Physics
Spontaneous Emission of Radiation
Quick fact
An atom in an excited state typically stays there for only about 10⁻⁸ seconds before spontaneously emitting a photon—a blink nearly 100 million times faster than a camera flash.
Why this is interesting
You flip a switch and light floods the room—but how does an atom decide to 'glow' on its own, without any push? That mysterious, automatic release of light is called spontaneous emission.