Eli5 why fluorescent and neon colors glow brighter under black light then other colors

Question

I was looking in the blacklight I have in the bathroom and realized how brightly my neon orange hair stood out but not my red shirt and don’t understand why

In: 3

Answer 1

The word “fluorescent” is actually a technical term; it means something which absorbs ultraviolet light and then re-emits it as visible light.

Not all fluorescent materials are brightly coloured, though. My favourite example is that the quinine in tonic water is fluorescent, so a gin and tonic will glow bright blue under UV light. I would definitely encourage you to drink a gin and tonic in your bathroom, or any other space illuminated with a black light.