The earliest known depiction of a ghost dates back to a 3,500-year-old Babylonian tablet that has been among the holdings of the British Museum since the 19th century. Though it has never been publicly exhibited, and it’s small enough to fit in your hand, the clay stone contains detailed directions on how to get rid of ghosts. Myriad cultures around the world revel in describing ghosts, ranging from the Navajo’s “Chindi,” a spirit created