Light & Shadows (Year 3–6) (Years 3–6) — Science

Light comes from sources like the Sun and a torch. We need light to see, shadows form when light is blocked, and mirrors reflect light. Never look at the Sun.

Light is all around us in the daytime. Without light, we could not see a thing! Let us find out where light comes from and how it makes shadows.

Why this matters: Understanding light helps you know why the sky goes dark at night, why your shadow follows you, and how to keep your eyes safe from the Sun.

Where does light come from?

A thing that makes its own light is called a light source. The Sun is the biggest light source we have. A torch, a candle, a lamp and a TV screen all make their own light too.

Light source	Not a light source
The Sun	The Moon
A torch	A mirror
A candle	A book

The Moon is not a light source. It looks bright, but it is really bouncing back light from the Sun.

Why we can see things

We see things because light bounces (reflects) off them and goes into our eyes. In a dark room with no light at all, we see nothing, even with our eyes wide open.

A red apple looks red because it reflects red light off its skin and into your eyes. Turn the light off, and the apple is still there, but no light reaches your eyes, so you cannot see it.

How shadows form

A shadow is made when an object blocks the light. The light cannot go through the object, so a dark shape appears behind it.

Solid things like a wall or a person make clear shadows because light cannot pass through them.

Changing the size of a shadow

Move an object closer to the light and its shadow gets bigger. Move it away and the shadow gets smaller. Try it with a torch and your hand!

Reflections and staying safe

A mirror is very smooth, so it reflects light neatly and you can see yourself in it. Still water can do this too. Never look straight at the Sun, even with sunglasses — it is so bright it can hurt your eyes for ever.