Since the Nebra Sky Disk (also known as the Nebra Sun Disk) of Germany emerged into public knowledge in about the year 2000, archaeologists and astronomers have put forward their theories about how it worked and what it meant to the ancient society that fabricated it.
I have assessed it from the standpoint of the scientific knowledge that was encoded into ancient European megalithic sites or early edifices, such as those of the Giza Plateau, and so will now give an account of how I, personally, would have used this artefact as a memory device, based upon easily decipherable, ancient mathematical methodologies.
The Nebra Sky Disk of Germany, recovered from a cache of illegally acquired artefacts in the possession of an antiquities dealer in 1999. The dimensions of the Nebra disk tell us how it functioned as a memory device for recalling principles of navigation and the lunisolar calendar system. Similar mathematical systems of calibration are built into the Ring of Brodgar in Scotland or the Southern Circle at Avebury Henge*, etc. The Nebra disk is thought to have been fabricated 3600-years ago.