* Artificial light is a phenomenon, not a substance: It's the result of various processes that generate electromagnetic radiation in the visible spectrum.
* Different sources, different processes: Artificial light can be produced by many methods, each with its own chemical and physical basis:
* Incandescent bulbs: Heat a filament until it glows (primarily tungsten).
* Fluorescent bulbs: Electricity excites mercury vapor, which releases ultraviolet light that then excites a phosphor coating to produce visible light.
* LEDs (Light-Emitting Diodes): Electrons move through a semiconductor material, releasing photons of light.
* Lasers: Stimulated emission of light from excited atoms or molecules.
So, rather than a single formula, we describe artificial light based on its source and the process involved in producing it.
