Why do certain glasses and goblets 'sing' when you run your finger aroun!
Question: Ever run your hand against a wall or board and hear it squeak? its the same effect. Its the vibrations from your finger tip against the glass. the glass above the water line vibrates, causing the sound. thats why changing the amount of water, wine or other liquid changes the pitch or tone of the "Singing".
Answers: Ever run your hand against a wall or board and hear it squeak? its the same effect. Its the vibrations from your finger tip against the glass. the glass above the water line vibrates, causing the sound. thats why changing the amount of water, wine or other liquid changes the pitch or tone of the "Singing".
that's a characteristic of crystal (how you can tell the expensive stuff from the plain old glass stuff)
add on: I would venture to guess it is a 'vibration' issue, and the resulting sound would vary under different conditions.
It's the surface tension that real crystal has.
because they are made of crystal
It's harmonic vibration. If the glass is cracked, it won't do it.