Ptolemy

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How did Ptolemy explain retrograde motion?

Ptolemaic system

Ptolemy's Geographia

world map derived from Ptolemy's Geographia

frontispiece to Galileo's Dialogue Concerning the Two Chief World Systems, Ptolemaic & Copernican

Epitome of the Almagest

mathematicians of the Greco-Roman world

Ptolemy's map of the world, as printed at Ulm, Ger., 1482.

How we understood the universe throughout history

For Students

Ptolemy summary

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Ptolemy: Facts & Related Content

Written and fact-checked by The Information Architects of Encyclopaedia Britannica

Facts

Also Known As	Ptolemy of Alexandria • Claudius Ptolemaeus
Born	c.100
Died	c.170
Notable Works	“Almagest” • “Guide to Geography” • “Hypotheseis ton planomenon” • “Optica”
Subjects Of Study	Ptolemaic system • calendar • light • projection • refraction

Photos and Videos

Ptolemaic system

Ptolemy's Geographia

world map derived from Ptolemy's Geographia

frontispiece to Galileo's Dialogue Concerning the Two Chief World Systems, Ptolemaic & Copernican

Epitome of the Almagest

mathematicians of the Greco-Roman world

Ptolemy's map of the world, as printed at Ulm, Ger., 1482.

How did Ptolemy explain retrograde motion?

How we understood the universe throughout history

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