When the sky became a machine

Newton's Principia came out in 1687 and did to Kepler exactly what Kepler had done to Ptolemy. Kept the results, threw out the reason. The ellipses, the speeding up and slowing down, the squares and cubes, all of it fell out of one rule about masses pulling on each other across empty space. The planets do not move in harmony. They fall. They fall toward the Sun forever and keep missing, and the shape of the missing is an ellipse. No chord. No world soul. No breath. A formula, and the formula was enough.

The divorce

Astrology did not lose an argument. It lost the definition of what counts as an explanation. Ptolemy's heat and moisture, the Stoic sympathy, Kepler's seal in wax, all of them said the sky does something to you and here is how. After Newton the question became: show me the force, give me the equation, tell me what it does to a cannonball. The gravitational pull of Mars on you at birth is real and it is about the pull of the midwife. Nobody could produce a second force, so the educated classes dropped the subject quietly, the way you stop mentioning a cousin.

You can date it by the books. William Lilly's Christian Astrology, London, 1647, is eight hundred pages of method by a man who advised Parliament and called the Great Fire. Nothing of that weight was written in English again for two hundred years. The universities that had taught astrology beside medicine dropped it by the early 1700s. Almanacs kept going for farmers, somebody invented the newspaper horoscope in 1930, but the subject had lost its seat at the table and it never got it back.

The part the clean story leaves out

Newton wrote more words on alchemy and Bible prophecy than on physics. He translated the Emerald Tablet, the as above, so below text, into English in his own hand and tried to work out what its sentences meant in a furnace. He believed the ancients had known the law of gravity and hidden it in myths. He spent years on the measurements of Solomon's temple. When his papers were auctioned in 1936, the economist John Maynard Keynes bought a trunk of them, read them, and decided Newton was not the first of the age of reason but the last of the magicians: a man who saw the entire universe as a riddle set by God and expected to solve it by thinking hard enough.

So the man who turned the sky into a machine did not believe it was only a machine. He thought the machine was a message. That is Pythagoras in a powdered wig: the math is real and it also means something and a clever enough reader can get the meaning out. His followers kept the first half, dropped the second, and called what was left Newtonian.

What crossed the gap

Two things. The first is the math itself, which is why the site next door can put Saturn where it stood over Dover at 10:30 on an April morning in 1990 to a fraction of an arc minute. That is Newton's gift to astrology, and it is a strange one: the enemy's physics turned out to be the best thing that ever happened to the accuracy of a horoscope.

The second is the question. Newton's universe is more ordered than anything Plato imagined, a clock so exact that eclipses a thousand years out are predicted to the second. Whether we are inside that order did not get answered. It got moved to a different department. For two hundred years the department was theology. Then it was a psychiatrist in Zurich who kept getting horoscopes drawn up for his patients, and he is next.