Hans Jenny (7 February 1899 – 9 January 1992) was a soil scientist and expert on pedology (the study of soil in its natural environment), particularly the processes of soil formation. He served as 1949 President of the Soil Science Society of America.
Hans Jenny was born in Basel, Switzerland. He earned a diploma in agriculture from the Swiss Federal Institute of Technology (ETH Zurich) in 1922, and a D. Sc. degree in 1927 for a thesis on ion exchange reactions.
Following an appointment at the University of Missouri, he joined the faculty at Berkeley in 1936. International recognition came to Jenny after the 1941 publication of Factors of Soil Formation: A System of Quantitative Pedology. His synthesis of field studies with the abstract formalism of physical chemistry set down the generic mathematical relationship that connects the observed properties of soil with the independent factors that determine the process of soil formation:
Hans Jenny may refer to:
Hans Jenny (16 August 1904, Basel – 23 June 1972, Dornach) was a physician and natural scientist who coined the term cymatics to describe acoustic effects of sound wave phenomena.
Jenny was born in Basel, Switzerland. After completing a doctorate he taught science at the Rudolph Steiner School in Zürich for four years before beginning medical practice.
In 1967, Jenny published the first volume of Cymatics: The Study of Wave Phenomena. The second volume came out in 1972, the year he died. This book was a written and photographic documentation of the effects of sound vibrations on fluids, powders and liquid paste. He concluded, "This is not an unregulated chaos; it is a dynamic but ordered pattern."
Jenny made use of crystal oscillators and his so-called tonoscope to set plates and membranes vibrating. He spread quartz sand onto a black drum membrane 60 cm in diameter. The membrane was caused to vibrate by singing loudly through a cardboard pipe, and the sand produced symmetrical Chladni patterns, named after Ernst Chladni, who had discovered this phenomenon in 1787. Low tones resulted in rather simple and clear pictures, while higher tones formed more complex structures.