In this system the entire universe was part of a great sphere.
This sphere was split into two sections, an outer celestial realm and an inner terrestrial one.
The dividing line between the two was the orbit of the moon.
While the earth was a place of transition and flux, the heavens were unchanging..
Greek cosmology.
The first “cosmologies” were based on creation myths in which one or more deities made the universe out of sheer will, or out of their bodily fluids, or of the carcass of some god they defeated, etc.
A few examples of such “theories” of the universe are provided in this chapter..
In Greek mythology, the cosmos consists of three realms; the heavens, the earth, and the underworld.
The heavens were held aloft by the four great pillars, each ruled by a primordial giant known as a Titan.
The east pillar was home to Hyperion, who presided over the heavenly light..
The cosmos (Ancient Greek: κόσμος, romanized: K\xf3smos, /ˈkɒzmɒs/, US also /-moʊs, -məs/) is another name for the universe.
Using the word cosmos implies viewing the universe as a complex and orderly system or entity..
Plato first proposed that the planets followed perfect circular orbits around the Earth.
Later, Heraclides (330 B.C.) developed the first Solar System model, placing the planets in order from the Earth it was is now called the geocentric solar system model..
In the 3rd century BCE, Aristarchus of Samos proposed an alternate cosmology (arrangement of the universe): a heliocentric model of the Solar System, placing the Sun, not the Earth, at the center of the known universe (hence he is sometimes known as the "Greek Copernicus")..
