ABSTRACT
Energy is absorbed, reflected, and radiated by all plants and animals and most animals use some of the information carried by radiant energy to modify their subsequent behavior. Regardless of the behavior examined, the unceasing flow of radiant energy affects the behavioral system. Hence ethologists must renew or make their acquaintance with the physical properties of radiation. For the sake of those whose memories are rusty, I briefly survey some features of the physics of electromagnetic radiation.
