What it's about
How a glow stick makes light without a battery, and why a cold one glows dimmer.
- For: little ones and curious kids, up to about 8
- Length: 2¾ minutes
- Out:
- Where: free on YouTube
How Does a Glow Stick Glow?
Grumble's glow stick for the night parade is glowing, but there's no battery, no bulb and no switch. How does it work? Hoots shows what's hiding inside: two liquids that make light when they mix, just like fireflies.
On the couch
Kids can shout their guess before the answer comes. Ask again on the couch, and see who remembers!
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In the video, Hoots asks:
Two matching glow sticks: one goes in cold water, one in room-temperature water. Which one will glow brighter?
The answer
The room-temperature one! Cold slows down the reaction that makes the light, so the cold one glows dimmer.
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After watching
Try it together: put one glow stick in a cup of cold water and one in a cup of room-temperature water, wait a few minutes, and compare. Glow sticks always stay closed: never open, cut or bite one.