2. BIOGRAFÍA Sir Isaac Newton (December 25, 1642 – March 20, 1727 or January 4, 1643 – March 31, 1727 was an English physicist, mathematician, astronomer, philosopher, and alchemist; who wrote the Philosophiae Naturalis Principia Mathematica (published July 5, 1687), where he described universal gravitation and, via his laws of motion, laid the groundwork for classical mechanics. Newton was the first to demonstrate that the same natural laws govern both earthly motion and celestial motion. Newton also developed Newton's law of cooling, describing the rate of cooling of objects when exposed to air. Finally, he studied the speed of sound in air, and voiced a theory of the origin of stars.
