Star Trek has predicted future technology yet again.
Engineers at England's University of Bristol claim that they have tested the world's most powerful acoustic tractor beam and that it can capture and levitate objects -- potentially even human beings.
In a paper published in Physical Review Letters (via Daily Mail) engineers detail that their approach uses rapidly fluctuating acoustic vortexes -- think of them as sound tornadoes -- made of a twister-like structure that has a silent core surrounded by a loud outside. While researches have previously been able to use acoustic tractor beams to move small objects, attempts to move larger ones resulted in the objects spinning uncontrollably. The new approach allows the objects to hover in the silent core, protecting the items from damage and spinning. This change is something that senior research associate on the project Dr. Mihai Caleap thinks may make it possible to eventually move very large objects.
"In the future, with more acoustic power it will be possible to hold even larger objects," Caleap said. "This was only thought to be possible using lower pitches making the experiment audible and dangerous for humans."
Instead, the new approach uses ultrasonic waves at 40kHz, a pitch similar to what only bats can here, making the proposed beam safe for human beings to be exposed to.
Tractor beams have a long history in science fiction, even before being popularized in Star Trek. They were first described by author E.E. Smith in the novel Spacehounds of IPC first published serially by the magazine Amazing Stories in 1931. The device was later featured in Star Trek, in this incarnation being shown to draw objects -- often large spaceships -- toward or away from the beam's emitter. In the very first episode of Star Trek back in 1966, the USS Enterprise is shown being forced to break free from a tractor beam drawing the ship towards a hostile craft.
But if you're hoping to be able to use a tractor beam to move a large object like a car or a spaceship anytime soon, you might be disappointed. The first attempts at using this new approach to tractor beams allowed researches to hold a small, two-centimeter polystyrene sphere so the ability to hold larger objects is a bit of a way into the future.