'''Light''', or '''visible light''', is [[electromagnetic radiation]] of a [[wavelength]] that is visible to the human [[eye]] (about 400–700 [[nanometre|nm]]). In a [[Science|scientific]] context, the word ''light'' is sometimes used to refer to the entire [[electromagnetic spectrum]].[http://www.lightsources.org/cms/?pid=1000166] (What Is a Light Source?) Light is composed of an [[elementary particle]] called a [[photon]]. | '''Light''', or '''visible light''', is [[electromagnetic radiation]] of a [[wavelength]] that is visible to the human [[eye]] (about 400–700 [[nanometre|nm]]). In a [[Science|scientific]] context, the word ''light'' is sometimes used to refer to the entire [[electromagnetic spectrum]].[http://www.lightsources.org/cms/?pid=1000166] (What Is a Light Source?) Light is composed of an [[elementary particle]] called a [[photon]]. |