You find that an oil slick floating on water when viewed from above has many different colors reflecting off the surface. The index of refraction of water is 1.33 and the index of refraction of the oil is 1.2. At paint (c) the wavelength of the reflected light is 490 nm for normal incidence. What is the minimum thickness of the oil at this location? Your solution MUST include a completely annotated diagram explaining the interference effect that results in this measurement including any relevant phase shifts, which boundaries play a role etc