Refraction and Reflection

Refraction is the change in direction of a wave due to a change in its speed when a wave changes from one medium to another. Refraction occurs whenever you have a wave moving across the boundary where into a new medium and it hits at some angle. The greater the angle, the more refraction will happen. Light diffraction basically is the spreading out of waves when they pass through small aperture or passes around side of an obstacle. It's largely responsible for the rainbows for example we'll talk about light in a future episode.