In the future of the Star Trek series, the crew of the U.S.S. Enterprise would occasionally need to tow another ship. When they did so, they didn’t pull out the tow cables – they used a beam of light called a tractor beam to pull the other ship.
This isn’t as far-fetched a concept as it sounds. NASA is actively working to develop these as a means of sample collection for their rovers. And now scientists at the University of St. Andrews and the Institute of Scientific Instruments have developed a working (albeit quite miniature) tractor beam themselves.