Talk:Optics/WS1
Optics is the study of the behavior and properties of light, including its interactions with matter and its detection by instruments.[1] The word optics comes from the ancient Greek word ὀπτική, meaning appearance or look.[2]
Optics often describes the behavior of visible light and the behavior of ultraviolet and infrared light, which are similar to visible light but are not detectable by the naked human eye. Other phenomena such as X-rays, microwaves, and radio waves can be described with optical principles because all of these, along with visible light, are types of electromagnetic waves.[1] During the nineteenth century the physicist James Clerk Maxwell discovered that light is a type of electromagnetic radiation; since that time optics has largely been regarded as a sub-field of electromagnetism within theoretical physics.
Classical electromagnetism can be used to describe most everyday optical phenomena. It is usually simpler to use one of the two broad simplifying assumptions for describing light: to treat light as a ray or as a wave. Geometrical optics, developed in the 16th and 17th century, treats light as a collection of rays that travel in straight lines unless they are bent through refraction. Physical optics was developed in the 19th century and accounts for the wave-like nature of light, which is needed in particular to explain interference and diffraction.
Together, geometrical and physical optics encompass classical optics, a system of models capable of describing and predicting many optical phenomena. However, in certain situations, more modern approaches must be used for accurate predictions and explanations. In particular, observations that light behaves both as a particle and as a wave were first correctly explained in the early twentieth century when quantum mechanics replaced classical electromagnetism. Quantum optics deals with the best model of light scientists have developed to date: the photon.
Optical science is relevant to and studied in many related disciplines including electrical engineering, photography, psychology, and medicine (particularly ophthalmology and optometry). Practical applications of optics are found in a variety of technologies and everyday objects, including mirrors, lenses, telescopes, microscopes, lasers, and fiber optics.