The Day the Universe Changed - James Burke [67]
Galileo reproduced this abstract concept the other way round, as it were, by releasing balls down a wooden groove that was curved. With bits of thread and pegs, and Santori’s pulsemeter, Galileo experimented with different balls and slopes, until he was able to say that when an object ran down the slope, during equal amounts of time along its journey it accelerated at the same rate. This was the ‘32 feet per second per second’ law.
This behaviour also explained the problem Copernicus had not been able to crack: why falling objects do not fall to the ground to the west of their starting-point on a turning earth. Galileo argued that as the earth turned, everything on it turned too, so the falling object moved east with the earth. The two components resolved so as to cause the object to reach a spot vertically below its release point. He referred to common experience by saying it was like dropping an object from the top of a ship’s mast. It hit the deck, because both the ship and the object were travelling together. This explanation destroyed the Aristotelian separation of violent and natural movement, and provided the framework in which mathematics could be applied to the movement of the planets.
There was also at the time a new idea abroad about what caused the object to drop in the first place. In 1600 Queen Elizabeth I’s personal physician, William Gilbert, had published a compendious volume on magnets, called De Magnete. After eighteen years’ work, principally aimed at discovering why the compass behaved as it did, Gilbert had surmised that the earth was a giant magnet with north and south poles of attraction, and that it was this magnetic attraction which caused things to fall to and remain on the surface of the planet. The magnetism was strong enough to counter the effect of the earth’s rotation, which, from the twenty-four-hour cycle and the size of the globe was known to be extremely fast.
The world was now no longer one of mysterious ‘essences’ and ‘qualities’ which gave objects desires and tendencies. It was a world in which ‘natural’ motion had become acceleration according to a natural law. ‘Violent’ motion was, like the attractive property of the earth, a force acting on natural motion. It had become important now to ask how things happened, not why.
Throughout this period, the centre of activity in almost every field was shifting steadily north, away from the Mediterranean. With the major metal industries now in Protestant Germany and the Portuguese spice imports going to northern Europe where the most profitable markets were, Antwerp had become a centre for international trade by the middle of the sixteenth century. The Low Countries had held a pre-eminent position in the economy of the north since the Middle Ages, when their textile industry had been the key factor in the recovery of the European economy after the Black Death. It was in Holland that Portuguese spices were finally exchanged for German precious metal.
The Italian banking representatives were also in Holland, where a sophisticated credit system was slowly developing. Above all, in mid-century the heavy-handed rule of the distant Spanish king, Philip II, was increasingly resisted by the Protestants in the northern part of the Low Countries. Guerrilla warfare finally broke into full-blooded conflict in 1586 when the rebellious Dutch, under William of Orange, began to take the country from the Spaniards.
Holland, the northern province, had been accustomed to running its own affairs and had been the first to break with Spanish rule. Conditions worsened until, in 1576, Spanish troops sacked Antwerp. The city was never to recover its former international position. As a result of the war, in 1579 the northern provinces met in Utrecht and signed a treaty to resist the Spaniards on a permanent’ basis. In 1581 they signed the formal act of abjuration, separating themselves from Spain and setting up the Dutch Republic, with Amsterdam as its capital.
In the same year an ex-accountant from Antwerp,