4.3    THE PHOTONS REFRACTION

The refraction is the physical phenomenon that appears when the light passes trough the surface border of two media with different light average velocity of propagation.  The light obeys the Snell law of refraction that determines the angle at which the light is refracted according to the light velocities in each medium:

The Snell law states:

n₁sinθ₁ = n₂sinθ₂

where: n₁ = c/ç₁ and n₂ = c/ç₂  are the refraction index of each medium

We will give an explanation of the phenomenon based on the concept of trains of photons.

In general, light is emitted as a three-dimensional arrangement of trains of photons but a two dimensional array is enough to explain the phenomenon because of its symmetry.

All the photons maintain links with the nearer photons such that the array is compact and it is maintained aggregated while entering the second medium. If the second medium has a slower average velocity the beam is forced to brake on one side first than the other. The figure shows that, if ç₂ < ç₁ the left part of the array is comprised because the photons of this side are braked first (by atoms of the medium) than those of the right side. Is intuitive that this produces a torque that makes the array rotate in the border region and this is what produces a new angle of propagation of the array in the second medium.

A prism separate white light in the rainbow spectrum. This could be explained considering a large beam as a large train composed of short sub-trains with different color of photons each (this is in accordance with Newton’s experiment of the disk with all colors which when rotating at enough velocity it is seen as a white disk).The refraction angle is dependent on the color of the incident photons and they will refract in different angles each at their time.