Pretend we have a multi-slitted grating whose slits are infinitesimally small. We On each slit is a detector. If we shine (UPDATE) [strike]light[/strike] monochromatic light through the grating, what distribution pattern occurs on the screen past the grating? I understand the train of thought to a slight variation of the preceding scenario. In this alternate scenario, instead of multiple photons passing through the slits simultaneously ( i.e. light shining through), photons pass through the grating one at a time. Here, the photons won't give rise to the familiar distribution pattern shown in the image. While each passing photon would normally interfere with itself (we can't definitively know the photon's position, so we take its trajectory to be the combination of pathways through each slit -- and hence, it's as if mutliple photons were entering simultaneously), by putting a detector in place, we localize its position and destroy the intereference distribution. If this reasoning is true, I can't extend it to the scenario I want to resolve. In this scenario, while the interference pattern arising from the passage of any one photon is destroyed, does not the interference pattern arising from the passage of multiple, distinct photons remain? Hence, should not the pattern be shown?