diffused light is projected onto a supported thin film in the form of a truncated sphere . the device has a light source disposed at the bottom end of a housing constructed of a light shielding material , and a diffuser plate at the top end of the housing to emit light into the truncated sphere . in one embodiment the plate carries a layer of liquid soap from which a bubble is blown . the housing may also carry a clear glass dome over its top end adjacent which the thin film is supported . decorative interference patterns of luxuriant colors result .