by Decoding the Heavens- Solving the Mystery of the World's First Computer (retail) (epub)
Etched onto the scale were tiny solo letters, not evenly spaced but in alphabetical order around the dial. Their meaning became clear from studying the other inscriptions on the front face. Only snatches of a few of these lines were visible, and they said things like: ‘Vega rises in the evening’, ‘The Hyades set in the morning’ and ‘Gemini begins to rise’.
These newly translated morsels were familiar enough. Such text was common on a type of calendar used by the Greeks from the fifth century onwards called a parapegma. They were a bit like primitive weather forecasts; their purpose was to correlate repeating astronomical events such as the risings and settings of particular constellations with phenomena on Earth, like weather patterns or the flooding of the Nile. Such calendars became the main method by which people marked the passing of the seasons, as well as providing invaluable information for farming and navigation.
Parapegmata probably developed from simple inscriptions that listed astronomical events – such as the dawn rising of the constellation Sirius – alongside the expected weather for that time of year. Later, these got a bit more sophisticated and they would be engraved on a stone tablet, say, with a peg hole alongside each item on the list. That way you could move the peg forwards by one hole every day and always know what time of year it was, without having to observe the stars directly.
The inscriptions on the Antikythera mechanism clearly served a similar purpose. They didn’t have peg holes, though. Instead, reference letters were inscribed at the appropriate points on the zodiac scale. When the Sun pointer reached a particular letter, the user could refer down to the appropriately lettered item on the list below.
The text even gave Price a clue to the mechanism’s origin. The parapegma with the closest wording we know to the one on the Antikythera mechanism was written by the ancient astronomer Geminus, who made his observations on the island of Rhodes.
As Virginia Grace and her colleagues would later discover, the ship on which the Antikythera mechanism was found almost certainly stopped off at Rhodes shortly before she sank. Here, Price found his own evidence of a link with the island. It’s not certain when Geminus lived, but most scholars plump for the first century BC. Geminus’s astronomy wasn’t all that impressive – his writings mostly summarised the work of others for future students – but he was likely to have been on Rhodes at the time that the Antikythera ship sailed.
Price kept looking. On the back of the mechanism were two dials, one above the other. Each seemed to consist of a series of concentric rings, perhaps five on the top and four on the bottom, which were divided into segments of about six degrees each. Strings of letters and numbers were inscribed within these segments, though it wasn’t clear what they meant. Each of the back dials also had a miniature dial embedded in its face, off-centre like the second hand on an old-fashioned watch. The inscriptions on the back were even more fragmented than those on the front. But even from the few legible words translated by George Stamires, Price could get an idea of the subject matter. They said things like ‘two pointers, whose ends carry’, ‘the Sun’s rays’, ‘ecliptic’, ‘Venus’ and ‘protruding’. As previous scholars had suspected, these inscriptions seemed to form an instruction manual for the mechanism.
Although he wasn’t sure what the back dials were for, Price guessed from the inscriptions that they had something to do with demonstrating the cyclical relations of the Moon, the Sun and maybe even the planets. As the wheels turned the dials must have calculated their respective movements through the sky, just as astronomical clocks did many centuries later. The Antikythera mechanism might not have shown hours and minutes, but nonetheless, he argued, it was concerned with ‘time, in its most fundamental sense, measured by the wheeling of celestial bodies through the heavens’.
Beyond such sweeping statements, however, Price had no idea what the back dials would have shown. And despite his early optimism it was even harder to work out what was happening inside the mechanism. At least 20 gearwheels survived in the fragments, all cut from a flat sheet of bronze about 2 mm thick. In the middle of the mechanism was a flat bronze plate, with trains of gearwheels leading above and below it. They were driven by an axle that came in through the side of the case and turned a little gear that was positioned parallel to the side of the box (at right angles to all of the other gearwheels). This ‘crown’ wheel engaged with the big four-spoked wheel that drove all the other gears.
But there the trail ran cold; the intricate workings of the machine remained frozen deep inside those stubborn, calcified lumps. Unless he could reconstruct the internal mechanism, Price couldn’t prove any of his conclusions – they were merely speculation, based on a few barely legible words. And not knowing how the gearwheels functioned was immensely frustrating. At last Price had the Antikythera mechanism in his hands and he had begun to understand its purpose, but the ‘particular go of it’ remained a mystery. He wrapped the pieces carefully inside an old cigar box, tucked it out of sight at the back of a shelf, and admitted defeat, at least for the time being. The knowledge encoded in humanity’s oldest surviving machine was hidden from him.
After his intense summer in Athens, Price took a position at the prestigious Institute for Advanced Study at Princeton in New Jersey. Again he was surrounded by brilliant scientists, many of them Europeans who had fled the Nazis in the years before the Second World War. He just missed Albert Einstein, who worked at the institute until his death in 1955, but elsewhere on the leafy campus was the mathematician Kurt Gödel, who was grappling with places that Price’s graphs could never reach: the theoretical limits of knowledge and beyond. The scientific historian Otto Neugebauer, though officially based at nearby Brown University, also spent a lot of time at Princeton and shared with Price much of his enormous knowledge of ancient astronomy.
Price didn’t think much about Gödel – whose ideas about the limitations of mathematics didn’t sit well with Price’s rational, measurable world view – but he was inspired by the institute’s director, Robert Oppenheimer. During the war, Oppenheimer had been the scientific leader of the Manhattan Project, which succeeded in developing the first nuclear bomb. As director, Oppenheimer was razor-sharp but impatient, jumping from topic to topic and staying with each just long enough to grasp key questions and confound the experts who had worked in the field all their lives, before he moved on to new ground. Critics tutted that he never concentrated on one subject long enough to make the progress that a physicist of his brilliance should have been able to achieve. But Price admired the audacity of it, and felt that he and Oppenheimer had a lot in common.
One of the first things Price did at Princeton was lecture on the Antikythera mechanism and his conviction that it held the key to the origin of modern machines. News of Price’s work soon reached the author Arthur C. Clarke (another of Price’s heroes, along with H. G. Wells), who had recently moved to Sri Lanka. As well as writing science fiction, Clarke was a keen diver and had just published several books about underwater exploration. It is unclear how he first heard about the Antikythera mechanism – the memory was lost to him in the later stages of his life; perhaps it was from Jacques Cousteau, with whom Clarke attended the first US skin divers’ convention in Boston in February 1959. But when he did finally learn of this mysterious artefact, he felt that Price was on to something of fundamental importance.
Clarke introduced Price to Denis Flanagan, the passionate editor of Scientific American. Flanagan duly persuaded Price to write an article about the mechanism and it appeared as the magazine’s cover feature in June 1959. Again, Price called for a complete rethink of the history of technology: ‘Nothing like this instrument is preserved elsewhere,’ he said. ‘On the contrary, for all that we know of science and technology in the Hellenistic age we should have felt that such a device could not exist.’
Price sent a copy of this article to Clarke. ‘Please find some more,’ he wrote hopefully at the top. But neither Clarke nor anyone else has ever found anything comparable (Clarke once rec
alled that the most advanced artefact he had ever found as a diver was an early nineteenth-century soda-water bottle).
After two years at Princeton, Price took a job at Yale as the university’s first professor of history of science. Price set about filling his department in New Haven, Connecticut, with graduate students, as well as scientific instruments. Antiques from past centuries, mostly wood and brass, decorated every room of the department and of his suburban home. He would tinker with them, as he had with the physics equipment he tended so faithfully as a student back in London, and he soon became known as the man to whom instruments spoke. Like Virginia Grace with her amphoras, Price could coax a story out of any mysterious mechanical object, gleaning how it worked and what it did from subtleties in the design that others barely noticed.
Yet he couldn’t make any progress on the Antikythera fragments. Over and over he studied the drawings and photographs he had brought back with him, and he visited Athens again in 1962 to check his readings and confirm that the pieces fitted together as he thought. He even tracked down Albert Rehm’s unpublished notes on the device, which had been kept in Munich since Rehm’s death after the war. But he still couldn’t work out how the gears functioned, and the further cleaning that he had insisted on wasn’t progressing as he had hoped. The archaeologists Virginia Grace and Gladys Weinberg contacted him after seeing his article in Scientific American to ask if he might publish a reconstruction of the mechanism alongside their work on the other contents of the Antikythera wreck. Humiliatingly, when their paper was published in 1965 he could still add nothing to his previous study.
Worse, his theories about the mechanism had made little impact. One account of his work, an article in the Athens press by a senior American professor, even scoffed that Price had been fooled by the layers of corrosion into thinking that the Antikythera mechanism was much older than it really was. It was a planetarium, said the professor scornfully, similar to one with which he had been taught the layout of the solar system as a child in school in Austria some 60 years before. It had clearly fallen on the site of the Antikythera wreck by chance, many centuries later.
Such ridicule stung sharply. Price often woke in the night, staring at the ceiling and wondering whether he could be wrong about the mechanism, whether for all the evidence he had been taken in by some cruel hoax. Was he wasting his reputation on a dead end? But during daylight hours Price allowed himself no such indulgence and kept busy on other projects. Mercurial, his colleagues called him, and they could only watch breathlessly as he rode from one topic to the next on a wave of a childlike enthusiasm. Like Oppenheimer, Price revelled in becoming an instant expert on everything and telling those who had spent their careers quietly mastering a subject exactly where they were going wrong. Whatever anyone else told him they studied, he felt a compulsion to join them – to see what they saw, do what they did, and to better it.
He was soon giving both historians and sociologists a run for their money. By counting the number of scientific papers published in different fields, and analysing precisely who was citing who, Price extended his theories about the growth of science. Traditional historians were still distinctly unimpressed by Price’s claims, which they felt were simplistic and driven more by a love of the dramatic than any true understanding of social development or the accumulation of knowledge. They hated how he ignored inconvenient data points for the sake of a good story, although their criticisms also contained a hint of snobbery. Then Price stopped bothering with historians and started talking to scientists. They loved his work – at last, instead of advancing fuzzy opinions someone was studying science with numerical methods that made sense to them. His ideas about the growth of science have since been cited in journals from aeronautics to zoology. And in March 1965 Price was afforded one of science’s highest honours, an invitation to give a lecture at the Royal Institution in London.
Price’s theories may not have seized the popular imagination like Parkinson’s Law, but he helped to lay the foundations of a whole new field of study: scientometrics, the science of science itself. He concluded that science had grown by five orders of magnitude (more than 16 doublings) in the three centuries since the foundation of the Royal Society, meaning that ‘80 per cent to 90 per cent of all the scientists who have ever lived are alive now’. He argued that the pattern of recent citations among the world’s scientific papers could reveal the areas where research was actively progressing, not to mention the relative importance to science of particular journals, authors, institutions and even countries. And he declared the secret of distinguishing science from non-science: the higher the proportion of citations of newer papers (those less than five years old) compared to older ones (more than 20 years old), the more likely that an article is scientific.
Price himself believed, as usual, that he was uncovering universal truths about the nature of knowledge and where it was taking humanity. Little green aliens coming to Earth would understand the Planck constant, the velocity of light, or the wave equation no matter how much they differed from us. Surely, he mused, they would also recognise his scientometrics.
Hoping all the time that he might unearth further clues to the ancient mechanism that started it all, Price also followed up his interest in the history of astronomical instruments and clocks. With the help of his students he studied and catalogued all of the ancient sundials and astrolabes he could get his hands on. And in 1967 he persuaded National Geographic to pay for him to go to Athens to investigate the Tower of the Winds, in return for writing an article about it in the magazine when he got back.
The octagonal tower is one of the only buildings from ancient Greece or Rome that has never been buried or demolished, or even lost its roof. It was built at the beginning of the first century BC, around the time of the Antikythera mechanism, by a Macedonian astronomer called Andronicus Kyrrhestes. On its faces are carved eight winged demigods – one for each of the eight winds – their intense yet flowing features still as evocative as ever. Etched beneath them are eight sundials, with webs of lines that showed both the time of day and the season from the direction and length of the shadows cast. Missing today is the bronze weathervane in the form of Triton, son of the sea god Poseidon, that once swung with the wind to point to the appropriate divinity: Lips, for example, god of the south west wind, which used to carry ships into Piraeus, Athens’s port.
The inside of the tower, by contrast, has been completely gutted. It was used as a church in early Christian times and then, during Turkish rule, as a prayer site by Muslim dervishes, whose whirling dances brought them closer to God. In the 1760s two British antiquarians dug down through the centuries of trodden dirt and bones and found the original floor. Carved into the marble was a mysterious pattern of holes and grooves. Some huge and complicated equipment had once stood there, they concluded, and guessed it was some sort of water clock. In Roman texts the tower was referred to as an horologium, which means ‘hour indicator’. And the ancient name of the spring that runs above the tower in the hill of the Acropolis is Clepsydra, which literally means ‘water thief’ and was a name often used for water clocks.
No archaeologist had ever attempted to suggest how the water clock might have worked, since its mechanism had completely disappeared. But Price was confident he could solve the mystery. Deciphering what the floor markings had once supported, he reckoned, was like ‘recreating the workings of a suburban kitchen in an empty room, using the relative positions of the sockets, pipe holes and rectangular floor stains as evidence’.
His extensive knowledge of ancient Greek water clocks was essential – much of it from writings of the Roman architect Vitruvius in the first century BC. These clocks didn’t have the complex clockwork mechanism and escapement of modern clocks; instead, a regular flow of water measured time as it passed. Vitruvius described two basic types of clepsydra made by the Greek engineer Ctesibius. The simplest, common in Egypt since about the third millennium BC, consisted of a water vessel with a hole in the bottom, wh
ich measured time as the water level dropped. It wasn’t very accurate, because the flow rate depends on the weight of the water above, so these clocks slowed down as the water level fell. Ctesibius invented a better version in the third century BC that was adopted throughout the Greek and Roman worlds. Water poured into a container that was engineered to keep a constant water level – either by an overflow pipe near the top or by a ballfloat that blocked the inflow pipe when the tank was full, a bit like the stopcock in a modern-day cistern.
Water then dripped from a hole in the bottom of the container at a constant rate into another cylindrical vessel. The rise in this water level over the day was used to measure the passing hours. With each new dawn, the tank was emptied and the clock was started again. Price felt sure that the Tower of the Winds was a giant version of just such a clock.
Price and his colleagues – a photographer and his wife, and a draftsman sent by National Geographic – spent days painstakingly clearing the floor of the tower; moving the marble rubble, sweeping away the dirt, and cleaning out the drain holes with a plastic-handled potato peeler, until they had an exact floor plan of the tower and a small cylindrical chamber that adjoined it.
In the smaller chamber they discovered that the stone joints of the floor had been reinforced by lead-coated bronze clamps. Something heavy must once have rested there. Nearby, a discoloured groove ran up the wall and there was a rectangular hole in the floor. Price concluded that this chamber must have housed the clock’s main water tank. The groove in the wall probably held a lead pipe, carrying water under pressure from the nearby stream up into the top of the water tank. The hole in the floor must have been where the tank was emptied at the end of each day.
