What Glows Under A Black Light?
There are a lot of natural phosphors in your teeth and fingernails and in manmade material, including television screens, some paints, fabric and plastics. The first thing most people notice when you switch on a black light is that some of their clothing glows. This is because most laundry detergents contain phosphors to make whites appear brighter in sunlight. Sunlight contains UV light that makes the whites glow brighter than white. Dark clothes don’t glow because the dark pigments absorb the UV light. Black lights also have some practical applications. Appraisers use them to detect forgeries of antiques. Many paints made today contain phosphors that will glow under a black light, while older paints do not contain phosphors. Repairmen use them to find invisible leaks in machinery by injecting a little fluorescent dye into the fuel supply and illuminate it with a black light. Law enforcement officers can use them to identify counterfeit money. Many countries include an invisible fluor
