Refraction of Light

• Refraction occurs when waves pass through materials of different optical densities
• When waves pass into a denser medium (air to glass)

  • speed decreases
  • wavelength decreases
  • frequency stays the same
• When waves pass into a less dense material (glass to air)

  • speed increases
  • wavelength increases
  • frequency stays the same
• When waves pass into a denser material (air to glass)

  • along the normal, the direction doesn't change
  • at an angle to the normal, the ray moves towards the normal
• When waves pass into a less dense material (glass to air)

  • along the normal, direction doesn't change
  • ray moves away from the normal
• When white light passes through a triangular prism, it splits into a rainbow of colours