# Snell's law

## Snell's law

[snelz]
noun Optics.
the law that, for a ray incident on the interface of two media, the sine of the angle of incidence times the index of refraction of the first medium is equal to the sine of the angle of refraction times the index of refraction of the second medium.

Origin:
named after Willebrod Snell van Royen (died 1626), Dutch mathematician

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2013.
Cite This Source Link To snell's law
Collins
World English Dictionary
 Snell's law (snɛlz) —n physics the principle that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant when a light ray passes from one medium to another [C17: named after Willebrord Snell (1591--1626), Dutch physicist]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
00:10
Snell's law is always a great word to know.
So is ort. Does it mean:
 a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
 a scrap or morsel of food left at a meal.
Encyclopedia Britannica
Encyclopedia

snell's law

in optics, a relationship between the path taken by a ray of light in crossing the boundary or surface of separation between two contacting substances and the refractive index (q.v.) of each. This law was discovered in 1621 by the Dutch astronomer and mathematician Willebrord van Roijen Snell (1580-1626; also called Snellius). The account of Snell's law went unpublished until its mention by Christiaan Huygens in his treatise on light.

Learn more about Snell's law with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source