Does the (assumption of) ubiquitousness of EM fields explain single particle interference well/better? Below is a rough logic, however it maybe need modifications. The double slit or the mach-zehnder or any object changes the configuration of time-space and EM fields. The photon may not know in advance what it will encounter in it's path however the EM fields might change instantaneously to reflect any changes in the configuration. Thus the photon may appear to "know" things in advance, however it is due to the change in the EM field that reflect the change in obstacles in the path of the photon. The photon may appear to take the shortest path because of the way the configuration of time-space (and EM fields) is.