Geocentrism is highly regarded by the Church and has been the basic cosmology of Western European society until the establishment of the "heliocentric theory" in the 16th century.
In the distant 4th century B.C., the light of ancient Greek wisdom shone on the earth, and the brightest star was the great philosopher Aristotle. He has not only made outstanding achievements in the fields of biology and physics, but also put forward unique insights in the field of cosmology. He firmly believed that the earth was spherical and located at the center of the universe. In this theory, the earth and celestial bodies such as the sun and moon are made up of substances with very different properties. It is worth noting that the matter on Earth is composed of the four basic elements of water, air, fire, and earth, while the celestial bodies are made up of a mysterious substance called "ether".
Aristotle further elaborated that the universe is bounded. This massive structure is centered on the Earth and extends outward, containing a total of nine spheres. On top of these spheres, celestial bodies such as the Sun, Moon, and Mars revolve around the Earth in a certain orbit. They believe that these objects complete a cycle every 24 hours. However, over time, observations of the planets gradually revealed some unexplained phenomena. The earth-centered theory of celestial motion does not seem to be able to satisfactorily explain the complex trajectory of the planets, and its loopholes and limitations are gradually revealed.
Around the 2nd century BC, an astronomer named Ibaches made revisions and innovations based on Aristotle's theories. He introduced complex concepts such as the current wheel and the average wheel, and tried to reduce the number of celestial spheres to 7. Although these improvements make up for the shortcomings of the original theory to a certain extent, they still fail to completely solve the problem of irregular planetary motion.
Around 140 AD, the astronomer Claudius Tolemy inherited and developed Aristotle's geocentric theory in a comprehensive and in-depth way. He not only divided the universe into two layers, heaven and earth, but also pushed this theory to a new level through his own research and writings. His work, The Almagest of Astronomy, became a classic of this period and laid a solid foundation for later astronomical research. In the construction of the geocentric theory of the universe, Tolemy believed that the earth was at the center of the universe, a point of rest. In his description, the sun, moon, and planets all follow a complex trajectory. Not only do they rotate at a uniform speed in a small circular orbit called the "Wheel", but the center of this Wheel is also located in a larger orbit called the "Wheel", which rotates around the Earth in the same way. This design allows the movement of celestial bodies to be more accurately matched with the observed data. It is worth mentioning that Tolemy also specifically pointed out that the earth is not exactly at the center of the wheel, but at a certain distance from it. This makes the entire model of the universe more complex, but also improves its ability to move celestial bodies. When it comes to the orbits of Mercury and Venus, Towlemy's model also shows its unique wisdom. He found that if the center of the two planets were placed on the line between the Earth and the Sun, then their actual trajectories could be better explained. This discovery has important implications for later astronomical research. More subtly, Towlemy proposed that, in addition to the movements described above, the sun, moon, and planets should also make one daily rotation around the earth with a higher celestial body, the "sidereal heaven." This view not only adds complexity to the model, but also makes it more accurate in its description of celestial motion. Overall, Claudius Tolemy's geocentric theory of the universe was a highly creative and accurate model for its time. Although advances in science and technology have led to a better understanding of the universe over time, Tolemy's work still occupies an important place in the history of astronomy. His contribution lies not only in his precise mathematical models and the application of physical principles, but also in his spirit of exploration of the unknown and his profound philosophical reflections. Hotspot Engine Program