Isaac Newton

the pre-Einstein scientist

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 also shares credit with Gottfried Leibniz for the development of differential calculus.

longer bio

http://www.metaweb.com/wiki/wiki.phtml?title=Newton

Freeman Dyson on Isaac Newton and JohnMaynardKeynes as a review of James Gleick's bio of Newton.