Ripple Tank Interference: Two/Three-Source Superposition (2D)

Sources

Separation (d) 0.60

Phase step (Δφ) 0°

Wave

Wavelength (λ) 0.15

Amplitude decay 1.00

Probe (click the tank)

Path diff. Δr

0.000

Δr / λ

0.00

Interference type

Height at probe

0.00

Elapsed time

0.0 s

How it works

Every point of the tank sums a damped travelling wave from each coherent point source at wave speed c = 1:

h(x,y,t) = Σ⁢i⁢ A / sqrt(1 + decay·r⁢i) · sin(k·r⁢i - ωt + φ⁢i)
k = 2π/λ,  ω = 2πc/λ,  r⁢i = distance to source i

This is exact superposition, not an approximation - the colour field you see is that sum evaluated on a live grid every frame, the same principle a real ripple tank demonstrates. Click anywhere in the tank to drop a probe: the panel reads off the true path-length difference Δr = r₀ - r₁ between the first two sources at that exact point and classifies it against the wavelength:

Constructive - Δr/λ within 0.1 of a whole number (crests line up).
Destructive - Δr/λ within 0.1 of a half-integer (crest meets trough).
Partial - anywhere in between.

The phase-step slider gives each source i = 0,1,2… an extra offset φ⁢i = i·Δφ, turning the pair (or triple) into a simple phased array and shifting the nodal (destructive) lines without moving the sources - the same trick used to steer a beam in phased-array radar and ultrasound.

Click / tap the tank to probe path difference