Some questions have been haunting me about this experiment for some time. I'm mainly interested in what we observe from the perspective of the projection screen. First lets imagine that there is only one slit, and we are observing from the projection screen looking back at the slit with the laser behind it. We would have a direct view of the light source through the slit. It may be more effective to imagine "us" as a tiny camera to help with the scale of the small projection. Now observing from the same spot we change to the double slit. Now we don't have a direct view of the source light, or maybe we have a view of the left and right side of the source with the middle of the two slits blocking part of our view in which case we still see the source in part. Now if we move to the right or left into one of the dark areas on the projection screen I assume we don't see the source at all, and we don't see any light coming from the slits. Is this correct? Next we move farther to the right or left into then next lit area of the projection screen. What do we see now? We should see light coming from somewhere, presumably from the slits, but can we see the source? What if we move to the right or left extreme to the last light band on the projection screen, where do we see the light coming from and do we see the source of the light? It seems to me that observing from any lighted area on the projection screen should give us a clear view of the source, however unlikely that sounds, unless the light is reflecting off the side of the slits. Even then we should see the source in the reflection I would think. Sorry, I wasn't sure which section this question belongs in.