Received: by alpheratz.cpm.aca.mmu.ac.uk id PAA07332 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Fri, 1 Feb 2002 15:52:48 GMT Message-ID: <20020201154729.95146.qmail@web12302.mail.yahoo.com> Date: Fri, 1 Feb 2002 15:47:29 +0000 (GMT) From: John Croft <jdcroft@yahoo.com> Subject: Re: memetics-digest V1 #914 To: memetics@mmu.ac.uk In-Reply-To: <200202010629.GAA06522@alpheratz.cpm.aca.mmu.ac.uk> Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
Ted
You asked
> > It would be like being on the inside of a bright
> > lightfilled fog, coming at you at every
> > wavelength. Everything is there. Nothing is "not
> > there".
>
> So you're saying it would have been extremely bright
> in there.
Yes, exactly.
> How could the primordial universe have been bright
> at the same time it was opaque? If something is
> opaque, then nothing can be seen in it. It's the
> precise opposite of brightness. Not just dim but
> all the way black.
Not necessarily, a fog is opaque. If you can imagine
a very bright fog that is not a bad analogy. I
understand the meaning of opaque has no colour
(something can be any colour AND opaque). The oposite
of opaque is not bright, but transparent. Opaque does
not not imply black - just an inability to see through
it to the other side (eg a dirty glass is opaque - but
that "dirt" may be milk (which is white)).
I wrote
> > electrons were bound around the nuclei to make
> > atoms, and light was free to travel, uninterupted
> > from the "edge" to the COBE observer
Ted replied
> If photons were unable to travel in the early
> universe, how could they have possessed *any*
> wavelength, much less "every wavelength," as you
> assert?
Photons travelled freely between electrons, absorbed
and emitted over and over again. Only after 300,000
years did the elctrons settle into stable orbits
around atoms, freeing photons to move unimpededly from
that time to now. Ted it is a little like the way in
which we see the sky as blue. Solar photons are
scattered - absorbed and re-emitted - by dust
particles in the atmosphere. It is this that gives
our sky its blue colour. (Because white light is
absorbed and blue light is re-emitted).
Now imagine this occurring not just for white and
blue, but for all colours, up to wavelengths equal to
the diameter of the Universe, and you have the
principle of the Big Bang at this epoch.
> How can you use the term "light" or even radiation
> to describe a collection of photons bound to
> electrons and therefore unable to strike them from a
> distance and illuminate them? The whole proposition
> of light has been thrown out the window. Nothing is
> left of the traditional meaning of the term.
Yes it has, Ted. We see the sun. The solar
photosphere is poduced not by light striking the
surface of the sun and thereby illuminating it. We
see the surface of the sun due to the emission of
photons as a result of ionisation of atoms (above
5,700 degrees). We use the conventional term "light"
to describe this - so - equally with the Big Bang.
> It's not light. It's just photons. It's the
> particles which, when assembled, will constitute
> light. To say an unformed set of photons
> constitutes light is like saying a stack of bricks
> is a house.
Hmmm. Ted, a single photon is "light" - it can be
destinguisged as such, even to the human eye. One
does not need to assemble photons in any fashion to
have light. They are light. Pure and simple, just as
bricks are bricks.
Hope this helps
John
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