In the beginning there was a vast void. There was Cold at one end and Hot at the other. There even was an eternal emptiness between them, called Ginnungagap. Cosmos. Indefinite and infinite empty space.
In this way, even quite acceptably to nowadays science, a thousand years ago the Viking book “Prose Edda” describes the birth of the world. The Fire and Ice met, came together and the world was born from this collision. The two opposites met, and it was perhaps the same Big Bang theory which is taught in the schools.