spontaneous emission

Spontaneous emission is the process by which an excited atom or molecule releases energy and emits a photon (light particle) without any external influence. This happens when the energy level of the atom drops back to a lower state naturally. In simple terms, it's like a light bulb that turns on by itself for a brief moment, shining light on its own. This phenomenon is fundamental to many areas of physics and is essential for technologies like lasers and fluorescent lights, where controlled light emission is crucial.