How light reflects, bends, focuses and interferes — from Snell's law and lenses to the bright and dark fringes of interference and the colours of the spectrum. Every experiment in this field is live.
Ten interactive experiments — all live.
Bounce light off flat, concave and convex mirrors — see the law of reflection and find the focal point.
Open simulator →Watch light bend between materials, with total internal reflection past the critical angle.
Open simulator →Trace principal rays off a concave or convex mirror to locate the real or virtual image.
Open simulator →Move an object near a converging or diverging lens and trace the rays that form its image.
Open simulator →Send waves through two slits and watch the bright and dark interference fringes appear on the screen.
Open simulator →Squeeze light through one narrow slit and watch it spread into a broad central band with side fringes.
Open simulator →Split white light through a prism into the full rainbow of colours — violet bends most, red least.
Open simulator →Chain polarizing filters and watch light dim by cos²θ — even reappearing through three crossed filters.
Open simulator →Add slits one by one and watch the double-slit's soft fringes sharpen into the razor-thin lines of a spectrometer.
Open simulator →Tune a soap film's thickness and watch colours cancel and reinforce — then flip to a lens coating and null the reflection.
Open simulator →