The tree is up, the house is decorated and the presents wrapped. Christmas songs are playing on the radio and festive scents are drifting in from the kitchen. Take a few minutes to put your feet up and listen to this beautiful rendition of the Sugar Plum Fairy from Tchaikovsky’s The Nutcracker.
How do glasses produce sound work?
When you brush around the top of a glass with your finger an eerie but beautiful sound is made. As your finger brushes around the rim it sticks and slips, sticks and slips, sticks and slips, producing a wave of movement that causes the glass to vibrate at its resonant frequency (the exact wave frequency that causes the molecules in the glass to vibrate and bang against each other). As the glass vibrates, so does the air around it, producing a sound wave. As the airwaves meet your ear, you hear the sound. Adding water to a glass gives it a higher mass, making its resonant frequency sound lower in pitch.
This trick is used to create the magical musical instrument called a glass armonica. I love how these physical properties produce such beauty.
Have a Merry Christmas everyone!
May you always be amazed by and thankful for the amazing world we live in.