Newton's Principia for the Common Reader

Upon receiving the 1983 Nobel prize in physics Subrahmanyan Chandrasekhar (1910 - 1995) delivered a lecture `On stars, their evolution and their stability'. His closing remarks were on the mathematical theory of black holes, which, he said, `is a subject of immense complexity; but its study has convinced me of the basic truth of the ancient mottoes, The simple is the seal of the true and Beauty is the splendor of truth. During the last ten years of his life Chandrasekhar returned to the primary document of all astrophysics, Newton's Principia, where he found those mottoes confirmed in many places. His aim was to make a conversion of Newton's largely geometrical demonstrations - so difficult to follow for many modern readers - into classical mathematical analysis. In contrast to several other scholars and scientists he concentrated on the book itself, forsaking collateral reading of any of the extant Newtoniana. Newton's different `Propositions' are presented here, one by one, as they appear in Principia; followed by the author's comments and explanations, expressed in `modern' form. Some science historians have assumed that Newton, in fact, first derived his results by using calculus (which he himself had invented), and then reformulated the derivations in a geometrical form, the mathematical language of his own age. Chandrasekhar argues why he does not believe in this legend, stating that Newton's `physical and geometrical insights were so penetrating that the proofs emerged whole in his mind'. To a modern reader, having completed a few years of university studies in mathematics, this erudite book brings out the beauty and the ultimate simplicity of Newton's mechanics.