In a scene in Star Wars: A New Hope, the Millennium Falcon is drawn towards the Death Star by an invisible tractor beam. And in Star Trek: First Contact, it's the Borg cube which snares the USS Enterprise in its inexorable grip (below). In fact, the tractor beam is such a staple of popular science-fiction it’s easy to forget that it doesn't actually exist – until now.
Scientists from the Czech Republic and the University of St Andrews have created a beam of light which can attract objects towards it (see artist's impression, below). Given its microscopic dimensions, the ray is not yet ready to get to grips with something the size of a starship, but it is hoped it could be used as an aid to medical testing, for example in examining blood samples.
Usually, when light and matter interact, objects are repelled by the stream of photons. Only recently have researchers discovered a point at which this force reverses and pulls objects towards the light source. The UK-Czech team is the first to provide a practical demonstration of this property.
Professor Pavel Zemanek said of the break-through: "The whole team have spent a number of years investigating various configurations of particles delivery by light.
"I am proud our results were recognised in this very competitive environment and I am looking forward to new experiments and applications. It is a very exciting time."
Dr Oto Brzobohaty added: "These methods are opening new opportunities for fundamental phonics as well as applications for life-sciences."
Neither scientist made specific mention of applications in inter-galactic space travel – but we're sure it's only a matter of time...