The Antikythera mechanism is an absolutely high-technology astronomical system that was discovered onboard a greek shipwreck. Dated between 100 and 200BC it was a millenium in advance compared to the usual scale of technology development.
In this post ‘An Ancient Device Too Advanced to Be Real Gives Up Its Secrets at Last‘, detailed explanations are given on the device and the process of finding out about its usage.
The sophistication of the device has led some to claim it is a hoax. On the other hand it is reasonably possible that the secret of this science got lost when the Romans dominated Greece. At the end of the day only those who win write history.
Beyond the marvelous story of this device, its discovery and the discovery of its function, this gives to think about the fact that it is always possible to regress as a society and forget about great discoveries, plunging the world a millenium back.
Of course it might be less probable nowadays because of the multiple copies of our knowledge (compared to the unique scrolls of the Alexandrian Library), but this event demonstrates the possibility of such occurrence. We always need to be wary that it might occur again.
