Light Behaving Strangely
Light is a wave, a particle, and a deep mystery. These 20 simulations explore what happens when photons interfere, diffract, polarize, and refract. Watch Young’s double slit create fringes from nothing, see soap bubbles paint themselves with thin-film interference, and discover why the sky is blue and sunsets are red. From Newton’s rings to fiber optic total internal reflection, every phenomenon here is a window into the wave nature of light.
When waves meet, they create patterns of stunning beauty—constructive and destructive interference paint the world with light and shadow.
Young’s most famous experiment: light through two slits creates an interference pattern. Adjust wavelength, slit width, and separation.
Why soap bubbles shimmer with rainbow colors. Light reflects from both surfaces of a thin film, creating wavelength-dependent interference.
A curved lens on flat glass creates concentric rings of color. The air gap varies with radius, creating a natural interference pattern.
Add waves of different frequencies and amplitudes. Watch beats emerge, standing waves form, and Fourier synthesis build any shape from sine waves.
A 2D wave simulation: place point sources, walls, and slits. Watch diffraction, interference, and reflection unfold in real time.
When light bends around obstacles, it reveals its wave nature through beautiful bending patterns that defy ray optics.
Even one slit spreads light into a central maximum flanked by weaker fringes. The narrower the slit, the wider the pattern.
Thousands of slits create razor-sharp spectral lines. CDs, DVDs, and spectrometers all exploit this. Separate white light into its rainbow.
Light through a circular aperture creates the Airy pattern—concentric rings that limit the resolution of every telescope and camera.
X-rays bouncing off crystal lattice planes interfere constructively at specific angles. The technique that revealed DNA’s structure.
Divide a wavefront into concentric zones that alternately add and cancel. Block the right zones and you get a lens with no glass.
Light changes speed at boundaries, bending its path and creating phenomena from rainbows to mirages to total internal reflection.
Drag a light ray across the boundary between two media. Watch it bend, and discover the critical angle where total internal reflection begins.
White light enters a prism and exits as a rainbow. Each wavelength bends differently—Newton’s crucial discovery about the nature of color.
Trace rays through a raindrop: one reflection creates the primary bow at 42°, two reflections make the fainter secondary bow at 51°.
Beyond the critical angle, light bounces back completely. The principle behind fiber optics, diamonds’ sparkle, and desert mirages.
Hot air bends light upward, creating phantom lakes in deserts. Trace rays through a temperature gradient and watch the mirage appear.
Light is a transverse wave with direction. Filtering, scattering, and rotating that direction creates phenomena from blue skies to 3D movies.
Rotate polarizing filters and watch light intensity follow Malus’s law. Cross two filters to block all light—then add a third to let it through!
Why is the sky blue and sunsets red? Short wavelengths scatter more. Watch a beam pass through an atmosphere and see color separate.
At one magic angle, reflected light is perfectly polarized. This is why polarized sunglasses cut road glare—Brewster figured it out in 1815.
Some crystals split light into two beams with different polarizations. Place calcite on text and watch every letter double.
Sugar solutions rotate the plane of polarization. Different wavelengths rotate by different amounts, creating a rainbow between crossed polarizers.