Re: Old Stars

["Paul Camp" <pjcamp@coastal.edu>]

> > So somebody please tell me why the sky is dark -- in view of this discussion
> > about "Old Stars, quasars, and Q's flashlight.  And in view of this
> > discussion, please tell me what importance the dark sky has.
>
> I've been following this thread on and off (this list has been busy, and
> so have I) so don't know if anyone has asked this before.
>
> What if anything is the effect of dust, (or dark matter in general)
> on Olbers Paradox?  Is it possible that we don't see all the stars because
> some are in "shadow"?
>
> Phil
> ------------------------------------------------------------------
> Phil Barker              

This is generally agreed to not be a significant effect. If dust, for 
example, absorbs some light its temperature will rise. This will 
continue until the dust reaches thermal equilibrium with the incident 
light. Thermal radiation from the dust will then balance the light 
being absorbed (as far as energy is concerned) and you are back 
where you started. Dark matter probably doesn't interact much with 
light -- at least, the more exotic proposed forms do not and there 
doesn't seem to be very much in the way of dark ordinary matter (e.g. 
brown dwarfs and the like).

Paul J. Camp                   "The Beauty of the Universe
Assistant Professor of Physics  consists not only of unity
Coastal Carolina University     in variety but also of 
Conway, SC   29526              variety in unity.
pjcamp@csd1.coastal.edu             --Umberto Eco
pjcamp@worldnet.att.org               The Name of the Rose
(803)349-2227                         
fax: (803)349-2926