system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 How does UV light reveal bodily fluids

We’ve all seen it in movies and stuff but how does it work?
gpt
Basically, when a photon uv particle hits a phosphoric material (like pee or sweat) it excites the electrons in the phosphorus. When the electrons move back to their original position, it's releases energy which we see as light :)