Nicolaus Copernicus discovered and formulated the heliocentric theory, which proposed that the Sun, rather than the Earth, is at the center of the Universe. According to his model, the Earth rotates daily on its axis and revolves annually around the Sun, along with other planets orbiting the Sun in circular paths. This was a fundamental shift from the long-prevailing geocentric model that placed Earth at the center
. His major work, De revolutionibus orbium coelestium ("On the Revolutions of the Celestial Spheres"), published in 1543, laid out this theory with mathematical and astronomical data. Copernicus explained that the apparent retrograde motion of planets is due to Earth's motion, and he described three distinct motions of Earth: daily rotation, annual revolution around the Sun, and axial precession
. Copernicus's model simplified planetary motion calculations by eliminating many of the complex epicycles used in the Ptolemaic geocentric system, although his system still retained some circular orbits and epicycles
. His heliocentric theory marked the beginning of a major paradigm shift in astronomy, influencing later scientists like Galileo and Kepler
. In summary, Copernicus discovered that:
- The Sun is near the center of the Universe and is stationary.
- Earth and other planets revolve around the Sun.
- Earth rotates daily on its axis and revolves annually around the Sun.
- The retrograde motion of planets is explained by Earth's motion.
This discovery fundamentally changed humanity's understanding of the cosmos and initiated the Copernican Revolution
