Divine mechanics in a garden shed
By Ed DaveyBBC News, London
A great little article from the BBC website.
The former Science Museum curator has created a working replica in his garden workshop at his Hammersmith home. ‘Mechanics of the heavens’
He believes it was designed to calculate planetary movements – using dazzling mathematics and a fiendish array of more than 30 cogs. ”People worried about the mechanics of the heavens,” explained Mr Wright. “They wanted to understand the sky. ”Many people had horoscopes cast – they would want to know where the sun and moon were when they were born. ”It could also have made a philosophical point. ‘I can use this mechanism to control the sky – is this how the divinities do it?’”
When Mr Wright began, the only major paper on the topic was by Yale University’s Derek Price.
Mr Price had suggested dates were entered into the device to calculate the information about the heavenly bodies. “At first glance it looked as if Price had solved all the problems,” recalls Mr Wright. “It was only when I looked again I saw his calculations didn’t really work.
“He was playing fast and loose with the data.” Derek Price cannot defend his work, having died in 1983. But Mr Wright concurred that early estimates by Mr Price’s team – that a major cog had 128 teeth – were incorrect. He claims to have proved a subsequent suggestion by Derek Price that it had 127 teeth instead.
A figure of 128 would mean the position of the moon became a few degrees out each year.
“It’s about 0.8% wrong,” he said. “That may not sound much, but if you multiply it up it causes huge problems.
“Mathematics done well has an elegance and clarity”
“It’s like the running of your watch – only a very small percentage error and you start missing trains.”
His research was given fresh impetus in 1983, with the discovery of the second oldest device with complicated gearing – a 6th century Byzantine sun dial.
Astonishingly, a man simply brought it in to the Science Museum off the street, claiming to have brought it from a street trader in Lebanon.
Mr Wright recalled: “After working on the sun dial I went back to the mechanism. ”I wanted to see whether I could get any further in solving the mystery.”
He was forced to work on it in his spare time – without a research team. He estimates he has spent more than 1,000 hours on the project, working at night and on weekends with Australian researcher Allan Bromley.
“We were sure we could find new data,” he said. By the turn of the millennium, they had made 700 radiographs of the mechanism, which were taken to Sydney.
But Mr Bromley developed terminal cancer. Wright recalls: “I knew Bromley was dying slowly, but he was in denial. ”I needed to fetch back our data, but I had to wait until he admitted he had not got long left. ”As soon as I got it I was able to check all the thoughts that had been festering in my head.”
Mr Wright was convinced the front of the device was a planetarium, with a hand for each of the five planets known to ancient Greek astronomers moving around a Zodiac circle. One of the biggest challenges the ancient designer faced was that the planets – which usually move from west to east in the night sky – stop occasionally and go back the other way.
To read more visit the bbc website - http://www.bbc.co.uk/news/uk-england-london-18448518
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