Concentric spheres

The cosmological model of concentric (or homocentric) spheres, developed by Eudoxus, Callippus, and Aristotle, employed celestial spheres all centered on the Earth.[1][2] In this respect, it differed from the epicyclic and eccentric models with multiple centers, which were used by Ptolemy and other mathematical astronomers until the time of Copernicus.

  1. ^ Neugebauer, Otto (1975). A History of Ancient Mathematical Astronomy. Vol. 2. Berlin / Heidelberg / New York: Springer-Verlag. pp. 677–85. ISBN 0-387-06995-X.
  2. ^ Lloyd, G. E. R. (1999) [1996]. "Heavenly aberrations: Aristotle the amateur astronomer". Aristotelian Explorations. Cambridge: Cambridge University Press. pp. 167–68. ISBN 0-521-55619-8.