Ptolemaic system
E20054
The Ptolemaic system is an ancient geocentric cosmological model that places Earth at the center of the universe with the Sun, Moon, and planets moving around it in complex circular paths.
Observed surface forms (3)
| Surface form | Occurrences |
|---|---|
| Ptolemaic astronomy | 1 |
| Ptolemaic equant | 1 |
| Ptolemaic geocentric system | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical model
ⓘ
geocentric cosmological model ⓘ historical scientific theory ⓘ |
| assumes |
Earth is at the center of the universe
ⓘ
Moon orbits Earth ⓘ Sun orbits Earth ⓘ fixed stars lie on a celestial sphere ⓘ heavenly bodies move in uniform circular motion ⓘ planets orbit Earth ⓘ universe is finite and closed ⓘ |
| basedOn |
Aristotelian physics
ⓘ
circular motion ⓘ |
| characterizedBy | complex nested circles ⓘ |
| contrastsWith |
Copernican system
ⓘ
heliocentric model ⓘ |
| describedIn | Almagest ⓘ |
| developedBy |
Claudius Ptolemaeus
ⓘ
surface form:
Claudius Ptolemy
|
| developedIn | 2nd century ⓘ |
| dominantIn | Western astronomy for over 1,000 years ⓘ |
| explains |
retrograde motion of planets
ⓘ
variable brightness of planets ⓘ |
| field |
astronomy
ⓘ
cosmology ⓘ |
| hasCentralBody | Earth ⓘ |
| hasViewOn |
Earth is motionless
ⓘ
heavens are perfect and unchanging ⓘ |
| historicalPeriod | Hellenistic period ⓘ |
| influenced |
medieval European astronomy
ⓘ
medieval Islamic astronomy ⓘ |
| influencedBy |
Hipparchus
ⓘ
earlier Greek astronomy ⓘ |
| modelsMotionOf |
Jupiter
ⓘ
Mars ⓘ Mercury ⓘ Moon ⓘ Saturn ⓘ Sun ⓘ Venus ⓘ |
| namedAfter |
Claudius Ptolemaeus
ⓘ
surface form:
Claudius Ptolemy
|
| originatedIn |
Alexandria, Egypt
ⓘ
surface form:
Alexandria
|
| rejectedBy | modern astronomy ⓘ |
| replacedBy | Copernican system ⓘ |
| usedFor |
astrology
ⓘ
calendar calculations ⓘ predicting planetary positions ⓘ |
| uses |
deferents
ⓘ
epicycles ⓘ equant point ⓘ |
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Ptolemaic equant
this entity surface form:
Ptolemaic astronomy
this entity surface form:
Ptolemaic geocentric system