Consider this: Two antennas are set up in a vacuum. They both radiate electromagnetic waves of the exact same frequency, and an interference pattern can be observed on a screen placed some distance away. Now suppose the emission density was reduced (in both antennas) to one photon at a time, such that when either of the antennas is firing a photon, the other one isn't until the first photon reaches the screen. We don't know which antenna is firing the photon at any certain time. Assuming the coherence time of the antennas is large enough to allow 5 (or any other random number more than 1) of these alternating photon emissions. Will interference occur? can we even control the photon emission in the way I described? If interference occurs, will it also occur if we set the antennas to randomly shutdown, one at a time, between single photon emissions?