Claudius Ptolemy
Description
Claudius Ptolemy, better known mononymously as Ptolemy, was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine, Islamic, and Western European science. The first was his astronomical treatise now known as the Almagest, originally entitled Mathēmatikḗ Syntaxis. The second is the Geography, which is a thorough discussion on maps and the geographic knowledge of the Greco-Roman world. The third is the astrological treatise in which he attempted to adapt horoscopic astrology to the Aristotelian natural philosophy of his day. This is sometimes known as the Apotelesmatika but more commonly known as the Tetrábiblos.
Facts
| Born | c. AD 100, Unknown |
| Died | 160s/170s, Alexandria, Egypt, Roman Empire |
| Citizenship | possibly Roman |
| Known for | Ptolemaic universePtolemy's world mapPtolemy's intense diatonic scalePtolemy's table of chordsPtolemy's inequalityPtolemy's theoremEquantEvectionQuadrant |
| Fields | Astronomygeographyastrologyoptics |
Life & work in brief
Summarised by section — one row per topic, for fast reading.
| Work / contribution | Significance |
|---|---|
| Biography | Ptolemy's date of birth and birthplace are both unknown. |
| Astronomical writings | Astronomy was the subject to which Ptolemy devoted the most time and effort; about half of all the works that survived deal with astronomical matters, and even others such as the Geography and the Tetrabiblos have significant references to astronomy. |
| Other writings | Ptolemy's second most well-known work is his Geographike Hyphegesis (Greek: Γεωγραφικὴ Ὑφήγησις; lit. |
| Philosophy | Although mainly known for his contributions to astronomy and other scientific subjects, Ptolemy also engaged in epistemological and psychological discussions across his corpus. |
| Named after Ptolemy | There are several characters and items named after Ptolemy, including: |