# Snell's Law

Topics: Refraction, Snell's law, Refractive index Pages: 3 (519 words) Published: May 15, 2013
Introduction

Snell's Law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through boundary between two different isotropic media, such as water and glass.

It's also commonly known as ''The Law Of Refraction''

What is light : How is light propagated through different optic medium?

Light is the natural agent that stimulates sight and makes things visible; electromagnetic radiation from about 390 to 740 nm in wavelength.
In optics, Snel's Law is used to calculate the path of waves to compute the angles of incidence and refraction.
The law is also used in metamaterials, which allows light to be bent ''backwards'' at a negative angle of refraction with a negative refraction index.

What is refraction?
Deflection from a straight path undergone by a light ray or energy wave in passing obliquely from one medium into another, in which the velocity is different.
Refraction occurs when a beam of light is bent and is caused by a change in the speed of the beam as it passes from one transparent medium to another.
The transmission of light across a boundary between 2 media is accompanied by a change in both speed and wavelength of wave. the light wave cages direction, speeds up and slows down and transforms into a shorter or larger wave at the boundary.

The only time a wave can be transmitted across a boundary, change it's speed and still not refract is when the light wave is perpendicular to the direction which approaches the boundary.
When the light wave changes speed and approaches the boundary at an angle, refraction is observed.

History Of Snell.

Willebrord Snellius was born 13 June 1580 and died 30 October 1626.
He was a Dutch astronomer who's name has been attached to the law of refraction of light, but the law was accurately described by Ibn Sahl when he used the law to derive lens shapes that focus light with no...