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
Emerson effect that there must be two different photosystems involved in photosynthesis, one driven by short-wavelength light and one driven by long-wavelength (PS1 and PS2). They work together to enhance efficiency and convert the light energy to forms that can be absorbed by the plant. The light excites the chlorophyll molecules at the reaction centre and causes an increase in energy. As the molecule becomes less excited, its energy is transported through a chain of electron carriers to the next photosystem which does much the same thing and produces energy-carrying organic molecules. Emerson effect The Emerson effect is the increase in the