For over 1400 years, the dominant model of the universe was the geocentric model of the Greek astronomer Ptolemy.

The geocentric model placed a stationary Earth at the center of the universe, with the sun, moon, and planets revolving around it.

Nicolaus Copernicus, a Polish astronomer, proposed a revolutionary heliocentric (sun-centered) model in his book published in 1543.

The Copernican model placed the Sun at the center of the universe, with the Earth and other planets revolving around it.

This model offered a simpler and more elegant explanation for the observed motion of the planets, particularly retrograde motion.

The idea of a moving Earth was radical and challenged both scientific orthodoxy and the religious teachings of the Catholic Church.

Initially, the Copernican model was not widely accepted and was seen as a mathematical convenience rather than a physical reality.

Johannes Kepler later improved upon the model by showing that planets move in elliptical, not circular, orbits.

The work of Galileo Galilei provided the first direct observational evidence to support the heliocentric theory.

The Copernican Revolution fundamentally changed humanity's understanding of its place in the cosmos and was a key turning point in the Scientific Revolution.