geotsentrism

Geotsentrism, also known as the geocentric model, is an astronomical model in which the Earth is assumed to be the center of the universe. In this model, the Sun, Moon, planets, and stars all revolve around the Earth. This view was widely accepted in many ancient civilizations, including ancient Greece, and was the dominant model in European astronomy for over 1400 years.

The geocentric model was based on observable phenomena. From Earth, it appears that the Sun rises in the east and sets in the west, and that the stars and planets move across the sky in predictable patterns, seemingly orbiting our planet. Ancient philosophers and astronomers developed complex systems to explain these motions. Aristotle, for instance, proposed a series of concentric spheres, each carrying a celestial body, rotating around a stationary Earth.

Ptolemy, in the 2nd century AD, further refined the geocentric model in his work the Almagest. He introduced epicycles and deferents, which were circular paths within larger circular paths, to account for the observed retrograde motion of planets – the apparent backward movement of planets in the sky. This Ptolemaic system became the standard astronomical framework for centuries.

The geocentric model faced challenges over time, but it wasn't until the Renaissance that a competing heliocentric (Sun-centered) model, championed by Nicolaus Copernicus, began to gain traction. The heliocentric model, supported by observational evidence from astronomers like Galileo Galilei and theoretical work by Johannes Kepler, eventually superseded geocentrism due to its greater explanatory power and simplicity in describing planetary movements.