Refraction is the bending of light as it passes from one medium to another. The change in velocity of light when it travels from one medium to another causes it to change direction. This phenomenon is governed by Snell's Law, which relates the angles at which light enters and exits a medium to the refractive indices of the two media involved.

Snell's Law

Snell's Law is mathematically represented as:

n1 * sin(theta1) = n2 * sin(theta2)

where n1 and n2 are the refractive indices of the initial and final medium respectively, and theta1 and theta2 are the angles of incidence and refraction measured with respect to the normal to the interface between the two media.

Example

Let's consider a ray of light traveling from air (n1 = 1.00) to water (n2 = 1.33). If the angle of incidence of the ray is 45 degrees, we can calculate the angle of refraction using Snell's Law.

Applying Snell's Law:

sin(45) = 1.33 * sin(theta2)

Simplifying the equation, we find that the angle of refraction, theta2, is approximately 34 degrees.

Applications of Snell's Law

Snell's Law is fundamental in understanding various optical phenomena, such as the bending of light in lenses, the formation of rainbows, and the behavior of light in prisms. It helps us quantify how light changes direction when it encounters interfaces between different materials.