A computer based experiment to show that Snell’s law follows from Fermat’s principle

Abstract

Understanding reflection and refraction are an integral part of school and college learning. In nature even birds and fish (Archer fish) very skillfully use refraction to strike down prey present above or below the water surface. Fermat’s principle allows one to look beyond the reasons behind the laws governing the reflection and refraction. A pedagogical computer based experiment (CBE) is proposed to demonstrate the simplicity of usage of Fermat’s principle for undergraduate physics students in universities and school students pursuing secondary education by implementing a program written in open source software Scilab and also through MS Excel/Open Office. In this work we probe: (i) the refraction across a plane interface and (ii) reflection from a parabolic mirror and arrive at many useful propositions.