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Ned Wright's TBBNH Page (A2)



 
 
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Old August 26th 03, 05:58 PM
greywolf42
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Default Ned Wright's TBBNH Page (A2)

This post continues the discussion of 'Ned' Wright's website "Errors in The
Big Bang Never Happened."

Several people have independently pointed me to Ned Wright's website "Errors
in The Big Bang Never Happened." One of those was the sci.physics.research
moderator -- who used this website as justification for refusing any mention
of TBBNH -- or any references contained therein. The crank.dot.net site
lists "Ed (sic) Wright's invaluable page detailing the errors in ... Eric
Lerner's arguments from The Big Bang Never Happened." So I guess it's time
to discuss "Ned Wright's TBBNH Page. Last modified 4-May-2000, © 1997-2000"
http://www.astro.ucla.edu/~wright/lerner_errors.html


Ned separated his site into three sections:

A: Errors in Lerner's Criticism of the Big Bang
B: Errors in Lerner's Alternative to the Big Bang
C: Miscellaneous Errors

Ned Wright's site begins as follows:

================================================
"Eric Lerner starts his book "The Big Bang Never Happened" (hereafter BBNH)
with the "errors" that he thinks invalidate the Big Bang. These are

"1.The existence of superclusters of galaxies and structures like the "Great
Wall" which would take too long to form from the 'perfectly homogeneous' Big
Bang.
"2.The need for dark matter and observations showing no dark matter.
"3.The FIRAS CMB spectrum is a "too perfect" blackbody.

"Are these criticisms correct? No, and they were known to be incorrect in
1991 when Lerner wrote his book."
=============================================== =

This post deals only with 'Big Bang' item A2, above (The existence of dark
matter) :

================================================
Is there dark matter?

There is certainly lots of evidence for dark matter. When one looks at
cluster of galaxies, the gravitational effects of the cluster can be
measured three ways. One is by the orbital motions of the galaxies in the
cluster. This was first done by Zwicky in 1933 (Helv. Phys. Acta, 6, 110)! A
second looks at the hot gas trapped in many big clusters of galaxies. The
third way looks at the bending of light from galaxies behind the cluster by
the mass in the cluster (gravitational lensing). All three methods give
masses that appear to be very much larger than the mass of the stars in the
galaxies in the cluster. This is usually given as the mass-to-light ratio,
and M/L is several hundred solar units for clusters of galaxies and only
about 3 for the stars in the Milky Way near the Sun.
=============================================== =

Above, Ned outlines three different ways to determine the existence of dark
matter:
1) Motions of galaxies in clusters of galaxies.
2) Gas 'trapped' in 'many' big clusters.
3) Gravitational lensing.

================================================
The paper that Lerner cites as evidence for a lack of dark matter, Valtonen
and Byrd (1986, ApJ, 303, 523), claims that the Coma cluster of galaxies and
the other great clusters of galaxies are not bound objects. However, the
observed velocities within the cluster would cause them to disperse in much
less than the age of the Universe, so this claim is quite strange.
=============================================== =

The claim is only "strange" if you ignore what Lerner (and Valtonen and
Byrd, and Shaya) actually wrote. Ned's statement about 'the observed
velocities with in the cluster' is a pure non-sequiteur, because the V&B's
paper (and the discussion in TBBNH) claims that many of the 'cluster
galaxies' aren't really within the cluster! In order to understand that,
one must actually look at the argument. The discussion is on pages 36 to 39
of TBBNH:

"Mauri Valtonen ... and Gene Byrd ... teamed up to take a critical look at
this evidence for dark matter. They started with galactic clusters, where
they knew there was a potential complication. The redshift of the galaxies
was being used for two purposes: first, to measure the distance to the
galaxies and thus to see IF they were even part of the cluster; and second,
to measure their velocities WITHIN the cluster. There was a potential for
error: a galaxy nearer to us than the cluster to which it appeared to belong
could be mistaken for one in the cluster that is moving toward us, while one
farther away could be misidentified as a cluster galaxy moving away (Fig.
1.8). It would then be an 'interloper' -- appearing to be part of the
cluster, but actually being far behind it. If these interlopers (which are
not in fact part of the cluster) are included in calculations, THEIR
VELOCITIES WOULD DRIVE UP THE APPARENT MASS OF THE CLUSTER, CREATING
APPARENT MASS WHERE THERE IS NONE -- 'missing' mass. To go back to the
hammer-thrower, the error would be the same as watching a film of the
athlete and accidentally measuring the speed of a flying mammer in the
background, rather than the speed of the hammer he is actually holding. If
the background hammer was far faster, the strength of the athlete would be
overestimated, just like the mass of the cluster." (emphasis in original)

"Astronomers had observed the curious fact that in virtually every cluster
of galaxies the brightest galaxy seemd to be moving away more slowly than
the cluster it belonged to -- that is, the brightest galaxy's redshift was
always less than the average redshift of the cluster as a whole."

"Valtonen and Byrd showed tht this should be expected if some of the galxies
apparently in the cluster are really interlpers, not actual cluster members.
Since the 'cone' of our vision widens with distance, there weill be more
interlopers BEHIND the group than in front of it (Fig. 1.9) -- and they'll
be redshifted relative to the true center of the cluster. If, as seems
reasonable, the brightest galaxy (because it's largest) is generally near
the center, its redshift will be LESS than the average of all the galaxies
thought to be in the group, including the predominantly background
interlopers." (emphasis in original)

"There was another reason, the two astronomers found, that the cluster mass
might be overestimated. Cluster tend to b edominated by a pair of extremely
heavy elliptical galaxies. Astronomers believe these galaxies grew to be as
much as a thousand times more masive than our own galaxy by gravitatioanlly
swallowing smaller neighbors. But Byrd and Vatonen, using computer
simulations, discovered that small galaxies might suffer a different fate:
they might be caught in the pair's gravitainal field and be thrown away from
the cluster at high speed."

"Here was another source of error. If astronomers included escaping
galaxies as memebers of the cluster, thinking them still bound to it by
gravity, again they would overestimate the gravity of the cluster and
therefore its mass, just as the hammer-thrower's strength would be
overestimated if the speed of the hammer was measured AFTER he had let go of
it. If astronomers included BOTH the galaxies that had been flung away from
the cluster AND the interlopers in their calculations, the cluster's mass
would be greatly exaggerated. In fact, Valtonen and Byrd found that these
two errors would account for ALL of the 'missing mass': in pairs of
galaxies, groups of galaxies, and clusters there is NO dark matter. And
when they examidned the motions of small nearby companions, they found the
galaxies themselves weighed just as much as the visible matter composing
them." (emphasis in original)

"Valtonen and Byrd's results have no receive important confirmation from
Columbia's Shaya. Shaya measured the velocities and position of hundereds
of galaxies in a broad reion, in effect weighin all the matter in the
clusters at once. He found a vlue of omega, .03, very close to the value of
..02 found by Byrd and Valtonen. Again, ther is just no room for dark
matter -- about half the matter is in galaxies and their bright stars,
another half in glowing gases tightly bound into the clusters and
superlclusters, gas that can be observed by radio telescopes."

"These results have been published in leading journals, yet have stirred
little discussion and no attempts at refutation. They completely eliminate
any evidence for dark matter -- what you see in the universe is what there
is. The implication is that the many papers written aoubt axions, heavy
neutrinos, cold dark matter, and hot dark matter are entirely without any
real foundation. But without dark matter, the Big Bang theoriests say, no
galaxies, stars, or planets can form. As a scientist on the COBE team, John
Mather, quipped, 'If these theories are right, we sholdn't be here.'"

================================================
Furthermore, the X-ray and gravitational lensing evidence now available show
that Valtonen and Byrd were incorrect.
=============================================== =

(I am presuming here that the "X-ray evidence", above, refers to Ned's
method #2 -- gas 'trapped' in 'many' big clusters.)

Ned Wright simply ignores Valtonen & Byrd (and Shaya), by claiming that two
other theoretical approaches reach different conclusions. Ned should at
least have referenced a study or two for the X-ray and lensing methods.

Claims that measurements via other theoretical methods 'require' dark matter
does not in any way 'disprove' the analysis of Valtonen and Byrd, and Shaya!
We don't get to pick the data we like, in science.

The observations are discrepant (assuming Ned's unreferenced and undescribed
studies are indeed at odds with V&B). This does not mean that it is
Valtonen, Byrd and Shaya that are 'wrong.' It means 'something is wrong,
somewhere.' Ned's statement about "observed velocities within the cluster"
makes it clear he made no attempt to even look at the data or the argument
presented. Had he actually read and understood the argument, he could never
have made such a statement about TBBNH, Valtonen and Byrd, or Shaya.


Now -- a priori -- it is possible that Valtonen, Byrd, and Shaya are in
error. But there has been no scientific weighing of the evidence. It is in
no way an "error" on the part of Lerner or TBBNH in 1991! Ned says two
other theories come up with different conclusions. A different conclusion
is not an 'error.' Especially if the substance of the arguments have not
been discussed!


================================================
The only way to satisfy these observations without a lot of dark matter is
to hypothesize that the force of gravity is much stronger at large distances
than Newton (or Einstein) would predict. This model is called MOND, for
Modification Of Newtonian Dynamics, and it has some adherents. But no good
relativistic version of MOND exists, and the existence of gravitational
lensing in cluster of galaxies requires a relativistic theory that makes the
same change for light and for slow moving objects like galaxies.
=============================================== =

Here, Ned creates a complete strawman. Lerner never discusses (or needs) a
change in the force of gravity.

The simplest way to satisfy the observations is to examine each of the three
types of papers for possible errors. Which is not possible if Ned doesn't
provide the references. I have not examined any papers on Xray emission
from 'gas trapped in many big clusters.' So I currently have no idea
whether these results are more likely flawed than Valtonen and Byrd, and
Shaya.

But let's look briefly into the gravitational lensing studies and compare it
to the cluster studies. Valtonen and Byrd, and Shaya's method is purely
geometrical. No error in H0 or (first order) variation in the Hubble
constant itself will affect these results. No change in cosmology or
assumptions will affect them either.

A contemporaneous discussion of gravitational lensing is "Gravitational lens
models of arcs in clusters", Bergmann et al, 1990, ApJ, Part 1, vol. 350,
Feb. 10, 1990, p. 23-35, (1990ApJ...350...23B).

Here is the ADS abstract:
"It is now well established that the luminous arcs discovered in clusters of
galaxies, in particular those in Abell 370 and Cluster 2244-02, are produced
by gravitational lensing of background sources. The arcs are modeled and
constraints are placed on the distribution of the mass in the clusters and
the shape and size of the sources. The models require, as expected, a large
amount of dark matter in the clusters and a mass-to blue-light ratio for the
cluster which exceeds 100 solar mass/solar luminosity and could be as high
as 1000 solar mass/solar luminosity depending on cosmological parameters and
the distribution of the dark matter. Furthermore, it is found that in the
case of the arc in A370 the dark matter must have a different distribution
than the luminous galaxies, while for the arc in Cl 2244 the dark matter can
have a distribution similar to that of the light matter (galaxies) or a
separate distribution. "

If we look into the details of this paper, we find that one of the
'cosmological parameters' that must be input into these models is omega
(which theoretically includes 'dark matter' ratios). Which certainly brings
in at least a touch of circularity in the calculation of the ratio of dark
matter to visible matter in the clusters.

In short, the conclusions in gravitational lensing mass estimates require a
lot of variation with 'cosmological parameters.' And these studies give
widely-varying results about the distributions of dark matter needed to
match observation. This is hardly a good sign for observational
confirmation. A first step, but far less reliable a process than Valtonen
and Byrd, and Shaya's pure geometric requirements.


================================================
Furthermore, if the MACHO results hold up, then the MOND model will fail for
the halo of the Milky Way. If we then need dark matter to explain the Milky
Way halo, it is most reasonable to use the same explanation in distant
clusters of galaxies.
=============================================== =

Ned here brings up a fourth 'method' for imputing dark matter. However, we
DON'T need dark matter (or MOND) to explain the Milky Way halo (sic -- disk
rotation). You'll find the discussion in "Ned Wright's TBBNH Page (C), items
2 and 3. To summarize, Ned references a newsgroup post by Ted Bunn. Ned and
Ted assert that Lerner claims that the Solar system is maintained in it's
orbit by EM forces. Which is a claim that is both ludicrous and not
contained anywhere in TBBNH.


See "Ned Wright's TBBNH Page (A3) for the perfection of the CMB.

A courtesy copy of this post is provided to Ned Wright.

greywolf42
ubi dubium ibi libertas


 




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