Sir Isaac Newton was born on December 25, 1642 in Woolsthorpe, near Grantham in Lincolnshire, England. Newton is clearly the most influential scientist who ever lived. His accomplishments in mathematics, optics, and physics laid the foundations for modern science and revolutionized the world. Newton studied at Cambridge and was professor there from 1669 to 1701, succeeding his teacher Isaac Barrow as Lucasian professor of mathematics. His most important discoveries were made during the two-year period from 1664 to 1666, when the university was closed and he retired to his hometown of Woolsthorpe. At that time he discovered the law of universal gravitation, began to develop the calculus, and discovered that white light is composed of all the colors of the spectrum. These findings enabled him to make fundamental contributions to mathematics, astronomy, and theoretical and experimental physics.Newton summarized his discoveries in terrestrial and celestial mechanics in his Philosophiae naturalis principia mathematica (mathematical principles of natural philosophy) in 1687, one of the greatest milestones in the history of science. In it he showed how his principle of universal gravitation provided an explanation both of falling bodies on the earth and of the motions of planets, comets, and other bodies in the heavens. The first part of the Principia is devoted to dynamics and includes Newton's three famous laws of motion; the second part to fluid motion and other topics; and the third part to the system of the world, for example, the unification of terrestrial and celestial mechanics under the principle of gravitation and the explanation of Kepler’s laws of planetary motion. Although Newton used the calculus to discover his results, he explained them in the Principia by use of older geometric methods.Newton's discoveries in optics were presented in his Opticks in 1704, in which he elaborated his theory that light is composed of corpu...