Refraction is the bending of a wave as it passes from one medium into another medium with a different density, which changes the wave's speed. This phenomenon is commonly observed with light waves but can occur with any type of wave, including sound and water waves.
Characteristics of Refraction
- Change in Speed and Direction - When a wave, such as a light wave, enters a new medium at an angle, its speed changes due to the different densities of the mediums. This change in speed causes the wave to bend. For example, light waves slow down when entering a denser medium like water from air, causing the light to bend towards the normal (an imaginary line perpendicular to the surface).
- Dependence on Wavelength - The degree of refraction depends on the wavelength of the wave. Different wavelengths of light refract by different amounts, which is why a prism can split white light into its constituent colors, creating a spectrum. This dispersion is a result of the variation in refractive index for different wavelengths.
- Snell's Law - The relationship between the angles of incidence and refraction is described by Snell's Law, which states that the ratio of the sine of the angle of incidence [tex](\(\theta_i\))[/tex] to the sine of the angle of refraction [tex] (\(\theta_r\))[/tex]is constant and is equal to the ratio of the wave's velocities in the two media or the inverse ratio of the refractive indices of the media: [tex]\[ n_1 \sin(\theta_i) = n_2 \sin(\theta_r) \][/tex]
- where [tex]\(n_1\) and \(n_2\)[/tex] are the refractive indices of the two media.
