Once the figment of science fiction authors’ imaginations, tractor beams are inching closer to reality.
The first group, composed of researchers from four U.K. universities, spent nine months perfecting their tractor beam, which used sonic beams to guide a small, half-inch prism.
Rather than using sound waves they produced waves in a tank of water. Like splashing at a beach ball in a pool, an outward flowing current carried the ping-pong ball away from the wave source. When the waves got bigger, the wave pattern started getting weird. Rather than successive rows of waves forming in front of the wave maker, an array of peaks started appearing.
Who knows? Between early photon-powered tractor beams and these latest sonic and aquatic versions, tractor beams are seeming less fictional every day.