The Science of Discworld II

possession of engineering. We tend to think of the Greeks as ‘pure thinkers’, but that’s the result of selective reporting. Yes, the Greeks were renowned for their (pure) mathematics, art, sculpture, poetry, drama and philosophy. But their abilities did not stop there. They also had quite a lot of technology. A fine example is the Antikythera mechanism, which is a lump of corroded metal that some fishermen found at the bottom of the Mediterranean Sea in 1900 near the island of Antikythera. 2 Nobody took much notice until 1972, when Derek de Solla Price had the lump X-rayed. It turned out to be an orrery: a calculating device for the movements of the planets, built from 32 remarkably precise cogwheels. There was even a differential gear. Before this gadget was discovered, we simply didn’t know that the Greeks had possessed that kind of technological ability.
    We still don’t understand the context in which the Greeks developed this device; we have no idea where these technologies came from. They were probably passed down from craftsman to craftsman by word of mouth – a common vehicle for technological extelligence, where ideas need to be kept secret and passed on to successors. This is how secret craft societies, the best known being the freemasons, arose.
    The Antikythera mechanism was Greek engineering, no question. But it wasn’t science, for two reasons. One is trivial: technology isn’t science. The two are closely associated: technology helps to advance science, and science helps to advance technology. Technology is about making things work without understanding them, while science is about understanding things without making them work.
    Science is a general method for solving problems. You’re only doing science if you know that the method you’re using has much wider application. From those written works of Archimedes that still survive, it looks as if his main method for inventing technology was mathematical. He would lay down some general principles, such as the law of the lever, and then he would think a bit like a modern engineer about how to exploit those principles, but his derivation of the principles was based on logic rather than experiment. Genuine science arose only when people began to realise that theory and experiment go hand in hand, and that the combination is an effective way to solve lots of problems and find interesting new ones.
    Newton was definitely a scientist, by any reasonable meaning of the word. But not all the time. The mystical passage that we’ve quoted, complete with alchemical symbols 3 and obscure terminology, is one that he wrote in the 1690s after more than twenty years of alchemical experimentation. He was then aged about 50. His best work, on mechanics, optics, gravity, and calculus, was done between the ages of 23 and 25, though much of it was not published for decades.
    Many elderly scientists go through what is sometimes called a ‘philosopause’. They stop doing science and take up not very goodphilosophy instead. Newton really did investigate alchemy, with some thoroughness. He didn’t get anywhere because, frankly, there was nowhere to go. We can’t help thinking, though, that if there had been somewhere, he would have found the way.
    We often think of Newton as the first of the great rational thinkers, but that’s just one aspect of his remarkable mind. He straddled the boundary between old mysticism and new rationality. His writings on alchemy are littered with cabbalistic diagrams, often copied from early, mystical sources. He was, as John Maynard Keynes said in 1942, ‘the last of the Magicians … the last wonder-child to whom the Magi could do sincere and appropriate homage’. What confuses the wizards is an accident of timing – well, we must confess that it is actually a case of narrative imperative. Having homed in on Newton as the epitome of scientific thinking, the wizards happen to catch him in post-philosopausal mode. Hex is having a bad day, or perhaps is trying to tell them something.
    If Archimedes wasn’t a scientist and Newton was only one sometimes, just what is science? Philosophers of science have isolated and defined something called the ‘scientific method’, which is a formal summary of what the scientific pioneers often did intuitively. Newton followed the scientific method in his early work, but his alchemy was bad science even by the standards of