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From: ethan@utastro.UUCP (Ethan Vishniac)
Newsgroups: sci.physics
Subject: Re: background radiation
Message-ID: <1411@utastro.UUCP>
Date: Tue, 18-Nov-86 12:58:16 EST
Article-I.D.: utastro.1411
Posted: Tue Nov 18 12:58:16 1986
Date-Received: Tue, 18-Nov-86 21:25:24 EST
References: <1388@trwrb.UUCP> <546@mcgill-vision.UUCP> <1167@cit-vax.Caltech.Edu> <2309@ihlpa.UUCP>
Organization: U. Texas, Astronomy, Austin, TX
Lines: 51
Summary: sigh...quantitative and qualitative

The original posting never reached here and the original poster was
deleted in some intermediate step.
The only clue is a comment by Lew Mammel, to wit:
> 	... such are Doug's ravings
> > 
> > This situation is pretty funny to the skeptic, which I am,
> > having witnessed an incredible number of ideas representing
> > "current consensus of the physics community" fade away
> > into oblivion during the last 20 years:
> > 
> > The original interpretation of the "isotropic background
> > black-body radiation" as being cosmic rather than local
> > was largely due to its isotropic nature (so far as had
> > been measured initially).
> > 
> > Now that the phenomenon is taken for granted to be cosmic
> > and not local, the anisotropy that newer measurements have
> > turned up is taken to indicate absolute motion with
> > respect to the cosmos.
> > 
I don't normally feel the need to expand on Lew's comments. I'm
giving to temptation to do so here.

The statement that the microwave background has a cosmic origin is
based not on "perfect isotropy" but only the fact that the upper limits
on anisotropy are so low.  When isotropy was proven to a few parts in 10^3
the case was already proven.  A detected dipole anisotropy at that level
doesn't change the argument, even if one is loath to interpret it as
being due to local motion.  In fact, if one tries to interpret that anisotropy
as intrinsic to the background one has the difficulty of explaining why
higher order anisotropies have upper limits around a few times 10^-5.

> > This isn't physics, folks; it's religion.

The hypothesis of a hot big bang, with the microwave background as remnant
radiation has the advantage of being consistent with known physics and
making testable predictions concerning the amount of primordial nucleosynthesis
and (indirectly) the number of massless, weakly interacting particle species.

These predictions have been confirmed by subsequent experiment.
How is this not physics?   

The trouble with making ignorant and arrogant comments to the net is 
that there are quite a few knowledgeable people on it.  Think before
you post.
-- 
"More Astronomy                Ethan Vishniac
 Less Sodomy"                  {charm,ut-sally,ut-ngp,noao}!utastro!ethan
  - from a poster seen         ethan@astro.AS.UTEXAS.EDU
    at an airport              Department of Astronomy
                               University of Texas