(Please make sure to turn your volume down before watching this video)
Ernst Chladni was an 18th century German physicist and musician who is known as the ‘father of acoustics’ . Chladni was very much interested in the properties of acoustic phenomena and wrote a work entitled Entdeckungen über die Theorie des Klanges (“Discoveries in the Theory of Sound”) where he discussed a technique in which he drew a violin bow over a metal plate whose surface was covered with sand. He observed that when he drew the bow to the point it reached a resonant tone, the sand would move and gather along the nodal lines where the surface was still, creating differing linear patterns depending on the tone. These patterns are now called Chladni figures (see image below). The video above replicates Chladni’s findings with the use of an electronic tone generator as opposed to a violin bow which allows a more accurate adjustable frequency range, and thus more pattern arrangements. Variations of Chladni’s technique are still commonly used in the design and construction of acoustic instruments such as violins, guitars, etc.