Reading passage Go to the questions
The machine from the sea
A In 1900, a group of sponge divers sheltering from a storm near the small Greek island of Antikythera discovered the wreck of an ancient ship on the seabed. Over the following months, divers recovered bronze and marble statues, glassware and pottery from the wreck, which had sunk in the first century BC. Among the finds were several shapeless lumps of corroded bronze and wood, which attracted little attention at first.
B In 1902, the archaeologist Valerios Stais noticed that one of the lumps contained a gear wheel. This was astonishing: geared machinery of such precision was not thought to have existed in the ancient world. Some scholars suggested that the object must be a later item that had somehow ended up on the wreck; others thought it might be an astrolabe, a simpler instrument for observing the stars. For half a century, the fragments remained largely a curiosity.
C The first systematic study was carried out by Derek de Solla Price, a British-born physicist and historian of science. Beginning in the 1950s, and later using X-ray images made with the Greek radiologist Charalampos Karakalos, Price was able to see gears hidden inside the corroded fragments and count their teeth. In 1974 he published Gears from the Greeks, in which he argued that the device was an astronomical calculator, a kind of mechanical model of the heavens. His reconstruction contained errors, but his central claim has stood the test of time.
D A major breakthrough came in 2005, when an international team, the Antikythera Mechanism Research Project, brought powerful new imaging equipment to the National Archaeological Museum in Athens. High-resolution X-ray computed tomography allowed researchers to examine the inside of the fragments layer by layer, while a separate technique, which photographs a surface under light from many different angles, revealed faint inscriptions on the outer surfaces. Thousands of letters that had been unreadable for two thousand years could now be studied.
E The results showed that the mechanism, operated by turning a handle, could display the positions of the Sun and Moon in the sky, the phases of the Moon, and the dates of future eclipses. A dial on the back even tracked the four-year cycle of the great athletic games of ancient Greece, including the Olympics. Inscriptions refer to the planets as well, and most researchers believe the device originally showed their positions too, although the gears that would have done this have not survived. In total, around thirty bronze gears remain.
F Who built the device, and why, is still uncertain. It was probably made in the second or first century BC, and the knowledge it contains draws on Babylonian astronomy as well as Greek mathematics. Some historians have linked it to workshops on the island of Rhodes, a centre of astronomy at the time, but there is no firm evidence. It may have been a teaching instrument, a display piece for a wealthy owner, or both.
G What is clear is that nothing of comparable complexity is known from anywhere in the world for more than a thousand years afterwards. Geared astronomical clocks did not appear in Europe until the medieval period. The mechanism is therefore a reminder that the history of technology is not a smooth upward line: knowledge can be developed, lost, and only rediscovered centuries later.
