Wave Interference Visualizer
Two coherent sources, live canvas. Watch constructive (bright) and destructive (dark) fringes emerge.
Blue = wave crest, red = trough. Stripes of strong blue/red are bright fringes; flat grey is a dark fringe.
Formula
Dark fringes (destructive): path difference = (n + ½)·λ
Two-slit fringe spacing: Δy = λ·L / d
Physics behind two-source interference
When two coherent wave sources radiate from nearby points, the waves superpose everywhere in space. Where the two path lengths differ by an integer number of wavelengths, the waves arrive in phase and reinforce (bright). Where they differ by a half-integer, they cancel (dark). Young's double-slit experiment was the first direct evidence that light behaves as a wave, and the same principle operates in sound, water waves, and quantum-mechanical matter waves.
Related tools
FAQs
What is constructive interference?
Waves meeting in phase — amplitudes add.
What is destructive interference?
Waves meeting half a cycle out of phase — they cancel.