Medieval understanding of space was shaped by a combination of religion, philosophy, and early scientific observation. The dominant belief placed Earth at the center of the universe, surrounded by ...

With the geocentric model, the earth is at the center of the universe, and the planets rotate around the earth. But from the outset, this model was flawed. Astronomers observed that the planets do not ...

Seleucus of Seleucia was an ancient astronomer who defended heliocentrism, arguing that Earth orbits the Sun and rotates on ...