Who proposed the heliocentric theory, stating that the Earth revolved around the Sun?

The heliocentric theory, which posits that the Earth revolves around the Sun, was proposed by Nicolaus Copernicus. This revolutionary idea marked a significant departure from the geocentric model, which placed the Earth at the center of the universe. Copernicus's work, particularly in his book "De revolutionibus orbium coelestium" published in 1543, laid the groundwork for modern astronomy by suggesting that the Sun is the center of our solar system and that the planets, including Earth, orbit around it.

His model not only explained the apparent retrograde motion of planets more accurately than previous models but also set the stage for later astronomers, like Galileo and Kepler, to build upon his ideas. Galileo is often associated with supporting the heliocentric theory through his observations, while Kepler refined the model with his laws of planetary motion. Newton later explained the mechanics of this motion through his law of gravitation. Copernicus is thus recognized as the originator of the heliocentric model, making him a pivotal figure in the Scientific Revolution.