This is a preview. Log in through your library . Abstract Fermat 's principle of stationary travel time serves as a powerful tool for solving direct and inverse problems of wave propagation in media ...

IN the wave theory of light, the geometrical laws of optics—rectilinear propagation, reflection and refraction—and other results besides, rest on a single principle. The fundamental postulate is that ...

Ever wonder how a mirror works? If you want to find the path that light takes when reflecting off a surface, you could use Fermat's Principle. This states something like this: The path that light ...