Stretch plastic wrap tightly over a bowl and sprinkle a thin layer of rice or salt on top, then place it near a speaker playing music or a low hum. Watch the grains jump and form patterns as the sound's vibrations pass through the surface, comparing how different pitches change the pattern.
What you need
- a bowl
- plastic wrap
- rice or fine salt
- a speaker or phone playing music
How to do it
- 1Stretch plastic wrap tightly over the top of a bowl, securing it if needed.
- 2Sprinkle a thin, even layer of rice or salt on the surface.
- 3Place the bowl close to a speaker and play a low, deep sound, then a high one, watching how the grains move differently.
- 4Try several songs or tones and compare which ones make the biggest jumping pattern.
Variations
- If a speaker with adjustable volume isn't available: humming loudly and steadily near the bowl produces a similar, smaller effect.
- How it ends: settling on the 'best' sound for making the grains dance gives the experiment a fun conclusion.
💡 Parent tip
Bass-heavy music tends to produce the most dramatic effect -- it's worth testing a few genres to find the best one together.
What your child develops
- Sound and vibration science — making an invisible force (sound waves) visible is a genuinely striking demonstration
- Comparative observation — noticing how pitch changes the pattern builds careful, structured observation skills
- Cause and effect — a direct, immediate link between sound and physical movement
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