Science · Year 1 · Sound and Light: Sensing Our World · Term 4

Light and Shadows: Blocking Light

Students will investigate how shadows are formed when light is blocked by an object, exploring shadow size and shape.

• ACARA Content Descriptions
• AC9S1U04

About This Topic

Shadows form when an opaque object blocks light rays from a source, such as the sun or a torch, creating a dark area on a surface behind it. Year 1 students explore this by explaining how their body makes a shadow, comparing shadows from small and large objects, and predicting changes in shadow size as they move objects closer to or farther from the light source. These investigations highlight how light travels in straight lines and how object position affects shadow properties.

This content meets AC9S1U04 in the Australian Curriculum by examining how light allows us to see objects and how shadows reveal light direction and blocking. It fosters key inquiry skills: making observations, forming predictions, and conducting simple tests. Students connect daily experiences, like playground shadows, to scientific explanations, building confidence in evidence-based thinking.

Active learning suits this topic perfectly since shadow effects are instant and visible. When students manipulate torches, objects, and screens in pairs or small groups, they test predictions firsthand, observe patterns, and refine ideas through discussion. This approach turns passive watching into discovery, deepening retention and enthusiasm for light science.

Key Questions

1. Explain how your body makes a shadow.
2. Compare the shadow made by a small object to a large object.
3. Predict how the size of a shadow changes as you move closer to a light source.

Learning Objectives

• Explain how an opaque object blocks light to create a shadow.
• Compare the size and shape of shadows cast by objects of different sizes.
• Predict how the distance between an object and a light source affects shadow size.
• Demonstrate how moving an object closer to or farther from a light source changes its shadow.

Before You Start

Properties of Light

Why: Students need a basic understanding that light travels and allows us to see objects before investigating how it can be blocked.

Observing and Describing Objects

Why: Students must be able to observe and describe the physical characteristics of objects to compare their shadows.

Key Vocabulary

light source	Anything that produces light, such as the sun or a torch.
opaque	An object that does not allow light to pass through it.
shadow	A dark area formed when an opaque object blocks light.
block	To prevent light from passing through an object.

Watch Out for These Misconceptions

Common Misconception

Shadows are always the same size as the object.

What to Teach Instead

Shadow size depends on object distance from the light source; closer objects make larger shadows as rays diverge. Pair experiments moving objects reveal this pattern quickly, and group discussions help students articulate the straight-line travel of light.

Common Misconception

Shadows only appear in complete darkness.

What to Teach Instead

Shadows form anytime light is blocked, even in bright sunlight. Outdoor whole-class shadow tracing shows daytime examples and links to light direction, correcting ideas through direct observation and shared photos.

Common Misconception

Light bends around objects to create shadows.

What to Teach Instead

Light travels in straight lines, so shadows match object shapes sharply with one source. Station rotations with single torches demonstrate crisp edges, while comparing multiple lights explains fuzzy borders via peer testing.

Active Learning Ideas

Pairs: Torch Shadow Play

Pairs shine a torch on small and large objects against a white screen. They draw shadow shapes, then slowly move objects closer to the torch to predict and observe size changes. Pairs record before-and-after sketches on worksheets.

30 min·Pairs

Small Groups: Shadow Size Stations

Prepare three stations with torches at fixed distances and sets of objects. Groups rotate every 10 minutes, measuring shadow lengths with rulers and comparing small versus large objects. Groups share one key finding per station.

45 min·Small Groups

Whole Class: Outdoor Body Shadows

Students pair up outside and trace each other's shadows with chalk at two times, 30 minutes apart. Class returns to compare tracings and discuss why lengths changed with sun movement. Chart results on the board.

25 min·Whole Class

Individual: Prediction Drawings

Each student draws predicted shadows for an object near, middle, and far from a light source. They test predictions using a desk torch, then note matches or surprises in a journal.

20 min·Individual

Real-World Connections

• Stagehands use spotlights and props to create dramatic shadows for theatre performances, controlling the size and placement of shadows to enhance the mood and storytelling.
• Photographers adjust lighting equipment and subject positioning to manipulate shadows, using them to add depth, texture, or a specific artistic effect to their images.

Assessment Ideas

Exit Ticket

Give students a drawing of a simple object and a light source. Ask them to draw the shadow and write one sentence explaining why the shadow formed.

Discussion Prompt

Ask students: 'Imagine you are standing in the sun. What happens to your shadow if you walk closer to a wall? What happens if you walk farther away?' Encourage them to explain their predictions using the vocabulary learned.

Quick Check

During a hands-on activity, observe students as they move objects closer to and farther from a torch. Ask them to hold up their hands to show if the shadow is getting bigger or smaller, and ask them to explain why.

Frequently Asked Questions

How to teach shadow formation in Year 1 Australian Curriculum?

Start with familiar examples like body shadows, then use torches for controlled tests per AC9S1U04. Guide students to observe, predict, and compare shadow sizes by moving objects. Simple tools like rulers and worksheets support fair testing, while daily links to sun shadows make concepts relevant and build inquiry skills over several lessons.

What hands-on activities for light and shadows Year 1?

Try torch shadow stations where small groups measure size changes, or outdoor chalk tracing of changing shadows. Pairs can explore object shapes with playdough cutouts. These 20-45 minute tasks emphasize prediction and observation, aligning with curriculum expectations and providing data for class charts to spot patterns.

Common misconceptions about shadows for Year 1 students?

Students often think shadows match object size exactly or only form in dark rooms. They may believe light curves around blocks. Address these with torch experiments showing distance effects and outdoor hunts proving daytime shadows. Structured talks after activities help revise ideas using evidence from their tests.

How does active learning help Year 1 shadow investigations?

Active learning engages students by letting them create and manipulate shadows with torches and objects, testing predictions in real time. Pairs or groups discuss observations, like size changes, fostering collaboration and deeper understanding. This beats lectures since immediate feedback builds accurate mental models of light rays, boosting retention and scientific talk skills over passive demos.