Ptolemy, Claudius

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Ptolemy, Claudius(Latin Claudius Ptolemaeus) (Flowering activity 127-148), the famous astronomer and geographer of antiquity, the efforts of which the geocentric system of the universe (referred to as Ptolemaeva) has become final form. Nothing is known about the origin, place and dates of birth and death of Ptolemy. Dates 127-148 were obtained on the basis of the ptolem in Alexandria and near her observations. His star catalog, which is part of an astronomical essay Almagest, dated 137. All other information about the life of Ptolemy occurs from later sources and are quite dubious. It is argued that on the board of Avereliya (161-180), he was still alive, but died at the age of 79 years. From here we can conclude that he was born at the end of 1 century. The most famous works of Ptolemy are Almagest and Geographywho have become the highest achievement of ancient science in the field of astronomy and geography. The work of Ptolemy was considered so perfect that they were dominated in science for 1400 years. During this time in Geography Almost a single serious amendment was not made, and all the achievements of Arab astronomers were committed in essence only to minor improvements. Almagesta. Although Ptolemy was the most revered authority throughout the ancient science, to call him a brilliant mathematician, an astronomer or geographer is impossible. His gift was the ability to collect together the results of studies of their predecessors, use them to clarify their own observations and submit everything together as a logical and completed system outlined in a clear and honed form. The excellent educational and reference work created by him made it possible to maintain a rather high level of knowledge on the relevant subjects. It can be said that the modern era of scientific research in these areas has begun from repulse authority Almagesta and Geography.

Almagest.

The name is the connection of the Arabic-defined article and the Greek word "Megyste", which means the "greatest" (meant "Xuntaxis" is a system, since the original name of labor is Matematic Suuntaxis. Mathematical system). This work has crowned the age-old efforts of Greek astronomers to explain the complex movement of the shone. It consists of 13 books, which are not only described, but also analyzed the entire set of astronomical knowledge of the time.

I and II Books Almagesta Serve the entry where the main astronomical assumptions of Ptolemy and its mathematical methods are described. It presents its evidence of the sphericity of the Earth and the sky, as well as the central position of the Earth in the Universe. Ptolemy believes that the earth is fixed, and the sky makes a daily rotation around the heavenly axis. In the book I, there is a chord table for arcs, tightening angles from 1/2 to 180 degrees in a step of 1/2 °, - equivalent to the sinus table for half the corners. The idea of \u200b\u200bthe table is borrowed from the lost work of the Greek Astronomer of Hippark (approx. 190 - after 126 BC); She became the starting point for the further development of trigonometry. Book II contains such methods of mathematical geography as the definition of the longest day per year for a point with a given latitude and the definition of latitudes ("climates") in the duration of the longest day in these belts in the duration of the longest day in these belts.

In III and IV books, the movement of the Sun and the Moon is discussed. Ptolemy takes the theory of hypharch to explain the anomalies of the solar movement (caused by the Earth's orbit ellipticity) using the epicycles and eccentric hypothesis. Ptolemy the theory of the moon's appeal is much more difficult. He puts forward the assumption that the moon moves through the epicycle, the center of which moves from the West to the east along an eccentric detention. In turn, the center of the Deferrant turns around the Earth from the east to the West, and all this mechanism lies in the plane of the visible movement of the moon. For an observer on Earth, the opposite movements of the epicycle center and the drawing compensate each other in relation to the line connecting the Earth and the Sun. Thus, the epicycle is in the apogee of the eccentre at the moments of the new moon and full moon, and in Periguee - during the first and last quarter. This scheme successfully overcame the main disadvantage of the Hypan theory of the moon's appeal and taking into account the periodic "sharing" of the lunar apogee, named later, for which the Ptolemy turned out to be almost the right meaning.

The book discusses different topics: the construction of the theory of the appeal of the moon continues, the construction of astrolabia is described, the size of the solar, lunar and earth shadows, the diameters of the sun, the moon and the earth are estimated, as well as the distance to the Sun. VI The book is devoted to sunny and lunar eclipses. In the VII and VIII, the book describes stars on constellations. The latitude and longitude of each star is given in degrees and minutes, and the star values \u200b\u200bare indicated in the range from 1 to 6. It is not quite clear how this catalog was the fruit of Ptolemy's own observations, and how much borrowed from Hippark, taking into account the precession for the past three centuries. It also discusses the precession of the equinox point, the structure of the Milky Way and the design of the heavenly globe.

The IX-XIII books are devoted to the movement of the planets - the problem that Hipparch left without consideration. IX Book considers the order of planets (their relative distances from the Earth), their periods of appeal; Here the author proceeds to the theory of conversion of Mercury. X The book is devoted to Venus and Mars, and XI - Jupiter and Saturn. In the XII book, the standing and inverse movement of each of the planets, as well as the maximum elongations of Mercury and Venus are discussed. The main scheme of Ptolemy represents Venus and the three top planets as the bodies moving from the west to the east of the epicycles, the centers of which are moving in the same direction on eccentric depents. It is assumed that the epicycle center moves with a constant angular speed not around the center of its drawing, but around a point lying on a straight line connecting the land with the center of the drawing and removed from the ground to the tween distance between it and the center of the Deferent. Epiciklas and drawers are inclined to ecliptic at different angles. The Mercury Movement Scheme is even more complicated.

Geography.

In his field of knowledge Geography Ptolemy took the same place that Almagest In astronomy. It was believed that this essay concludes a complete statement of the subject and practically infrequently, so right up to the Renaissance the theoretical geography of slave was followed by him. However, as a scientific treatise Geography Undoubtedly inferior Almagesta. Although Almagest And imperfect in the sense of astronomy, it is interesting from the point of view of mathematics. IN Geography The same achievements in theory are adjacent to serious omissions in their application. Ptolemy begins with a clear statement of mapping methods - determining the astronomical latitude and longitude of the place and methods of the image of spherical surfaces on the plane. It then proceeds to the main part of its treatise, built on approximate numbers of navigators and earth farms. Although Ptolemy presents the subject of its research in mathematical form and in the work of the impressive list of more than 8,000 names of places - cities, islands, mountains, mouths, etc., it would be wrong to think that this work is a scientific research. It is precisely because the theoretical aspects of the cartography are presented in this book quite satisfactory even for a modern elementary textbook, we can be sure: Ptolemy knew that in his time the true coordinates of the seats were not yet accurately defined.

In I book Geography Ptolemy discusses the reliability of determining the relative positions of points on Earth astronomical methods and on measurements of distances on the surface and estimates of travelers traveled. He recognizes that astronomical methods are more reliable, but indicates that there are no other data for most places, except for travelers. Ptolemy considers the most reliable mutual control of ground and astronomical methods. Then he gives clear instructions for building a world map on the sphere (very similar to the modern globe), as well as on a flat surface with a conical projection or an improved spherical projection. The remaining seven books almost completely consist of a list of names of various places and their geographic coordinates.

As the overwhelming majority of data was received by travelers (approx. 120 AD. They were collected by the predecessor of Ptolemy Marin Tyr), the Atlas Ptolemy contains many errors. Eratosphen calculated by Eratosphen almost the correct magnitude of the earth's circle was underestimated by a posidomy of more than a quarter, and this understated value used Ptolemy. The zero meridian in Ptolemy passes through the Canary Islands. Due to the exaggerated travelers, Asia's size was obtained that the world known by that time stretched by more than 180 ° (in reality by 130 °). At the 180th Meridian of his card is China, a giant land, stretching from the top of the map to the equator. Hence it followed that the unknown part of the Asian continent stretches even further, where the Pacific Ocean is now depicted. This was the classic, preserved presentation of the Ptolemy's presentation about the Earth as a sphere, reduced by a quarter compared with the actual size and covered by land, occupying 2/3 of the northern hemisphere. It was it who inspired Christopher Columbus confidence that before India needs to get, moving in the western direction. Ptolemy accompanied his work atlas from 27 cards: 10 regional maps of Europe, 4 African maps, 12 Asian maps and a consolidated map of the world known by the world. The book won such authority that even a century after the travels of Christopher Columbus and Magellan, who were not given the main provisions GeographyStill there were cards in the style of Ptolemy. Some of his erroneous performances persistently repeated on the cards of 17 and 18 centuries., And as for internal Africa, his card was published even at 19 V.

Other jobs.

The versatility of the Ptolemy and his amazing gift of clear and clear presentation was also manifested in other treatises, for example, optics and music. Work on optics is preserved only in Latin translation from Arabic - also transfer from a lost Greek original. It consisted of five books, of which I are lost the book and the end of the V book. Books III and IV are devoted to the reflection of light. Ptolemy resorted to measurements to prove that the angle of the fall is equal to the reflection angle. The book V is devoted to the refraction of light. It describes experiments on refraction in water and glass at different angles of falling and an attempt is made to apply these results in astronomy to assess the degree of refraction of light coming from a star through the earth's atmosphere. Treatise Ptolemy is the most complete work on mirrors and optics, preserved from ancient times.

Harmonics Ptolemy gained a reputation as the most scientific and well-compound treatise on the theory of musical lands from all that was preserved in Greek. This is the second most important, after the works of the aristochene (the second half of the 4th century. BC), treatise on ancient music. However, the writing of Ptolemy has a more practical orientation. Among other works Ptolemy - Treatise on astrology Apotellesmatics in four books called usually Tetrabiblos. This essay was as reputable in its field as Almagest In his.

Influence of the theory of Ptolemy

Proceedings of Ptolemy fell rooted in science for almost 1400 years, but its influence on social, political, moral and theological views turned out to be even longer and persisted until the revolution of the 18th century. The anthropocentric land theory of anthropocentric land, located in the geocentric universe, was widespread, especially through medieval encyclopedias. The reconciliation of the Christian doctrine with the ancient heritage carried out by Albert Great (approx. 1193-1280) and the Foma Aquinsky (1225-1274), made the teachings of ancient acceptable and useful for the Middle Ages and Renaissance.

The study of the universe led to the revision of human relations with the outside world. The planets established by Ptolem and his assumption about the impact of each of them on a certain group of people was interpreted by the church as part of the Great Hierarchy, or Chain, Genesis. The highest link of this chain was God and Angels, then followed a man, woman, animals, plants and, finally, minerals. This doctrine, together with history, from the Book of Genesis on the creation of the world for 6 days was the main background of all European poetry and prose since the Middle Ages to 18 V. It was believed that the Great Chain of Genesis has a divine origin and determines the division of a feudal society for three estates - the nobility, clergy and the third estate, each of which plays its role in society. This view was so firmly rooted in society that Galilee, defending the heliocentric theory of Copernicus, was in 1616 to be given under the court of the Inquisition in Rome and forced to renounce his views.

Evidence of the influence of Ptolemy on literature countless. Some authors directly point to Ptolemy as the highest authority. Others, like Dante and Milton, make the Universe Ptolemy the basis for building their own worlds. Mentions are mentioned in the works of Choser Almagesta And there are links to the works of Ptolemy.

The concept of cosmic order permeates all the creativity of E.Penster, all creatures "are built into the right row". The authors of the Elizabethan era talked about the need for order and multi-levelness in the chain of Genesis and the effect of stars on life as a tool of divine providence. In the world, Ptolemy people live the heroes of Shakespeare. In 8 songs Lost Paradise Milton Adam expresses doubt in the Ptolemy system, and Archangel Rafail, dividing him, says not so much about her truth, how much about greater reasonability and suitability for human existence in comparison with heliocentric. Another 18 century. POP B. History experience Exclamations: "On Being the Redhead chain!", Which is necessary for the Universe, since otherwise "planets with the sun will result in NamAum," and a person will be immersed in "Unreight delusion".