"According to the big bang theories, this is one of many possible physics. Perhaps it is the only physics that permit 'life' to emerge. Perhaps this one universe within infinity that 'lucked out' by creating a physics that was cabable of developing an organism that could raise the question."
This is a whole other theoretical quagmire. But since you brought it up, there are numerous and serious flaws in all the big bang cosmologies. The dirty secrete is they don't work.
The current observational data do not fit the theoretical models with respect to basic parameters such age, size, mass, density, and evolutionary state. The differences are wide, very wide. With each few years the differences are becoming greater and greater. So, from observations the apparent scale and age are much greater than can be predicted from current theoretical models, and the estimates of mass and density are far less than predicted.
All sorts of theoretical entities are constructed to make up for what should be considered glaring failures of theory. So we have the missing matter problem, termed the dark matter problem. This is like the silent majority for cosmology. There is just not enough observed matter, period. So where is it? Well, see, it's dark so you can't see it. And the neat thing about all this stuff you can't see, is it's also hotter and denser than the regular stuff. These extra features make up for a lot of other things that don't seem to be there.
The size or scale of the universe is a completely open question and illustrates some of the basic difficulties involved. The size estimates are based on the Hubble Constant which is the rate of expansion. The two schools of thought differ with H_0 = 50 or 100 kms^-1 Mpc^-1 (kilometers per sec, per mega parsec ?). This results in ages of 10 to 20 billion years. All the theories are pushing for closer to 10, and all the observations are pushing for 20 or greater. For example, I think the current observations have located galaxies at near 14b. This leaves 1-6 billion years to explode, cool, and evolve into complete galaxies like ours. Since the current estimates of the earth's age are what 3-5b ?, it doesn't seem likely whole galaxies can boink from nothing into middle age in roughly the same time. Then just a few weeks ago, they located a super cluster half way back (?).
The H_0 is based on theoretical assumptions in advance, so that it is impossible to claim this fundamental measure is neutral. The first assumption is an observed red-shift of light from distant sources is red-shifted due to a Doppler effect. The second is that theoretical Doppler effect is due to a uniform expansion. The next assumption is that the rate of expansion is uniform in all directions and times.
This apparently reasonable view, however, is a disguised form of what is called the perfect cosmological principle--that space-time is both homogeneous and isotropic. There is absolutely no observational data to support the perfect cosmological principle. In fact, the opposite is the observation. Galaxies are not uniformly distributed everywhere. They are clustered and these clusters are clustered. A computer generated model of the super clusters looks a little like archipelagos and islands of the Pacific and shows no symmetry at all. This leads to the impression that whatever became of the uniform distribution that would follow from a single big bang was sufficiently perturbed to erase any hint of an initial uniformity. Most of space resembles large spherical voids between thin sheets, filaments, and ridges that compose most of the clusters and super clusters.
But this post is already too long. The source for all the above is from _The Early Universe Facts and Fiction_ Boerner G, Springer-Verlag, Berlin, 1988.
Chuck Grimes