[Cheese]

By Tuning a Laser to Pull Rather Than Push, Researchers Design a Working Tractor Beam

The Fudan University team won’t be capturing rebel tranports with their beam any time soon--it only works (theoretically) at the nano-level--but it does achieve an interesting turnabout of physical force. We know photons exert an outward momentum; this is what allows solar sails to harness sunlight to generate small amounts of thrust. But carefully tuned to meet two conditions, a system can be created to turn “push” into “pull.”