Blocking Light to Make Shadows

Active, hands-on exploration helps students grasp that light travels in straight lines because they see rays in action. When children manipulate objects and light sources themselves, abstract concepts like shadow formation become visible and memorable through direct observation.

• Year 2
• Science
• 4 activities
• 30 min–45 min

Learning Objectives

1. Explain how opaque objects prevent light from passing through, thereby creating a shadow.
2. Compare the shapes of shadows cast by objects with different geometric forms.
3. Predict how the size of a shadow changes when the object casting it moves closer to or further from a light source.
4. Identify the light source, the opaque object, and the shadow in a given scenario.

Experiential Learning

⏱ 35 min·Pairs

Torch Distance Challenge: Shadow Sizes

Pairs set up a torch, object, and screen in a dark space. Place the object at three distances from the torch, predict shadow size each time, then measure with rulers. Record results in a class chart and explain patterns.

Prepare & details

Explain what causes a shadow to form.

Facilitation Tip: During the Torch Distance Challenge, circulate with a ruler and ask pairs to measure shadow length at 10cm, 20cm, and 30cm from the torch to anchor their observations in data.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 40 min·Small Groups

Shape Shadow Match-Up: Object Gallery

Small groups project shadows of various objects like balls, sticks, and leaves onto paper using torches. Mix projections on a wall, then match each shadow to its object. Note how edges transfer from object to shadow.

Prepare & details

Compare the shadows created by different shaped objects.

Facilitation Tip: For the Shape Shadow Match-Up, provide a mix of objects and pre-cut shapes so students notice how edges define shadow outlines clearly.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 45 min·Whole Class

Outdoor Stick Shadows: Time Tracking

Whole class places identical sticks in sunny spots and marks shadow tips with chalk every 15 minutes. Measure lengths, sketch changes, and predict next positions. Compare morning and afternoon data.

Prepare & details

Predict how moving an object closer to a light source affects its shadow.

Facilitation Tip: In Outdoor Stick Shadows, assign small groups a fixed stick length and have them mark shadow tips with chalk every 15 minutes to track changes over time.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Experiential Learning

⏱ 30 min·Pairs

Puppet Shadow Play: Prediction Game

Individuals craft simple puppets from card, then pairs use torches to test shadow predictions by changing distance or angle. Perform short shows, noting size shifts. Share best observations.

Prepare & details

Explain what causes a shadow to form.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Teaching This Topic

Teach this topic by letting students experience the physics firsthand before naming concepts. Avoid front-loading definitions; instead, let observations guide vocabulary. Research shows that prediction-observation-reflection cycles deepen understanding more than lectures. Keep materials simple and repeatable so students can test ideas independently.

What to Expect

Students will confidently explain that light travels straight, objects block light to create shadows, and shadow size changes with distance. They will use precise vocabulary like ‘opaque,’ ‘translucent,’ and ‘transparent’ when describing their findings.

Watch Out for These Misconceptions

Common Misconception

During the Torch Distance Challenge, watch for students who think shadows stay the same size regardless of object position.

What to Teach Instead

Have pairs measure shadows at 10cm, 20cm, and 30cm from the torch, then graph results on shared paper to reveal the clear pattern that closer objects cast larger shadows.

Common Misconception

During the Shape Shadow Match-Up, watch for students who think all objects block light equally.

What to Teach Instead

Ask groups to rotate through stations with different materials and rank shadow darkness from 1 (darkest) to 5 (lightest), then discuss why some materials block more light than others.

Common Misconception

During Puppet Shadow Play, watch for students who explain shadows by saying light bends around objects.

What to Teach Instead

Place a straight-edged object between the torch and screen, then ask students to trace the edge of the shadow and compare it to the object’s shape to see that light travels in straight lines without bending.

Assessment Ideas

Quick Check

During the Torch Distance Challenge, ask each pair to explain how moving the object closer to the torch changes the shadow size and record their observations on a shared chart.

Discussion Prompt

After Outdoor Stick Shadows, show a sundial image and ask students to explain how the stick blocks sunlight to create a moving shadow, then predict what would happen if the stick were taller.

Exit Ticket

After Puppet Shadow Play, give each student a half-sheet with a torch, object, and shadow drawn; ask them to label the light source, object, and shadow, and write one sentence explaining why the shadow appears.

Extensions & Scaffolding

• Challenge students to create a shadow that matches a given outline by adjusting object shape and distance during the Shape Shadow Match-Up.
• Scaffolding for struggling learners: provide translucent and transparent materials during the Torch Distance Challenge so they compare shadow darkness levels.
• Deeper exploration: Have students design a shadow puppet show using three different materials (opaque, translucent, transparent) to demonstrate their understanding of light blocking.

Key Vocabulary

Opaque	An object that does not allow light to pass through it. Opaque objects block light, which causes shadows to form.
Shadow	A dark area formed when an opaque object blocks light. The shadow's shape is usually similar to the shape of the object blocking the light.
Light Source	Something that produces light, such as the sun or a lamp. Light travels in straight lines from the light source.
Transparent	An object that allows light to pass through it completely. Transparent objects do not cast distinct shadows.
Translucent	An object that allows some light to pass through but scatters it. Translucent objects cast fuzzy or indistinct shadows.