Black light, or ultraviolet (UV) light, illuminates white objects due to the properties of phosphors used in fluorescent lamps. These phosphors absorb UV light and re-emit it as visible light, which is why white objects appear to glow. The process involves electrons in the phosphor atoms gaining energy and then releasing it as visible photons. This phenomenon is similar to how red light interacts with red and white objects, highlighting the specific absorption and emission characteristics of different wavelengths.
PREREQUISITESStudents of physics, lighting designers, and anyone interested in the science of light and color perception.
Um, if that were true, the object would only emit UV. In fact, it is emitting a different wavelength than that which it is absorbing.moose said:I believe what you are asking is the same type of question as:
"Why does red light only light up red and white things?"
I think it's the same answer too ;)
Yes, but read thisDaveC426913 said:Um, if that were true, the object would only emit UV. In fact, it is emitting a different wavelength than that which it is absorbing.
howstuffworks said:UV light waves are too short for us to see -- they are completely invisible -- so fluorescent lamps have to convert this energy into visible light. They do this with a phosphor coating around the outside of the tube.
Phosphors are substances that give off light -- or fluoresce -- when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons jumps to a higher energy level, causing the atom to vibrate and create heat. When the electron falls back to its normal level, it releases energy in the form of another photon. This photon has less energy than the original photon, because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum