fluorescences

Fluorescence is a type of photoluminescence, a process where a substance absorbs light or other electromagnetic radiation and then re-emits it at a longer wavelength. This emission of light occurs very shortly after the absorption, typically within nanoseconds. The process involves the excitation of electrons within the molecules of the substance to higher energy levels. When these electrons return to their ground state, they release energy in the form of photons, which we perceive as light. The color of the emitted light is characteristic of the fluorescent substance and depends on its chemical structure. Fluorescence is distinct from phosphorescence, where the emission of light is delayed for a longer period. Common examples of fluorescent materials include certain minerals, organic dyes, and biological molecules like chlorophyll. Fluorescence has numerous applications in science and technology, such as in fluorescent microscopy for visualizing biological structures, in fluorescent tagging for detecting specific molecules, and in fluorescent lamps for lighting. The phenomenon is also observed in everyday items like highlighters and security markings on currency.