Fermat's principle

American

noun

Optics. the law that the path taken by a ray of light in going from one point to another point will be the path that requires the least time.

Fermat's principle British

noun

physics the principle that a ray of light passes from one point to another in such a way that the time taken is a minimum

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of Fermat's principle

First recorded in 1885–90; named after P. de Fermat

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023