Hello. I just have some questions about Young's Double-Slit experiment and light wave interference. I think i got the right answers, but i just want to know if i grasped the concept correctly. 1-If we perform young's double slit experiment under water, how would the interference pattern be affected? -well, since this is performed under water, we would be dealing with water waves, so they can't really diffract once they pass the slits, right? Because they're mechanical waves and lack that property, therefore there would not be any intereference pattern on the screen. 2- As a soap bubble evaporates, it appears black just before it breaks. Explain this phenomenon in terms of the phase changes that occur on reflection from the two surfaces of the soap film. -i think it turns black before it breaks because at that point, the beams interfered destructively (which explains the darkness). but i'm not really sure...it turns black where the film of the soap bubble is thinnest since color also depends on the thickness of film. 3-A certain oil film on water appears brightest at the outer region, where it is the thinnest. From this information, what can you say about the index of refraction of oil relative to that of water? -well, since it is brightest at the outer region, constructive interference occurs there, so would the index of refraction of oil be lower than that of water, since if it were larger, the two reflections would be out of phase and interfere destructively. Did i get the right concept? Please, I need to move on with my assignment, but I can't do so unless I know whether or not I truly understand this. Thank you very much for your time.