Sir Isaac Newton | The 'Discoverer' of Gravity

We take Sir Isaac Newton’s views of the way things move so much for granted these days that it is hard to fathom just how extraordinary they were in the 17^th Century, and just what a revolutionary breakthrough they were. Before Newton, there had been no notion that the movement of fish in the oceans or branches on a tree moving from a breeze had anything whatsoever with the ‘movement of the heavens’, let alone that they were predictable in any way at all. They were seen to be controlled by unique, local factors, or else by the whim of the gods. The universe was, essentially, a mysterious and unpredictable place.

With his law of gravity and his three laws of motion, Newton showed that every movement, large or small, on the ground or in the furthest reaches of space, behaves according to the same simple, universal laws. In Newton’s ‘Principia Mathematica’, widely known as perhaps the greatest science book ever written, he suddenly blew away the universe’s chaotic mystery and showed that everything everywhere behaves in an orderly, entirely understandable way. It was as if the entire universe had been revealed at last as some great incredibly complex clockwork machine, and Newton’s laws were the keys to its working. Incredibly, it was shown that the laws worked out with experiments in laboratories here on the ground can be applied across the universe.

Even more significant, Principa Mathematica showed how every single movement in the universe can be analyzed mathematically, and Newton provided the mathematical tools to do it, with two newly created branches of mathematics—differential and integral calculus. Armed with Newton’s laws and Newton’s mathematics, it became possible not to just work out what is going on in every movement, from the lifting of a water glass, to the orbit of a planet, but predict what would happen when, for instance, a bus travels across a new bridge or when the spacecraft is launched. He made it possible, in theory, to predict the movement of everything in the universe forever, from the greatest star to the tiniest molecule.

Isaac Newton is generally considered to be the first great modern scientist and his book Principia as the first of all the most important scientific achievements of the last 350 years. It was a product of a science that prides itself on observation, experiment and pragmatic, honest logic. Yet in some ways, as some have written, he was also the last great magician of the medieval age. He spent more than half of his life avidly researching alchemy and astrology, spending day after day and night after night secretly working in his lab trying to turn base metal into gold, or scanning ancient texts into insight. This work was more important to him even than his science. He was not content with his discoveries of the workings of the physical world, but wanted to also discover the mechanics of human life. Although many of us would be apt to dismiss all this work as ‘mumbo-jumbo’ not worthy of such an intelligent mind, it has been said that his acceptance of the possibility that there are mysterious forces in the world that led him to the idea of an invisible gravitational force—something that the more rationally minded Galileo had not been able to accept.