Watch a Levitating Drop of Water Turn Into a Star

Mechanical engineers at Clemson University can perform feats that might previously have been attributed to a spiritual presence. Using ultrasonic waves, they can levitate drops of water, reshaping them and holding them up in the air. In the 2013 video above, they demonstrate how water can be held in midair between two opposing sound waves, called an ultrasonic standing wave field. The water droplet doesn’t stay solid, but can be reshaped into a star. 

This bit of physics is handy for a magic show, but the Clemson University researchers hope to utilize it to cleanse the air of dangerous pollution. The goal is to be able to levitate millions of drops at one time to remove coal dust and other dangerous particles from the air. The theory is that water droplets, powered by ultrasonic waves, could stay suspended in air long enough to collect the tiny particles of exhaust and dust in the area, and accumulate into a mass of water that would eventually grow heavy enough to sink into a drain.

Pollution-related respiratory diseases are a serious problem, even in the modern era. Cases of black lung, caused by breathing in coal dust over a prolonged period of time, are resurging among Appalachian coal miners. Though coal isn’t as big an industry as it once was, this type of research could help protect its workers. 

Banner image by Craig Mahaffey / Clemson University