Editing Cymatics (section)

==Work of Hans Jenny==
In 1967 [[Hans Jenny (cymatics)|Hans Jenny]], a student of the [[anthroposophy|anthroposophist]] [[Rudolf Steiner]], published the first of two volumes in German entitled ''Kymatic''; the second was published posthumously in 1972.) He showed the evolution of harmonic images by subjecting inert substances to oscillating [[sound wave]]s. His substantial body of work, based on rigorous scientific methodology, developed Chladni's experiments, highlighting intricate, organic, harmonic images that reflected many universal patterns found throughout nature and especially living organisms. Jenny spread powders, pastes, and liquids on a metal plate connected to an oscillator which could produce a broad spectrum of frequencies. The substances were organized into different structures characterized by geometric shapes typical of the frequency of the vibration emitted by the oscillator. According to Jenny, these structures, reminiscent of the [[mandala]] and other forms recurring in nature, would be a manifestation of an invisible force field of the vibrational energy that generated it. He was particularly impressed by an observation that imposing a vocalization in ancient Sanskrit of ''[[Om]]'' (regarded by Hindus and Buddhists as the sound of creation) the lycopodium powder formed a circle with a centre point, one of the ways in which ''Om'' had been represented.

In fact, for a plate of circular shape, resting in the centre (or the border, or at least in a set of points with central symmetry), the nodal vibration modes all have central symmetry, so the observation of Jenny is entirely consistent with well known mathematical properties.<ref>{{cite thesis|doi=10.1017/S0013091515000139|title=Proceedings of the Edinburgh Mathematical Society (2016) 59, 287–300}}</ref> From the physical-mathematical standpoint, the form of the nodal patterns is predetermined by the shape of the body set in vibration or, in the case of acoustic waves in a gas, the shape of the cavity in which the gas is contained. The sound wave, therefore, does not influence at all the shape of the vibrating body or the shape of the nodal patterns. The only thing that changes due to the vibration is the arrangement of the sand. The image formed by the sand, in turn, is influenced by the frequency spectrum of the vibration only because each vibration mode is characterized by a specific frequency. Therefore, the spectrum of the signal that excites the vibration determines which patterns are actually nodally displayed. The physical phenomena involved in the formation of Chladni figures are best explained by classical physics.<ref>{{cite web|url=https://demonstrations.wolfram.com/ChladniFigures/|website=Wolfram|title=Chladni Figures - Wolfram Demonstrations Project}}</ref>