Fifty years ago, tractor beams that move large objects through space made an appearance on the show "Star Trek." About five years ago, we started seeing the technology actually demonstrated in the lab over short distances and in the water. Now, as Star Trek celebrates a half-century of boldly going places, David Grier's lab at New York University is working with NASA to develop a working tractor beam that could one day be used in space.
This tractor beam makes use of some odd properties of light waves to pull objects along a path.
In the above video from NYU, Grier, a physics professor, explains how his team developed the technology by first working off the idea that light waves have an actual force. You can see this in action when you look at a comet, which always has its tail pointing away from the sun thanks to the force of light "blowing" on its dust cloud.
The work first experimented with a method of using these forces exerted by light to hold microscopic objects in one place. The method was dubbed "optical tweezers." But when one of the researchers' experiments with optical tweezers failed, it led to the discovery that they could also use the forces of light to actually pull tiny objects in one direction, just like a tractor beam.
The beam of light used to create this desired effect doesn't really look anything like what we see in Star Trek. It's more of a twisted beam of light in the shape of a helix, according to Grier.
Grier and his team have been scaling up this concept recently. At first, their tractor beam could only move microscopic objects over microscopic distances, but now those distances have increased from centimeters to meters and they're currently working on a tractor beam that could move objects over several kilometers.
This is the point where real-life tractor beams start to have real-life potential. Indeed, NASA has a slideshow presentation on tractor beams that makes liberal use of Grier's work and discusses how spacecraft or surface rovers could use tractor beams to gather samples of dust and particles for study.
That's still a far cry from the massive tractor beams used by Starfleet to tow entire starships, but as Grier and I have both pointed out during Star Trek's 50th anniversary celebration this month, humans are starting work on developing tractor beams a few hundred years before it happened in the fictional universe created by Gene Roddenberry, so we've got a sizable head start in making science fiction into science fact with this technology in particular.
You can get a quick tour of Grier's lab in another video from NYU below.