A light ray in a diagram is used to show how light moves and changes when it passes through different materials.

  • Geometric optics uses the concept that light is made up of rays to explain how it behaves as it encounters different materials and media.
  • Light rays are not tangible, they are a theoretical idea used to create a simplified explanation of light.
  • Ray diagrams use straight lines and arrows to demonstrate how light travels through space.
  • In reality, light is not composed of rays. More precise descriptions of light’s characteristics use terms like photons or waves.
  • A light ray is a graphical depiction of a slender light beam moving through either a vacuum or a medium.
  • The closest equivalent to a light ray in real life is a narrow, concentrated light beam generated by a laser.