Scientists create tractor beam

Scientists at Scotland's St. Andrews University have invented a miniature working version of a Star Trek-style "tractor beam." The device the researchers created has the ability to pull tiny particles suspended in water towards it via a beam of light, instead of pushing them away, which normally happen, The Daily Telegraph reported Friday. The team published its study in the Nature Photonics journal. Unfortunately, researchers said their device cannot be replicated on a larger scale because it would require a much more powerful laser. Researchers moved particles that were five microns wide. Dr. Tomas Cizmar, who led the study, explained: "The problem is that this is based on the transfer of momentum between photons [light particles] and the object, and unavoidably there is also a transfer of energy. If you imagine you would like to attract a football, the amount of energy it would transfer would be huge and it would immediately burn up the football." "We can probably go further but at some point the heating up would be a huge problem," Cizmar said.