AI Image - Portrait of Isaac Newton, 1680s, (2023). Newton (1642-c1726) was an English mathematician, physicist, astronomer, alchemist, theologian and author who made significant contributions to the fields of classical mechanics, optics, and infinitesimal calculus. He is famed for his discovery of gravity when he watched an apple fall from a tree. He used the Latin word gravitas (weight) for the effect that would become known as gravity, and defined the law of universal gravitation.