Harvester beam still under development. Get it? Farm equipment joke! That one goes out to all you yokels in the midwest reading Geekologie on a dial-up connection and daydreaming about corn. Haha, do I know you guys or what? Anyway -- an "attractive" tractor beam. BUSTED BEAM'S FACE IS STILL BUSTED. Would not talk to unless vomity drunk.
...researchers from Hong Kong and China have calculated the conditions required to create a laser-based "pull".
The trick is not to use a standard laser beam, but rather one known as a Bessel beam, that has a precise pattern of peaks and troughs in its intensity.
Seen straight-on, a Bessel beam would look like the ripples surrounding a pebble dropped in a pond.
If such a Bessel beam were to encounter an object not head-on but at a glancing angle, the backward force can be stimulated.
Granted this is all hypothetical at this point, and, if it does work, is only expected to work over very short distances, but still -- you've gotta start somewhere. Or you could, I dunno, ASK SOMEONE WHO'S BEEN ABDUCTED BY ALIENS. That guy -- the one sitting on the inflatable donut -- ask him how they do it. "I just had hemerrhoid surgery." LIES!
Thanks to TK 745, Jennaiii, JHolloway, Aido, Paulo and Doug, who don't need tractor beams because they've got attractive personalities. Except Paulo, he's unbearable to be around (I can say that cause I know him and it's true).