How Shadows Work: Making Shapes Dance on the Wall
Hold your hand in front of a flashlight tonight and look at the wall. Your hand makes a giant dark shape โ bigger than your real hand! Some people think that looks like magic. There is a real reason it happens, and once you know it, you can make your own shadow show.
What You'll Learn
By the end of this lesson you will be able to: โข Explain why shadows form when light hits an object. โข Predict what happens to a shadow when you move closer to or farther from a light. โข Create at least two shadow puppet shapes with your hands. โข Understand how storytellers use shadows to surprise an audience.
Light Travels in Straight Lines
Light moves in straight lines called rays. You cannot bend a ray of light the way you can bend a straw. When a ray hits something it cannot pass through โ like your hand โ the light stops there. The spot behind the object where no light lands is the shadow. Think of it like standing in the rain. The dry patch on the ground behind you is exactly where the rain could not reach.
Use your phone flashlight in a dark room. Hold your hand 30 centimeters from the wall and notice the shadow. Then slowly move your hand closer to the flashlight โ the shadow grows huge and fuzzy. Move your hand back toward the wall โ the shadow shrinks and sharpens. You just discovered how distance changes shadows!
Why Your Shadow Changes Size
Light spreads outward from a bulb like ripples from a stone dropped in water. When your hand is close to the light, it blocks many spreading rays โ so the shadow is huge. When your hand is close to the wall, it blocks only the rays heading straight at that small spot. This is why your shadow on the ground is long in the morning (the sun is low and far away) and short at noon (the sun is nearly overhead and the angle is small).
Shadow Puppets: Telling Stories With Light
People have used shadow puppets for more than 2,000 years. In ancient China and Indonesia, storytellers held puppets behind a lit screen so the audience only saw the shadows. The shapes looked mysterious โ even though they were just cut-out figures on sticks. With just your two hands you can make a rabbit (two fingers pointing up as ears), a dog (flat hand, thumb up), or a flying bird (cross your thumbs and flap your fingers). Magicians use these exact tricks today to create moments of wonder.
Match each hand position to the shadow shape it creates.
Terms
Definitions
Drag terms onto their definitions, or click a term then click a definition to match.
Why does a shadow form behind an object when a light shines on it?
Shadow puppet storytelling began more than 2,000 years ago in which part of the world?
Flashcards โ click each card to reveal the answer
Put On a Shadow Puppet Show
1. Gather a flashlight, a plain white wall or hung sheet, and a dark room. 2. Practice three shadow shapes: a bunny (two fingers up), a bird (cross thumbs, flap fingers), and a snapping mouth (flat hand opening and closing). 3. Ask a family member to sit facing the wall as your audience. 4. Tell a short story using your puppets โ at least three sentences. Example: the bird meets the bunny and they escape from the snapping monster. 5. Move your hands closer to the light during dramatic moments to make shadows grow huge. 6. Deliverable: perform your story, then explain to your audience one reason why shadows change size when you move your hands.
Want to keep learning?
Sign up for free to access the full curriculum โ all subjects, all ages.
Start Learning Free