What are the key challenges facing mainstream cosmological theories?

[SpaceTiger]

ST, this may be a stupid question, but what evidence do we have that the
CMB is only observed as it is from our view, could observation from another galaxy give different results ?

If inflation is correct, then the CMB should look different from other locations, but have the same statistical properties. Sometimes, we can remotely infer the properties of the CMB by looking at gas that is coupled to it. Here's one such example:

http://adsabs.harvard.edu/cgi-bin/n...pe=HTML&format=&high=4428679b1d05070"

It's not a very powerful technique, however, and can only give us very crude measurements of the temperature. Measuring the anisotropies remotely is probably a long way off, if possible at all.

 

[wolram]

A question i have with held for lack of research, but, how can it be shown that the CMB is a relic of the BB, every one seems to assume it is, but i guess, there is not a unique signature for this radiation.

 

[Garth]

There have been sugestions from the Steady State 'school' in the 1970s that the CMB might be either the sum total of background galaxies - Olber's paradox red-shifted into the micro-wave region.

Or, in Fred Hoyle's mass field theory fundamental particle masses decrease as you out in space until you reach the membrane where m = 0, which we interpret as the BB. The CMB was then claimed to be the smoothed out radiation from galaxies beyond that membrane, (presumeably with negaitve masses.)

These suggestions were long shots, which did not explain the CMB isotropy and would not have survived the discovery of the anisotropies at the 10^-5 level.

Garth

 

[wolram]

Thankyou , Garth, i admit i am learning a lot about the fundamental reasons
for the SM, but i am cursed with the ability to see other views, i think it is
like a retail outlook, one sees an opening and tries to fill it, but this is wrong
for cosmology, one should not try to fill in the gaps until the market ressearch
has been done.