When you think of visualizing sound, you might think of the iTunes visualizers you used to play with years ago, or perhaps a waveform that shows the volume of a digital audio file comes to mind. The ...

HAVING to prepare some lectures on sound, I wished, if possible, to illustrate, without any very complicated apparatus, the way in which a sound-wave is propagated.

Be it water, light or sound: waves usually propagate in the same way forwards as in the backward direction. As a consequence, when we are speaking to someone standing some distance away from us, that ...