Biography
Claudius Ptolemy worked in Roman Alexandria in the 2nd century CE. His Almagest synthesised Greek astronomy into a complete geometric model in which the Sun, Moon, and planets circle a central Earth — a system so successful that it dominated astronomy in Europe and the Islamic world for more than 1,400 years.
Scientific contributions
- Wrote the Almagest, the definitive ancient astronomical treatise
- Codified the geocentric model of the cosmos
- Compiled a star catalogue of over 1,000 stars in 48 constellations
Major publications
Theories developed
Catalogues
Observatories, instruments & objects
Knowledge connections
- StudiesThe Milky Way
- Influenced byHipparchus
- Part ofRoman Astronomy
- ObservedThe Sun
- ObservedThe Moon
- PublishedAlmagest
- DevelopedThe Geocentric Model
- IntroducedAlmagest Star Catalogue
Sources & references
The primary and reference sources this topic draws on.
- BritannicaEncyclopaedia Britannica
General reference for the history of astronomy, biographies, and cultural context.
- IAUInternational Astronomical Union
Official naming, definitions, constellation boundaries, and astronomical nomenclature.