We have all seen it in the movies: a woman belts out a loud, high pitch note that can shatters the glass in the entire building, from the wine glasses to the windows. But can a voice really reach a frequency high enough to shatter glass? Glass has a natural resonant frequency which is the speed at which it will vibrate if disturbed by a stimulus such as a sound wave. However, not all glass has the same natural resonance. Wine glasses are especially resonant because of the goblet shape which is why, when struck, they emit a pleasant, ringing sound. It is at that ringing note a singer must reach in order to shatter the glass, vibrating the air molecules around the glass, causing the glass to vibrate as well. If the corresponding note is sung loud enough, the glass will eventually vibrate its self into smithereens. But what is that frequency a singer sings to vibrate a wine glass and just how loud would she have to sing to make it shatter? Also, what else would contribute to making the glass easier to break? Research the idea and tell me your findings and thoughts.
I've seen this on Mythbusters before, I believe the singer had to hit a high C to break the glass. Also it depends on how thick or thin the glass is oon how easily it will break.
ReplyDeleteadding speakers and giving the person a mic will contribute significantly to making the glass easier to break...if that is ''legal.''
ReplyDeleteYes the human voice can alone be enough to shatter glass according to this website that documented a mythbysters show, Human voice with no amplification
ReplyDeleteThis was the big test: no amplification with Vendera singing with his lips almost directly against the glass.
After 12 glasses: no breakage
Adam gave it a try: "The best case scenario shatters in my face, how do you think that makes me feel?" Not surprisingly, Adam couldn't do it.
Vendera came back (20th attempt): BREAK!
confirmed: an unassisted human voice can break a glass
http://kwc.org/mythbusters/2005/05/mythbusters_breaking_glass_a_r.html <- my source of information on this topic.
ReplyDeleteWhen trying to shatter glass with your voice, you have to hit a very high freqency with your voice. But first you have to find out the glasses frequency so you can reach that & higher. To find the glasses frequency, you can dip your finger in water & run it along the rim of the glass, or tapping the glass gently. Once you hear the noise (frequency) you have to achieve that frequency with your voice, or higher to make it shatter. But if you are going to try this, wear eye protection to cover your eyes from glass!
ReplyDeleteJust like sciencegeek101 said, in the experiment I found, if you would like to try this wear safety goggles..... 1.Put your lips almost directly against the glass. This is not necessary, as your mouth can be several inches away, but the closer you get the more focused the tone of your voice will be.... 2. Sing powerfully - cheap glasses will break at a lower decibel, such as 80-90 decibels. The glasses used on MythBusters were very expensive hard titanium crystal glasses, more amplification (roughly 105+ decibels) was needed to break the glasses....
ReplyDeletehttp://www.wikihow.com/Break-a-Glass-with-Your-Voice
ReplyDeleteWithout actually looking anything up, my initial thought is that the harder (read more expensive) crystal glass would break easier because it is more rigid and less flexible then cheaper glass.
ReplyDeleteOnly the finest leaded crystal is reasonably able to be broken with the human voice alone. Additionally, the glass needs to have microscopic defects in certain positions to be able to shatter, which is why on mythbusters it took so many different trials to finally work.
ReplyDeletehttp://www.scientificamerican.com/article.cfm?id=fact-or-fiction-opera-singer-can-shatter-glass
I believe there is few that can actually get a glass to break, but i think that if they hooked up a mic...just about anyone could get the glass to break.
ReplyDeleteTo the first comment: It is a high C in legend, which means that is the general note people think of when they are asked this question or when they see it. In reality, it depends on the glass being used as to what note you would have to hit to shatter it, but you are right that the thickness of the glass does play a insignificant role in trying to shatter the glass. A greater thickness would require a louder pitch.
ReplyDeleteTo ruby: That is exactly where I found my information and it's true that it is easier for the glass to break if it holds microscopic defects unseen to the naked eye because those little scratches and cracks help weaken the glass.
And to nerdman and Mrs. Clause: I would probably think that too...
I will have to check out the Myth-busters trial of this for I have never seen it, especially since a lot of you made a great deal of reference to it.
Keep up the great work and keep coming with those comments!
things that would contribute to breaking more easily would be the thinner the glass and the shape it is like it says above wine glasses are known to break because of their goblet shape maybe u can enhance that somehow... call up Mariah Carey we gotta an experiment on our hands.
ReplyDeleteIt has to do with resonance. Lightly strike the glass and it will ring. That tone is it's natural frequency. If you then make a tone that is at that same frequency, the glass will vibrate as well. If the tone you make is loud enough, then the vibration will cause the glass to flex more than the strength of the glass can withstand and the glass shatters. The lower the frequency of the glass the easier it is to shatter the glass.
ReplyDeleteIt depends if the glass is crystal or not. You would have to match the resonance frequency.
ReplyDeleteThanks to all who commented on this post!
ReplyDelete