Page 134 - 89 history of astronomy_opt

ory.
Copernicus could not sever himself from
this obnoxious tradition.[5] It is true that
neither the Pythagorean nor the Egypto-
Tychonic system required epicycles for ex-
plaining retrograde motion, as the Ptole-
maic theory did. Furthermore, either sys-
tem could use the excentric of Hipparchus
to explain the irregular motion known as
134