The Mystery of Uneven Seasons

Abstract

In spite of the success of the 2-sphere universe model, there were troubling observations. Ancient Greek astronomers discovered that the four seasons were unequal, and the intersection point between the ecliptic and the celestial equator was not fixed. The former suggested that the Sun is not moving around the Earth at a uniform rate, and the latter suggested that the Sun’s path in the sky is shifting relative to the stars. These problems, along with the peculiar motions of the planets, were the unsolved mysteries of ancient astronomy.