By the time Isaac Newton was born in England in 1643, natural philosophers (today we call them scientists) thought that the Universe was much smaller than we now know it to be. They also conceived the Universe as unchanging and eternal, as basically the same always, with no beginning and no end. In 1727, the year Newton died, that was the picture that he and his contemporaries still had.
But Newton himself opened the Pandora’s Box of our awareness of the Universe and our place in it, by showing that the “force” that acts on us to keep our feet on the ground is the same one that keeps the planets in orbit around the Sun. His mathematical formulation of the law of universal gravitation is still used today to calculate, for instance, the trajectory of the spaceships that we have been sending to the Moon and beyond since the late 1960s. The escape velocity—the speed required to avoid the pull of gravity of the earth and prevent the spaceships from crashing back to the ground—was also calculated using Newton’s theory of gravity. (By the way, that escape velocity here on Earth is 11 kilometers per second.)
By 1687, when Newton published his main opus, the Principia, only 55 years had elapsed since the Catholic Church sentenced Galileo Galilei to life imprisonment for postulating the “heresy” that the earth is merely one of six planets orbiting the Sun (Uranus and Neptune and the former planet known as Pluto had not been discovered). The Earth-centered picture, with the planets and the Sun orbiting Earth, was the preferred choice of the Church, supposedly because it was in line with the idea of god’s creation of the earth and of us humans as his main achievement and everything else as accessory to us.
Never mind the contradiction of that notion with another cherished tenet of Christians: That god’s supposedly main creation is a bunch of imperfect, wretched sinners. Religious dogmas defy logic and common sense and are internally inconsistent, which shows that priests and their fellow travelers hardly care for the truth. On the contrary, they do whatever they can to suppress it, mainly because it is bad for business.
A lesson of the drama of Galileo’s trial is that we have to avoid at all costs the tyranny of religion. Theocracies and everything approaching them are still one of the perils to be dodged. Priests of all sorts acting as such—whether Catholic or Protestant, Muslim mullahs or Jewish rabbis—have never made a single discovery about what they deem to be their Lord’s creation. Secular scientists have illuminated more about the workings of the Universe than priests and their supposedly sacred texts will ever do. Moreover, no bloody conflict has ever been initiated and sustained in the name of science or the pursuit of knowledge.
Today, and even by Newton’s time, we have no choice but to accept the facts. We are not at the center of our solar system; we are not at the center of our galaxy. Rather, the spiral arm where we are located (which is made of stars and intergalactic gas and dust) is about two-thirds removed from the galactic center, and our galaxy is no more at the center of the Universe than is any other of its hundreds of billions of galaxies.
It is even likely, given the latest theoretical musings, that our universe is only one of many billions or even trillions of universes in a vast cosmos, a tiny part of all that there is. Each bubble of energy, each universe, would have its own constants of nature, its own “laws” of physics. In that scenario, we are alive because we happen to be part of the only universe, or one of the few universes, with the necessary conditions for the emergence of life and of beings capable of asking how it all began.