Photoacoustic effect a rotating slotted wheel. He noticed that the resulting acoustic signal was dependent on the type of the material and correctly reasoned that the effect was caused by the absorbed light energy, which subsequently heats the sample. Later Bell showed that materials exposed to the non-visible (ultra-violet and infra-red) portions of the solar spectrum can also produce sounds and invented a device, which he called "spectrophone", to apply this effect for spectral identification of materials. Bell himself and later John Tyndall and Wilhelm Röntgen extended these experiments, demonstrating the same effect in liquids and gases. However, the results were too
Ultraviolet communication in butterflies the pterins absorb the ultraviolet light. Thus, butterflies are able to reflect ultraviolet light as a result of the organization and composition of their wing scales resulting in thin layer constructive interference and can absorb ultraviolet through the action of pterin pigments. Butterflies receive ultraviolet signals by utilizing a special photoreceptor pigment in the butterfly eye. The butterfly eye is similar to the average insect eye in that it is composed of numerous ommatidia. Each butterfly ommatidium contains nine photoreceptors with generally each photoreceptor utilizing a single visual pigment. A UV sensitive visual pigment is responsible for a butterfly’s ability