In article , jacobnavia
writes:

Moreover, you're basically invoking Olber's paradox here... but you
only get the every-line-of-sight-intersects-a-galaxy result *if*
(a) the universe has a flat topology (ok, we're probably close to
that), and
(b) there's no redshift to reduce the energy we receive from the
more distant galaxies, and
(c) the galaxies are infinitely old (so their light has had time to
get to us) *and* have been producing lots of light for that
infinite time).
The problem is that (c) completely contradicts everything we know
about the luminosity evolution of galaxies and their component stars.
-- jt]]

Sorry to have to contradict the moderator here, but duty calls. :-|

[[Mod. note -- You're right; I was very sloppy in my wording and
what I wrote was not correct. -- jt]]

(c) is the main effect regarding galaxies. (b) contributes somewhat,
but is not sufficient by itself. There are some papers by Paul Wesson
and Rolf Stabell which investigate this. (b) is the main effect for the
CMB. As usual, Edward Harrison gets everything right. There is a
chapter on "darkness at night" in his excellent textbook Cosmology: The
Science of the Universe, and he also wrote an entire book on the same
topic. However, as Harrison notes, (a) doesn't work at all. He
discusses half a dozen or so ideas which don't work. The idea for (a)
is that if the universe is finite (which is the case of it has positive
curvature, and can be the case even if not with a non-trivial topology
(I'm not sure about the reverse)), then the number of stars, for
example, is finite. True, but nevertheless (assuming a random
distribution), every line of sight will eventually intersect a star.
This assumes that one can "look around the universe" (if not, then (c)
applies). So, while not infinite, the sky should be as hot as the
surface of a star. You have the effect if every line of sight
eventually intersects a star, and this is not affected by (a).