LYCOS RETRIEVER 
Ptolemy: Earth
built 231 days ago
Ptolemy's mistake had big consequences. Much later, Christopher Columbus read his Geography. Since Ptolemy said the earth was fairly small, Columbus thought it would be easy to sail around the world. He didn't know there was enough room for another continent!
Source:
Ptolemy began by accepting the generally held theory that the Earth did not move but was at the centre of the universe. The planets and stars were considered, for philosophical reasons, to move continuously in perfectly circular orbits. He then elaborated on the theory in an attempt to account for the astronomical puzzles that the theory presented, such as the apparent backwards motions of the planets and the apparent variations in size or brightness of the Moon and planets. Ptolemy proposed that the planets, Sun, and Moon moved in small circles whose centres moved around much larger circles, which were centred on the Earth. In this way he made his system fit most of the observations that astronomers had recorded.
Source:
Ptolemy explained and extended Hipparchus's system of epicycles and eccentric circles to explain his geocentric (Earth-centered) theory of the solar system. Ptolemy's system involved at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time. He believed the planets and sun moved around the Earth in this order: Mercury, Venus, Sun, Mars, Jupiter, Saturn.
Source:
Maps based on scientific principles had been made since the time of Eratosthenes (3rd century BC), but Ptolemy improved projections. It is known that a world map based on the Geographia was on display in Autun, France in late Roman times. In the 15th century Ptolemy's Geographia began to be printed with engraved maps; the earliest printed edition with engraved maps was produced in Bologna in 1477, followed quickly by a Roman edition in 1478 (Campbell, 1987). An edition printed at Ulm in 1482, including woodcut maps, was the first one printed north of the Alps. The maps look distorted as compared to modern maps, because Ptolemy's data were inaccurate. One reason is that Ptolemy estimated the size of the Earth as too small: while Eratosthenes found 700 stadia for a great circle degree on the globe, in the Geographia Ptolemy uses 500 stadia.
Source:
Ptolemy erroneously assumed a short circumference of the earth, which ended up influencing Christopher Columbus that he could reach Asia by sailing west from Europe. Additionally, Ptolemy showed the Indian Ocean as a large inland sea, bordered on the south by Terra Incognita (unknown land). The idea of a large southern continent sparked countless expeditions.
Source:
Through this hypothesis Ptolemy explains how the constant movement of the planets creates an ever-changing atmosphere to which all the Earth's creatures are sensitive. Just as two similar seeds grow differently as a result of their environment, so is each soul affected by the celestial atmosphere at the time of its birth. In the principle of sympathy and antipathy the aspects and movement of the stars continue to produce favourable or injurious conditions -determined by the individual's personal disposition.
Source:
MORE ABOUT
Earth