Objective To understand the wave properties of light, especially the phenomenon of interference .
Light travels in waves.
Sometimes, two or more waves join together. Interference is the addition, or coming together, of several waves. Constructive Interference happens when two or more waves come together to form a larger and stronger wave, matching their crests and troughs . Destructive Interference is when two or more waves come together and cancel each other out to make a weaker wave. This interference is like that seen with water waves.