Phase Difference
The angular difference between corresponding points on two waves or between different points on a single wave.
Governing formula
Δφ = (2π / λ) Δx = (2π / T) Δt
SI unit
rad (radians)
In depth
Phase difference dictates interference outcomes: integer multiples of 2π yield constructive interference; odd multiples of π yield destructive interference.
Examples in the real world
Noise-canceling headphones producing a sound wave with a π phase difference (180° out of phase) to cancel ambient background noise.