Wavefronts 3D Simulation
Rays are convenient but wavefronts are what is physically there. This 3D simulation shows waves spreading as expanding surfaces and lets you place obstacles and boundaries to watch how those surfaces reflect and refract.
How to use this simulation
- Switch between plane and spherical wavefronts
- Insert reflecting surfaces and refracting boundaries
- Rotate the 3D view and toggle the ray overlay
What to look for
- Spherical fronts from a distant source flatten into plane fronts
- Fronts bunch closer together in the slower medium as the wavelength shortens
- Rays always stay perpendicular to the wavefront, however it is bent
The physics behind it
A wavefront joins points oscillating in phase, and rays are simply lines drawn perpendicular to it. Huygens' construction treats every point on a front as a source of secondary wavelets whose envelope forms the next front. That single idea explains reflection, refraction and diffraction without needing separate rules for each.