Using the properties of light to create illusions is a lot of fun. Have you ever noticed how images appear differently through a glass of water? This phenomenon is related to the refractive properties of light, an ability to change direction when it passes through another medium.
You will need:
- Some sand
- A clear long drink glass
- A drawing of your choice
- Adhesive paper
- A carafe of water
From 4 years old
Difficulty : easy
Let's experiment
Pin your drawing to the wall. It should not be more than 2 in wide
In front of your drawing, place your empty glass at a distance of 4 in.
Now look at your drawing through the glass and fill it with water until the level is higher than your drawing. What do you observe?
Understand the experiment
The light is bowing
Magic? No, it’s optics.
You know that light travels through air as well as through water. But if the water is transparent, it’s also much denser. The molecules are much closer together than in air.
As a result, when light passes from air to the aqueous medium, it changes direction. This is called light refraction.
When the light has to travel through a cylindrical glass, it bends to enter the glass of water, and bends again when it leaves the glass of water.
Depending on the distance between the drawing and your glass, your image can turn completely around the vertical axis.
Did you know?
By exploiting the refractive properties of light, scientists have been able to create contact lenses to relocate light to the retina of people with impaired vision.
