What did the early greeks picture the solar system?
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Answer:
Do you mean, HOW did they picture the solar system? You need to Google "astronomy" and "ancient Greece" and see what you come up with.
I believe the Greeks (along with the rest of the world) believed the Earth was at the center of the solar system.
Early History, False Leads
Aristarchus of Samos proposed that the Earth revolved around the Sun, but the idea was rejected by later Greek astronomers, in particular by Hipparchus. Ptolemy, living in Egypt in the 2nd century AD, expressed the consensus when he argued that all fixed stars were on some distant sphere which rotated around the Earth. Ptolemy tried to assemble and write down all that was known in his day about the heavens, and his influence was great, extending (as noted below) even to the 1600s.
Yet anything that moved across the celestial sphere--Sun, Moon and planets--had to be able somehow to slip around it. The planets, in particular, were hard to understand, because their motion was not simple.
Venus and Mercury moved back and forth across the position of the Sun, sometimes rising before the Sun as morning stars, sometimes setting after it as evening stars, but never appearing in the midnight sky. Mars, Jupiter and Saturn, on the other hand, did not follow the Sun in the sky. They all tended to move in the same direction around the ecliptic, but now and then they would stop, move backwards for a while ("retrograde motion"), and then resume their usual motion.
For a discussion of the discovery of the solar system which includes a "moving picture" illustrating retrograde motion, click here.
Ptolemy tried to explain all that, using a theory which started with Hipparchus. Following the work of Aristarchus and Hipparchus, it was accepted that the Moon moved around Earth. Ptolemy assumed that the Sun, planets and the distant stars (whatever those were) also moved around the Earth (For a dissenting opinion, see here). To the Greeks, the circle represented perfection, and Ptolemy assumed Moon, Sun and stars moved in circles too. Since the motion was not exactly uniform (a point examined in section #12a, from a more modern viewpoint), he assumed that the center of these circles was some distance away from the Earth.
While the Sun moved around Earth, Venus and Mercury obviously moved around it, on circles of their own. But what about Mars, Jupiter and Saturn? Cleverly, Ptolemy proposed that like Venus and Mercury, each of them also rotated around a point in the sky that orbited around Earth like the Sun, except that those points were empty. The backtracking of the planets now looked similar to the backtracking of Venus and Mercury. The center carrying each of those planets accounted for the planet's regular motion, but to this the planet's own motion around that center had to be added, and sometimes the sum of the two made the planet appear (for a while) to advance backwards.
This "explanation" left open the question what the planets, Sun and Moon were, and why they displayed such strange motions. But worse, it was also inaccurate. As the positions of the planets were measured more and more accurately, additional corrections had to be introduced.
Yet Ptolemy's view of the solar system dominated European astronomy for over 1000 years. One reason was that astronomy almost stopped in its tracks during the decline and fall of the Roman Empire and during the "dark ages" that followed. The study of the heavens continued in the Arab world, under Arab rulers, but of all the achievements of Arab astronomers, the one in which they exerted the greatest influence was the preservation and translation of Ptolemy's books.
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