Nature is reporting new results on the Antikythera Mechanism, the extraordinary ancient clock dredged up from the sea in 1901.
The mechanism, which is dated at approximately 100 BC, had 37 gears (of which 30 survive) and is an astronomical clock with complex epicyclic gearing. It was already known to have the Metonic cycle (comparing solar and lunar cycles), the Saros cycle (predicting eclipses) and a moon phase dial. New analysis of X-rays of the machine has confirmed that the Metonic cycle is marked in Corinthian months, thereby placing the device more precisely and providing evidence for early regulation of month lengths to regulate the calendar. In a special treat for the world's press, a previously unidentified dial has been shown to depict the four year Olympiad cycle. Obviously a dial that counts to four is not terribly scientifically interesting, but culturally it's quite exciting.
I find this device amazing; it's 1500 years older than other known clocks of similar capability. Imagine if it turned out that Charlemagne used an iPhone. Nature has a news article and a very interesting video as well the paper. (Thanks to Greer Gilman for tipping me off about this.)