The Antikythera Mechanism, an analog computer from the second century, was discovered in an ancient Grecian shipwreck in 1901. Although researchers could tell it was a computing machine when they found it, little else was known about it for a very long time.
Alexander Jones, an NYU historian, toldThe Washington Post, "In this very small volume of messed-up corroded metal you have packed in there enough knowledge to fill several books telling us about ancient technology, ancient science and the way these interacted with the broader culture of the time."
In 1959, physicist Derek de Solla Price claimed that he could tell from this gear alone that the computer was meant to calculate "astronomical events." For a while, this was all we knew...until very recently.
The secret to decoding this machine turned out to be this tablet made up of 3,500 Greek characters that were meant to describe the functions of the machine. For the longest time the tablet was nearly unreadable, having been damaged by the waters of the shipwreck in which it was found.
This is predicted to have been the original look of the machine. It mostly likely had three clock-like interfaces, which were meant to predict the turning of the (then) five known planets, as well as the Olympic games (amongst other sports events) and the date of the next eclipse.
It's truly a unique machine, and our knowledge of it is not even complete!
There are 20 more gears left to salvage that could hint at further uses and technological intricacies of the machine, and it'll take further discoveries to truly figure out this ancient computer's many subtleties. It's eerie just how close the ancient Greeks came to the technology we have today.