Wave characteristics

What is a wave?

  • Waves carry energy from one place to another.
  • Because waves carry energy, some waves are used for communication, eg radio and television waves and mobile telephone signals.
  • There are many types of waves including sound waves, water waves and all the parts of the electromagnetic spectrum.
  • Some types of waves need to be transmitted through matter, either a solid, liquid or a gas. For example, water waves have to travel in water. Sound waves need a solid, a liquid or a gas to travel in.
  • The waves in the electromagnetic spectrum, like light or UV waves, do not need any matter to travel in.

How does sound travel through the air?

Question

Can you think of an everyday situation that reminds us that electromagnetic waves can travel through a vacuum? (Clue - most of space is a vacuum.)

On Earth, we receive light, heat and other radiation from the Sun. These waves have travelled through the vacuum of space for most of their journey.