Virtual ripple tank

Wave Interference Simulator

Drop wave sources into a ripple tank and watch them interfere. Draw walls and slits, add a lens or a curved mirror, move a source to hear the Doppler effect, and measure the bright and dark fringes of the double-slit experiment.

WAVELENGTH–
SOURCES0
VIEWWaves

Intensity along the probe line

bright fringes = peaks

Wave height at the probe centre

over time
    How the simulation works
    1. The tank is a grid. Each step, every point moves toward the average of its neighbours — the discrete 2D wave equation.
    2. Sources push the water up and down like a sine wave. Walls hold the water still, so waves reflect off them.
    3. In a "slow" medium waves travel at 1/n of the normal speed, which bends (refracts) them at the border.
    4. The edges have a soft absorbing border so waves leave instead of bouncing back.
    5. Intensity is the time-averaged square of the wave height: what a screen would show as brightness.

    Grid units: one cell is the length unit and the wave speed is 0.5 cells per step. Everything runs in your browser.

    Using Wave Interference Simulator

    A virtual ripple tank. Place wave sources, draw walls, slits and lenses, and watch interference, diffraction, reflection and refraction happen. Measure the bright and dark fringes of the double-slit experiment.

    1. Press Play: two sources make circular waves that cross and form interference stripes.
    2. Click to add a source or drag one to move it. Draw walls with the Wall tool or slower regions with the Slow tool.
    3. Try the examples: double slit, single slit, reflection, refraction through a lens, Doppler effect, standing waves.
    4. Switch the view to Intensity to see the average brightness pattern, and read the probe chart across the screen.
    5. Change frequency, wave speed and damping in Settings; download a PNG or the intensity profile as CSV.

    Example

    Double slit: a plane wave passes two narrow openings and forms bright and dark fringes on the far side.
Doppler: a moving source squeezes the waves in front and stretches them behind.

    Questions & answers

    What is wave interference?

    When waves overlap their heights add. Crest + crest makes a bigger wave (constructive), crest + trough cancels (destructive), creating a stable pattern of strong and calm regions.

    What does the double-slit experiment show?

    Waves passing two slits spread out and interfere, producing bright fringes where the path difference is a whole number of wavelengths: d·sinθ = mλ.

    What is diffraction?

    Waves bend around obstacles and spread after passing through an opening, most strongly when the opening is about the size of the wavelength.

    How is the simulation computed?

    It solves the 2D wave equation on a grid with a finite-difference method, with absorbing edges so waves leave the tank instead of bouncing back.

    What does Intensity view show?

    The time-averaged square of the wave height — what a screen or eye would see as brightness. Interference fringes stand out clearly.

    Can it show refraction?

    Yes. The Slow tool paints a region where waves travel slower, like glass for light or shallow water for ripples; the waves bend at its border.

    Does it run on my device only?

    Yes. Everything runs in your browser.

    KEEP YOUR WORKFLOW MOVING

    A useful next step for your task.

    Browse Simulations

    Help improve this tool

    Report a problem or suggest an improvement

    Describe the issue without pasting private tool input. Feedback goes to our admin inbox.

    Find another tool · Read practical guides