I need help with this question: "Name the wave phenomenon that is responsible for the formation of regions of different color when white light is reflected from a thin film floating on water." In my handy-dandy high-school physics book, it says that "The different thickness of the gasoline is what causes the different regions of different color." This is not a phenomenon of light, but rather a phenomenon of the gasoline.... I know how thin films work, how some bounces off, experiences a phase change and then interferes deconstructively with light bouncing off the water while in the oil, but this does not really explain the different regions of different colors... So how do I accurately answer the question?