Newton is such a giant in the history of Maths and Physics that it isn’t really possible to do him justice in a short blog post.
The basic facts first. Newton was born in Lincolnshire, in eastern England, in 1642. His early family life was unhappy, but he had the fortune to go to a good school – the King’s School in Grantham – which gave him an excellent grounding in the Classics and in Maths. He continued his studies at Trinity College, Cambridge, which he entered in 1661. Here he began to study the work of the great philosophers, and was exposed to mathematical and scientific theory, which he continued to develop in the following years.
In 1687 he published his greatest work: Philosophiae Naturalis Principia Mathematica. This translates as Mathematical Principles of Natural Philosophy and is often shortened to the Principia. It has been called the single most influential book on Maths and Physics and dominated the scientific view of the universe for the next three hundred years. As far as Maths is concerned, he is said to have “distinctly advanced every branch of mathematics then studied.”
In 1705 he was knighted, the first time a scientist was accorded this honour, becoming Sir Isaac Newton. Newton never married, and his life ended in 1727. He is buried in Westminster Abbey.
His contributions to Physics cover fields such as Astronomy, optics – and, of course, gravitation. Did an apple ever fall on his head? Probably not, but it does seem true that it was falling apples that led him to wonder why objects fell to Earth, and led him to develop gravitational theory. In Maths his greatest work concerned differential calculus. Until then Maths had been overshadowed by the “static” geometry of the Greeks. Calculus – the ability to accurately calculate rates of change – allowed scientists and engineers to make sense of motion and a dynamic world as never before. The motion of fluids, the orbits of the planets: all could now be calculated accurately. Newton actually called differentiation “the method of fluxions”; the rate of change at a point was “fluxion”, with the two variables called “fluents.” (It is still a common phrase to say that matters “are in a state of flux”.)
Newton decided not to publish straight away, concerned his unconventional ideas would be ridiculed. But in 1684 the German mathematician Leibniz published a paper with his own version of the theory. In the end, the Royal Society credited Newton with the discovery, Leibniz with the first publication.
Although Calculus was his greatest contribution, Newton developed many other areas of Mathematics. These include the Binomial Expansion, the invention of fractional powers, and a method for solving equations by successive approximations (versions of which are built into your calculator).
Later in life he wrote a number of religious tracts, he became a Member of Parliament, he was Master of the Royal Mint, and President of the Royal Society. It is possible that he became increasingly eccentric, and possibly died, because of the ingestion of mercury which he used in many of his experiments.