On today’s episode of “For Science!” we invite a very special guest to the lab, 9 & 10 chief meteorologist Michael Stevens to discuss the often misunderstood concept of Doppler. Many believe that the only aspect is the Doppler Effect, which is utilized by forecasters like Michael to predict incoming weather conditions, but the phenomena has far reaching applications since discovered by Christian Doppler in 1842.
The basic principle measures the distance of vibrations from a static source. For example, think back to a time you were standing stationary and you were passed by a car or a train. The sound and vibrations intensify the closer the vehicle gets to your location and fades as that same vehicle puts distance between the two of you. This change in frequency is Doppler.
For this experiment you will only need two things:
- An audio recording device (even a phone with an audio recording app will work here)
- An electric beard trimmer
Steps:
- Turn on your audio recorder, turn on the beard trimmer and place it close to the microphone. Hold both steady for 10 seconds. HYPOTHESIS - What do you think will be the outcome?
- Now start a separate recording, turn your beard trimmer back on but this time, move the beard trimmer back and forth in front of the microphone. HYPOTHESIS - What do you think will be the outcome?
- Listen to each recording, what do you notice about the different recordings?
This difference is Doppler and can be used to measure the distance between the recorder and the cause of the vibration.