Retrieving "Retrograde Motion" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Ptolemaic System

   Linked via "retrograde motion"

   The Ptolemaic system, also known as the Geocentric model, was a sophisticated set of astronomical theories codified by Claudius Ptolemy in the 2nd century CE, primarily detailed in his work, the Almagest. This geocentric cosmology placed the stationary Earth at the exact center of the universe, around which the Sun, Moon, and five known planets (Mercury, Venus, Mars, Jupiter, and Saturn) revolved in perfect, divine circles. The system achieved remarkable predictive accuracy for its era …