The Whirling Dervishes may be a familiar sight to those who have visited Turkey. During such performance, a dancer from the mystic order of Sufi that has vows of austerity and poverty, spins on the spot. The performance brings the dancer's skirt into a hypnotic flow while the performer reaches a state of trance. After examining the swirling skirt, scientists have established that it can be correlated with weather patterns of Earth.
The patterns seen by tourists during the dance ritual that traces its roots 700 years ago to Persia, are acting because of the same Coriolis forces that help create strong hurricanes. The team of scientists wanted to explain why people see the skirt changing its shape during the dance such as forming a cone-shaped skirt with a triangular base.
Physics experts James Hanna of Virginia Tech-Blacksburg, Martin Muller of the University of Lorraine, and Jemal Guven of the National Autonomous University of Mexico published the findings of their research titled "Whirling Skirts and Rotating Cones" in the New Journal of Physics.
"The dancers don't do much but spin around at a fixed speed, but their skirts show these very striking, long-lived patterns with sharp cusp-like features which seem rather counterintuitive. Because the sheet is conically symmetric, material can flow along its surface without stretching or deforming. You can think of the rotating Earth, for example, with the air of the atmosphere free to flow around it," said Hanna in an interview with Phys.org.
"The flow of a sheet of material is much more restrictive than the flow of the atmosphere, but nonetheless it results in Coriolis forces. What we found was that this flow, and the associated Coriolis forces, plays a crucial role in forming the dervish-like patterns," Hanna added.
Using the right equations, the proponents of the study were able to reproduce shapes that are similar to the skirts of a Whirling Dervish.
"The resemblance of these solutions to real whirling skirts is better than one might expect, given that gravity has been neglected. However, a detailed investigation of pattern selection and stability is warranted before saying more," the study stated.
The model produced during the study may be useful for looking into the stresses on rotating components of certain machines. However, according to the authors, the study was focused on answering queries due to curiosity and not focused on practical applications.