Light makes shadows — Science, 4–6 years
Light travels from a source, such as the Sun or a lamp. When an object blocks some of that light, a darker shape appears behind it: a shadow.
A shadow is blocked light
A shadow appears when light cannot reach part of a surface. You need a light source, an object in the way and a surface where the shadow can fall. The shadow copies some of the object’s outline, but it is not a dark object hiding there.
Why do shadows matter?
People first needed shadows to understand when the Sun was high or low and to find shade from bright heat. By comparing shadows, they could notice that the Sun’s position changes during the day. This turned a strange dark shape into a useful clue about light and time.
Move the lamp
Stand a toy in front of a lamp and place a wall behind it. First move the lamp close to the toy: the shadow on the wall becomes large. Now move the lamp farther away: the shadow becomes smaller. The toy did not change; the distances between the lamp, toy and wall changed.
The shadow is not a second object
A shadow looks like a dark copy, so it is reasonable to think it is something attached to the object. But it has no weight and cannot be picked up. Move the lamp or the object, and the shadow changes because it is made by blocked light.
Shadows outside school
Trees, umbrellas and buildings make shadows that give people and animals a cooler place. A sundial uses a changing shadow to show the time approximately. At night, a torch makes a shadow on a wall, but only where its light is blocked.
Keep exploring
Other languages
Loading MyLeoNes™…