Sir Isaac Newton is renowned for his discovery of gravity. His groundbreaking work in the late 17th century laid the foundation for classical mechanics. In his famous work "Philosophiæ Naturalis Principia Mathematica," published in 1687, Newton formulated the laws of motion and universal gravitation, explaining how objects attract each other through gravitational force. His insights provided a mathematical understanding of gravitational interactions that helped describe the motion of celestial bodies. Newton’s work not only advanced the field of physics but also influenced the scientific revolution, shaping our understanding of the natural world.