Turn off every light at night. Now you cannot see your toys. Our eyes need light. The Sun, a lamp and a flashlight make their own light. The Moon only bounces sunlight back to us.
Blocks light: shadowWindowlets light through
Blocking light makes a shadow
Light shines on a ball. The ball blocks the light. A dark shape forms behind it. That dark shape is a shadow. Light passes through a clear window. It makes almost no shadow.
Closer light, bigger shadow
Hold a toy near a flashlight. The toy blocks lots of light, so its shadow is big. Move the light far away. The shadow shrinks. Slide the light below and watch.
Shadows change all day
In the morning the Sun is low, so shadows are long. At noon the Sun is high, so shadows are short. In the evening they grow long again. On cloudy days, shadows look faint.
For parents
Goal: Your child learns which things make light, how shadows form, and why shadows change size and length.
Ask: does this make its own light, or does it just shine?
Outside, ask: where is the Sun? So where will your shadow be?
Check your shadows in the morning and at lunch, and compare the length.
Away from the screen: At night, use a flashlight to make shadow puppets on a wall. Move the light closer and farther away and watch the shadow grow and shrink. On a sunny day, mark the tip of a stick's shadow with a stone every hour.
Real photo