astronomy

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 * 1) The Greek contribution was more of applying logical thinking and geometry to the observations
 * 2) They figured out the earth went around the sun and the moon went around the earth
 * 3) They calculated the size of the earth
 * 4) Greek astronomers were
 * 5) Anaxagoras: Figured out what caused eclipses
 * 6) Aristarchus: Figured out the earth went around the sun
 * 7) Thales: Figured out the earth was round
 * 8) Invented the 'order of magnitude' system to determine the brightness of stars in 135 BC
 * 9) The word planets come from the Greek word planetes meaning wanderere.
 * 10) The Greek first thought of the universe being centered on something other than the Earth
 * 11) The five naked-eye visible planets were plotted against a combined solar and lunar calendar by the Greeks, and it was the Pythagoreans who eventually figured out that the Evening Star and the Morning Star were, in fact, the same wandering planet Venus.
 * 12) The science of attempting to determine why the planets move the way they did dates back to ancient Greek Astronomy, and while Eudoxus' model (described above) was the root, it eventually branched out with more spheres, spheres that were slightly off center to one another, and planets that were on rotating circles on spheres that rotated as well
 * 13) It was in ancient Greek Astronomy that a sun centered cosmos was born. Aristarchus proposed a sun-centric model of the cosmos in the 3rd century BC, which was not well received. It wasn't until Copernicus, nearly 2,000 years later, that this idea gained acceptance. Aristarchus also took the lengths of shadows of monuments to derive the curvature of the Earth – measuring the shadow length at noon on the summer solstice for a monument at Alexandria and another at Thebes. From the differences in shadow lengths, and a little bit of experimentation, he was able to derive the degree of curvature of the Earth. By plugging in the distance between the two monuments, he was able to give a rough estimate of the size of the Earth. (Since his initial measurement for the distance between the two monuments was in error, his calculated size of the Earth was too small by almost 40%). He also used these same procedures to estimate the distance between the Sun and Earth, and the Moon and Earth in earth radii.
 * 14) Unlike the Babylonians and Egyptians, ancient Greek Astronomy was mathematical, rather than religious in nature. This view of Astronomy was profoundly important in the differentiation between Astronomy and astrology. Greek astronomical thinking formed the foundation of much scientific and mathematical thought that laid the foundations for the world we live in today.



Tusi's lunar theory, illustrated, not altogether correctly, in this figure along with Tusi's device for producing rectilinear from circular motions