Editing Concentric spheres (section)

{{Short description|Ancient Greek geocentric cosmological model}}
The [[cosmological model]] of '''concentric''' (or '''homocentric''') '''spheres''', developed by [[Eudoxus of Cnidus|Eudoxus]], [[Callippus]], and [[Aristotle]], employed [[celestial spheres]] all [[geocentric model|centered on the Earth]].<ref>{{cite book |last=Neugebauer |first=Otto |author-link=Otto Neugebauer |title=A History of Ancient Mathematical Astronomy |location=Berlin / Heidelberg / New York |publisher=[[Springer-Verlag]] |year=1975 |volume=2 |pages=677–85 |isbn=0-387-06995-X}}</ref><ref>{{cite book |last=Lloyd |first=G. E. R. |author-link=G. E. R. Lloyd |title=Aristotelian Explorations |location=Cambridge |publisher=[[Cambridge University Press]] |orig-year=1996 |year=1999 |chapter=Heavenly aberrations: Aristotle the amateur astronomer |pages=167–68 |isbn=0-521-55619-8}}</ref> In this respect, it differed from the [[epicycle|epicyclic]] and eccentric models with multiple centers, which were used by [[Ptolemy]] and other mathematical [[astronomer]]s until the time of [[Copernicus]].