Scientists are one step closer to levitating humans.
The world's most powerful tractor beam has successfully been used to pick up a small object, allowing it to hover in space at their command. And within a few years they'll be able to move onto bigger things – and maybe even people, the researchers said.
Acoustic tractor beams use precisely focused sound to vibrate things into the air. That means that they can grab at most things, unlike magnetic beams which rely on holding metals.
But until now they have been limited to only tiny objects, and larger ones would simply spin off uncontrollably. The new research shows, however, that using fast vortices that spin like whirlpools of sound and allow them to stay in place.
That allows the tractor beam to avoid the problem of objects spinning out of control, which is caused by the fact that some of the motion of the vibration is transferred to the object, and leads to it spinning around. Instead, the new tool makes a twister around the object – while the outsides are loud, it is silent at the centre and allows the object to float without flying out.
Even before such technology could be used on humans, it might allow doctors to be able to manipulate things inside the body without actually cutting people open, they have suggested. It might also allow for production lines where nothing actually touches the thing that's being made, for instance.
"Acoustic researchers had been frustrated by the size limit for years, so its satisfying to find a way to overcome it," said Dr Asier Marzo, lead author on the paper. " I think it opens the door to many new applications."
