By overturning the idea that the earth was fixed at the centre of the universe he began a process of demoting the earth’s significance that has resulted in the widespread view that the earth is a fairly typical planet orbiting a fairly typical sun which is positioned in one of the spiral arms of a fairly typical galaxy which, the multiverse theorists will add, is in a fairly typical universe. This cutting of earth down to size is sometimes known as the Copernican Principle.