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Anaximander. The main features of Archaic Greek cosmology are shared with those found in ancient near eastern cosmology.They include (a flat) earth, a heaven (firmament) where the sun, moon, and stars are located, an outer ocean surrounding the inhabited human realm, and the netherworld (), the first three of which corresponded to the gods Ouranos, Gaia, and Oceanus (or Pontos).
In ancient Greece, astronomy was a branch of mathematics; astronomers sought to create geometrical models that could imitate the appearances of celestial motions. Identifying the astronomical work of Eudoxus as a separate category is therefore a modern convenience.
Aristarchus of Samos (/ ˌ æ r ə ˈ s t ɑːr k ə s /; Ancient Greek: Ἀρίσταρχος ὁ Σάμιος, Aristarkhos ho Samios; c. 310 – c. 230 BC) was an ancient Greek astronomer and mathematician who presented the first known heliocentric model that placed the Sun at the center of the universe, with the Earth revolving around the Sun once a year and rotating about its axis once a day.
In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (from Ancient Greek ἐπίκυκλος (epíkuklos) 'upon the circle', meaning "circle moving on another circle") [1] was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets.
Early Greek cosmology refers to beliefs about the structure (cosmography) and origins of the cosmos (Greek kosmos) primarily from the 8th to 5th centuries BC before it was superseded by ancient Greek astronomy, which was demythologized and involved the systematic study of the world.
In Greek antiquity the ideas of celestial spheres and rings first appeared in the cosmology of Anaximander in the early 6th century BC. [7] In his cosmology both the Sun and Moon are circular open vents in tubular rings of fire enclosed in tubes of condensed air; these rings constitute the rims of rotating chariot-like wheels pivoting on the Earth at their centre.
It is also a key source of information about ancient Greek astronomy. Ptolemy set up a public inscription at Canopus, Egypt, in 147 or 148. N. T. Hamilton found that the version of Ptolemy's models set out in the Canopic Inscription was earlier than the version in the Almagest.
Antikythera mechanism, main fragment, c. 205 to 87 BC Carlo G Croce, reconstruction of Dondi's Astrarium, originally built between 1348 and 1364 in Padua. The Antikythera mechanism, discovered in 1901 in a wreck off the Greek island of Antikythera in the Mediterranean Sea, exhibited the diurnal motions of the Sun, Moon, and the five planets known to the ancient Greeks.