Katoptrik

Katoptrik is a branch of optics that deals with the properties of light as it relates to reflection. It is one of the oldest branches of optics, with ancient Greek scholars like Euclid and Ptolemy making significant contributions to its understanding. The fundamental principle of katoptrik is the law of reflection, which states that the angle of incidence is equal to the angle of reflection, and that the incident ray, the reflected ray, and the normal to the surface at the point of incidence all lie in the same plane.

This branch of optics is concerned with how light bounces off various surfaces, particularly mirrors. It explores the formation of images by plane mirrors, which are virtual, upright, and laterally inverted. It also investigates the behavior of light reflected from curved mirrors, such as spherical mirrors. Concave mirrors can form real or virtual images depending on the object's position, and convex mirrors always form virtual, diminished, and upright images. Katoptrik also examines phenomena like multiple reflections and the optical illusions that can arise from them. Understanding katoptrik is crucial for the design and function of optical instruments that utilize mirrors, such as telescopes, periscopes, and even everyday items like rearview mirrors.