Why do things glow in the dark?
Glow's Secret Staircase
Why do things glow in the dark?
You flip off the light switch, and suddenly your star stickers shine. Your watch face glows green. That weird toy from the arcade radiates a soft light even though there's no battery, no bulb, no power source at all. What kind of magic is this?
It starts with a trick of physics called phosphorescence. Certain materials — like the stuff on your stickers — can absorb light energy during the day and then release it slowly, bit by bit, when the lights go out. They're basically batteries, but instead of storing electricity, they store light itself.
