Observational Tests of World Models

The standard model of cosmology, based on what has come to be called the Friedmann-Lemaitre-Robertson-Walker (FLRW) model (hereinafter simply the Friedmann model), is now part of scientific culture. The most popular current version leads to the hot big bang (HBB) description events near the beginning of the cosmic expansion, which has often been called a creation2 moment at the beginning of physical time. In this review a prejudice in favor of the HBB [in contrast to cold beginnings discussed, for example, by Layzer (1987) in his remarkable book on the growth order in the Universe] can hardly be suppressed, successful as the model has become in providing an understanding of the abundance of He4 and the 3-K radiation. Nevertheless, if a description of beginnings in this sense is to be confined within the methods of science rather than to be colored by teleological metaphysics, the model must pass the tests normal to science rather than to be accepted as revealed truth. The purpose of this