Real life Star Trek tractor beam developed – but it won't be dragging space ships any time soon
- Researchers have so far managed to move microscopic spheres of silica suspended in water over distances of 30 micrometres
- But Nasa have already been in touch…
Professor Greer on “How things go together”:
Star Date 24102012: We have detected evidence of a working tractor beam.
Two physicists working at New York university have developed a technique for using beams of light to draw a particle toward a source and claim to have demonstrated it experimentally.
Professor David Grier and David Ruffner, a graduate student, working at the Department of Physics and Centre for Soft Matter Research say they have realised the Star Trek-style technology – only on a miniscule scale.
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Science fiction technology: The crew of the star ship Enterprise often used their tractor beam to help friendly ships in distress and capture enemy vessels
Whenever a friendly star ship was in distress, it was no problem for the crew of the Enterprise to activate their tractor beam and drag the vessel to safety.
However, until now the technology has remained beyond the reach of real-world physicists, with the best they could manage being laser-based tweezers that can drag particles across microscopic distances in two dimensions.
Now in a paper published in the journal Physical Review Letters – and available in full here – Professor Grier and Mr Ruffner describe a technology that goes one better, by actually pulling particles towards their beam’s source.
It is well known that light can push objects – a property that forms the basis for the idea of using solar sails – but getting light to drag something has so far proved to be more difficult.
The NYU tractor beam is based on Chinese research published last year into a kind of laser called a Bessel beam, which emits light in concentric rings.
That study calculated that a such a beam could be designed to make a particle inside it emit photons on the side facing away from the beam’s source, forcing the particle to recoil towards that source.
No-one has as yet been able to make such a beam, but the NYU researchers got around the problem by instead projecting two Bessel beams side by side down a microscope and using a lens to angle them so they overlap.