I just finished reading a biography on Isaac Newton. A lot has already been written about Newton, and I don’t have a lot of original insight to contribute, but I’ll briefly summarize my thoughts. The book (“Isaac Newton” by James Gleick) was excellent, and my only complaint is that it was too short. It chronicles Newton’s life from birth – in an obscure village farmhouse, to obscure parents – to his death at age 84, at which point he had grown relatively wealthy, powerful, and famous. Even at his death, though, his legendary status and place in history was just beginning.
Newton was brilliant, but also a loner. He never married and had few friends, and he spent much of his time alone, reading and performing experiments and writing. Much of what he wrote was entirely private and he did not publish, yet it was groundbreaking in scope. In a nutshell, Newton single-handedly invented calculus, creating concepts like derivatives (measuring the rate of change over time) and integrals (measuring the area under a curve) and connecting the two; he was the first to set forth an accurate theory of light by using a prism to show that white light is composed of the spectrum of all colors of the rainbow; and he effectively “discovered” gravity. Without going into a lot of detail, it’s hard to even comprehend these achievements without full historical context.
Before Copernicus, Galileo, Kepler, and Newton, and a few other remarkable scientists who lived in the 1500s and 1600s, it was generally taken for granted that the earth is stationary, that other planets, the moon, and the sun (and the stars) all move around the earth in regular cycles, and that there is a fundamental distinction between the imperfect earth and the perfect celestial sphere, or series of spheres, in the heavens (perfect in part because of their religious association with God). In Newton’s time, it had only recently been discovered that the planets, including Earth, move around the sun (Copernicus), and that these orbits are not even perfect circles but are elliptical (Kepler). The use of the telescope also revealed lunar craters and other imperfections, as well as moons orbiting other planets like Jupiter (Galileo). This was all an affront to Christianity and its view of the world. But there were still enormous questions about nature: why did the planets orbit at all? What was keeping them from flying apart at great speed? The concept of a “force” of attraction hadn’t been invented yet – and there was argument about whether space was even a vacuum or was filled with the mysterious “ether.” Newton showed decisively that such a force existed (gravity), even if he couldn’t explain its cause, and that space is a vacuum – there is no ether. Furthermore, matter is the same everywhere in the universe, whether on earth or other planets or stars: it is all composed of the same types of matter and obeys the same natural laws.
Setting forth well-articulated theories of gravity and optics, and creating a new, more powerful mathematics are not even Newton’s biggest achievements. It was his insistence on using data and math – to measure things that were previously unmeasured – that was truly a colossal shift in the way that societies approached nature. Newton, more than any other person, is responsible for taking what was previously called “philosophy” and hammering out concrete rules for how to measure things and how to approach questions scientifically, so that theories could be tested and disproven using evidence and data.
There have been many things written about Newton, but a famous poem by Alexander Pope probably summarizes his life and his contributions as well as anything else:
“Nature and nature’s laws lay hid in night;
God said, Let Newton be! and all was light.”