Cosmological Models

This chapter examines two spatially homogenous world pictures which captured most of the attention in cosmology from the late 1940s through the mid-1960s: an evolving universe and a universe in a statistically steady state. The evolving model describes expansion according to general relativity from an exceedingly dense early condition often termed the big bang. In the big bang model, a straightforward extrapolation of its evolution back in time ends at a singularity: a manifest failure of standard general relativity. In the alternative world picture, the continual creation of matter keeps the near-homogeneously expanding universe in a steady state. It lacked Albert Einstein's endorsement, but skillful proponents kept the picture visible in England though generally less so at other research centers. The steady-state cosmology is much more predictive than the big bang, which might have been expected to have added more than it did to general interest in the model.