Naked Science Forum
General Science => General Science => Topic started by: nick2price on 23/04/2009 23:20:26
-
I know it is possible to break glass with high frequency sound, but is it possible to achieve the same with ice?
Is it to do with finding out the resonant frequency of ice?
Any help would be appreciated.
-
It also depends upon the frictional losses in ice as it vibrates. Glass shatters because the internal friction losses are low enough for a large amount of resonant energy to build up and, thus, the distortion takes the glass past its stress limit.
You would need to look up the detailed physical properties of ice. It may well be that the ice would have so much internal friction that it would 'damp' any resonance. This could mean that you would need to 'drive' it with an unrealistically high level of sound.
-
Breaking glass with sound is caused by setting up a resonance in the structure made from the glass rather than in the material itself. What breaks a wine glass when the soprano hits the right note is the same note you get when you run your finger around the rim. A cube of that same glass would not break with that note. Although sound with enough intensity may well shatter it.
It would be the same with ice. So much would depend on the shape of the structure if you wished to create the resonance I believe you are referring too. Very few naturally occurring ice structures would be so conveniently shaped. However sound, in the form of shock waves, can certainly break ice, usually along pre-existing weaknesses betwen ice sheets. It is not exactly the same, but explosive charges are used to start avalanches so they are not a later hazard to people who wish to ski.
-
Breaking glass with sound is caused by setting up a resonance in the structure made from the glass rather than in the material itself. What breaks a wine glass when the soprano hits the right note is the same note you get when you run your finger around the rim. A cube of that same glass would not break with that note. Although sound with enough intensity may well shatter it.
It would be the same with ice. So much would depend on the shape of the structure if you wished to create the resonance I believe you are referring too. Very few naturally occurring ice structures would be so conveniently shaped. However sound, in the form of shock waves, can certainly break ice, usually along pre-existing weaknesses betwen ice sheets. It is not exactly the same, but explosive charges are used to start avalanches so they are not a later hazard to people who wish to ski.
It isn't just the structure which affects the resonance. It is the Q of the resonator and this depends upon the internal losses of the material. You could never break a rubber wineglass in that way because the amplitude of resonance could never build up high enough. Likewise, metals do not shatter, either, under these circumstances, because they have metallic bonding and can deform.
My point was that you would need to know the actual physical properties of ice before you could predict whether this would work or not.
-
No, it isn't just the structure that affects the resonance but it isn't just the material either. You may be able to destroy a solid sphere of glass with enough sound energy (quite a lot) but you certainly can shatter a wine glass with relatively little. The material is the same but the shape is different. Of course the Q is key factor as this relates (inversely) to the loss of energy at resonance through benign dissipation.
A rubber wineglass must make the wine taste really horrible. I think I will stick to the crystal for the Savigny-les-Beaune I am going to have with my lunch and trust there are no evil people around with powerful sound sources :-)
-
Careful if you intend to have ice with it.
-
Ice with a fine red; I don't think so.
-
Not in the interests of Science?
-
Sacrilege.
-
It depends upon the frictional structur vibrates. Glass shatters because the internal friction losses are low enough for a large amount of resonant energy to build up and, thus, the distortion takes the glass past its stress limit.
-
Which is what the second post of this thread says.
-
Did you get anywhere with this? I am researching the subject with respect to breaking up ice on the superstructure of ships. Was this close to your reason for asking?