Refraction , originating in the Latin word refractive, is the action and the consequence of refracting . East verb refers to getting some radiation modify your address when passing obliquely from one medium to another with different propagation speed.

Refraction, therefore, is a modification of the address of a wave when it passes from one medium to another. For this change to occur, the wave must have an oblique effect on the surface that separates both media and these must have different refractive indices.

The term refraction is often confused with reflection , so it is necessary to define the latter slightly: it is the bounce that a lightning experiences when it hits a smooth and polished surface and returns to the previous medium. In this case it is fulfilled that: the normal and the incident ray form an angle equal to that of the normal one with the reflected ray; the normal, the incident ray and the reflected one are in the same plane.

It is known as refractive index to the ratio between the propagation speeds of a wave in the empty and in another medium X . The change in address, on the other hand, can be explained through the call snell's law which, in turn, derives from Fermat principle .

He Fermat principle , meanwhile, belongs to the scope of the optics (The branch of physics that considers light to be a wave, thanks to which it explains certain phenomena that it could not, if taken as lightning), and proposes the following: the path that light travels when it propagates between two Points is such that it could not be done in less time.

Since this statement does not cover all possibilities, the same principle was extended to correspond with the discoveries and concepts of the physical modern, so that at present it can be explained as follows: the path that the light travels when it propagates between two points is such that the time it takes does not change, regardless of the possible changes that are applied to the trajectory.

The snell's law (which is also known by the name Snell-Descartes law), is a formula used to calculate the angle of refraction of light when it crosses the surface which separates two propagation means (either from light or from any electromagnetic wave), which must have different refractive indices. It should be noted that the name of the mathematician behind this discovery is Willebrord Snel van Royen, and that the double 'l' emerged as a combination of Snel and Will ebrord.

Another statement in Snell's law is that the result of multiplying the breast of the angle of incidence by the index of refraction is constant for all the rays of light that affect the surface that separates two means.

He example The most common refraction is the phenomenon that occurs when a rod or a wooden stick is introduced into a cup filled with water. Due to the refraction of the light, an optical effect is generated that makes the rod look like broken .

It is important to note that refraction is a phenomenon that can be seen in any wave , beyond the light. The waves that are generated by a earthquake and the radio waves They are also susceptible to refraction.

The atmospheric refraction Finally, it makes the stars look above the real position, since what is observed is modified by the phenomenon of refraction that produces the atmosphere .