Can You Really Shatter a Glass with Sound?
This was one of the most famous consumer electronics TV commercials of the 1970s and begat the meme “Is it live or is it Memorex?”
That spot convinced millions of home-tapers that Memorex cassettes were the way to go. But is it actually possible to break a glass with sound? The BBC took a look:
You’re probably familiar with the urban legend: the opera singer ascends the stage and clears his throat. His audience cheer and wave their champagne flutes in anticipation. He opens his mouth – and a roomful of glasses smash to pieces. We have no record that this has ever actually happened, but there were rumours that the legendary tenor Enrico Caruso could quiver a glass into a million pieces.
And according to physics, it should be possible. It all comes down to a phenomenon known as resonance.
Read all about the science here.
The Mythbusters did exactly this in a 2005 episode.
http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/human-voice-shatter-glass/