First long-distance optical tractor beam can repel and attract objects and could be used in controlling atmospheric pollutionLaser physicists hold built a reversible tractor beam and are using it to retrieve tiny particles.
It has nowhere near the pulling power of tractor beams envisaged in science fiction, but the first long-distance optical tractor beam has so far moved particles one fifth of a millimetre in diameter a distance of up to 20cm.
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Source: theguardian.com