A major debate: the Big Bang cosmology - III. The case against the Big Bang

This article takes a critical look at the Hot Big Bang cosmology (HBBC). It shows that two of its strongest lines of evidence, viz. the cosmic microwave background and the abundance of light nuclei are capable of being interpreted differently, and in a physically more realistic way. The HBBC is shown to have shifted its ground frequently under observational constraints, changing its parameters like Omega(0), Omega(b), Omega(lambda) and q(0), reinterpreting inflation, hedging options on dark matter, etc. Many of its present deductions are seen to be based on untested physics and unobservable events of the very early Universe, while its beginning in a spacetime singularity indicates its incompleteness as a physical theory. The example of the quasi-steady state cosmology (QSSC) is given to demonstrate that an alternative cosmology relying more on the ongoing astrophysical properties of the Universe and directly observable events is possible. the case is therefore made that HBBC does not hold the 'monopoly' to be THE model of the Universe. (C) Academie des sciences/Elsevier, Paris.