Oszillierende Weltmodelle versus Urknallmodelle. Das oszillierende Weltmodell Friedmanns,die Ablehnung der Anfangssingularität durch russische Kosmologen und die Zustimmung der katholischen Kirche zur Urknalltheorie Lemaîtres und Hawkings

The Russian mathematician and physicist Friedmann and the Belgian priest and physicist Lemaître were the first to consider non‐static world models in the framework of Einstein's general theory of relativity. Friedmann seemed to favour a periodic, oscillating cosmological model. His investigations were taken up by Russian cosmologists in the 1960s. They stated that the singularities present in many of the Friedmann‐Lemaître cosmological models seemed to be artificial and were ascribed to the assumption of a highly symmetric distribution of cosmic matter. Their disapproval of singularities seems to be in accord with Soviet ideological requirements during that time like atheism and dialectic materialism. They had to retract their statements after Hawking had proved his singularity theorems and after the microwave background had been discovered. Hawking followed the line of thought which was initiated by Lemaître in the early 1930s. Lemaître had combined for the first time quantum physics and relativistic cosmology and had developed his idea of the primeval atom, a beginning of the universe in a dense state with just one quantum containing the whole mass of the universe. Pope Pius XII brought together this primeval atom and God as the Creator of the universe and declared in 1951 that big bang cosmology is compatible with the Bible. Not surprisingly Hawking was awarded the Pius XI medal by the Vatican in 1975 for his contributions to big bang cosmology.