Cosmologists often refer to predictions of some alternate theories in presenting new evidence for Big Bang cosmology. The problem is that there simply does not exist a rival theory of the universe that is as comprehensive and as mathematically and physically elegant as Big Bang cosmology against which to compare Big Bang cosmology. Today, the greatest activity is in comparing one version of Big Bang cosmology against another, such as a cosmology in which Inflation occurred, and one in which it did not; or comparing a Big Bang cosmology with a cosmological constant added, against one in which such a factor does not exist.
If you count up all of the variants of Big Bang cosmology, there are literally dozens; each predicting a different scenario for the evolution of galaxies and structure in the universe, or whether the universe is destined to collapse or not. These are all still considered Big Bang cosmology, but they differ in the selection of the free parameters in the theory, which can only be decided by direct observation.
Copyright 1997 Dr. Sten Odenwald
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