I think that the splitting of the photon’s path is pretty much entirely a human construction—the smaller the components it is split into, the more accurate the calculation, and each partition is itself an approximation that can be refined by splitting it up further in exactly the same manner. Essentially, it’s a shortcut to doing a path integral over the entire range down to the planck level. Maybe… I’m not sure!
Very late response:
I think that the splitting of the photon’s path is pretty much entirely a human construction—the smaller the components it is split into, the more accurate the calculation, and each partition is itself an approximation that can be refined by splitting it up further in exactly the same manner. Essentially, it’s a shortcut to doing a path integral over the entire range down to the planck level. Maybe… I’m not sure!