QI The Book of the Dead

works of Voltaire: ‘I learned, to my dismay, that there were close on one hundred large volumes in small print which that monster had written while drinking seventy-two cups of black coffee per diem.’ Like John Dee, he set himself a punishing work schedule, studying for up to twenty hours a day and sleeping less than three hours a night. He also indulged in more traditional student pursuits: drinking, smoking, gambling to excess and, briefly, falling in love with a girl called Anna. This period of his life came to an abrupt end when he lost all the money his father had sent him for his studies in a card game. Deeply ashamed at what he had done, he gave up gambling and smoking for good and forswore all further contact with women.
    While at Graz, Tesla encountered the Gramme dynamo, the cutting edge of electrical engineering at the time. It was a dual-purpose machine that when supplied with mechanical energy generated electricity, and when supplied with electrical energy could be used as a motor to drive things. Tesla was enchanted byit but puzzled by its constant sparking. The basic principle of generating electricity by ‘induction’ – introducing a rotating wire into a magnetic field – had first been described by Michael Faraday forty years earlier. The electricity Faraday had produced was called ‘alternating current’, because it continually switched direction as the electrons in the rotating wire swept past first the north and then the south pole of the magnet. In order to produce ‘useful’ electricity, this alternating current had to be converted into ‘direct’ current, similar to the electricity produced by a battery, where the electrons all flow in one direction, from the positive to the negative terminal. To achieve this, a switch, called a commutator, short-circuited the generator at each half-spin, so that the current continued its flow in the same direction. This shorting was what caused the dynamo to spark. Tesla thought this an overly complex, even clumsy solution. Why not find a way of harnessing the alternating current, he asked? His professors laughed at him, pointing out that would be tantamount to producing a perpetual motion machine. Early attempts to produce motors with alternating current had been dismal failures.
    Tesla never completed his degree. In 1881 he moved to Budapest and found work as a telephone engineer. This suited him much better than academia, and it was during this time that he came up with his first invention, a kind of early loudspeaker. Towards the middle of that year, Tesla began to suffer from a peculiar condition: a multiple sensory overload where sunlight blinded him, the ticking of a watch sounded like the blows of a hammer, vibrations from traffic made him lose his balance and his pulse spiked and plummeted wildly. His doctors were baffled and at one point thought they would lose him, but then it stopped, as suddenly as it had started. Soon afterwards, walking in the parkas he was convalescing, and reciting a passage from Goethe’s Faust to a friend, he had an epiphany:
    As I uttered these inspiring words the idea came like a flash of lightning and in an instant the truth was revealed. I drew with a stick in the sand the diagram shown six years later in my address before the American Institute of Engineers. The images were wonderfully sharp and clear and had the solidity of metal .
     
    What he had seen that afternoon was to change the world. It was a detailed vision of the electrical Holy Grail, the alternating current motor. His solution was brilliantly simple: to rotate the magnetic field as well as the coil. And, instead of a single circuit, to have two, but each timed differently, so that, like the firing of pistons in a combustion engine, when one was down the other would be up, and the forward momentum of the motor would be maintained. No sparks, no loud vibrations – and the motor’s motion was reversible. Tesla had literally ‘seen’ the future. But his vision went even deeper. His recent illness had made him sensitive both to light and to vibration. Now he saw the connection between the two. Alternating current produced a frequency, a wave, as the electrons whizzed backwards and forwards. It was a relatively low-frequency wave, but light was also a wave, a vibration, though at a far higher frequency. Suddenly the whole universe was revealed as a vast symphony of electrical vibration. And, if this alternating current could be transformed