When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common ...

Radar is quite spectacular in telling us exactly where rain is falling by pinging precipitation with radio waves! Our weather radar can determine more than just a storm’s location, but its movement as ...

We have all noticed how the horn of a speeding car changes as it approaches: each wave-peak is emitted from a closer point, so the wave is “squeezed” and the pitch increases. As the car recedes, the ...

The Doppler effect can be heard particularly clearly when a train passes by. The presence of the same effect in the generalised telegraph equation indicates the wave nature of heat transport over ...

Sound is a form of energy. It is that form of energy which makes us hear. Sound wave is a vibratory disturbance in a medium which carries energy from one point to another without there being a direct ...

The Doppler effect, named after Christian Andreas Doppler, is the apparent change in frequency or wavelength of a wave that is perceived by an observer moving relative to the source of the waves. The ...

The Doppler effect has helped us measure the world around us, from the movement of stars and clouds to sound frequencies. Gillian Isoardi from Queensland University of Technology explains how it works ...