Light and Shadows (KS2 Science)

SC13Light and Shadows

Light travels in straight lines.

We see because light travels from a source, bounces off objects, and enters our eyes.

How we see.

💡 light source→📦 object→👁️ eye

light travels source → object → eye (we see the reflected light)

Light travels in straight lines — which is why shadows form and mirrors reflect.

Learn the Ideas

1Light comes from sources.

The Sun, lamps, flames and screens give out light. The Moon is NOT a source — it reflects the Sun’s light.

Sun · lamp · flame

2We see reflected light.

Light bounces off objects into our eyes. We can’t see in complete darkness because there’s no light to reflect.

reflect → eye

3Shadows form when light is blocked.

Because light travels straight, an opaque object blocks it and casts a shadow the same shape. Closer to the light = bigger shadow.

blocked light = shadow

💡 Key IdeaA common myth: we do NOT see by light coming out of our eyes. Light enters our eyes from sources or reflections — that's the whole reason a dark room is invisible.

Worked Example

How do you make a shadow bigger without moving the object?

Move the light

bring the light source CLOSER to the object

→

Why

the object blocks light spreading at a wider angle

→

✓ Result

a larger shadow is cast on the wall

Watch Out! Common Mistakes

‘Our eyes send out light to see.’

The opposite! Light travels INTO our eyes from sources and reflections. If it came out of our eyes, we could see in the dark — we can’t.

‘The Moon makes its own light.’

It reflects! The Moon has no light of its own — it shines by reflecting sunlight, which is why it has phases.

‘Light can bend around corners.’

It travels straight! Light goes in straight lines — that’s exactly why an object casts a sharp shadow of its own shape.

⬇ Cheat Sheet

LIGHT AND SHADOWS

Light comes from sources (Sun, lamp) — the Moon reflects.
We see reflected light entering our eyes.
Light travels in straight lines.
Shadows form when opaque objects block light; closer light = bigger shadow.

Example: light closer to object → bigger shadow.

📖 Continue Your Journey

✓ SC1 Classifying Living Things ✓ SC2 Habitats and Adaptation ✓ SC3 Food Chains and Webs ✓ SC4 The Skeleton and Muscles ✓ SC5 Digestion and Teeth ✓ SC6 The Circulatory System ✓ SC7 Plants and Photosynthesis ✓ SC8 Life Cycles and Reproduction ✓ SC9 States of Matter and the Water Cycle ✓ SC10 Materials and Their Properties ✓ SC11 Reversible and Irreversible Changes ✓ SC12 Forces and Magnets SC13 Light and Shadows SC14 Sound SC15 Electricity and Circuits SC16 Earth and Space

→

Next Lesson: SC14 SoundVibrations you can hear.

📄 Free printable: Download the Light and Shadows cheat sheet (PDF) — keep it by your child's desk.

Quick summary

Light comes from sources like the Sun and lamps; the Moon only reflects.
We see reflected light entering our eyes — not light leaving them.
Light travels in straight lines.
Shadows form when opaque objects block light; a closer light makes bigger shadows.

Frequently asked questions

How do we see objects?

Light from a source bounces off the object and travels into our eyes. In complete darkness there's no light to reflect, so we see nothing.

Does the Moon make its own light?

No — the Moon reflects sunlight. That's why it shows phases as different amounts of its lit side face Earth.

How do shadows form?

Because light travels in straight lines, an opaque object blocks it and casts a shadow of its own shape. Moving the light closer makes the shadow bigger.

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SC12 Forces and Magnets