Fluorescence β Substances That Eat Light and Glow
A world that glows under UV light
Turn on a blacklight and white clothes glow, highlighter text lights up. How does this work?
Energy Conversion
When molecules in fluorescent material absorb UV light (high energy), their electrons jump to an excited state. When these electrons drop back down, they lose some energy as heat and emit the rest as lower-energy (longer wavelength) light.
UV (~380nm and below) β visible light (~400-700nm). Invisible light becomes visible, so it appears to "glow."
Fluorescence in Daily Life
Laundry detergent: Contains optical brighteners. They convert UV into blue light, making clothes appear whiter. That's why laundry glows under blacklight.
Highlighters: Ink contains fluorescent dye. They look extra bright on paper because reflected light + fluorescence combine.
Banknote anti-counterfeiting: Bills have patterns printed in fluorescent ink. Verifiable with UV lamps.
Scorpions: Scorpion exoskeletons contain fluorescent compounds and glow green-yellow under UV. The reason is still not entirely clear.
How It Works
Fluorescent material absorbs UV (high energy) β electrons jump to excited state
Electrons return to ground state, emitting energy difference as light
Emitted light has longer wavelength (lower energy) than absorbed β visible light