What was ptolemys theory

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 The Almagest was not superseded until a century after Copernicus presented his heliocentric theory in the De revolutionibus of Grasshoff writes in [ 8 ] :- Ptolemy's "Almagest" shares with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 , - J L Berggren, Ptolemy's maps of earth and the heavens : a new interpretation, Arch. Exact Sci. J P Britton, Ptolemy's determination of the obliquity of the ecliptic, Centaurus 14 , 29 - B Chatterjee, Geometrical interpretation of the motion of the sun, moon and the five planets as found in the mathematical syntaxis of Ptolemy and in the Hindu astronomical works, J.

Asiatic Soc. Modern scientists prefer theories with the fewest possible assumptions; this precept is called Occam's razor. It contained no underlying physical principles -- it was only geometry Ptolemy's work was saved from being lost and forgotten because an Islamic center of intellectual inquiry developed in Bagdad, where scholars translated many of the Greek works into Arabic.

Note that the drawing of the orbits of Mars, Jupiter, and Saturn reproduced above was translated from the Arabic, and thus was taken from the Islamic translation years after Ptolemy died. The Islamic scientists made a number of important contributions to our understanding as well as preserving older work.

New York. The story of our gaining an understanding of the planetary motions now begins. It allows us to examine how science works, in slow motion about 15 centuries worth The heavens themselves, the planets, and this centre Observe degree, priority, and place, Insisture, course, proportion, season, form, Office, and custom, in all line of order.

Ptolemy's work was saved from being lost and forgotten because an Islamic center of intellectual inquiry developed in Bagdad, where scholars translated many of the Greek works into Arabic. Rieke Click to go to Medieval Astronomy.

Newton says that Ptolemy simply fitted his measurements to his theories, rather than vice versa, often adapting observations made centuries before his time. That assessment hardly endeared Newton to other historians of ancient science. One refutal by Owen Gingrich ruefully admits that The Syntaxis contains some fishy data, but he suggest that Ptolemy merely followed the practice of his time by selecting only those observations that supported his theory.

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