The term "Copernican" refers to the ideas and theories proposed by the astronomer Nicolaus Copernicus, who lived in the 16th century. He is best known for introducing the heliocentric model of the solar system, which posits that the Sun is at the center, and the Earth and other planets orbit around it. This was a significant shift from the previously accepted geocentric model, which placed the Earth at the center. The Copernican Revolution marked a major turning point in the history of science, leading to advancements in astronomy and changing humanity's understanding of its place in the universe. Copernicus's work laid the groundwork for later astronomers, such as Galileo Galilei and Johannes Kepler, who further developed and supported the heliocentric theory.