The Antikythera Mechanism: The Worlds Oldest Computer

The Antikythera Mechanism: The Worlds Oldest Computer

Have you ever wondered how ancient people kept track of the movements of the stars and planets? How did they know when to expect eclipses, or when to celebrate the Olympic Games? The answer may lie in a mysterious device that was discovered more than a century ago in a shipwreck near the Greek island of Antikythera.

The Antikythera Mechanism is an ancient Greek device that was used to calculate and display information about astronomical phenomena. It was an intricate device made of bronze and wood, with dozens of gears and cogs that worked together to perform complex calculations. The device could also perform basic arithmetic like addition, subtraction, multiplication, and division. The Antikythera Mechanism is sometimes called the world's oldest computer for its ability to perform astronomical calculations.

The device was discovered by sponge divers off the coast of Antikythera in 1901. It was found as one lump, later separated into three main fragments which are now divided into 82 separate fragments after conservation efforts. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is approximately 13 centimetres (5.1 in) in diameter and originally had 223 teeth.

The Antikythera Mechanism was fabricated out of bronze sheet, and originally it would have been in a case about the size of a shoebox. The doors of the case and the faces of the mechanism are covered with Greek inscriptions, enough of which survive to indicate clearly much of the device's astronomical, or calendrical, purpose. It is believed that a hand-turned shaft (now lost) was connected by a crown gear to the main gear wheel, which drove the further gear trains, with each revolution of the main gear wheel corresponding to one solar year.

On the front of the mechanism is a large dial with pointers for showing the position of the Sun and the Moon in the zodiac and a half-silvered ball for displaying lunar phases. The drive train for the lunar position is extremely sophisticated, involving epicyclic gearing and a slot-and-pin mechanism to mimic subtle variations (known as the “first anomaly”) in the Moon’s motion across the sky. This motion was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and it is speculated he may have been consulted in the machine's construction.

Two large dials are on the back of the mechanism. The large upper dial has a five-turn spiral slot with a moving pointer to show the 235 lunations, or synodic months, in the Metonic cycle. This cycle is almost exactly 19 years long and is useful in regulating calendars. A subsidiary four-year dial showed when the various Panhellenic games should take place, including the ancient Olympic Games. The large lower dial has a four-turn spiral with symbols to show months in which there was a likelihood of a solar or lunar eclipse, based on the 18.2-year saros eclipse cycle.

The Antikythera Mechanism was an incredibly sophisticated device that was far ahead of its time. Its manufacture is currently dated to 100 BC, give or take 30 years . It must have been constructed before the shipwreck, which has been dated by multiple lines of evidence to approximately 70–60 BC . In 2022 researchers proposed its initial calibration date, not its construction date, could have been 23 December 178 BC. Other experts propose 204 BC as a more likely calibration date. Machines with similar complexity did not appear again till the astronomical clocks of Richard of Wallingford and Giovanni de’Dondi in the 14th century.

The Antikythera Mechanism is now widely regarded as one of the most remarkable achievements of ancient science and technology. It reveals that ancient Greeks had advanced knowledge of astronomy and mathematics, and that they were able to construct intricate devices that could model and predict celestial phenomena with remarkable accuracy. The Antikythera Mechanism is now on display in the National Archaeological Museum in Athens, where it attracts thousands of visitors every year. The device has also inspired many researchers and enthusiasts to study its secrets and try to replicate its functions. Several working models of the mechanism have been built, using modern materials and techniques, to demonstrate how it might have operated in ancient times. Some of these models are also exhibited in museums around the world, such as the Smithsonian Institution in Washington, D.C., and the Science Museum in London.

The Antikythera Mechanism remains a fascinating and mysterious object that challenges our understanding of ancient history and culture. It shows that ancient Greeks were not only philosophers and artists, but also engineers and inventors who could create sophisticated machines that could rival those of later centuries. The Antikythera Mechanism is a testament to the human curiosity and ingenuity that has driven scientific discovery and innovation throughout history.

In conclusion, the Antikythera Mechanism is a remarkable device that reveals the advanced knowledge and skills of ancient Greek scientists and engineers. It is a unique example of an ancient analogue computer that could perform complex astronomical calculations and predictions. It is also a valuable source of information about the ancient Greek culture and worldview, as it reflects their interest in astronomy, mathematics, and sports. The Antikythera Mechanism is a treasure of ancient science and technology that deserves to be studied and appreciated by modern generations.
To Top