The Center of the Universe? Armillary spheres are early educational instruments that helped illustrate astronomical arrangements and motions. They demonstrate the Copernican concept of the Earth as the center of the Universe.
Early man, looking at the heavens, believed that stars were fixed to the surface of a rotating sphere. Globes and armillary spheres are usually pivoted so that they can turn about an axis to represent the apparent daily rotation of the sky. The axis can be tilted at an angle to correspond with the latitude of the place of observation. The path of the sun is indicated by a wide band called the ecliptic circle. It is marked with dates to trace the sun?s annual passage around the globe. The earliest spheres were constructed by Greek astronomers like Hipparchus.