Interactions of light

contrast reflection, absorption, refraction, and scattering.

Contrast reflection

When light passes from from one type of medium to another type of medium, the medium being composed of substances like air, glass or water, one or both of two different types of changes take place in the direction of the ray of light as it strikes the surface separating the two mediums. These changes in direction of light are called reflection and refraction.


Absorption is what happens when light energy is transformed into heat.


  • The speed of light in a vacuum is constant at 300,000,000 m/s

  • The speed of light slows down through a medium

  • Bigger the wavelength faster the light


  • Scattering of light is what happens when light travels out in many different directions

  • A good example of this is the color of the sky.

  • Blue and violet are the shortest wavelengths.