Understand the Factors that Affect Shadows

Shadows are created when a light source shines on an opaque object that the light energy cannot travel through.

Can we change shadows?

Yes!

Although we cannot affect how much the Sun shines, we can change the materials and the distance from the Sun to the object, to see how this affects the shadow.

If we conduct our own experiment we can use a more controlled light source, like a torch or a lamp and we can change this too, to see what effect that will have!

If you have a chance, try it yourself - grab a torch and some different objects and see if you can change their shadows!

So we can change:

-  The light source - the direction of the light

-  The density/opacity of the object - is it opaque, translucent or transparent?

 - The distance between the object and the light source.

Do you know what each of these factors will do to the shadows?

Have a quick think!

By changing the direction we can make the shadows appear longer or shorter and change the direction of the shadow - if we shine it above an object the shadow appears underneath it but if we shine it to one side, the shadow will appear on the opposite side of the object!

Changing the material can change how strong the shadow is. Opaque objects will let no light through and make dark shadows, so what do you think would happen to translucent materials? They will make a fainter shadow because they let some light through.

Finally, changing the distance between the light source and the object changes the size of the shadow. When an object is closer to the light, it will appear larger because it is blocking more of the light out.

When we move the object away from the light source, the shadow will appear smaller because it is blocking less of the light energy.

We are going to use this information to help us to make predictions and draw conclusions about experiments in this activity.

Let's go, super scientist!