Every second of every day, the sun emits wave after wave of radiation hurling toward our planet. Even though we can’t see most of this radiation with the naked eye, scientists have learned how to use these invisible waves to our advantage. From infrared systems to guide missiles to ultraviolet-sterilized laboratory work areas, visible light’s closest neighbors on the electromagnetic spectrum have a lot to offer us. This book explores the science and discovery of infrared and ultraviolet radiation, as well as the ingenious ways scientists and engineers have used them, including in common household devices such as remote controls for our televisions and in cutting-edge medical treatments.