Sir Isaac Newton PRS (25 December 1642 – 20 March
1726/27)[a] was an English mathematician, physicist, astronomer,
alchemist, theologian, and author (described in his time as a "natural
philosopher"), widely recognised as one of the greatest mathematicians
and physicists and among the most influential scientists of all time.
He was a key figure in the philosophical revolution known as the
Enlightenment. His book Philosophiæ Naturalis Principia Mathematica
(Mathematical Principles of Natural Philosophy), first published in
1687, established classical mechanics. Newton also made seminal
contributions to optics, and shares credit with German mathematician
Gottfried Wilhelm Leibniz for developing infinitesimal calculus.

In the Principia, Newton formulated the laws of motion and universal
gravitation that formed the dominant scientific viewpoint for
centuries until it was superseded by the theory of relativity. Newton
used his mathematical description of gravity to derive Kepler's laws
of planetary motion, account for tides, the trajectories of comets,
the precession of the equinoxes and other phenomena, eradicating doubt
about the Solar System's heliocentricity. He demonstrated that the
motion of objects on Earth and celestial bodies could be accounted for
by the same principles. Newton's inference that the Earth is an oblate
spheroid was later confirmed by the geodetic measurements of
Maupertuis, La Condamine, and others, convincing most European
scientists of the superiority of Newtonian mechanics over earlier
systems.