Fans of space sagas Star Wars and Star Trek will be very familiar with "tractor beams," the projected force-fields utilised by spaceports, planetary bases, space stations, and star-ships to lock onto crafts and guide them to a safe designated landing site.
New research conducted at Dundee University in Scotland has now used ultrasound energy to create a "tractor beam" with properties similar to its science-fictional equivalent.

During the study, which was published in the journal APS Physics, scientists managed to remotely pull a hollow triangular object towards the energy source, push it away and also rotate it.
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