Background
Claudius Ptolemy probably lived on into the reign of Marcus Aurelius (161-180).
(One of the most important surviving ancient texts on Astr...)
One of the most important surviving ancient texts on Astrology. The Earth stood fixed at the center of the universe, with crystalline spheres within spheres whirling around it. In balance, the universe had a vast influence on earthly events, which was the basis for the belief in Astrology. This explanation stood for nearly a millennium and a half, bolstered by its acceptance as orthodoxy by the Catholic Church, until Copernicus and Galileo demolished it and placed the heliocentric (sun-centered) system in its place. --Sacred Texts
http://www.amazon.com/gp/product/1461118255/?tag=prabook0b-20
( The Almagest is by far the greatest work in astronomy i...)
The Almagest is by far the greatest work in astronomy in ancient times. In a massive series of thirteen books, Ptolemy shows how every detail of the motions of the sun, moon, planets, and stars can be expressed using geometrical models that can be used to compute celestial positions with remarkable accuracy The present selection covers all the essential features of Ptolemys treatment of the heavens, omitting only more difficult and abstruse matters such as the moons motion and the calculation of eclipses. In the interest of conciseness, development of planetary theories is restricted to two planets, one inferior (Venus) and one superior (Mars). Ptolemys text is accompanied by extensive notes and introductions that are aimed at making the book accessible to students encountering Ptolemy for the first time. This edition is designed to provide everything needed for a one-semester course, or it can be a component of a more general course on planetary theory or history of astronomy.
http://www.amazon.com/gp/product/1888009438/?tag=prabook0b-20
(Geography of Claudius Ptolemy, originally titled Geograph...)
Geography of Claudius Ptolemy, originally titled Geographia and written in the second century, is a depiction of the geography of the Roman Empire at the time. Though inaccurate due to Ptolemy's varying methods of measurement and use of outdated data, Geography of Claudius Ptolemy is nonetheless an excellent example of ancient geographical study and scientific method. This edition contains more than 40 maps and illustrations, reproduced based on Ptolemy's original manuscript. It remains a fascinating read for students of scientific history and Greek influence. CLAUDIUS PTOLEMY (A.D. 90- A.D. 168) was a poet, mathematician, astronomer, astrologer, and geographer who wrote in Greek, though he was a Roman citizen. He is most well-known for three scientific treatises he wrote on astronomy, astrology, and geography, respectively titled Almagest, Apotelesmatika, and Geographia. His work influenced early Islamic and European studies, which in turn influenced much of the modern world. Ptolemy died in Alexandria as a member of Greek society.
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(This book is a definitive introduction to models of compu...)
This book is a definitive introduction to models of computation for the design of complex, heterogeneous systems. It has a particular focus on cyber-physical systems, which integrate computing, networking, and physical dynamics. The book captures more than twenty years of experience in the Ptolemy Project at Uc Berkeley, which pioneered many design, modeling, and simulation techniques that are now in widespread use. All of the methods covered in the book are realized in the open source Ptolemy Ii modeling framework and are available for experimentation through links provided in the book. The book is suitable for engineers, scientists, researchers, and managers who wish to understand the rich possibilities offered by modern modeling techniques. The goal of the book is to equip the reader with a breadth of experience that will help in understanding the role that such techniques can play in design.
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astronomer geographer astrologer
Claudius Ptolemy probably lived on into the reign of Marcus Aurelius (161-180).
Ptolemy is known to have made astronomical observations at Alexandria in Egypt between 127 and 141. The earliest and most influential of Ptolemy's major writings is the Almagest. Consisting of four books, the Apotelesmatica is Ptolemy's contribution to astrological theory. The Apotelesmatica was long the main handbook for astrologers. Claudius Ptolemy made some researches in harmonics and optics. These, the last two works in the surviving corpus of Ptolemy's writings, investigate two other fields included in antiquity in the general field of mathematics. The Harmonics in three books became one of the standard works on the mathematical theory of music in late antiquity and throughout the Byzantine period. The Optics in five books discussed the geometry of vision, especially mirror reflection and refraction. The Optics survives only in a Latin translation prepared by Eugenius, Admiral of Sicily, toward the end of the 12th century, from an Arabic version in which the first book and the end of the fifth were lost. The doubts surrounding its authenticity as a work of Ptolemy seem to have been overcome by recent scholarship. Most of the deviations from Ptolemaic methods in medieval astronomy are due to the admixture of non-Greek material and the continued use of pre-Ptolemaic elements. His book the Apotelesmatica was always recognized as one of the works most clearly defending the scientific basis of astrology in general, and of genethlialogy in particular. The Harmonics ceased to be popular as Greek music ceased to follow the classical modes, and the Optics was rendered obsolete by Moslem scientists. Ptolemy's fame and influence, then, rest primarily on the Almagest, his most original work, justly subtitled The Greatest.
(Geography of Claudius Ptolemy, originally titled Geograph...)
(This book is a definitive introduction to models of compu...)
( The Almagest is by far the greatest work in astronomy i...)
(One of the most important surviving ancient texts on Astr...)
In 13 books of the Almagest it establishes the kinematic models (purely mathematical 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 of heliacal risings and settings. Ptolemy also provides a catalog of 1, 022 fixed stars, giving for each its longitude and latitude according to an ecliptic coordinate system. Ptolemy's is a geocentric system, though the earth is the actual center only of the sphere of the fixed stars and of the "crank mechanism" of the moon; the orbits of all the other planets are slightly eccentric. Ptolemy thus hypothesizes a mathematical system which cannot be made to agree with the rules of Aristotelian physics, which require that the center of the earth be the center of all celestial circular motions. In solar astronomy Ptolemy accepts and confirms the eccentric model and its parameters established by Hipparchus. For the moon Ptolemy made enormous improvements in Hipparchus's model, though he was unable to surmount all the difficulties of lunar motion evident even to ancient astronomers. Ptolemy discerned two more inequalities and proposed a complicated model to account for them. The effect of the Ptolemaic lunar model is to draw the moon close enough to the earth at quadratures to produce what should be a visible increase in apparent diameter; the increase, however, was not visible. The Ptolemaic models for the planets generally account for the two inequalities in planetary motion and are represented by combinations of circular motions: eccentrics and epicycles. Such a combination of eccentric and epicyclic models represents Ptolemy's principal original contribution in the Almagest. In the two books of Planetary Hypotheses, an important cosmological work, Ptolemy "corrects" some of the parameters of the Almagest and suggests an improved model to explain planetary latitude. In the section of the first book preserved only in Arabic, he proposes absolute dimensions for the celestial spheres (maximum and minimum distances of the planets, their apparent and actual diameters, and their volumes). The second book, preserved only in Arabic, describes a physical actualization of the mathematical models of the planets in the Almagest. Here the conflict with Aristotelian physics becomes unavoidable (Ptolemy uses Aristotelian terminology but makes no attempt to reconcile his views of the causes of the inequalities of planetary motion with Aristotle's), and it was in attempting to remove the discrepancies that the "School of Maragha" and also Ibn al-Shatir in the 13th and 14th centuries devised new planetary models that largely anticipate Copernicus's. In the first book of the Apotelesmatica he attempts to place astrology on a sound scientific basis. Astrology for Ptolemy is less exact than astronomy is, as the former deals with objects influenced by many other factors besides the positions of the planets at a particular point in time, whereas the latter describes the unswerving motions of the eternal stars themselves. In the second book, general astrology affecting whole states, societies, and regions is described; this general astrology is largely derived from Mesopotamian astral omina. The final two books are devoted to genethlialogy, the science of predicting the events in the life of a native from the horoscope cast for the moment of his birth. In his book the Geography, that consists of eight books, Ptolemy sets forth mathematical solutions to the problems of representing the spherical surface of the earth on a plane surface (a map), but the work is largely devoted to a list of localities with their coordinates. Despite his brilliant mathematical theory of map making, Ptolemy had not the requisite material to construct the accurate picture of the world that he desired. Aside from the fact that, following Marinus in this as in much else, he underestimated the size of the earth, concluding that the distance from the Canaries to China is about 180° instead of about 130°, he was seriously hampered by the lack of all the gnomon observations that are necessary to establish the latitudes of the places he lists. For longitudes he could not utilize astronomical observations because no systematic exploitation of this method of determining longitudinal differences had been organized. He was compelled to rely on travelers' estimates of distances, which varied widely in their reliability and were most uncertain guides. His efforts, however, provided western Europe, Byzantium, and Islam with their most detailed conception of the inhabited world.
Ptolemy's brilliance as a mathematician, his exactitude, and his masterful presentation seemed to his successors to have exhausted the possibilities of mathematical astronomy and geography. To a large extent they were right. Without better instrumentation only minor adjustments in the Ptolemaic parameters or models could be made.