Decoding the Heavens
Page 13
Among the evidence Price cited was a manuscript written around 1000 AD by an eminent Islamic astronomer called Abu Rayhan al-Biruni. It described a geared calendar that al-Biruni called the Box for the Moon, which could be fixed to the back of an astrolabe. In it a train of eight gearwheels calculated the positions of the Sun and the Moon in the zodiac, as well as the phase of the Moon. An astrolabe with a very similar calendar, made in Iran in the early thirteenth century, survives to this day (in the Museum of the History of Science in Oxford). Price argued that these Islamic instruments were direct descendants of the Antikythera mechanism, and that when the knowledge passed back to Europe it triggered the sudden flowering of astronomical clocks. This explained why the first mechanical clocks spread so quickly and involved such complex displays of the heavens – the technology for these displays had already existed for centuries.
Gears from the Greeks showed that by relying on the few technical manuscripts and artefacts that have survived into modern times, historians were far behind in their understanding of what the ancients could do. Technology that had been attributed to Europeans in medieval and Renaissance times and beyond had in fact been mastered by ancient civilisations. Price believed he had shown that it was this knowledge that had finally triggered the explosion of technological advance in Europe that led to our own modern civilisation. His decades of conviction had paid off. He was finally ready to rewrite history.
But things didn’t quite happen that way. Certainly, specialists in the history of technology welcomed Price’s paper. The German scholar Aage Drachmann, for example, complemented Price on his ‘comprehensive and unimpeachable investigation’, while his British counterpart John North concluded that ‘the reader . . . can hardly deny that the mechanism is the most important scientific artefact from classical Greek times’. Arthur C. Clarke, too, continued to champion the importance of the Antikythera mechanism, and included it in his first series of Arthur C. Clarke’s Mysterious World, filmed in 1980.
But beyond this handful of enthusiasts, nothing much changed. Ancient history was discussed and understood and taught just as it had been before. The Greeks were still regarded as philosophers, masters of ideas, but uninterested in technical expertise, while the more philistine Romans excelled at shows of strength such as amphitheatres and aqueducts, but didn’t have the intellectual imagination to equal the thinking of the Greeks. Any credit for our own technical expertise was always to be given much closer to home, to the fathers of modern-day science in Renaissance Europe.
One problem was that the gap between the Antikythera mechanism and the next known mention of a geared mechanism was well over a thousand years. The device appeared to prove that the Greeks had invented clockwork, but to say that the surviving Islamic instruments were part of the same technological line required a huge leap of faith, whatever one’s opinion of Price. And his paper, although brilliant when discussing the wider context and significance of the device, was tortuously hard to follow when it discussed the gearwork, with jumps of logic that were never fully explained. So although nobody challenged his conclusions, nobody followed them up either.
It didn’t help that Erich von Däniken, the controversial Swiss author, had featured the Antikythera mechanism in Chariots of the Gods? (1968), in which he argued that alien space travellers visited the Earth thousands of years ago, giving ancient civilisations advanced technology such as batteries and uncorrodible metal, and inspiring much of their religion. The Antikythera mechanism, said von Däniken, was proof that the Greeks had technology they couldn’t have developed on their own (in a later book he even developed the idea that aliens used the device in their spaceships to navigate by the stars).
Chariots of the Gods sold millions, becoming a worldwide phenomenon. And it put the Antikythera mechanism firmly into the category of oddball mysteries, rather than a finding to be taken seriously by mainstream historians. Even after Price had published his paper, the mechanism was seen as an inconvenient aberration, mentioned as an afterthought, if at all. The ultimate snub came when Price’s mentor from his years at Princeton, Otto Neugebauer, published his huge, massively comprehensive History of Ancient Mathematical Astronomy in 1975. He relegated the Antikythera mechanism to a rather derogatory footnote. In the decades to follow, although the details of Price’s reconstruction were generally accepted, the wider implications were pretty much ignored. Both judgments were to prove wrong.
Back at the Athens museum, the fragments were at least put on public display. The attitude of staff there didn’t change much, but in 1980 the mechanism did catch the eye of Richard Feynman, who since watching the New Mexico bomb test had become one of the most famous physicists in America. He went to Athens for a few days’ break from lecturing, and wrote to his family on 29 June from the side of the pool of the Royal Olympic Hotel. The day before he had visited the archaeological museum and seen so many art objects and statues that he got all mixed up and his feet started to hurt. He felt he had seen it all before, except for one thing ‘so entirely different and strange that it is nearly impossible’. It was some kind of ancient machine with gear trains, he said, like the inside of a modern wind-up alarm clock.
When Feynman asked for more information, he was greeted with blank looks. ‘In fact the lady from the museum staff remarked when told the Prof. from America wanted to know more about item 15087, “Of all the things in the museum why does he pick out that particular item, what is so special about it?”’
The Greeks must think all Americans to be terribly dull, he mused, after tracking down Price’s work and finding out he was from Yale, ‘only interested in machinery when there are all those statues and portrayals of lovely myths and stories of gods and goddesses to look at’.
But there was one man on whom Price’s paper made a lasting impression. At the Science Museum in London’s elegant South Kensington a 26-year-old assistant curator called Michael Wright read the 70 pages avidly from beginning to end. He was responsible for looking after the museum’s collection of Industrial Revolution machines, and Price’s words lit the spark of what was to become a lasting obsession. He, too, was fascinated by how machines were put together, and when he saw Price’s detective work it was like a glimpse into an exciting new world. He wished the project had been his own.
A few things didn’t quite make sense to him, however, such as why the maker of the Antikythera mechanism would have used something as complicated as a differential gear to calculate the phases of the Moon, when a simple gear train would have done the trick just as well. And he thought it was odd that inscriptions suggesting that the mechanism might have shown the movements of the planets, which Price had discussed in his earlier Scientific American article, were now hardly mentioned. But Price seemed to have the whole thing sewn up. Wright put his confusion down to inexperience, filed away the paper, and got on with his work.
Gears from the Greeks was Price’s last word on the Antikythera mechanism; he felt he had said all there was to be said on the matter. From that point on he looked ahead, to what he believed would be the next technological driver of knowledge: modern computers. Although most electronic computers at the time were slow grey boxes with the simplest of circuitry and just a few kilobytes of memory, Price predicted that the world was entering a ‘computer age’, in which the next step would be three-dimensional chips that allowed machines to jump to conclusions and think creatively – like people. Just as the linear arithmetical thinking of the Babylonians had given way to the three-dimensional geometry of the Greeks, computers would enjoy a similar evolution.
Only this time, instead of modelling the heavens, they would be modelling the brain. Computers more intelligent than humans weren’t a huge step away, Price believed, and he saw such a scenario as wholly positive. Any resistance to the idea of super-intelligent computers was as backward as the Catholic Church’s silencing of Galileo in the seventeenth century. Galileo used telescope observations as evidence that the Earth went round the Sun – contradicting the
church’s view that the Earth was at the centre of the solar system, which followed that of the ancient Greek philosopher Aristotle. But in Price’s view, that wasn’t why the astronomer was seen as such a threat. ‘What was at issue was the validity of using a little bit of tubing with two bits of glass in it to attain knowledge that made you wiser than Aristotle and all the Church Fathers,’ he said in an interview in 1982. ‘Galileo was claiming that with an artificial device he knew things about the universe that the greatest minds of the past couldn’t have known.’
Yet today we have no problem with the idea that a device can see what we can’t; we happily rely on radio telescopes, X-ray imagers or particle accelerators and we believe in quarks, pulsars and DNA – all things quite undetectable by our naked senses. Just as Galileo’s telescope improved on the eye, ushering in a whole new world of discovery, Price looked forward to the day when computers would improve on the brain.
He couldn’t wait to dive into this new field of artificial intelligence, despite his health troubles after a heart attack in 1977. His family and friends urged him to slow down, but he couldn’t imagine a life without work, or travel. In September 1983, having just undergone surgery after a third heart attack, he flew to London to stay with his old friend Anthony Michaelis – the editor who had published his first piece on the Antikythera mechanism in Discovery more than 25 years before.
One evening during his stay, the two were due to have dinner with Michaelis’s girlfriend, Stefanie Maison. She planned to meet Michaelis during the day to get food for that night’s meal, but in the morning he called and in an odd voice told her not to buy too much. ‘Derek’s not coming,’ he said.
During the night, Price’s heart had given up for the last time. As the stars in their constellations shone high above London’s skyline, down below the light of a truly original mind was extinguished.
6
The Moon in a Box
The gods confound the man who first found out
How to distinguish hours! Confound them too,
Who in this place set up a sundial,
To cut and hack my days so wretchedly
Into small portions!
— MACCIUS PLAUTUS
JUDITH FIELD BURST trumphantly into Michael Wright’s cluttered office. It was lunchtime at the Science Museum in London and, as usual, Wright was eating sandwiches at his desk and catching up on his reading.
Wright looked after the museum’s engineering collection and Field was his opposite number, responsible for its astronomical instruments. She often used to come and sit in his office, drinking his tea (he made very good tea) and trying to outsmart him. Although he was meant to be responsible for contraptions from the time of the Industrial Revolution, Wright shared her interest in astronomical devices – the older the better – and they used to test each other’s knowledge with newly discovered objects or snippets of information.
But today was different, Wright could see that. Today she really had something special. She reached into a padded envelope that she had been carrying, pulled out four battered pieces of metal and placed them on the desk in front of him with a flourish. ‘What do you think of that?!’
The pieces were dark and worn, but otherwise in good condition. The largest was a flat, round disc, about twelve centimetres across, with a hole in the middle. It had Greek inscriptions on one face – including what looked like a list of city names and numbers, some graduated scales and a second hole offset from the centre, surrounded by a circle of seven intricately carved heads. The next piece was a disembodied metal arm that seemed to fit the central hole, with a hoop at one end for hanging the instrument vertically, rather like an astrolabe. And then the surprising bit. Two little axles, between them carrying four toothed wheels and a ratchet. The largest wheel, about four centimetres across, had two penny-sized circles cut out of it, and more writing around its edge.
As Wright turned the pieces over in his hands, Field related how she had come by them. A Lebanese man had walked in off Exhibition Road – straight off the street – and approached one of the uniformed security guards in the foyer. He said in broken English that he had something that might be of interest to the museum and pulled the metal bits out of his pocket as proof. Seeing the ancient lettering inscribed on the pieces, the guard figured he had better take the foreigner seriously, and called Dr Field.
Even though the instrument was in pieces, Wright knew that it was different from anything he had seen before. It was centuries old: the Greek inscriptions and the city name ‘Constantinople’ suggested straight away that it came from the Byzantine Empire – the Greek-speaking eastern territory created with Constantinople as its capital when the Roman Empire split into two in the third century AD. From the inscriptions on the main plate and the hanging arm he recognised it as a sundial. The remains of several similar instruments had been found from Hellenistic and Roman times. They were simple to use, although making them accur-ately involved some quite sophisticated knowledge of the movements of the Sun.
This type of sundial consisted of a disc with two scales round the edge, one for the latitude and one for the time of year. A bar called a gnomon fixed to the front of the flat disc by a pin in the centre, so you could rotate it, setting the angle depending on the latitude you were at. Then the arm slid around the edge of the disc to the appropriate time of year and the whole thing could be hung vertically, so that the bar was in line with the Sun. A stalk sticking out of the gnomon at one end cast a shadow, and you’d read the time off the hour lines engraved down the rest of the bar. The gnomon of this sundial was missing, but the latitude scale, month scale and list of cities and their latitudes, plus the hanging arm, were all similar to other ancient sundials that had been found.
But the gearwheels didn’t fit at all. Sundials measure shadows; they have no need for wheels. And apart from the strange and unique Antikythera mechanism, no clockwork was known until the Islamic world. Between these two extremes there was nothing; a huge gaping hole for more than a thousand years. By the time the technology appeared again, the Greek and Roman civilisations had fallen, the Islamic world had risen, and Arabic was the new language of science. But this instrument wasn’t Arabic. It was Greek.
Field had already made a rough count of the neat triangles.
‘Look,’ she said to Wright. ‘This one has 60 teeth!’ Field was a careful scholar, fiercely proud of her PhD; Wright didn’t often get to tell her she was wrong.
‘No,’ he said, after a glance at the inscriptions. ‘It has 59.’
The frown he knew was coming. ‘How can you possibly know that?’
‘It’s numbered in Greek around the edge.’ He traced his finger clockwise around the circumference of the wheel. ‘Here, see, the numbers run 1 to 30, and then 1 to 29.’
Soon afterwards, Wright’s supervisor, clock expert Rodney Law, came in for tea and the three chattered excitedly. By the time the pot was empty, one thing was clear. The 59-tooth wheel must relate to the movement of the Moon. On average, a synodic month (the time from one new Moon to the next) is about 29.5 days. So most ancient lunar calendars had months that alternated in length between 30 days and 29 days. If this gearwheel had turned by one tooth a day, then the numbers around the edge would have shown the day of the month.
The Lebanese collector had temporarily left the pieces with Field so that she could investigate the device. His intent soon became clear, however. He wanted to sell it the museum. This presented a problem. The museum trustees were reluctant to buy anything that didn’t have ‘provenance’, that is, an established paper trail showing where it had come from and who had owned it. There was no guarantee that items without provenance had not been stolen at some point, and the museum couldn’t be seen to support the black market in smuggled artefacts.
But all the Lebanese owner could or would say about the pieces was that he had bought them a few weeks earlier from a street trader in Beirut (and even this story he later retracted). It was June 1983 and Lebanon was in t
he midst of a bloody civil war. Much of Beirut had been destroyed and thousands of its citizens killed under a hail of shells from the Syrian and Israeli armies. The city was in chaos and the idea that every artefact leaving the country should be accompanied by a tidy file of paperwork was laughable.
In the end the museum trustees decided that the geared sundial was too important to pass up; they couldn’t risk it disappearing into a private collection before academics had a chance to study it. After checking with Interpol that no one had reported a similar device stolen, they handed over a hefty but as yet undisclosed sum, and the two curators had their sundial.
Judith Field worked on the origin and dating of the instrument. The list of place names and latitudes provided her main clues. Constantinople was at the head of the list, followed by towns and provinces including Alexandria, Antioch, Rhodes, Athens, Sicily and Rome.
Constantinople was founded in 324 AD when Emperor Constantine I renamed the city of Byzantium after himself, to serve as a second Rome at the gateway between the Mediterranean and the Black Sea. The resulting empire encompassed what are now Greece, Turkey, Syria, Lebanon and Israel, and northern Egypt. Its borders expanded and contracted over the centuries as it faced invasions from all sides – the Huns of Attila to the west, the Persians to the east, the Vandals to the south – and when the western half of the empire collapsed in the fifth century. By looking at the city names listed on the sundial and comparing the times at which they existed in the Byzantine Empire, Field worked out that the instrument must date to the late fifth or early sixth century, perhaps around 520 AD.
It became clear early on that the instrument was unique. As she searched the literature she realised that the sundial was the second oldest clockwork instrument known, preceded only by the Antikythera mechanism. There was no trace of anything similar after it until the geared calendar described by the Islamic scientist al-Biruni in the eleventh century. It was a heady feeling, to work on something that was so utterly isolated in the historical record.