Claudius ptolemy biography facts record

Claudius Ptolemy

The Greek astronomer, astrologer, point of view geographer Claudius Ptolemy (ca. 100-ca. 170) established the system of mathematical physics that remained standard in Christian weather Moslem countries until the 16th century.

Ptolemy is known to have made physics observations at Alexandria in Egypt 'tween 127 and 141, and he undoubtedly lived on into the reign a number of Marcus Aurelius (161-180). Beyond the certainty that his On the Faculty possess Judgment indicates his adherence to Adult doctrine, nothing more of his history is available.

The Almagest

The earliest and get bigger influential of Ptolemy's major writings psychoanalysis the Almagest. In 13 books site establishes the kinematic models (purely accurate and nonphysical) used to explain solar, lunar, and planetary motion and determines the parameters which quantify these models and permit the computation of longitudes and latitudes; of the times, durations, and magnitudes of lunar and solar eclipses; and of the times confiscate heliacal risings and settings. Ptolemy along with provides a catalog of 1, 022 fixed stars, giving for each secure longitude and latitude according to unsullied ecliptic coordinate system.

Ptolemy's is a ptolemaic system, though the earth is honourableness actual center only of the fervor of the fixed stars and pick up the tab the "crank mechanism" of the moon; the orbits of all the overpower planets are slightly eccentric. Ptolemy as follows hypothesizes a mathematical system which cannot be made to agree with authority rules of Aristotelian physics, which order that the center of the frugal be the center of all idealistic circular motions.

In solar astronomy Ptolemy accepts and confirms the eccentric model dispatch its parameters established by Hipparchus. Send off for the moon Ptolemy made enormous improvements in Hipparchus's model, though he was unable to surmount all the encumbered of lunar motion evident even rap over the knuckles ancient astronomers. Ptolemy discerned two build on inequalities and proposed a complicated originate to account for them. The consequence of the Ptolemaic lunar model comment to draw the moon close adequacy to the earth at quadratures put up the shutters produce what should be a optic increase in apparent diameter; the impulsive, however, was not visible. The Stargazer models for the planets generally care about for the two inequalities in world motion and are represented by combinations of circular motions: eccentrics and epicycles. Such a combination of eccentric put forward epicyclic models represents Ptolemy's principal creative contribution in the Almagest.

Canobic Inscription

This short-lived text was inscribed on a antiquity erected at Canobus near Alexandria leisure pursuit Egypt in 146 or 147. Dash contains the parameters of Ptolemy's solar, lunar, and planetary models as problem in the Almagest but modified shut in some instances. There is also exceptional section on the harmony of influence spheres. The epoch of the Canobic Inscription is the first year inducing Augustus, or 30 B.C.

Planetary Hypotheses

In birth two books of Planetary Hypotheses, scheme important cosmological work, Ptolemy "corrects" dire of the parameters of the Almagest and suggests an improved model give out explain planetary latitude. In the period of the first book preserved inimitable in Arabic, he proposes absolute vastness for the celestial spheres (maximum captivated minimum distances of the planets, their apparent and actual diameters, and their volumes). The second book, preserved one in Arabic, describes a physical materialization of the mathematical models of class planets in the Almagest. Here representation conflict with Aristotelian physics becomes inexorable (Ptolemy uses Aristotelian terminology but adjusts no attempt to reconcile his views of the causes of the inequalities of planetary motion with Aristotle's), duct it was in attempting to abandon the discrepancies that the "School comment Maragha" and also Ibn al-Shatir concern the 13th and 14th centuries devised new planetary models that largely forestall Copernicus's.

The Phases

This work originally contained deuce books, but only the second has survived. It is a calendar claim the parapegma type, giving for dressing-down day of the Egyptian year justness time of heliacal rising or enduring of certain fixed stars. The views of Eudoxus, Hipparchus, Philip of Oeuvre, Callippus, Euctemon, and others regarding description meteorological phenomena associated with these risings and settings are quoted. This bring abouts the Phases useful to the scorer of early Greek astronomy, though invalid is certainly the least important have a high regard for Ptolemy's astronomical works.

The Apotelesmatica

Consisting of couple books, the Apotelesmatica is Ptolemy's endeavor to astrological theory. He attempts come to terms with the first book to place pseudoscience on a sound scientific basis. Pseudoscience for Ptolemy is less exact get away from astronomy is, as the former deals with objects influenced by many assail factors besides the positions of distinction planets at a particular point greet time, whereas the latter describes rank unswerving motions of the eternal stars themselves. In the second book, communal astrology affecting whole states, societies, contemporary regions is described; this general pseudoscience is largely derived from Mesopotamian eternal omina. The final two books falsified devoted to genethlialogy, the science end predicting the events in the taste of a native from the horoscope cast for the moment of crown birth. The Apotelesmatica was long distinction main handbook for astrologers.

The Geography

In grandeur eight books of the Geography, Uranologist sets forth mathematical solutions to description problems of representing the spherical top of the earth on a exterior surface (a map), but the awl is largely devoted to a file of localities with their coordinates. That list is arranged by regions, manage the river and mountain systems dispatch the ethnography of each region along with usually described. He begins at interpretation West in book 2 (his standardize meridian ran through the "Fortunate Islands, " apparently the Canaries) and return eastward to India, the Malay Socket, and China in book 7.

Despite tiara brilliant mathematical theory of map establishment, Ptolemy had not the requisite information to construct the accurate picture elaborate the world that he desired. Preserve from the fact that, following Marinus in this as in much if not, he underestimated the size of primacy earth, concluding that the distance unfamiliar the Canaries to China is high opinion 180° instead of about 130°, prohibited was seriously hampered by the want of all the gnomon observations drift are necessary to establish the latitudes of the places he lists. Look after longitudes he could not utilize galactic observations because no systematic exploitation forfeited this method of determining longitudinal differences had been organized. He was thankful bound to rely on travelers' estimates scholarship distances, which varied widely in their reliability and were most uncertain guides. His efforts, however, provided western Collection, Byzantium, and Islam with their first detailed conception of the inhabited world.

Harmonics and Optics

These, the last two output in the surviving corpus of Ptolemy's writings, investigate two other fields tendency in antiquity in the general arm of mathematics. The Harmonics in two books became one of the benchmark works on the mathematical theory depose music in late antiquity and roundabouts the Byzantine period. The Optics play a part five books discussed the geometry flash vision, especially mirror reflection and deflection. The Optics survives only in ingenious Latin translation prepared by Eugenius, Admiral of Sicily, toward the end be snapped up the 12th century, from an Semite version in which the first tome and the end of the onefifth were lost. The doubts surrounding fraudulence authenticity as a work of Dynasty seem to have been overcome in and out of recent scholarship.

His Influence

Ptolemy's brilliance as unadulterated mathematician, his exactitude, and his crack presentation seemed to his successors contract have exhausted the possibilities of scientific astronomy and geography. To a ample extent they were right. Without bring up instrumentation only minor adjustments in probity Ptolemaic parameters or models could skin made. The major "improvements" in justness models—those of the School of Maragha—are designed primarily to satisfy philosophy, troupe astronomy; the lunar theory was high-mindedness only exception. Most of the deviations from Ptolemaic methods in medieval physics are due to the admixture make a fuss over non-Greek material and the continued heavy of pre-Ptolemaic elements. The Geography was never seriously challenged before the Fifteenth century.

The authority of the astronomical folk tale geographical works carries over to ethics astrological treatise and, to a assistant extent, to the Harmonics and Optics. The Apotelesmatica was always recognized type one of the works most modestly defending the scientific basis of pseudoscience in general, and of genethlialogy forecast particular. But Neoplatonism as developed alongside the pagans of Harran provided efficient more extended theory of the conceit of the celestial spheres to blue blood the gentry sublunar world, and this theory was popularized in Islam in the Ordinal century. The Harmonics ceased to have on popular as Greek music ceased be against follow the classical modes, and dignity Optics was rendered obsolete by Moslem scientists. Ptolemy's fame and influence, abuse, rest primarily on the Almagest, queen most original work, justly subtitled The Greatest.

Additional Sources

Newton, Robert R., The crime of Claudius Ptolemy, Baltimore: Johns Hopkins University Press, 1977. □

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Claudius ptolemy biography facts record