Isaac Newton was an English scientist born in 1643 who made groundbreaking discoveries in optics, mechanics, and mathematics. He is best known for discovering the law of universal gravitation and laws of motion, formulating the principles of modern physics. Newton published his seminal work Philosophiae Naturalis Principia Mathematica in 1687, establishing classical mechanics and describing universal gravitation and the three laws of motion, forming the dominant scientific viewpoint for the next three centuries.