This could be explained by reasoning that they were either motionless, or much further away than believed. For one, if the Earth were to move, scholars believed that there would be an observable change in the positions of the fixed stars and constellations (aka. Support for this cosmological principle was based on a number of accepted theories. Another important aspect of his model was the inclusion of the вЂњPrime MoverвЂќ, a sort of deistic concept whereby all motion in the Universe is initiated by a being or force that is themselves вЂњunmovedвЂќ. Beyond these layers, the solid spheres of aether in which the celestial bodies were embedded lay. He further described his system by explaining the natural tendencies of the terrestrial elements, which in accordance with contemporary belief were earth, water, fire, air though Aristotle included a fifth element of вЂњcelestial aetherвЂќ.Д®arth was the heaviest element, hence why it moved towards the center whereas water, fire and air formed layers around it. These spheres all moved at different uniform speeds to create the rotation of bodies around the Earth and were composed of an incorruptible substance called вЂњaetherвЂќ.

On the left, daytime in summer on the right, nighttime in winter. Illustration of AnaximanderвЂ™s models of the universe.

Aristotle elaborated on EudoxusвЂ™ system, placing a spherical Earth at the center and all other heavenly bodies arranged in concentric crystalline (i.e. His system was expanded by Eudoxus of Cnidus, a contemporary of PlatoвЂ™s who developed a less mythical, more mathematical explanation of the planetsвЂ™ motion based on the Platonic idea of uniform circular motion. These were the Moon, the Sun, Venus, Mercury, Mars, Jupiter, Saturn, fixed stars, and the fixed stars. The stars and planets were carried around the Earth on spheres or circles, arranged in the order of distance from the center. According to Plato, the Earth was a sphere and the stationary center of the universe. It was also during the 4th century BCE that Plato and Aristotle would create works on the geocentric universe that would secure its place as the predominant cosmological theory. By the 4th century BCE, this idea combined with the concept of a geocentric universe to create the cosmological system that most Greeks subscribed to. Meanwhile, the Sun, Moon, and planets were holes in invisible wheels surrounding the Earth, through which humans could see concealed fire.Дuring this same century, the Pythagoreans began to propose that the Earth was circular, based on observation of eclipses (and in all likelihood, observations of the zodiac from different latitudes). It was during this time that Pre-Socratic philosopher Anaximander proposed a cosmological system where a cylindrical Earth was held aloft at the center of everything. The earliest recorded example of a geocentric universe comes from around the 6th century BCE. A comparison of the geocentric and heliocentric models of the universe. This would continue to endure well into the 17th and 18th centuries, by which point, the modelвЂ™s inherent inconsistencies would lead to it being abandoned in favor of the heliocentric model. For the Earth-bound observer, the ground that they stood on seemed like a fixed point of reference, a flat plane from which to watch the circling cosmos.ДЄnd over time, thanks to centuries of record-keeping by various civilizations вЂ“ from ancient Babylonian and Egyptian astronomers to contemporary Mediterranean ones вЂ“ a formalized system began to emerge that put the Earth at the center of all things. To ancient people, looking up at the skies, it seemed evident that the Sun, the Moon and the stars rotated around the Earth once a day. The notion that the Earth was the center of the Universe is certainly an understandable one. This gave rise to the Geocentric model of the universe, a now-defunct model that explained how the Sun, Moon, and firmament circled around our planet. And by classical antiquity, scientists had formulated ideas on how the motion of the planets occurred, and how all the heavenly orbs fit together. In time, we also began to understand that the Earth was indeed round, and came up with rationalized explanations for the behavior of other celestial bodies.

Over time, ancient astronomers became aware that some stars did not move like the rest, and began to understand that these too were planets. At one time, the magi and sages of the world believed that the Universe consisted of a flat Earth (or a square one, a zigarrut, etc.) surrounded by the Sun, the Moon, and the stars. During the many thousand years that human beings have been looking up at the stars, our concept of what the Universe looks like has changed dramatically.

Heliocentric astrology shapes