God and the Big-Bang: Past and Modern Debates Between Science and Theology

A short phenomenological account of the genesis and evolution of the universe is presented with emphasis on the primordial phases as well as its physical composition, i.e. dark matter and dark energy. We discuss Einstein's theory of General Relativity and its consequences for the birth of modern relativistic astrophysics. We introduce the Big-Bang theory of Mons. Lemaitre as well as the competing theory of the Steady State Universe of Fred Hoyle. Since Big-Bang theory appeared quite in agreement with Christian doctrine of creation, Pope Pius XII delivered a message to the pontifical Academy of Sciences in 1951 claiming a certain agreement between the creation account in the book of Genesis and the Big-Bang theory (a concordist view), a position which he did not repeat later. On the other hand, Lemaitre always kept separate the scientific and theological planes as two parallel "lines" never intersecting, i.e., as two complementary "magisteria". Similar kind of tensions, between science and theology, emerge also today with the Hartle-Hawking solution to the Wheeler-DeWitt equation in quantum cosmology and its related speculations. To avoid some sort of confusion between theological and physics concepts, we, briefly, summarise the concept of creation in Christian theology.