Scientists Create 'Tractor Beams' that Move Objects in Water
Researchers from Australia have created tractor beam on water. The technique could help control floating objects and even confine oil spills.
Tractor beams - seen in science-fiction movies and shows - are used to pull objects or even people. Previous research on the 'attractor beam" technology has focused on attracting objects using light. NASA is also working on a technology that could allow reeling-in objects. Similarly, Australian researchers have used lasers to move small objects. Recently, University of Dundee researchers had found a way to move objects using acoustic waves.
Now, physicists at the Australian National University have found that they can control water flow patterns with simple wave generators. This technique allows them to move free-flowing objects at-will.
"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; lead author of the study ."No one could have guessed this result."
For the study, the researchers used ping-pong ball in a wave tank to find the size and frequency of wave required to control the movement of the ball.
The team said that the right kind of waves can manipulate the movement of the ball. A wave generator used in the research created different types of waves that allowed the team to not only pull the object near them, but also in different directions, Gizmag reported.
"We found that above a certain height, these complex three-dimensional waves generate flow patterns on the surface of the water," said Professor Michael Shats, lead author of the study. "The tractor beam is just one of the patterns, they can be inward flows, outward flows or vortices."
Tractor beams are a staple of sci-fi movies and a puzzle for mathematicians and physicists. "It's one of the great unresolved problems, yet anyone in the bathtub can reproduce it. We were very surprised no one had described it before," Punzmann said in a news release.