The good news is they've made a better kind of tractor beam. The bad news is it's rubbish, only managing to line up minuscule polystyrene balls suspended in water. That wouldn't even make the cut as a Voyager episode.

Scientists from Scotland's University of St Andrews and the Czech Republic's Institute of Scientific Instruments came up with this latest take on the sci-fi innovation, which uses a light beam to line up particles. The team has managed to reverse the (Kepler) push effect that usually sees the light photons push microscopic particles away from the beam, with very specific parameters able to control what gets pushed away from or pulled toward the beam.

Sadly, this won't lead to any exciting space rescues. The amount of energy used would cause "huge problems" if scaled up to anything other than molecular proportions, with the team hoping it might instead find a use in the medical field for, say, separating cells in blood sample. [University of St Andrews via Daily Mail]