Pupils take an active role in this demonstration on light waves to show the Doppler effect in this video for KS3/4 physics lessons. Pupils find out what it's like to be a light wave travelling to Earth from a distant star in a playground demonstration, which shows redshift and blueshift as a result of the Doppler effect. Red- and blue-shifting of light is a difficult idea to grasp without a visual aid. This demonstration is a practical way of explaining the idea of light changing when the emitter is moving relative to the observer.

Video Series: Teaching Astronomy and Space
Release Date 2010