Simulations
Interactive, watermarked science demonstrations — pick one to adjust its parameters and run it.
Double-Slit Interference
INTERSTELLARShine coherent light through two narrow slits and watch the exact bright/dark fringe pattern form on a screen — adjust wavelength, slit separation, slit width, and screen distance to see the fringes tighten, widen, and even lose whole orders to the single-slit diffraction envelope.
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Malus's Law
FREEShine unpolarised light through a polariser and a rotating analyser and watch the transmitted intensity trace out cos-squared of the angle between them — then insert a third polariser between two crossed ones and watch light that should be fully blocked pass through again.
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Refraction (Snell's Law)
FREESend a light ray into the interface between two media — adjust the incidence angle and each medium's refractive index to see it bend according to Snell's law, or totally internally reflect once you pass the critical angle.
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Bend the Beam
FREEThe server picks a pair of materials (such as air and glass, or diamond and water) and a target for the angle the light leaves the boundary at (always achievable), you set the angle the beam arrives at, and a real refraction model judges where it ends up. Hitting the target refunds your run.
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Thin Lens (Image Formation)
ORBITPlace an object in front of a converging or diverging lens — watch the three principal rays trace out where the image forms, and see whether it's real or virtual, upright or inverted, magnified or reduced.
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