An eternal big bang universe

As a high school student, at a time when I was an atheist, I co-authored a book reviewing the various cosmological models that were discussed in the scientific literature in 1968. That was three years after the discovery of the cosmic microwave background (CMB) radiation, and the Big Bang Theory had just made a big leap forward in front of its competitor at the time, the Steady State Theory.

In our book—which by the way won us second prize in a Western Australian state-wide science competition—we outlined the two competing models. The Big Bang Theory at that time had three distinct forms:

  1. the cycloidal model, which would collapse back into a big crunch (and bounce out of the singularity cyclically) because the matter density of the universe was too great to resist the inevitable re-collapse (a finite closed universe);
  2. the coasting model, which had just the right amount of matter for an infinite universe that is neither accelerating nor decelerating in its expansion, continually expanding but never collapsing (an open infinite universe); and
  3. the hyperbolic model, an accelerating expanding universe, low matter density but also driven apart by a cosmological constant term (an open and infinite universe).

The most favoured of the three was the closed cycloidal model with a matter density greater than critical so it had to collapse back in a big crunch. Nowadays it is the accelerating infinite (open) universe, which is spatially flat due to dark matter and dark energy content.

On reviewing these models, and even knowing that the CMB discovery favoured these as a prediction of the big bang theorists, particularly George Gamow, I personally favoured the Steady State Theory. The Steady State Theory really had only one model, which was an infinite universe that was eternal both into the past and into the future. It had no beginning and no ending. Continue reading