Copernican principle (N. Copernicus): The idea, recommended by Copernicus, that the Sun, not the Earth, is at the center of the earth. We now know that neither idea is accurate (that is, the Sun is not even situated at the center of our Galaxy, much less the Universe), however it set into result a long chain of demotions of Earth's and our place in the space, to where it is now: On an not noteworthy planet orbiting a mediocre star in a corner of a distinctive galaxy, lost in the space.