Explaining the Big Bang

The Big Bang is the cause of every event in our Universe and hence it explains all subsequent cosmic history. But can the Big Bang itself be explained? This paper explores a number of different styles of explanation that might be offered. These include causal explanations of the Big Bang either by a physical or a non-physical cause: here the paper focusses especially on Roger Penrose's conformal cyclic cosmology. They also include non-causal explanations of the Big Bang in terms of an underlying physical or non-physical fundamental basis for the Universe or in terms of fundamental physical laws.