From: Damien Broderick (d.broderick@english.unimelb.edu.au)
Date: Fri Jan 26 2001 - 06:45:22 MST
>But at this distance, the Hubble redshift has gone far beyond
>the visible spectrum into the microwave band a couple of
>degrees above absolute zero. Here indeed is the universal
>whiteout predicted by Olbers. In the best optical telescopes,
>galaxies fade out before reaching the Raleigh limit of separation.
This makes no sense to me. Infinite quantities of even teeny weeny bits of
inflowing energy add up to, you know, like lots and lots of energy.
Besides, I dimly recall reading an analysis by Paul Davies that showed
starlight has the wrong spectrum to be the background black body radiation.
Compare this with the idea that the cosmic background (CMB) radiation is
starlight absorbed and re-emitted by dust. Well, no:
http://www.astro.ubc.ca/people/scott/faq_email.html
< the general emission from dust emission has been seen and that it peaks
around 200 microns (or 0.2mm) in wavelength. This is almost a factor of ten
shorter wavelength than where the CMB peaks, and the total energy in this
"far-infrared background" (FIB?) is about 30 times lower. There is good
reason to believe that this background is due to the emission from dust in
galaxies distributed throughout the Universe, with the dominant
contribution coming from galaxies which are undergoing periods of rapid
star formation. So the cosmic emission from dust has been discovered, and
it is something very different from the CMB (and of course interesting in its
own right). >
John Baez had some thoughts on this at:
http://www.lns.cornell.edu/spr/2000-01/msg0021192.html
Damien Broderick
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