If Star Trek has taught us anything, it’s that beaming things up is totally awesome. I wouldn’t mind beaming over another cup of coffee as I sit here right now, and that’s just for starters. Small strides have been made in the creation of real tractor beams (we’re talking microscopic). But here’s a new and interesting twist on this futuristic bit of technology: create it with water.
This is another one of those discoveries that shouldn’t work and has baffled, albeit happily, the scientists working on it. Professors Michael Shats and Horst Punzmann of the Australian National University figured out that wave generators, which you may have seen in swimming pools and smaller wave pools, can move objects floating in the water. But here’s where it gets weird: wave pools can move those objects against the waves.
The research team, who published their findings in Nature Physics, used ping-pong balls to experiment with controlling the direction they floated. They played with the size and the frequency of the generated waves until they figured out how to move the balls exactly where they wanted. And then the situation gets even weirder: the waves don’t actually account for the movement, at least not directly. The waves are responsible for creating surface currents, and that is what moves the floating balls.
The scientists used advanced particle tracking tools to confirm the cause of the counterintuitive manner of movement. When the generated waves exceed a certain height, they create specific flow patterns on the surface. “The tractor beam is just one of the patterns, they can be inward flows, outward flows, or vortices,” says Punzmann. This means scientists are able to control the movement of the objects on the surface, directing them pretty much anywhere, or keeping them stationary.
Such a technique could be particularly helpful when it comes to cleaning oil spills or other sea trash, and moving boats or other objects struggling in the water. It also may have applications in terms of changing water currents, which could have potentially widespread environmental impacts. Scotty would be proud.