A group of physicists at the Australian National University have created a water tractor beam, allowing them to control and manipulate objects floating in water.
Simple wave generators enabled the group to control water flow patterns, which in turn allowed them to move floating objects in whichever direction they chose.
“We have figured out a way of creating waves that can force a floating object to move against the direction of the wave,” said Dr Horst Punzmann, from the Research School of Physics and Engineering, who led the project.
The implications of the discovery were far reaching, according to Professor Michael Shats. While the experiment utilized a ping pong ball to demonstrate the movement and direction of the waves generated, other applications could include collection of floating debris, and even controlling and containing oil spills.
“The applications of this effect could be numerous,” Shats said. “For example, collecting the floating objects, manipulating small boats on the surface, or maybe collecting oil spills from the surface.”
The discovery could also give new insight into research on coastal geomorphology, the study of how coastlines are formed and changed, as well as help scientists better understand riptides, or rips.
“These results on the wave driven currents suggest new ideas about how rips on the beach can occur, in the presence of strong, realistic waves,” Shats said.
The group’s continued study into the effects of the wave generators allowed them to create new patterns of water manipulation, evidence by advanced particle tracking tools used during the project, which also revealed the depth of the generated waves. Other shapes were also tested in an attempt to generate different swirling flow patterns.
“We found that above a certain height, these complex three-dimensional waves generate flow patterns on the surface of the water,” Shats said. “The tractor beam is just one of the patterns, they can be inward flows, outward flows or vortices.”
Despite the complexity and simplicity of the patterns, the experiment is described by the group as mathematically unsolvable, that no mathematical theory exists to explain the results.
“It’s one of the great unresolved problems, yet anyone in the bathtub can reproduce it,” Punzmann said. “We were very surprised no one had described it before. The small waves are simple, but large waves are more complex than theory can explain.”