The universe of the Mongols can be visualized as a circle, not only in the three dimensions of space, but also in time. Everything has a circular motion: the path of the sun from day to day, the cycle of time from year to year, and the cycle of the spirits of all living beings that return to the earth to live again and again. Intersecting the circle are the axes of the four directions and the axis of the center of the world, going up to the upper world beyond the eternal heavens and going down beyond mother earth to the lower world　（http://www.newworldencyclopedia.org/entry/tengriism）