Hi all. I am just trying to get my head around the double slit experiment(I know im not the first) I am stuck trying to understand the initial state of the individual photons when they are being fired sequentially.(their direction and place of origin)(where the quantum confusion sets in) An analogy often used is to imagine a gun shooting through the slits(bullets representing photons)and the suprise one would get if they created interference bands despite being fired sequentially. The thing with this is that the gun would have an initial direction which could be used to infer which slit each bullet went through. Is the photon emitter not the same? light can be directed just like a machine gun(lasers for example)so how in this experiment is the emitter set up so that the individual photons are aimed at the two slits? how are the photons emitted such that we cannot infer their initial trajectory? Thanks, Dan.