Outside the new British Library building (Euston Road, London) stands a large statue of Sir Isaac Newton (1642-1727), sculpted by the Scottish artist, Sir Eduardo Paolozzi, in 1995 (see Figure 1). This powerful evocation of Newton was inspired by a rare watercolour of Newton, painted by William Blake at the end of the eighteenth century (see Figure 2), and now displayed as one of the prize acquisitions of Tate Britain. Why, of all the multitude of authors collected in the British Library (the largest library in the world), was Sir Isaac Newton, a scientist, selected for this unique honour? Perhaps because he is, arguably, the greatest British scientist that ever lived, and wrote perhaps the most important book ever written, Philosophiæ Naturalis Principia Mathematica. This book, originally published in Latin (see Figure 3), first appeared in 1687, and is most commonly referred to as Newton’s Principia. A second edition was published in 1713, and the definitive (third) edition was published in 1726, thirty-nine years after the first edition. It first appeared in English translation (Andrew Motte), under the title The Mathematical Principles of Natural Philosophy in 1729 (see Figure 4), and it is a modern update of this translation which is published here alongside the original Latin edition.
The work contains three books, and describes, inter alia, Newton’s Laws of Motion, Newton’s Law of Universal Gravitation, and the derivation of Kepler’s empirical Laws of Planetary Motion. It also develops arguments and methods that evolved into modern calculus. From this monumental work sprang all of modern physics, and as a description of the classical world, it remains unchallenged. Only the revolutions of Einstein’s theory of relativity and quantum mechanics have induced a rethinking of Newtonian mechanics, and it has stood the test of time for nearly four centuries. It remains the definitive description of the macroscopic world. With the discovery, in February 2016 (see weblink) of the first evidence for the existence of gravitational waves (obtained by colliding two black holes in the Laser Interferometer Gravitational-Wave Observatory, LIGO), it is both timely and fascinating to return to this revolutionary account from Newton of universal gravitation. As he said himself, in a letter to Robert Hooke (see the extract in Figure 5), “If I have seen further it is by standing on the shoulders of Giants.” Einstein stood on Newton’s shoulders and the LIGO team stood on the shoulders of Einstein.