Not Pulling Your Leg: Tractor Beams May Be Possible
by Adrian Cho on 14 November 2011, 5:59 PM |
Bizarre beam. A Bessel beam is made by overlapping ordinary light waves that travel at an angle (left). The entire beam propagates forward with an intensity profile (right) that remains constant along the length of the beam, and new calculations suggest it can act as a small-scale tractor beam.
Credit: Egmason/Wikimedia Commons
It's not nearly powerful enough to pull in the Millennium Falcon, but four groups of physicists have independently come up with the same basic idea for a real-life tractor beam. The laser beam the groups have dreamed up could drag an object the size of only a grain of salt or smaller, but experts say it could provide a new tool for manipulating tiny objects such as cells.
As for pulling a starship, don't hold your breath. The dragged object must be smaller than the length scale over which the light waves remain orderly and "coherent," Saénz says. So to feel the tug, the Millennium Falcon would have to be shrunk to less than a millimeter in length. And really, how much of Han Solo's ego could you fit into such a tiny ship?