Refraction

• Why do waves refract when moving from air into glass?

  Glass has a higher refractive index
• What happens when a wave goes into glass?

  It slows down and rotates towards the normal
• Why does the wave rotate when passing into glass?

  • The edge of the wavefront entering the glass first, slows down
  • The part in the air is still travelling faster
  • This causes a change in direction
• What is the ray which comes directly from the source e.g. raybox?

  Incident ray
• What is the angle between the normal and incident ray called?

  Angle of incidence
• What is the angle between the normal and the reflected ray called?

  Angle of reflection
• What is diffuse reflection?

  • Rough surface
  • Rays scattered
• What type of reflection happens on a smooth surface?

  Specular reflection
• What do rough surfaces do to waves and what is it called?

  • Scatter them in all directions
  • Diffuse reflection