THE refraction is the optical phenomenon in which there is a change in the speed of light due to the change of means of propagation. In a vacuum, the speed of light has its maximum value (3.0 x 108 m/s); but when penetrating different media, its speed is reduced according to the characteristics of the place where the light waves propagate.
We can see refraction in our daily lives: when an object is immersed in water and appears to be broken (see image that opens the text), in the formation of Rainbow (where two consecutive refractions generated when light enters and leaves a drop of water cause the light scattering), in the use of the refractive index as a parameter for quality control of various products etc.
When suffering two consecutive refractions through a prism, the white light spreads out in the colors that make up its electromagnetic spectrum
Refractive index
The refractive index (n) is the dimensionless quantity resulting from the ratio between the speed of light in a vacuum (c) and the speed of light in any medium (v).
From this magnitude, we can have an idea of how much the speed of light changes after changing the material medium.The equation above shows the inversely proportional relationship between the speed of light in the propagation medium (v) and the refractive index, so we can understand that the higher the refractive index, the slower the propagation speed of light in the medium and vice versa.
Diamond is one of the elements with the highest refractive index, that is, in this material, the speed of light is very low. Knowing that the speed of light in diamond is approximately 1.25 x 108 m/s, we can define the index of refraction of this element as follows:
n = c ÷ v
n = 3.0 x 10 8 ÷ 1.25 x 10 8
n = 2.4
The table below shows the index of refraction of some elements.
By Joab Silas
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/fisica/o-que-e-refracao.htm
