1. Swing a buzzer of any kind over your head in a circle. Ask some friends to stand off to the side, listen to the buzzer, and report their observations. Then switch places so you too can hear the...

1. Swing a buzzer of any kind over your head in a circle. Ask some friends to stand off to the side, listen to the buzzer, and report their observations. Then switch places so you too can hear the buzzer as it moves. How does the sound of the buzzer change? Why?

2. How does the Doppler effect provide evidence that we live in an expanding universe?