Why does the very thin region at the top of a soap bubblesometimes appear black?
1. It is too thin to reflect light. 2. Inverted light waves andnon-inverted light waves reflecting from the two surfaces canceleach other. 3. Both reflected waves are inverted or else neither isinverted. 4. No light passes through them.5. The rest of the filmcreates a shadow that obscures the colors we would otherwisesee.
