〰️ Wave Interference

Two coherent sources: bright fringes where the path difference is a whole number of wavelengths.

Patternλ = 80 px

Bright = constructive interference (path difference = n × λ)

Wavelength λ (px)

80

Physics

When two waves are in phase (path difference = 0, λ, 2λ, …) they add up (bright). When out of phase (½λ, 1½λ, …) they cancel (dark). This is the same idea as double-slit experiments.