Nicolaus Copernicus was a Renaissance mathematician and astronomer who formulated a model of the universe that placed the Sun, rather than the Earth, at its center. This revolutionary idea, known as heliocentrism, challenged the long-held geocentric view and laid the groundwork for modern astronomy. Born in 1473 in Torun, Poland, Copernicus published his seminal work, De revolutionibus orbium coelestium, in 1543. His theories sparked a scientific revolution, influencing later astronomers like Galileo Galilei and Johannes Kepler, and ultimately changing humanity's understanding of its place in the cosmos.