By Jo Marchant

In autumn 1900, Captain Dimitrios Kontos and his crew of sponge divers were sailing home from their summer diving grounds off Tunisia. They were heading for the island of Symi in the eastern Mediterranean, but were blown off course by a storm and sheltered by a barren islet called Antikythera.

After the storm’s retreat, they discovered on the seabed a spectacular shipwreck . A Roman ship from the first century BC, it was carrying stolen Greek treasures, including statues, armour and jewellery.

The divers salvaged the wreck for the Greek government, and the artefacts were taken to the National Archaeological Museum in Athens. Among the haul was a lump of rock no one unnoticed at first. Then it cracked open, revealing gearwheels, inscriptions, and dials. This “Antikythera mechanism” turned out to be the most stunning scientific artefact we have from antiquity. Nothing close to its complexity appears again for more than a thousand years.

For much of the last century this mysterious machine was largely ignored by mainstream historians. But thanks to a succession of men who devoted their lives to decoding the device (see video), its secrets have finally been revealed. It was a clockwork computer for calculating the varying movements of the Sun, Moon and planets, and even predicting future eclipses.

I first heard about the Antikythera mechanism in summer 2006. A paper revealing its workings was due to appear in the science journal Nature, where I was on staff as an editor. The story grabbed me immediately, and I travelled to Athens to see the remains of the mechanism, and meet those who had studied it.

In my new book, Decoding the Heavens, I describe the 100-year quest to understand the device. But along the way I became intrigued by the bigger tale, of where this unexpected technology came from and where it went for a thousand years. I was stunned to discover that the expertise embodied in the device was not lost. Traces were passed to the Islamic world, and back to Medieval Europe, where this ancient knowledge triggered much of the technology that shapes our lives today.

Jo Marchant in the author of Decoding the Heavens: A 2,000-Year-Old Computer and the Century-Long Search to Discover Its Secrets, published by Da Capo Press

By Jo Marchant

In autumn 1900, Captain Dimitrios Kontos and his crew of sponge divers were sailing home from their summer diving grounds off Tunisia. They were heading for the island of Symi in the eastern Mediterranean, but were blown off course by a storm and sheltered by a barren islet called Antikythera.

After the storm’s retreat, they discovered on the seabed a spectacular shipwreck . A Roman ship from the first century BC, it was carrying stolen Greek treasures, including statues, armour and jewellery.

The divers salvaged the wreck for the Greek government, and the artefacts were taken to the National Archaeological Museum in Athens. Among the haul was a lump of rock no one unnoticed at first. Then it cracked open, revealing gearwheels, inscriptions, and dials. This “Antikythera mechanism” turned out to be the most stunning scientific artefact we have from antiquity. Nothing close to its complexity appears again for more than a thousand years.

For much of the last century this mysterious machine was largely ignored by mainstream historians. But thanks to a succession of men who devoted their lives to decoding the device (see video), its secrets have finally been revealed. It was a clockwork computer for calculating the varying movements of the Sun, Moon and planets, and even predicting future eclipses.

I first heard about the Antikythera mechanism in summer 2006. A paper revealing its workings was due to appear in the science journal Nature, where I was on staff as an editor. The story grabbed me immediately, and I travelled to Athens to see the remains of the mechanism, and meet those who had studied it.

In my new book, Decoding the Heavens, I describe the 100-year quest to understand the device. But along the way I became intrigued by the bigger tale, of where this unexpected technology came from and where it went for a thousand years. I was stunned to discover that the expertise embodied in the device was not lost. Traces were passed to the Islamic world, and back to Medieval Europe, where this ancient knowledge triggered much of the technology that shapes our lives today.

Jo Marchant in the author of Decoding the Heavens: A 2,000-Year-Old Computer and the Century-Long Search to Discover Its Secrets, published by Da Capo Press