NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/sci/astro/8283

Text File | 1992-07-23 | 7.9 KB | 144 lines

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From: [e-mail] (Don Wells)
Subject: Re: Supermassive stars and HD limit (was Big Bang...)
In-Reply-To: [e-mail]'s message of Thu, 23 Jul 1992 02: 01:55 GMT
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In article <[e-mail]> [e-mail] (Tom Van
Flandern) writes:
   [e-mail] (Don Wells) writes:
   > the two optical jets in question are typical plasma jets..
   > observational and theoretical literature.. contradicts..
   > anyone who postulates that such jets are capable of ejecting either
   > compact objects or cool hydrogen clouds.

 TVF> The jets eject the objects?  That's not the model I was
 TVF> referring to. Supernova explosions eject the objects, and the
 TVF> jets are the residue ("wakes") in the paths of the ejections. I
 TVF> understand there is a full literature interpreting plasma jets
 TVF> in standard models.  We are here considering a different model.
 TVF> If this supernova ejection idea has been "contradicted" in the
 TVF> literature, I have yet to hear of it.

The observational and theoretical literature on the plasma jets
associated with radio galaxies and quasars flatly contradicts your
concept that the jets are wakes. The observations of nearby jets are
available with so much detail, and the consistency with plasma jet
models is so good, that there is essentially no possibility that you
can support your speculation with a physical model.

You must explain why a wake should show oblique shocks. You must
explain the nature of hot spots, and cocoons, and the various
instabilities that are seen. You will need to explain the polarization
data, which implies magnetic field structures. The polarization is
consistent with the fact that the spectra of the jets are featureless
continua which fit synchrotron emission models (fast electrons moving
in magnetic fields) quite well, and this sure doesn't sound like a
wake phenomenon!  Some of these objects are galaxies, so their
Hubble-Law distances, are known, and therefore you will need to find
an explanation for the faster-than-light moving-source phenomena. Then
there are the wiggling and bending phenomena, which are explained so
neatly and obviously by the plasma jet being sprayed by a moving
galaxy. My favorite example is the double-nucleus (merging) giant
elliptical in which both nuclei emit double jets at different position
angles, and the two jets on one side twist about each other! (The
obvious interpretation is Keplerian motion of the nuclei.) Your wake
would have no reason to twist, but two jets being *continuously*
sprayed over a period of time would quite naturally become two
intertwined helices.  I could go on and on, tabulating the vast amount
of observational facts which are known about jets, and I am not even a
specialist in the field. A real observational expert could talk for
*hours* on this subject. The bottom line is: the optical and radio
jets emitted by active galaxies and quasars are plasma jets, and they
simply cannot be wakes left by proto-quasars being ejected from
galaxies.

   > ..Meta model..hasn't.. come to grips with the full range of data..

 TVF> Don't you specialize?  And don't most astronomers?  How can one
 TVF> or a handful of astronomers proposing a new model be expected to
 TVF> come to grips with even a reasonable fraction of the data that's
 TVF> in a single issue of the ApJ?  New models have to start
 TVF> somewhere, and the gross tests come first.

Specialization? Yes, of course. For example, my dissertation and
post-doctoral fellowship was in (optical) observational cosmology.  I
would expect that any one trying to construct a new theoretical
cosmology would want to spend a lot of time listening to people like
me tell what they know about the (real) Universe. At the time I did my
dissertation, twenty years ago, there was much less data available.
You could have speculated about optical jets being wakes. Hardly
anyone would have contradicted you, because high-performance imaging
radio interferometers did not yet exist. Ten years later, circa 1980,
the VLA showed those jets fully resolved, with high S/N, and your wake
model would not have fit even the first year's worth of VLA data.

Those jets are a critical element of your whole theoretical
superstructure because they lend an air of plausibility to the
hypothesis that somehow nearby galaxies can eject quasars. If those
jets are neither wakes or a plausible ejection mechanism, the house of
cards is in danger of collapsing. If you want to restore this critical
element to your hypothesis you will need to study the vast literature
of the field and also get some experienced observers to show you real
data with full resolution and dynamic range (the figures in the
journals are never as good as seeing the data on an interactive
digital image display). Then you will know a small, but critically
important, part of what your Meta model must explain.

   > Weedman says on p.29: "The sequence of events has been...
   > ... a new curiousity has to be tested, requiring yet another new
   > sample. It can be readily appreciated why this becomes a frustrating game.
   > Examples of such sequences of events can be followed through [8 papers in
   > three sets]."

 TVF> A neat theory, but where are the specifics?  I can't recall
 TVF> offhand any important facts in this area which went away in
 TVF> newer samples.

Most extragalactic observers would dispute your use of the word
"facts". In fact, that is what Weedman was saying: the statistical
anomalies suggest hypotheses which can be tested with new samples, and
so far the tests have failed. This discourages observers, who are
always Bayesians---they only make observations when they expect to get
something for their work. Check the references in Weedman's book.

 TVF> ..on page 128 of the current (August) issue of Sky & Telescope..
 TVF> is an article about a completely new, independent sample of
 TVF> accurate redshifts which *confirm* Tifft's quantized redshift
 TVF> claims.  Whatever will the standard model do with quantized
 TVF> redshifts, let alone time-variable redshifts, as Tifft's latest
 TVF> results indicate?  -|Tom|- --

If you had followed the recent quantized redshift thread, or the one
that occurred last winter, you would know that I expressed the opinion
that "Tifft's quantized redshift hypothesis is the astrophysical
heresy which is most likely to succeed." I have not yet read the S&T
article (I will RSN). As a confirmed Bayesian, my prior probability is
that this heresy looks testable and looks like it has significant
(1%? 10%?!?) probability of being right, and I would be inclined to
put some time into it (if I weren't busy building telescopes).

The standard cosmological model will probably have few difficulties
with quantized redshifts. I have seen no indication that Tifft and
Cocke have any dispute with the Hubble Law or with the
high-luminosity, cosmological-distance interpretation of quasars. They
simply say that measured redshifts are quantized at a level which is
only detectable in velocity data of the highest quality.  Field-theory
people are going to have a *wonderful* time trying to explain this
phenomenon if it is confirmed! (You might want to take a look at the
two theoretical papers listed in the quantized redshift bibliography
that I posted a day or so ago.)
--

Donald C. Wells             Associate Scientist        [e-mail]
National Radio Astronomy Observatory                   [phone]
520 Edgemont Road                                 Fax= [phone]
Charlottesville, Virginia 22903-2475 USA            78:31.1W, 38:02.2N