[SOLVED] waves and light (conceptual questions) hey, i have a few conceptual questions related to waves and light. 1. what is the ratio of thickness of crown glass and water that would contain the same number of wavelength of light? (index of refraction for glass = 1.52, and for water, it's 1.33) i have no idea what this question is asking and even less of an idea of what to do or say. so help in clarifying the question itself is greatly appreciated. 2. explain why light from the two headlights of a car does not produce an interference pattern? is this a trick question? wouldn't they produce a pattern? however, since the frequency and speed of light is so high and the wavelength so short, the pattern would not be visible? thanks for the help in advance.