Light and shadows
Where light comes from, how we see, why shadows appear, and the rainbow hiding in sunlight. With a shadow-puppet experiment.
Read
Light comes from light sources: the Sun, a lamp, a candle flame, a torch. Without light, everything is dark and we cannot see.[3]
We see things because light bounces off them and goes into our eyes. A shiny mirror bounces light back neatly, so you can see yourself in it.[4]
Light travels in straight lines. When something is in the way, the light cannot go around it, so there is a dark patch behind it: a shadow.[3]
Sunlight looks white, but it is really all the colours of the rainbow mixed together. When sunlight shines through raindrops, the colours spread out and we see a rainbow.[1][5]
Try it: Shadow puppets
You need
- A torch
- A white wall or a sheet of white paper
- Your hands, or a cut-out animal shape on a stick
- A darkened room
Safety
Never shine a torch into anyone's eyes. Never look at the Sun.
What to do
- Darken the room. Shine the torch at the wall.
- Hold your hand between the torch and the wall. What appears on the wall?
- Move your hand closer to the torch. Is the shadow bigger or smaller?
- Move your hand closer to the wall. What happens to the shadow now?
- Make an animal shape and tell a shadow story!
What happens, and why?
Your hand blocks the light, and because light travels in straight lines it cannot bend around your hand, so a shadow forms. Close to the torch, your hand blocks a bigger part of the light, so the shadow is big. Close to the wall, the shadow is small and sharp.[3]
Play: Light or no light?
Does it make its own light, or not? Tap the right group.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16