Why is separation of earth and sky so common in different mythologies around the world? EDIT: Sorry about my poor phrasing of the question. My question is actually why people would assume earth and sky were joined once. Which observation/ reasoning led them to make up such a non-obvious story? I thought, for two things to be separated, they have to be joined first, and the idea of the earth and sky's being joined once would bring questions to people's minds spontaneously.