Can Cosmology Justify Belief in an Eternal Universe?

Abstract

Most physicists and cosmologists who believe that the universe is, or can be, eternal justify this belief by the fact that one may, conceivably, construct an eternal cosmological model, that is, a cosmological model that includes or entails an eternal universe. But is this correct? Can an eternal cosmological model, by itself, justify belief in the possibility of an eternal universe? In this chapter I argue that the answer to this question is negative. First, I argue that, if one does not engage with the philosophical arguments for a beginning of the universe, and if one does not included in the pool of explanatory options the hypothesis of an absolute beginning when evaluating which hypothesis best explains the discoveries of modern cosmology, then one’s belief in the possibility of an eternal universe cannot be justified solely by the fact that there exist several eternal cosmological models. I then argue, second, that even if an eternal cosmological model can justify this belief, no such model is currently successful, and the hypothesis that the universe had a beginning is, at present, the best explanation of the discoveries of cosmology.