In 1900, Elias Stadiatos was diving near the Greek island of Antikythera searching for sea sponges when he encountered what appeared to be a pile of dead, naked women on the ocean floor. Distressed, he surfaced and informed others of his find, and a closer inspection was made of the area. Elias’s “dead women” were in fact ancient statues lying in the midst of a Greek ship which had sunk there around 87 BC. The statues had been part of its luxurious cargo, which also included jewelry, pottery, fine furniture, and wine. The sponge divers brought up as many interesting objects as they could manage, producing an orgy of artifacts.

About two years later, on May 17, 1902, an archaeologist named Spyridon Stais was examining one of the pieces he found inside a wooden box about the size of a shoebox⁠—a chunk of green rock which had a gear wheel embedded within it. This gear was the first evidence of an ancient Greek computer which would come to be known as the Antikythera mechanism. Technology in the early 1900s did not allow for peering into the rock further, but it was clear that this was the oldest gear-driven mechanism ever to be discovered.

It would be almost sixty years before a science historian at Yale University named Derek J. de Solla Price suggested that this might be one of the celestial-body tracking instruments described in several ancient Greek texts. Experts balked, as some are wont to do, because it was generally thought that such stories were fictional, and that the ancient Greeks lacked the practical skills and technology to construct such an intricate computing mechanism. However, based on gamma ray scans in the early seventies, along with more recent high-resolution X-ray photographs by scientists at Yale, modern historians are fairly certain the device was used to accurately measure relative movements of astronomical bodies⁠—the sun, moon, planets, and stars⁠—a fairly complex task.

Subsequent modeling, both physical and digital, has further supported the theory that the Antikythera Mechanism is, in effect, a nearly-2,000-year-old astronomical computer.