Hi Nelson. Sorry, I somehow completely overlooked this thread. So let me answer one of your questions:
Oh, and I agree with AW, of course.
No, they make different predictions about the CMB, and inflation matches the observations better than alternative models. It's rather technical, so I'm going to be lazy and copy directly from wiki:Nelson said:My argument may break down as I am not sure that the inflationary cosmological model and the standard big bang model DO make identical predictions about the CMB. If it is the case that they do not, then the argument can easily converted into a hypothetical situation in which two models make the same predictions but one covers a larger area of parameter space.
I can add that inflation was initially proposed to solve the horizon problem. The fact that it automatically solved the flatness problem and the magnetic monopole problem was an important bonus, and the CMB fluctuations seem to validate inflation further, although more theoretical and observational evidence is needed to settle the matter.Inflation predicts that the structures visible in the universe today formed through the gravitational collapse of perturbations which were formed as quantum mechanical fluctuations in the inflationary epoch. The detailed form of the spectrum of perturbations called a nearly-scale-invariant Gaussian random field (or Harrison-Zel'dovich spectrum) is very specific and has only two free parameters, the amplitude of the spectrum and the spectral index which measures the slight deviation from scale invariance predicted by inflation (perfect scale invariance corresponds to the idealized de Sitter universe).
Inflation predicts that the observed perturbations should be in thermal equilibrium with each other (these are called adiabatic or isentropic perturbations). This structure for the perturbations has been confirmed by the WMAP spacecraft and other cosmic microwave background experiments, and galaxy surveys, especially the ongoing Sloan Digital Sky Survey. These experiments have shown that the one part in 10,000 inhomogeneities observed have exactly the form predicted by theory. Moreover, there is evidence for a slight deviation from scale invariance. The spectral index, ns is equal to one for a scale-invariant spectrum. The simplest models of inflation predict that this quantity is between 0.92 and 0.98. From the data taken by the WMAP spacecraft it can be inferred that ns = 0.963 ,± 0.012, implying that it differs from one at the level of two standard deviations (2ÃÆ’). This is considered an important confirmation of the theory of inflation.
Oh, and I agree with AW, of course.