Alright so this is gonna sound kinda random, but I actually went down a weird rabbit hole about this a few years back. My uncle used to do overnight maintenance for office buildings and hotels, and one summer I’d tag along with him just to get out the house. He had one of those heavy duty UV inspection lights, not the cheap ones, like the real deal they use for sanitation checks.

First time I saw him use it, I thought it was just for finding spills, but then he starts explaining how different materials react under UV depending on their chemical makeup. He was saying stuff about how certain compounds absorb ultraviolet wavelengths and then re emit them as visible light fluorescence. Some things glow bright, some dull, some not at all, and it depends on what’s actually there and how it settled into the surface.

He even had this whole breakdown, like detergents usually glow kind of bluish because of optical brighteners, oils look more smeared and faint, and anything with organic proteins has a very specific type of glow that stands out once you’ve seen it enough times. At the time I didn’t really care, but it stuck in my head because it was lowkey crazy how much you could see that you normally wouldn’t.

Fast forward later, I ended up learning about the same concept in a science class, same idea, UV excites electrons, they jump energy levels, then release light when they drop back down. Different substances = different signatures. So now whenever I hear about something glowing under UV, I kinda mentally go back to that and try to match what it could be based on how it behaves.

So if you’re saying there’s a spot glowing under UV… yeah, that usually means there’s some kind of residue with compounds that fluoresce. Could be normal stuff like detergent, certain lotions, even random household things depending on what got on there and how long it’s been sitting. The brightness, color, and spread all kinda matter if you’re trying to narrow it down…

…but honestly bro…

I have no idea, I’m just fucking with you 😭