Shattering glasses with the human voice?

[DSYoungEsq]

@Cervaise

The Mythbusters clip was fun, but a potentially significant problem with their methodology jumped out at me.

In their preliminary testing, when they were able to shatter a wine glass with amplified sound, they placed the glass on a hard surface in front of the speaker, and in fact taped it down. However, when they got to the final tests of unamplified human voice, the human subject held the glass in his hand while producing his sound.

This bothered me quite a bit. You’d think, for the sake of controls, that they would have secured the glass the same way in both tests. I don’t know whether the hand-held glass might have been more resistant to shattering, that is, if the softer fingers might provide some sort of cushioning or shock absorption compared to the hard tabletop, but the whole point of objective testing is that you don’t want to introduce these sorts of ambiguities.

Unless they do these things on purpose in order to generate mail so they have an excuse to revisit material and thus fill up a segment of the show rather than having to worry about coming up with yet another new topic to investigate…

Having demonstrated that sound COULD shatter the glass, it makes sense to jump to the opposite extreme. Should they have been unable to shatter the crystal with the unamplified human voice under the conditions shown, they could then add more rigorous conditions one by one to see which condition made the result possible. Thus, hold the glass to start, then try taping the glass down, then try having the singer sing through a narrow opening, etc.

Given that it shattered even when the glass was held in hands, we must conclude that the taping down was not a necessary part of the shattering.

[Ghanima]

I watched that Mythbusters not too long ago, and if I recall correctly, they never got an intact glass to shatter. They had to drill a hole in the glass to get it to shatter.

So what’s up with that?

[John_W.Kennedy]

You remember wrongly. The only hole drilled in anything was a hole drilled in a board interposed between speaker and glass to focus the sound. That was during the earlier tests. By the time they got to naked voices, they weren’t using it anymore.

[iTulipFred]

…to get it to resonate at its harmonic frequency. All ya need is wind:

- YouTube

In case HTML is on:

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[DSYoungEsq]

@iTulipFred

…to get it to resonate at its harmonic frequency. All ya need is wind:

http://www.youtube.com/watch?v=HxTZ446tbzE

Well, not really, but of course most of us have actually read all the responses in this thread and know the correct answer, instead of just jumping to the bottom and posting.