Understand How Shadows are Related to Light Sources and Materials

What is darkness?

Darkness is the absence of light.

So it only makes sense that if we shine a light at something and then block some of that light's path, we will create darkness behind it.

Objects that block a light source's path are just taking away the light in that area.

Did you know that using and making shadow puppets began around 2,000 years ago in China!

You can try making your own hand puppets. Try shining a lamp or torch at a plain background - a wall works well!

Then use your hands to make different shapes in front of the light - by blocking the light, a shadow will appear on the wall!

If we move our hands closer to the light source, what do you think will happen?

The shadow gets bigger the closer the object is to the light. So if we move our hands closer to the light source, our hands will look larger than life!

If we move our hands further away, the shadow will be smaller.

The closer the light source is to the object, the bigger the shadow will appear.

The length of a shadow can change too.

When a light is directly above or in front of an object, the shadow will be directly underneath or in front of the object. Have you ever noticed your shadow almost disappears in the middle of the day when the Sun is directly overhead?

When a light is to one side of a object, the shadow will appear in the opposite direction to the light source and it will be longer. This is why our shadow will be longer in the evening when the Sun is lower in the sky and to one side of us.

If you have a torch or lamp you can try this one yourself too! Try shining a light directly at your hand - the shadow should appear directly behind it.

Now try moving the light source to the left or right. What do you think will happen?

The shadow will now look longer - it might look like you have a very long hand and fingers!

So we can change the shadows we make by changing three things:

1  The distance between the light and the object it is shining on

2  The angle of the light hitting the object

3  The opacity of the material - this means how much light is let through the material

In this activity, we will be thinking about these three factors and how they change shadows!

Let's get started.