It is a staple of all space type science fiction employed to capture those nasty little spaceships or shuttles that are in trouble. Yes I am talking about the venerable tractor beam and as much as we might think that this is something forever in the realm of our imaginations the fact is that scientists are getting closer all the time to creating working versions.
The newest effort is from researchers at the Australian National University where they have announced that they have been able to move small particles a meter and a half using only the power of light.
The device works by shining a hollow laser beam around tiny glass particles. The air surrounding the particle heats up, while the dark center of the beam stays cool. When the particle starts to drift out of the middle and into the bright laser beam, the force of heated air molecules bouncing around and hitting the particle’s surface is enough to nudge it back to the center.
A small amount of light also seeps into the darker middle part of the beam, heating the air on one side of the particle and pushing it along the length of the laser beam. If another such laser is lined up on the opposite side of the beam, the speed and direction the particle moves can be easily manipulated by changing the brightness of the beams.
Rhode said that their technique could likely work over even longer distances than they tested.
Unfortunately this method requires heated gas so it won’t work in the cold vacuum of space but that doesn’t stop it from possibly being used here on Earth.