Reflection & Refraction

Light

• Light is part of the electromagnetic spectrum, so it is a transverse wave
• The vibrations of the electric and magnetic fields that make up the wave are at right angles to the direction the light is travelling
• Light can be reflected off a boundary and refracted through a boundary; both effects are covered in detail in the rest of this topic

Sound

• Sound waves are longitudinal waves; the air particles oscillate back and forth along the same line that the wave is travelling along
• Sound can also be reflected and refracted:
  • the reflection of a sound wave off a hard surface is called an echo
  • sound refracts when it crosses between media of different densities (for example, layers of warm and cold air, or air and water), bending its direction of travel

Why both bend

• The same wave phenomena work for any wave type (water ripples, sound, light, microwaves, even seismic waves) because reflection and refraction depend on how a wave's speed changes when it meets a boundary, not on whether it is transverse or longitudinal