9-9.30 PE with Joe
1st lesson: Numeracy
2nd lesson: Literacy
3rd lesson: Science
Refraction is the change in direction of a wave, caused by the change in the wave's speed. Examples of waves include sound waves and light waves. Refraction is seen most often when a wave passes from one medium to a different medium. Different types of medium include air and water.
When a wave passes from one medium to another medium, the wave will change its speed and its direction. For example, when a light wave travels through air and then passes through water, the wave will slow and change direction.
Another example is when light passes through a glass or perspex block which changes the direction of a light ray.
Light changes direction as it passes from air into the solid block.
Once it emerges the other side it changes direction again.
The pencil looks closer to the surface than it really is.
This is because the water bends the light.
The light appears to come from a point above where the
bottom of the pencil really is.
Have a go at doing the two investigations below to help you think scientifically about water bending light.