Almost all life depends on light for its survival. It is the ultimate basis for the food we eat (photosynthesis), and many organisms make use of it in basic sensory mechanisms for guiding their behaviour, be it through the complex process of vision, or by the relatively more simple photosens itivity of microorganis urthermore, light has profound implications for the field of medicine, both as a cause of disease (ie UV damage of DNA), and as a therapeutic agent (ie photodynamic therapy). These and other processes are the basis for the science of photobiolog which could be defined as the study...