Tractor Beams Are Getting Closer (Sort of) 70
xt writes "A recently submitted paper in arXiv claims that by using Bessel beams it is theoretically possible to pull particles towards the light source, opening up new avenues for optical micromanipulation (the direction of the force is size dependent, so it could be used for particle sorting). There is also a simpler article translated in English (original article in Greek)."
Re:Who wants a tractor beam? (Score:2, Insightful)
You expend all that time and energy to push the opposition into a decaying orbit (which, due to simple Newtonian physics, also costs you momentum in the opposing direction and requires that you make adjustments yourself). Meanwhile, the enemy have engines and can easily compensate for your push/pull, and take a few seconds out of their not-terribly-busy schedule compensating for your attempts to throw them off, and blow your ass out of the sky. With real weapons that actually do immediate damage.
This is kind of the same argument as "why shoot the gunfighter? Why not just walk up to him and push him to the ground?" Because, assuming you make it all the way to where he is and succeed in having him fall, he'll simply stand back up, dust himself off, give you a short nonplussed look, and increase your daily intake of lead by a few ounces of lethal speed-of-sound injection.
I did always wonder why "we're stranded!" stories never involved taking an object of significant mass nearby and using it as a target practice for a tractor or repulsor beam, though. Grab on to a moon, use it to push/pull yourself around until you can develop enough speed to establish a decent gravity slingshot, and off you go.
Guess it's not sexy enough in special effects.