Light

Light, or visible light, is electromagnetic radiation of a wavelength that is visible to the human eye (about 400–700 nm). In a scientific context, the word light is sometimes used to refer to the entire electromagnetic spectrum. Light is composed of elementary particles called photons.
Three primary properties of light are:
* Intensity, or brightness;
* Frequency or wavelength and;
* Polarization or direction of the wave oscillation.
Light can exhibit properties of both waves and particles. This property is referred to as wave-particle duality. The study of light, known as optics, is an important research area in modern physics.
Category:Optics
Category:Electromagnetic radiation