Hi; I'm new to the forum and I hope my question is not out of line. Has anyone ever done double slit experiments with macroscopic objects such as grains of sand, for instance. It seems to me that with appropriately sized and spaced slits in a mask of appropriate thickness, one should be able to reproduce, in the detector (a gel for instance) a pattern that would resemble an interference pattern. The size of the grains of sand combined with the correct spacing and size of the slits in a mask of appropriate thickness should illustrate that some paths to the detector are possible while others are not, without the necessity of resorting to wave functions to describe the paths. I would guess that as the separation between the slits, the size of the slits and the thickness of the mask were altered, so too would the "interference" pattern change in the detector.