As the classic film Citizen Kane opens, Charles Foster Kane lies in bed, alone in the dark clutching a snow globe. Inside the globe is a wooden cabin covered in white. After a minute, Kane whispers one of the most famous lines in film history—just one word—“Rosebud.” His hand goes limp, and the glass globe falls to the floor and shatters. It’s an iconic image—but it is one with some mystery. No one knows for sure who made Kane’s snow globe. In the absence of certainty, credit has been given…