In 1900, Greek sponge divers discovered a shipwreck off the Greek island of Antikythera. The artifacts they came back up with included money, statues, pottery, and various other works of art and craft, as well as a curious lump of bronze and wood that turned out to be by far the most important item onboard. When an archaeologist named Valerios Stais took a look at it two years later, he noticed that the lump had a gear in it.