Live radio sound science
Today the lovely Ester had me on her 'ready, steady, learn' segment on bFM to chat about this project. I figured the best way to explain it was for Ester to be day 41 in our 100 days and to carry out an experiment showing how sound vibrations can be changed resulting in a different pitch.
Taking an empty bottle, Ester blew into the top on the bottle (similar to how you would blow down into a flute, with your top lip sticking out more than your lower lip).
When you blow into the bottle, it creates an internal pressure inside the bottle because there is nowhere for the air to go. When there is enough pressure the air is pushed back out of the bottle through the other side of the hole that you are blowing in to. When these two air streams pass each other, the air vibrates, and this generates sound. Sound is just our ears hearing these vibrations and the slower the vibration the lower the pitch. If you blow in a smaller bottle, or fill the bottle you have with liquid, the pitch will increase as the vibration gets faster. This is because there is less air inside the bottle to vibrate and so it can happen faster.
To listen to Ester and I carrying out this experiment and chatting about this 100 days project click here: