The Antikythera Mechanism Is a 2,000-Year-Old Computer

115 years ago, divers found a hunk of bronze off a Greek island. It changed our understanding of human history.

One hundred fifteen years ago, an archeologist was sifting through objects found in the wreck of a 2,000-year-old vessel off the Greek island Antikythera. Among the wreck’s treasures — beautiful vases and pots, jewelry, a bronze statue of an ancient philosopher — was the most peculiar thing: a series of brass gears and dials mounted in a case the size of a mantel clock. Archeologists dubbed the instrument the Antikythera mechanism. The genius — and mystery — of this piece of ancient Greek technology, arguably the world’s first computer, is why Google is highlighting it today in a Google Doodle.

At first glance, the piece of brass found near the wreck looks like something you might find in a junkyard or hanging on the wall of a maritime-themed dive bar. What remains of the mechanism is a set of rusted brass gears sandwiched into a rotting wooden box. But if you look into the machine, you see evidence of at least two dozen gears, laid neatly on top of one another, calibrated with the precision of a master-crafted Swiss watch. This was a level of technology that archeologists would usually date to the 16th century, not well before the first. But a mystery remained: What was this contraption used for?

To archeologists, it was immediately apparent that the mechanism was some sort of clock, calendar, or calculating device. But they had no idea what it was for. For decades, they debated: Was the Antikythera a toy model of the planets? Or perhaps it was an early astrolabe (a device to calculate latitude)? In 1959, Princeton science historian Derek J. de Solla Price provided the most thorough scientific analysis of the contraption to date. After a careful study of the gears, he deduced that the mechanism was used to predict the position of the planets and stars in the sky depending on the calendar month. A main gear would move to represent the calendar year, and would, in turn, move many separate smaller gears to represent the motions of the planets, sun, and moon...