In the latest edition of the Hub Lab we are going to look at sound and hear about something called the Doppler Shift! 

Have a look as Phil of Science brings his big brain to the After School Hub.

In this experiment we will...
1. Explore sound and Doppler Shift
2. Observe the effect happening every day in real life.

How do you doppler?

For this investigation you'll need something that makes a consistent sound and a piece of strong string. This could be a buzzer or similar but whatever you're using, you need to be careful to: 
1. Not let the thing spinning go
2. Have the rope secured safely
3. Not whack into anything when swinging.

Maybe try it outside...

Once you’re happy and you give your apparatus an auld swing, you’ll observe that when the buzzer or sound source is moving towards you, in effect, it is catching up slightly with its own sound waves. With each sound of the buzzer, the source is a little closer to you.

The result is that the waves are squeezed together, and more of them reach your ear each second than if the buzzer were standing still. Therefore, the pitch of the buzzer sounds higher.

So, what do you think will happen with the buzzer is moving away from you? Are the waves getting closer together or further apart and what does that do to how the sound appears to you?

Have a think or even try it out! All the instructions and more are in this info sheet.

Tune in to After School Hub every day at 3.20pm on RTÉ2 and catch up on RTÉ Player.

And don't forget to keep sending us your own home experiments: Upload and win here