Question

What causes the colors that are seen in a soap bubble? (circle the correct answer) (a) Additives in the soap reflect various colors (b) Chemicals in the soap absorb various colors (c) Light waves reflected from the top and bottom surfaces of the soap film can add up constructively for particular wavelengths (d) Dispersion due to differences in indexes of refraction in the soap (e) The interactions of the light with a thin boundary layer where the soap and the water have mixed irregularly

Answer 1

Light was reflected from the top and bottom surfaces of the soap film can add up constructively for particular wavelengths The thickness of the film - or rather, its thinness - determines whether iridescence is apparent. Light is reflected from both inner ad outer surface of the top of the soap bubble. When an incoming light strikes the putter surface of the bubble, part of the light ray is reflected immediately, while the other part is transmitted into the soap film. After reaching the inner surface of the film, this transmitted light ray is reflected back toward the outer surface. When it leaves the outer surface. When it leaves the bubble, it travels in the same direction as the ray that was immediately reflected and is, therefore, parallel to that ray.