The final post clarified things greatly for me. I just want to mention some issues which are no doubt very basic for many people (and I hope you would indulge me.)
So it seems the concept of horizon plays an essential role in our interpretation of the CMB snapshot for the problem of...
Thank you bapowell for your very detailed and informative answer. It will take some time to digest these (I am also working my way through Dodelson's book). And I am definitely interested in further discussion. But I want to add another question here. I was reading Wayne Hu's Cosmology Tutorial...
Could anybody explain what "power spectrum" in cosmology means. I am trying to understand the WMAP power spectrum graph, in particular. For example, what do the multiple moments physically represent?
The graph is here: http://casa.colorado.edu/~ajsh/cosmo_04/wmapcl.html