Researchers Create Real Tractor Beams

Gadgetank writes "Researchers out of the Australian National University have created a device, working in conjunction with other necessary devices, that can literally move small particles with light. And only light. The way it works is by shining a hollow laser beam around some tiny glass particles. The researchers heat the air around the particles, and therefore cause the dark center of the beam to remain cool."

not a real tractor beam

[D3]

They use this to PUSH particles around, not PULL them.

Echolocation

[Anonymous Coward]

"seems like only yesterday..."
http://science.slashdot.org/story/10/09/08/1558201/Tractor-Beams-Come-To-Life [slashdot.org]

Not terribly novel

[toppavak]

Mechanical forces exerted on objects by light have been described since the 1970's and practically demonstrated since 1986 [wikipedia.org].

Re:not a real tractor beam

[LanMan04]

Quoth wikipedia (from the "Optical Tweezers" article:

Optical tweezers (originally called "single-beam gradient force trap") is a scientific instrument that uses a highly focused laser beam to provide an attractive or repulsive force (typically on the order of piconewtons), depending on the refractive index mismatch to physically hold and move microscopic dielectric objects. Optical tweezers have been particularly successful in studying a variety of biological systems in recent years.
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So does that mean this new method works on a different principle?