See Also: Snell's law(medicine)
snell(medicine)
Snell's law(dictionary)
snell(1)(dictionary)
snell(2)(dictionary)
Snell's law(encyclopedia)

Snell's law (sh)




Relationship between the path taken by a ray of light as it moves from one medium to another and the refractive indices of the two media.

Discovered in 1621 by Willebrord Snell (1580-1626), the law went unpublished until its mention by Christiaan Huygens. If n1 and n2 represent the indices of refraction of two media, and ¦È1 and ¦È2 are the angles of incidence and refraction that a ray of light makes with the line perpendicular to the boundary (the normal), Snell's law states that n1/n2 = sin ¦È2/sin ¦È1. Because the ratio n1/n2 is a constant for any given wavelength of light, the ratio of the two sines is also a constant for any angle.