the.com/chemiluminescence
Light made by chemistry, not heat — the glow that refuses to burn.
means The emission of light from a chemical reaction, with little or no accompanying heat.
from From Greek khemeia (alchemy) plus Latin lumen (light) and -escence, signaling a process underway — coined in the late 1800s as scientists distinguished cold glow from fire.
Glow stickSnap mixes chemicals; the crack releases the light.
Biological cousinFireflies do it living — that is bioluminescence.
Crime sceneLuminol glows blue when it meets blood's iron.
Cold lightEfficient because energy escapes as photons, not warmth.