Tibetan singing bowls are a type of bell, specifically classified as a standing bell. Rather than hanging inverted or attached to a handle, standing bells sit with the bottom surface resting. The sides and rim of singing bowls vibrate to produce sound. They were traditionally used throughout Asia and the practice of making sound with bronze bowls could go back 3,000 years to the Bronze Age.
Today singing bowls are employed worldwide both within and without spiritual traditions, for meditation, music, relaxation, personal well-being and religious practice. Singing bowls are used in health care by psychotherapists, massage therapists, recovery, stress and meditation specialists. They are popular in classrooms to help facilitate group activities and focus students' attention.
Recently, researchers have been investigating the connection between Fifth Century Himalayan instruments used in religious ceremonies and modern physics.
In a study published July 1, 2011, in IOP Publishing's journal Nonlinearity, researchers have captured high speed images of the dynamics of fluid-filled Tibetan bowls and quantified how droplets are propelled from the water's surface as the bowls are excited. The first of five videos demonstrating the intriguing dynamics can be seen in the accompanying video (left).
A Tibetan bowl, generally made from a bronze alloy containing copper, tin, zinc, iron, silver, gold and nickel, is a type of standing bell played by striking or rubbing its rim with a wooden or leather-wrapped mallet. This excitation causes the sides and rim of the bowl to vibrate, producing a rich sound.
The unique singing properties of Tibetan bowls were utilized as a way of investigating a liquid's interaction with solid materials – a situation that arises in many engineering applications such as the wind-loading of bridges and buildings.
When a fluid-filled Tibetan bowl is rubbed, the slight changes in the bowl's shape disturb the surface at the water's edge, generating waves. Moreover, when these changes are sufficiently large, the waves break, leading to the ejection of droplets.
The new findings could benefit processes such as fuel injectors and perfume sprays where droplet generation plays an important role. The high-speed videos allowed the researchers, from Université de Liège and the Massachusetts Institute of Technology, to quantify how the droplets were formed, ejected, accelerated, and bounced on the surface of the fluid.
For more information on the research project, click here.