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Tractor beams are suddenly a lot more plausible
Tractor beams now have a better shot at crossing from science fiction trope to reality, thanks to scientists at The Australian National University (ANU). They managed to push and pull a 0.2mm sized particle nearly 20cm using a "hollow" laser beam. That's a hundred-fold improvement over recent efforts at light propulsion, which have only moved microscopic particles short distances. The ANU team placed gold-coated glass spheres in the light-free center of the beams, creating hotspots on the surface that propelled the spheres via air reactions. The hotspot's location was changed by adjusting the polarization, giving scientists full control over the sphere's motion. Sure, it's not exactly the Death Star, but the scientists think it'll work over long distances -- meaning it could one day be used to, say, control pollution or move dangerous particles in the lab.
'Tractor beam' for water can pull boats in any direction
It can be difficult to get waterborne objects to go in the right direction -- just ask any boat captain who has had to fight waves on a choppy sea. However, researchers at the Australian National University have developed a "tractor beam" (really, a wave generator) that would make it trivial for you to float anything to its intended destination. The system creates complex 3D waves that have their own currents, letting you pull a target simply by adjusting the waves' frequencies and sizes. In fact, you can produce any flow you like; scientists in the lab made vortices on demand.
Australian researchers trap tiny particles in tiny tractor beam
Lasers. Is there anything they can't do? The latest addition to the 50-year-old technology's bag of tricks comes courtesy of a team of researchers from the Australian National University, who've managed to create a laser beam that effectively functions as a tiny tractor beam. The key, it seems, is that the laser beam is hollow, which allows tiny particles to be trapped in what the researchers describe as a "dark core," which in turn causes the particles to be pushed along the beam by an effect known as the "photophoretic force." As you might expect, that only works on very tiny particles, but the researchers are able to move them as far as one and a half meters, and they say that the technology could have a number of practical applications, including directing and clustering nano-particles in the air, and even transporting dangerous substances and microbes -- in small amounts, of course. [Thanks, Lester]
