Optics: Huygens' principle and bending of light

[kent davidge]

I know the technical details of why light bends towards "the normal" when meeting a more refractive medium must be complicated. But I was thinking about it in a more lay fashion. I was thinking if the bending can be explained using Christiaan Huygens' principle in that a light front is made of smaller "wavelets".

Suppose a "plane" wave front is coming in and meets a more refractive medium. Not all of the parts constituting the wave will enter the medium at the same time. Those already on the medium will have a small speed whilest the remaining partners will have a greater speed. This would cause a bending, like a V shape.

If one now draws a "normal line" crossing the two media one will find that the full wave has bend towards the "normal line", just as Snell's law states.

 

[Drakkith]

Yes, that's exactly what happens.

 

[kent davidge]

Yes, that's exactly what happens.

thanks