1. The problem statement, all variables and given/known data What characteristic of light is needed to produce interference patterns? ( like the grainly pattern of light demonstrated in lab) 3. The attempt at a solution ok,, so i missed lab and did a makeup so I never saw what is being described. I am guessing that the grainy pattern of light means that it was destructive interference, but I am not sure. my guess would be that the only requirment is for the light to be Coherent Light, but I really dont know, can anyone point me in the right direction? thanks in advance.