how do glass goblets create sound?

Question

how do glass goblets create sound? you know, when you rub the rim this sound goes off. any links to explain this would be appreciated.

I know how to do it, but why does it happen?

Answer 1

Every material (such as glass, steel, concrete) has a natural frequency at which it vibrates, called a resonant frequency. If you put energy into the substance at its resonant frequency, you will force it to vibrate or resonate (resonance is a forced vibration). In the case of the wine glass, your finger slides and sticks along the surface of the glass as you rub the rim (a wet fingertip has no oil and makes a better contact with the glass). The rubbing imparts energy to the glass molecules and causes them to resonate. The motion of your hand sets up a wave of vibration traveling through the glass. The vibrating glass causes air molecules to vibrate at the same frequency. The vibrating air molecules are the sound wave that you hear (the frequency or pitch of the sound wave is the same as the resonant frequency of the glass).

So, how does the water change the pitch of the singing wine glass? As the resonant wave moves around the glass, it drags the water molecules with it, creating a wave of water that you can see near the edge of the glass. The dragging water molecules effectively increase the mass (both the water and the glass molecules) and reduce the energy of the wave traveling through the glass. When the energy is reduced, so is the frequency of the wave in the glass, which is reflected in the pitch of the sound wave that you hear.

Read more from the source...hope this helps

Answer 2

Rubbing a slightly damp finger along the rim of fine crystal sets up vibrations in the crystal. Fine crystal has a very clear, high pitch. You can do this with other glass as well but the ring isn't quite as high or true a pitch. Ben Franklin loved the sound and created a new musical instrument called a Glass Harmonica. It consists off glass bowls (basically goblets with the stem but off) hung on a rod which rotates with foot pedals. The bottoms of the disks run through a water bath as they rotate and with all the disks lined up on the rod it can be played almost like a piano. Very cool sound! Try it yourself1 You can also take several glass of the same size, fill them with different amounts of water and you'll have different pitches.

Answer 3

Vibrations cause sound by disturbing the air molecules. The friction of your finger moving around the rim of a glass causes a tone. If the glass is fine crystal, you will get a better tone because of the clean molecular structure of the glass. The faster you move your finger, the higher the pitch. Think of a violin string and the cat gut scraping across it. It causes sound. The faster you bow the violin, the higher the pitch. It is the vibrations. Whether it's the bow moving across the violin string, or the friction of your finger rubbing on the glass rim, the effect is that it causes a sound. Your stereo speakers work in the same way. Electrical impulses cause the diaphragm of the cardboard speaker surface to vibrate back and forth. The faster the speaker vibrates, the higher the pitch. It is the way vibrations disturb the air medium that carry the sound. Sound is radio frequency. The human ear can hear those vibrations, up to 20,000 Hertz. Beyond that, the sound is ultrasonic and can't be heard, except by a radio receiver, which translates those vibrations, through electronic circuitry, into audible sound.

Answer 4

On a design level, mismatched glasses would look quite elegant and appropriate if, however, this somehow fits into the decor of the rest of the table, ie plates and centerpieces. Without knowing what you do and do not have control over in regards to the place settings, if you have some goblets and some flutes dispersed alternately...perhaps find a centerpiece with both squat/full and wispy/thin elements. Also, keep in mind the wine choices. Perhaps it is best to have both flutes AND goblets present for every setting? Overall though, it doesn't matter at all if the bride and groom glasses match the rest of the party =) Congrats!

Answer 5

Glass does not do this as good as crystal. But the way it works is by vibration. Sound travels in waves. The friction of your fingerprints and the molecules of the crystal create vibrations of the goblet. The vibrations of the goblet propogate to the air...vibrating the air. When the air vibrates it is perceived as sound.

Answer 6

you are creating this ring of air inside the glass fromand from the movement you make from rubbing your finger on the rim of the glass. the air then escapes while your doing so and you then get that sound =]

Answer 7

you have to drink the wine first...and it's the same concept of hearing the ocean from a seashell.....just lick your finger and rub the rim...easy!

Answer 8

I can tell you if they make a nice sound,,they are crystal.

Answer 9

the guys that play them use water

Answer 10

one word: Reverberation!