If I had two coherent point sources of visible light, above a piece of paper maybe, would you expect to see an interference pattern?
Then, if one had a slight shift in phase, would you then expect to see a different pattern, but still an interference pattern?
Then, say you had a strip of point sources with constant spacing and the ability to control the phase of each independently, could you sustainably create a point where each wave superimpose to create a bright spot?
Since the wavelength of visible light is so small I would expect the interference pattern to be practically invisible, but theoretically would there be one?
Would it be possible with enough point sources to create a point so bright that it would be visible to the naked eye?