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Australian Physicists Build Reversible Tractor Beam
An anonymous reader writes: Physicists at Australian National University have developed a tiny tractor beam that improves in several ways upon previous attempts. First, it operates on scales which, while still tiny, are higher than in earlier experiments. The beam can move particles up to 200 microns in diameter, and it can do so over a distance of 20 cm. "Unlike previous techniques, which used photon momentum to impart motion, the ANU tractor beam relies on the energy of the laser heating up the particles and the air around them (abstract). The ANU team demonstrated the effect on gold-coated hollow glass particles. The particles are trapped in the dark center of the beam. Energy from the laser hits the particle and travels across its surface, where it is absorbed creating hotspots on the surface. Air particles colliding with the hotspots heat up and shoot away from the surface, which causes the particle to recoil, in the opposite direction. To manipulate the particle, the team move the position of the hotspot by carefully controlling the polarization of the laser beam."
There is still a long way to go before we can use it to move a Ferenghi vessel or to fight off the Borg. We ought to make this a national priority. If you think the Ebola thing is scary, the Borg makes viruses look like sheer child's play.
...the ANU tractor beam relies on the energy of the laser heating up the particles and the air around them.
Oh, boy. It cooks you as it moves you.
Sounds like a great formula for a space rotisserie.