Ray Optics Bench
This is an optical bench where light travels in straight rays until it hits a surface, then reflects or refracts by the laws of geometric optics. Place a source that fans out a beam, then drop in converging and diverging lenses, flat and curved mirrors and a glass prism, and drag them around to see the rays redraw instantly. Lenses bring parallel rays to a focal point, mirrors bounce them at equal angles, and the prism bends different colours by different amounts so white light spreads into a spectrum. Refraction follows Snell’s law and total internal reflection kicks in past the critical angle, all computed live on a canvas.
Runs 100% in your browser — simulations are computed locally on your device.
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Notes
- Refraction obeys Snell’s law, n₁ sinθ₁ = n₂ sinθ₂: light entering denser glass bends toward the normal, and leaving it bends away, which is how a lens focuses.
- Past the critical angle light cannot leave the denser medium at all and reflects entirely inside it — total internal reflection, the effect that guides light down an optical fibre.
- A prism disperses white light because the refractive index is slightly higher for blue than red, so blue bends more and the colours fan out into a spectrum.
- Runs 100% in your browser — simulations are computed locally on your device.
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