system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did glow in the dark happen? And where did it get its source of energy to glow in the dark?
gpt
Around 1669, there was a German alchemist named Hennig Brand. He was in search of gold, and thought that it came from within man. What color is gold? It's a shade of yellow. What else is yellow that everyone is familiar with? Urine. So off went Hennig on a quest to extract gold from pee. He boiled down 5,500 liters of the stuff, and what was left over was a bunch of phosphorus. Phosphorus, for those who don't know, has a tendency to take in light, and hold it for a while, which makes it glow. This is why Hennig named it phosphorus, for the greek "light-bearer".
So glow in the dark resulted from a scientific fluke. The dude was trying to make gold in an early stab at chemistry.