Nicolás Copernicus was a Polish mathematician and astronomer born in 1473. He is best known for proposing the heliocentric model of the universe, which states that the Earth and other planets revolve around the Sun. This idea challenged the long-held geocentric view, which placed the Earth at the center of the universe. His groundbreaking work, "De revolutionibus orbium coelestium," published in 1543, laid the foundation for modern astronomy. Copernicus's theories influenced later scientists, including Galileo Galilei and Johannes Kepler, and marked the beginning of the Scientific Revolution. His contributions changed our understanding of the cosmos.