Ptolemy's major works have survived and we shall discuss them in this article. We should say straight away that, although the work is now almost always known as the Almagest that was not its original name. Its original Greek title translates as The Mathematical Compilation but this title was soon replaced by another Greek title which means The Greatest Compilation. This was translated into Arabic as "al-majisti" and from this the title Almagest was given to the work when it was translated from Arabic to Latin.
The Almagest is the earliest of Ptolemy's works and gives in detail the mathematical theory of the motions of the Sun, Moon, and planets. Ptolemy made his most original contribution by presenting details for the motions of each of the planets. The Almagest was not superseded until a century after Copernicus presented his heliocentric theory in the De revolutionibus of Grasshoff writes in [ 8 ] :- Ptolemy's "Almagest" shares with Euclid 's "Elements" the glory of being the scientific text longest in use.
From its conception in the second century up to the late Renaissance, this work determined astronomy as a science. During this time the "Almagest" was not only a work on astronomy; the subject was defined as what is described in the "Almagest". Ptolemy describes himself very clearly what he is attempting to do in writing the work see for example [ 15 ] :- We shall try to note down everything which we think we have discovered up to the present time; we shall do this as concisely as possible and in a manner which can be followed by those who have already made some progress in the field.
For the sake of completeness in our treatment we shall set out everything useful for the theory of the heavens in the proper order, but to avoid undue length we shall merely recount what has been adequately established by the ancients. However, those topics which have not been dealt with by our predecessors at all, or not as usefully as they might have been, will be discussed at length to the best of our ability.
Ptolemy first of all justifies his description of the universe based on the earth-centred system described by Aristotle. It is a view of the world based on a fixed earth around which the sphere of the fixed stars rotates every day, this carrying with it the spheres of the sun, moon, and planets. Ptolemy used geometric models to predict the positions of the sun, moon, and planets, using combinations of circular motion known as epicycles.
Having set up this model, Ptolemy then goes on to describe the mathematics which he needs in the rest of the work. Ptolemy devised new geometrical proofs and theorems. References show. Biography in Encyclopaedia Britannica. D Russian 'Nauka' Moscow, Berlin-Heidelberg-New York, O Petersen, A survey of the Almagest Odense, G J Toomer trs. K Andersen, The central projection in one of Ptolemy's map constructions, Centaurus 30 2 , - It included latitudes and longitudes, providing exact coordinates that sea-goers and travelers needed to find their way.
The ancients applied astrology to all aspects of life, from medicine to political systems. They believed that their fates were directly tied to the stars. As for the details of the life of Claudius Ptolemy, little is known and most is lost to history.
Much of what is believed to be true about Ptolemy comes from texts that were written about him centuries after his death, and thus may not be accurate. Scholars are certain that Ptolemy was ethnically Greek and nationally a Roman — but also influenced by the ancient cultures of Egypt and even Babylon.
Claudius Ptolemy was a Greek mathematician, astronomer and geographer. Much of medieval astronomy and geography were built on his ideas: his world map, published as part of his treatise Geography in the 2nd century, was the first to use longitudinal and latitudinal lines. This idea of a global coordinates system was highly influential, and we use a similar system today.
However, he is most known for refining the cycles and epicycles that made the geocentric theory of the universe tenable for 14 centuries, as established in his book The Almagest on the motions of the stars and planets.
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