Sir Isaac Newton is credited with the discovery of the law of gravity in the late 17th century. He formulated the law after observing that objects fall toward the Earth, leading to his realization that a gravitational force must be acting on them. This groundbreaking insight was part of his larger work on motion, encapsulated in his seminal work "Mathematica Principia," published in 1687. Newton's law of universal gravitation portrayed gravity as a universal force impacting all objects with mass, fundamentally changing our understanding of celestial and terrestrial motion.