Ray Optics, Fermat¿s Principle, and Applications to Gener...
Perlick, Volker
All kind ofinformationfrom distant celestialbodies comestous intheform of radiation. Inmost the of electromagnetic cases thisradiation propagation be can as a reasonable in described, terms of This is approximation, rays. truenot inthe but also inthe radio only ofthe electro opticalrange range Forthis the of reason laws areoffundamental magneticspectrum. optics ray for importance and astronomy, astrophysics, cosmology. to According arethe of g...
