Before Newton there were two worlds governed, apparently, by different physical laws: the sky, located beyond the Moon, and the Earth. Isaac Newton unified both creating a universal physics that equally governs everyday things and the most distant stars. Even today, when Newton’s ideas are considered only one part of a much larger scenario, described by Einstein, we ordinary citizens continue to see the world with Newtonian eyes. We use his laws both to throw a ball and to send a ship into outer space.
With such a unique vision of the world, Newton, perhaps the greatest genius that ever lived, could not be an ordinary human. He was a reserved, surly man, with a special sensitivity to the rhythms of nature but insensitive to the people around him. If something caught his attention, the rest of the world would vanish completely. When he was young, they gave up commissioning him to do work on the farm where he lived. If they ordered him to pick up the cattle, the cattle would not come back, and neither would Isaac, when crossing a bridge, he would remain engrossed, watching the water current or watching the swaying of the leaves. blown by the wind. He rarely studied but, when he did, a few minutes were enough for him to understand the issues that made his classmates grieve for hours. What impertinence!
At the University he was a solitary spirit “Amicus Plato amicus Aristotle magis amica veritas” -he used to say (Plato is my friend, Aristotle is my friend, but my best friend is the truth). he forgot to eat and sleep as if the world outside his focus faded into nothingness. If there was not enough mathematics to develop a problem, he invented it, one of his most notable discoveries was the infinitesimal calculus, with it, geometry came to life, ceased to be a set of static lines, parabolas or hyperbolas and turned into whimsical trajectories of a moving point. “Lines are described, and therefore are generated, not by the opposition of parts but by the continuous movement of the points,” he wrote.
One day he conceived the grandiose theory capable of explaining the movement of the Moon and the planets. Here is his story:
“In those days I was in the prime of my life for invention and I thought of mathematics and philosophy more than any other field… I began to imagine that gravity extended to the orbit of the Moon and… from the Laws of Kepler on the periodic times of the planets…, I deduced that the forces that keep the planets in their orbits must be reciprocally the squares of their distances to the centers around which they revolve, and therefore I compared the force necessary to keep the Moon in its orbit with the force of gravity on the surface of the Earth, and I found that they agree quite closely.”
They say that the inspiration came to him when he saw an apple fall from a tree in front of his mother’s house. Whether or not it is true, humanity has seen apples fall since the beginning of time but nobody, until him, had the brilliant vision of uniting, in the same law, the falling apple, the Moon that revolves around the Earth , to each planet or to each star of the Cosmos.
Newton was born on Christmas Day 1642 (the Julian calendar was still used in England). Much later, on Christmas 1968, a manned spacecraft named Apollo 8 circled the Moon. Inside, three human beings witnessed for the first time the extraordinary diversity of craters that mark the hidden face of our satellite. In one of the communications with Earth, astronaut Bill Anders was talking with his family when his youngest daughter asked him: “Who drives the ship?” Anders replied: “I think Isaac Newton does most of the work now.”
Listen to the biography of Isaac Newton.