The Human Cosmos. Jo Marchant

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СКАЧАТЬ with a shrine to Marduk, again decorated with vibrant blue bricks. The tower was called ‘Etemenanki’ – ‘House of the Foundation of Heaven and the Underworld’ – and was full of mythological and cosmological significance. There’s a clear resonance with the Ark in Gilgamesh: both were divided into seven storeys and covered an area of one ikû, around 90 metres squared.

      This structure was reflected in the sky too. Ikû is what the Babylonians called the great square of our modern constellation Pegasus, points out Andrew George, who studies Babylonian culture at SOAS in London. Etemenanki was ‘a structure founded in both levels of the universe at once – one whose hugeness . . . transcends the gap between them’. It was the home of Marduk and the ultimate source of Babylon’s – and the king’s – security and power. In the Bible, for which Nebuchadnezzar is the wicked king who sacked Jerusalem and exiled the Jews, it became the Tower of Babel.

      Much of this was confirmed by the German archaeologists who conducted the first scientific excavations of Babylon from 1899. By the time they arrived, however, there were hardly any clay tablets left. These had been removed by Rassam, who dug through large areas of the city in the 1870s, and by local people digging illegally, who sold them to antiquities dealers.³ Thousands of tablets were ultimately bought by the British Museum, where they caught the attention of a trainee priest called Johann Strassmaier.

      Born in rural Bavaria in 1846, Strassmaier joined the Jesuits aged nineteen. A few years later, Bavaria became part of the newly united Imperial Germany, and the Jesuits were targeted by Otto von Bismarck, the country’s first chancellor. Bismarck saw their deference to the Pope as a challenge to his secular government, and in 1872 he banned them from teaching or working in Germany. Strassmaier emigrated to a Jesuit college in England, where he specialised in studying languages. He was ordained in 1876, and two years later moved to a Jesuit-owned house in Mayfair, London, walking distance from the British Museum.

      But he couldn’t escape the tensions between secular and religious worldviews; scholars in London were clashing over a series of revolutionary scientific discoveries that appeared to undermine ideas in the Bible. In 1859, Charles Darwin had set out his theory of evolution by natural selection, challenging the biblical account of how species were created. Then, in 1872 came the Flood Tablet from Nineveh, causing some to claim that this crucial episode in the Old Testament was simply a reworked Mesopotamian myth. With a strong tradition of academic scholarship and an interest in defending the accuracy of the Bible, the Jesuits wanted to be part of the debate over the finds pouring out of Mesopotamia. Strassmaier was assigned to study cuneiform tablets at the British Museum, and set about teaching himself Akkadian.

      Strassmaier was a small man, affable and kind, with a round face and ‘a nose that cannot be easily forgotten’. He originally planned to write a book on the history of the Semitic languages, but was dismayed by the vast number of tablets that lay unread and eroding in the museum’s stores. ‘How can a history of these languages be written,’ he remarked to a colleague, ‘whilst 60,000 cuneiform tablets remain uncopied and untranslated?’ So he embarked on a schedule that he kept for almost twenty years, arriving at the museum’s student room at 10 o’clock each morning and working through until 4 o’clock without any breaks. In that time, he copied the symbols from thousands of tablets, producing neat ink drawings on A4 sheets of paper folded in half. Whereas curator George Smith had read texts from Nineveh, Strassmaier focused on the tablets coming out of Babylon. They mostly dated from the time after Nebuchadnezzar, between the fifth to the first centuries BC, during which the city fell to the Persians and then to the Greeks.

      At first, Strassmaier diligently copied economic records such as bills and contracts, the texts most scholars thought too boring to bother with. But he soon noticed large numbers of tablets with few words, just numbers. What text there was – planet names, for example – hinted that the subject matter was astronomical. The numbers made no sense to Strassmaier, so in 1880 he asked fellow priest Joseph Epping, who had been his maths teacher in Germany and was now based in the Netherlands, for help. Epping was reluctant at first. He couldn’t read cuneiform, and though astronomy was ‘not totally alien’ to him, he wrote later, the task seemed too daunting: ‘I did not believe to be such a computational artist, that I could solve an equation, that had so large a number of unknowns, and so little a number of knowns.’ But Strassmaier handed over his drawings, and eventually Epping started wrestling with the mystery numbers, looking for patterns that might reveal their meaning.

      He started on a fragment with seven columns of numbers that cycled up and down. It took him months to make sense of it. As Epping worked, other cuneiform scholars were just getting an inkling of the Babylonians’ facility with mathematics, using a number system based on 60 (which we reprise every time we write a time in hours, minutes and seconds, or an angle in degrees) to tackle algebra, fractions and even quadratic equations. But still, what he found was a bolt from the blue.

      In 1881, Epping announced that the numbers represent steps in a calculation of the dates and times of a series of new moons, covering the years 104–101 BC. Another text included a similar table for the positions of Venus and Jupiter. The calculations were impressively accurate, even taking account of subtle variations in the apparent speed of the moon and planets through the sky (caused by their elliptical orbits). Although Greek and Roman writers often refer to the Babylonians’ astral wisdom, no one had expected that alongside their magical omens and prayers, the scribes of Marduk developed a new type of mathematical knowledge about the cosmos. Epping called his discovery a ‘precious historical treasure’. The priests really could foretell the future, using accurate formulas to predict celestial events decades in advance.

      As more tablets have been catalogued and read, historians can now trace a gradual progression in the priests’ abilities. Enuma Anu Enlil, the handbook found in Ashurbanipal’s library, contains a series of omens that list risings and settings of Venus,⁴ dated to the second millennium BC. Some of the numbers seem to be based on observations but others have been corrected to fit a pattern. The scheme isn’t very accurate, but shows that the Babylonians were already trying to describe the heavens using mathematical rules. The later tablets from Babylon (and also some written by temple priests in the city of Uruk) show that from around the eighth century BC, the priests started keeping more systematic records, watching the sky each night and writing down everything they saw. These ‘astronomical diaries’ also include notable terrestrial events, from the level of the Euphrates river or prices of wool, barley and sesame, to reports of monstrous births.

      Within a few generations, the scribes started to notice ‘great cycles’: periods after which particular types of event roughly repeat. Ishtar repeats her wandering path after 8 years, for example, and Marduk after 71 years, while eclipses follow an 18-year cycle. By checking what had happened during previous great cycles they could monitor signs in the sky without even needing to watch.

      Then, around 400 BC, came another jump in sophistication. The priests invented the zodiac by dividing the ecliptic (the path through the sky followed by the sun, moon and planets) into 12 equal segments of 30 degrees, naming each one after a nearby constellation, such as ‘Bull of Heaven’ (now Taurus) and ‘Great Twins’ (Gemini). This gave them an accurate system for recording and computing events in the sky. Shortly afterwards, they came up with arithmetic methods to describe the repeating cycles recorded in their diaries.

      These were based on finding ‘period relations’, which express different astronomical cycles in terms of one another. For example, each planet moves around the zodiac at a characteristic speed (its ‘tropical cycle’), but superimposed on this is a zigzag pattern in which it sometimes stops or temporarily reverses direction (its ‘synodic cycle’).⁵ Venus can be described pretty well by a very simple relation – in eight years, it goes through eight tropical cycles and (almost exactly) five synodic cycles – while others are far more complex. The final step was to incorporate the subtle variations in speed that occur throughout these cycles, by adding or subtracting different values over time according to set rules.⁶

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