Star Trek's tractor beam is now a reality

Engage tractor beam: A researcher holds a device composed of 64 miniature loudspeakers that generate an ultrasonic acoustic field that traps and levitates a polystyrene bead. Photo: Reuters

[caption id="" align="alignright" width="400"] In Star Trek, tractor beams can hold ships captive or used to tow an adrift vessel.[/caption]

The tractor beam, a staple of science fiction including Star Wars and Star Trek that is employed to grab spaceships and other things remotely, is entering the realm of reality.