How Shadows Move and Change

Have you ever seen a dark shape on the floor that looks just like you?

That dark shape is your shadow.

Shadows are made when something blocks light.

Light comes from many places.

The sun gives us bright light outside.

In our classroom, light comes from ceiling lamps and flashlights.

Light travels in a straight line.

It shines until it bumps into an object.

Some objects let light pass right through them.

Clear glass lets light go through, so it does not make a dark shadow.

Other objects stop the light completely.

Your body, a wooden block, and a thick book all block light.

When light hits a book on a table, the light cannot pass through it.

A dark spot forms behind the book where the light cannot reach.

That dark spot is the shadow of the book.

You can change a shadow by moving the light.

Think about using a flashlight at your desk.

Put a wooden block on your desk.

Shine the flashlight straight down from high above the block.

The shadow under the block will be very short.

Now, move the flashlight down low to the side.

The shadow stretches across the table and becomes very long.

When the light moves, the shadow moves too.

The shadow always points away from the light.