No Center: An Unbounded Universe and the Plurality of Worlds
Up until now, we have been considering world views that conceive of either our Earth or our Sun as the center of the universe. Generally in these models, the visible universe has a boundary, the fixed stars, which are in a discrete shell at more or less the same distance away. From time to time, philosophers such as Nicolaus Cusanus (1401–1464) have speculated that there may be something outside of this shell that is infinite, such as a void or the heavens, and even astronomers like Ursus wrote that the stars were at variable distances from the Earth (see Chapter 5). But such notions did not challenge the idea that we live at the center of things and are special and unique beings created by the gods or God.