Fermat's principle

noun

Definition of Fermat's principle

  1. :  a statement in optics: the path actually followed by a ray of light undergoing reflection or refraction is one of either minimum or maximum time as compared with adjacent arbitrary paths except for reflection or refraction at an aplanatic surface or passage through an aplanatic lens for which the time is constant

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Origin and Etymology of fermat's principle

after Pierre de Fermat †1665 French mathematician, its formulator


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