Persistence-of-Vision LED Wand

1. Persistence-of-Vision LED Wand Materials: LED persistence wand or blinking LED strip moved rapidly What you do: Move blinking lights quickly in dim room. What students see: Letters/patterns appear suspended in space. Question: Are the letters really floating in the air? 2. Supercooled Water Freezes Instantly Materials: Unopened purified water bottle supercooled in freezer; ice crystal/bowl What you do: Tap bottle or pour onto ice. What students see: Liquid rapidly turns to slushy ice. Question: Why didn't it freeze in the freezer already? 3. Raw vs Hard-Boiled Egg Spin Materials: One raw egg; one hard-boiled egg What you do: Spin both, stop each briefly with a finger, then release. What students see: The raw egg starts moving again; the cooked egg stays stopped. Question: What is still moving inside the raw egg?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Are the letters really floating in the air? Question: Why didn't it freeze in the freezer already? Question: What is still moving inside the raw egg?