visible light
The only light that people can see is called visible light . This light consists of a very narrow range of wavelengths that falls between infrared light and ultraviolet light. Within the visible range, we see light of different wavelengths as different colors of light, from red light, which has the longest wavelength, to violet light, which has the shortest wavelength see Figure below . When all of the wavelengths of visible light are combined, as they are in sunlight, visible light appears white. You can learn more about visible light at this URL: http://www. youtube. com/watch?v=PMtC34pzKGc .