Reflection and refraction

The reflection and refraction of light

The law of reflection

    Objects can be seen by the light they emit, or, more often, by the light they reflect.
Reflected light obeys the law of reflection, that the angle of reflection equals the angle
of incidence.

For objects such as mirrors, with surfaces so smooth that any hills or valleys on the surface
are smaller than the wavelength of light, the law of reflection applies on a large scale.
All the light travelling in one direction and reflecting from the mirror is reflected in
one direction; reflection from such objects is known as specular reflection.

Most objects exhibit diffuse reflection, with light being reflected in all directions.
All objects obey the law of reflection on a microscopic level, but if the irregularities
on the surface of an object are larger than the wavelength of light, which is usually the
case, the light reflects off in all directions.

The law of refraction

Refraction is the bending of light (it also happens with sound, water and other waves)
as it passes from one transparent substance into another.

This bending by refraction makes it possible for us to have lenses, magnifying
glasses, prisms and rainbows.
Even our eyes depend upon this bending of light. Without refraction, we wouldn’t be able
to focus light onto our retina.

Wikipedia(2016), Refraccion of the light. Recovered from: https://es.wikipedia.org/wiki/Refracci%C3%B3n
BCC(2016), Refraccion and refrection of the light. Recovered from: http://www.bbc.co.uk/bitesize/higher/physics/radiation/refraction/revision/1/