Earth centered UNIVERSE

                               THE UNIVERSE (ORIGIN-1)

Ø  (1) Greek philosopher Aristotle wrote in his book ‘On the Heavens’ the earth is not a flat surface, rather it is spherical. He gave some amazing arguments for believing that earth is spherical, such as
First, he realized that eclipses of the moon are caused by the earth coming between the sun and the moon. The earth’s shadow on the moon was always round, which would be true only if the earth is spherical. But if earth is flat disc, then the shadow would have been elongated and elliptical.
Second, the Greeks knew from their travels that the North Star appeared lower in the sky when viewed in the south than it did in more northerly regions. From the difference in the apparent position of the North Star in Egypt and Greece, Aristotle even quoted an estimate that the distance around the earth was 400,000 stadia.
Third, a third argument that the earth must be round, for why else does one first see the sails of a ship coming over the horizon, and only later see the hull?
                                Like this way as long ago as 340 BC Aristotle first started exploring the universe by his way. He thought that the earth was stationary and that the sun, the moon, the planets, and the stars moved in circular orbits about the earth.

(2) This idea was elaborated by Ptolemy in the second century AD into a complete cosmological model. The earth stood at the center, surrounded b eight spheres that carried the moon, the sun, the starts and the five planets known at the time Mercury, Venus, Mars, Jupiter and Saturn.


THE COSMOLOGICAL MODEL OF PTOLEMY

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