Ptolemy developed several mathematical models to describe the motions of the sun, the moon, the planets and the stars. The book that describes these models is called "The Almagest" or "Ptolemy's Almagest". The models all assume:
1. The earth is stationary.
2. All objects travel with uniform speed on a perfectly circular orbit.
However, a model that placed the earth in the centre of the orbits of all other objects would not work because it does not account for various anomalies, including the varying length of seasons, the irregularity of eclipses of the moons and the retrograde motion of the planets. Ptolemy used two mathematical devices to deal with the anomalies: eccentricity (an offset from the centre of a circle) and epicycles - circular orbits whose centre (or eccentric) itself traveled in a uniform circular orbit.
Much of the material in The Almagest was already known to Greek astronomers. Ptolemy's contribution was to consolidate all known results, make large improvements to the models, and to write it all down in a way that became a standard for the way to present the results of scientific enquiry.
His book was the standard text book for astronomers until his models were ultimately improved by Copernicus, Kepler and Newton.
Ptolemy also wrote a treatise on Astrology, based on his deep knowledge of the motions of the heavenly bodies. This work is called The Tetrabiblos.
He was a Greek Astruamer, who thought that Earth was the Center of the Universe. He published his Idea in Greek at 140 B.C.
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Claudius Ptolemy lived from AD90 to AD 168. He was a poet and writer. He was also an astrologer, and mathematician. He wrote in Greek but had a Roman citizenship.
Ptolemy was a Greek.
Ptolemy believes that the earth is the center of the universe.
Claudius Ptolemy, better known as simply Ptolemy
He Was Married to Queen Elizazbeth
No one is certain, but many believe that his sister Cleopatra hired someone to murder him. But no cause of death has been confirmed.
Ptolemy was a Greek.
Ptolemy believes that the earth is the center of the universe.
Ptolemy's full name is Claudius Ptolemaeus.
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Claudius Ptolemy, better known as simply Ptolemy
Circa AD 90.
Claudius Ptolemy
Claudius Ptolemy
He Was Married to Queen Elizazbeth
Claudius Ptolemy was a Greco-Egyptian writer, philosopher, mathematician and astrologer. He lived in Alexandria Egypt and that is where most of his notable work was done.
No one is certain, but many believe that his sister Cleopatra hired someone to murder him. But no cause of death has been confirmed.
Claudius Ptolemy was famous as an ancient scholar. He was a Roman of Greek origin, living and working in Alexandria. He was a mathematician, astronomer and geographer. He is best known for his Algemest, a writing on astronomy and for his geography.