We all know something about waves; we’ve seen them in the sea and as ripples on a pond. We know that sound travels to our ears as a wave and that some properties of light can be explained by its wave nature. However, the mechanisms by which waves are propagated is perhaps not so well known. A particular feature of waves is that they are vibrations and it is this oscillatory behaviour which allows us to describe them in a quantitative sense.

We shall start with this simple idea to show that energy is transferred from one location to another. Many of the properties of waves, e.g. travelling and standing waves, interference, Doppler effect etc, will be described and illustrated by a wide variety of examples including waves on strings, water waves, seismic waves and tsunamis, waves in quantum mechanics and electromagnetic waves.