Physicists build reversible tractor beam
Laser physicists have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its centre.
It is the first long-distance optical tractor beam and moved particles one fifth of a millimetre in diameter a distance of up to 20 centimetres, around 100 times further than previous experiments.
“Demonstration of a large scale laser beam like this is a kind of holy grail for laser physicists,