3.8 Diffraction

Understand that waves can be diffracted when they pass an edge.


What is Diffraction?
Diffraction refers to various phenomena which occur when a wave encounters an obstacle. 
It is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings. (en.wikipedia.org/wiki/Diffraction)
Basically: Waves spreading into the shadow when they pass the edge