Yes, the two moons are analogous to slits, in that they're point-like objects interacting with a large, coherent wavefront. The "slits" will be identified (acco

Yes, the two moons are analogous to slits, in that they're point-like objects interacting with a large, coherent wavefront. The "slits" will be identified (according to the proposal) because the gravitationally distorted light path also introduces a time delay, such that it takes longer to pass by one moon than it does the other. This means the signal will be split into two pulses, one arriving before the other. You detect a pulse from moon 1, then another pulse from moon 2. You know which moon any particular photon passed by because you can look at when it arrived. The experimenter seems to be asking "can we observe interference between the two pulses even though we know which 'slit' the photon passed through because mumble mumble mumble gravity". But there is no way for interference to happen, gravity or otherwise. Those pulses do not overlap (as far as I can tell) by the design of the experiment, because they are not happening at the same time. In other words, if pulse 1 has wavefunction psi_1(x,t) and pulse 2 has wavefunction psi_2(x,t), then <psi_1|psi_2> is nearly zero-- there is no overlap. There is no `t` where psi_1 and psi_2 have appreciable magnitude (and where they do, we would expect to see interference anyway, and we would no longer be able to tell the origin of the photon). If there is no overlap, there is no interference, whether you are measuring planets or slits. So I don't see what we could possibly learn from this experiment, or where the experiment designer expects to see interference; it is all but guaranteed to deliver results that are exactly in line with a tabletop interference experiment.