the critical value for relativistic collapse of the bulk of the
material to a black hole, for the remnant would be hard to miss.
[...]
phi ~ GM/rc^2 ~ Omega z_r^2 / 2 (7.23)

The dynamical estimates to be discussed in section 20 indicate that
the density parameter is not less than about Omega ~ 0.1. Galaxies
are seen in abundance in redshift surveys to at least z ~ 0.5.
(...) The present value of the dimensionless potential phi is
then at least phi ~ 0.01. This means that, if the cloud radius at
maximum collapse were less than a few percent of the present value,
the conventional physics of general relativity theory says the
cloud would have suffered relativistic collapse, however violent
the explosion. ..."

g There are a couple of problems with Peebles' "collapse into a black
g hole" analysis. The first being that he uses a big-bang parameter
g -- omega -- to evaluate a non-big-bang theory.

Omega is defined as Omega = rho/rho_c, where rho is a density and
rho_c is the critical density. rho_c is certainly a result of BB
theory, but it is also a value that one can predict.

Well, yes. It can be predicted by using the big bang theory. However,
since this relies upon the big bang theory, then one cannot rely upon it to
critique a non-Big-Bang theory -- which has different assumptions.

It turns out to
be about 1E-29 g/cm^3. Thus, Omega ~ 0.1 is equivalent to saying a
density of 1E-30 g/cm^3. A density of rho ~ 1E-30 g/cm^3 is not
dependent upon the BB theory.

If 1E-29 is dependent upon BB, and you then multiply it by 0.1, then your
value is still dependent on the BB.

g The second is that Omega is observed to be 0.02 to 0.03 -- NOT the
g 0.5 that Peebles mentions, above. [...]

I could not find this statement by Peebles. Where does he state Omega
~ 0.5? He does state that the redshift range over which galaxies is
observed is z ~ 0.5.

My apologies for the mistake. He said "not less than about Omega ~ 0.1".

So my ratio, instead of being 0.5/.02 (at least 10), becomes 0.1/.02-3 or
about a factor of four.

And my conclusion (which you snipped) becomes:

This changes Peebles' conclusion to ".. if the cloud radius at maximum
collapse were less than a percent of the present value, ... general
relativity theory says the cloud would have suffered relativistic collapse."
Of course, there is no a priori reason for the 'collapsed' cloud to be less
than a few percent of the current universe size (100 Mly) -- let alone less
than a percent (40Mly)."

No significant change in conclusion.


g Peebles does not credit any prior author for this 'discovery' that
g a plasma universe (discussed since Alfven's work in 1966) could
g possibly collapse into a black hole. This implies that Peebles was
g the first to create this argument -- in 1993.

Alternately, this idea is so widely known that it is no longer
necessary to provide a reference. If I describe an orbit of an object
as elliptical, do I have to reference Kepler (1609)?

What an amusing strawman. Not.

Are you claiming this was 'so widely known that it wasn't necessary to
provide a reference?' I didn't think so, or you would have clearly stated
this. And it would have been trivial to provide a reference -- which you
can't.

And Peebles' certainly didn't think so -- as he mentioned Alfven (1966),
Klein (1971), Steigman (1976) and Milne. Had the 'plasma universe' been
'widely known' it would not have been necessary to provide references. One
can't have a 'well known' "disproof" of a theory -- if the theory itself is
not at least as 'well known.'

Besides, Ned would have referred to an earlier work than Peebles, if he knew
of one.

greywolf42
ubi dubium ibi libertas