# Simple Light Refraction Experiment

Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another.

## Change of speed causes change of direction

Light refracts whenever it travels at an angle into a substance with a different refractive index (optical density).

This change of direction is caused by a change in speed. For example, when light travels from air into water, it slows down, causing it to continue to travel at a different angle or direction.

How much does light bend?

When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it ‘bends’ more towards the normal line.

## Supplies Needed

• Piece of Paper
• Marker
• Glass
• Water

Step 1 – Get a sheet of paper, and draw two arrows on it. One arrow near the top and one arrow near the bottom. Make the arrows point in the same direction.

Step 2 – Fill a glass with water.

Step 3 – Slowly lower the piece of paper behind the glass of water.

Step 4 – Look through the glass of water and watch what happens.

## How Does the Experiment Work?

The scientific concept that is at work in this experiment is called refraction, which means the bending of light. Refraction occurs when light travels from one medium into another (i.e. Air to Water, Water to Air).

Refraction is the bending of light as it passes from one medium into another (i.e. Air to Water, Water to Air).

During the experiment, the light traveled from the image through the air, then through the glass cup into the water, and finally out of the glass cup and into the air once more before it reached our eyes.

This means that the light bends once when it traveled through the glass cup into the water, and then it bends again when it traveled out of the glass cup and into the air. As a result, the light paths cross and the image appears to be flipped horizontally (left/right).