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.Watch the video here to find out.