Why Do Shadows Grow and Shrink?
A torch, a toy and a dark room: discover how light makes shadows — and why they change shape.
⏱️ Micro Plan — 4 short parts · about 20 min in total
- 1The Question5 min
- 2Predict5 min
- 3Experiment & Discover5 min
- 4Reflect5 min
🎯 Learning objectives
After completing this lesson, the child should be able to:
- Observe how a shadow changes as the light moves
- Discover that light travels in straight lines
- Predict shadow size at different times of day
❓ Question
Why do shadows grow and shrink?
👀 Observation
Have you seen your shadow on a sunny day? In the morning it stretches long, at midday it is short, and in the evening it is long again. Draw your shadow at three times of day if you can!
🔮 Prediction
We will shine a torch at a toy. Guess first: what happens to the shadow if the torch moves closer? What if the torch shines from low down instead of up high?
🧪 Exploration
In a dark room, stand a toy on a piece of paper and shine a torch at it. Move the torch closer and farther. Shine from the side, from low down, from up high. Trace each shadow with a pencil.
🔍 Discovery
Torch close to the toy → a big shadow! Torch far away → a small one. Torch low down → a very long one. The shadow shape follows the light, every time.
💡 Explanation
Light travels in straight lines. The toy blocks the light, and the shadow is the place the light cannot reach. When the light comes from low down, the blocked patch stretches out long — like your morning shadow when the sun is low!
✏️ Practice
Predict: at midday, when the sun is highest, is your shadow long or short? (Short — the light comes from above!) Test it tomorrow at noon. Then try the Prediction Quiz.
🪞 Reflection
What about a cloudy day — where do the shadows go? (They spread out softly in every direction.) What else could block light to make a shadow? Go on — wonder about it.
🧪 Materials for this experiment
A torch · a small toy · paper and pencil · a dark room · a grown-up to be the audience for your discoveries