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[IMG]http://cdn.physorg.com/newman/gfx/news/2012/jfkumtfujfv.jpg[/IMG]
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Credit: Phys. Rev. Lett. 109, 163903 (2012) DOI:10.1103/PhysRevLett.109.163903
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David Ruffner and David Grier of New York University have developed a technique for using Bessel beams to draw a particle toward a source. In their paper published in Physical Review Letters they describe how they used their technique to pull 30 micrometer sized silica spheres suspended in water, towards a laser source.
A device that uses energy to pull an object towards a source is known as a "tractor beam" after the fictional technology of Star Trek fame. To date no such device exists, but this new work by Ruffner and Grier shows that it might be possible. Their work is based on a form of laser known as a Bessel beam.
A Bessel beam, named after its creator Friedrich Bessel, is a type of laser that directs light in concentric circles around a single dot rather than as a single beam. Unlike general laser beams, the light from a Bessel beam, at the dot, is not diffracted and because the dot is formed by light from the circles, it can reform if it encounters an object in its path. It's this property that allows for pulling a particle, the team found.
Last year, a Chinese research team calculated that it should be possible to direct a Bessel beam at a particle and fine tune it in such a way as to have the light that reforms after striking the front end, reform and strike the back end, which should in theory push the particle back towards the source. The end result should look like a tractor beam.
After finding they couldn't fine tune a Bessel beam to the degree required to move a particle, Ruffner and Grier tried using two of them– with a lens that bent the beams slightly to cause them to overlap. This resulted in a strobe effect with light alternating on and off on the back end of the particle, providing enough energy to push it back towards the original light source. The end result is an apparatus that when viewed by the human eye, provides the illusion of pulling a particle towards a source device, i.e. a tractor beam.
The tractor beam the two built would require far too much energy to scale up to allow for moving large objects, and likely would destroy those objects in the process if such a device were built. But it does suggest that such a device might be possible using another less energy intensive source
[B]More information:[/B] [I]Optical Conveyors: A Class of Active Tractor Beams, Phys. Rev. Lett. 109, 163903 (2012) DOI:10.1103/PhysRevLett.109.163903[/I]
[B]Abstract [/B]
[I]We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Trapped objects can be moved selectively upstream or downstream along the conveyor by appropriately changing the Bessel beams' relative phase. The same methods used to project a single optical conveyor can project arrays of independent optical conveyors, allowing bidirectional transport in three dimensions.
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Source:
[URL]http://phys.org/news/2012-10-physics-duo-tractor-dual-bessel.html[/URL]
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[IMG]http://ego-maniac.com/wp-content/uploads/2012/02/WHAT-IF-WE-ARE-THE-MOST-INTELLIGENT-ONES-IN-THE-UNIVERSE-AND-ALL-THE-ALIENS-FEAR-US-Conspiracy-Keanu.jpg[/IMG]
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Now we just need to perfect it.
For reasons.
:v:
Just thinking of all applicable ways to use tractor beams make my head explode.
[QUOTE]provides the [B]illusion[/B] of pulling a particle towards a source device[/QUOTE]
umm
[QUOTE=Madman_Andre;38139894]Now we just need to perfect it.
For reasons.
:v:[/QUOTE]
I could see this being used for asteroid mining, they say an energy intensive, scaled up source would destroy the object it's used on so essentially you'd have powdered material which might be easier to refine and transport.
So now we could literally use this process to burn material off an asteroid AND collect it with the same instrument.
BZZZ
BRRZZZZZZZZZZZZZ
NOW I CAN RAPE FROM A DISTANCE
[QUOTE=StoneRabbit;38140232][IMG]http://images1.wikia.nocookie.net/__cb20090527025857/half-life/en/images/6/62/Gravity_Gun.jpg[/IMG]
Soon ?[/QUOTE]Someone pull up the gravity gun Gmod video.
[QUOTE=StoneRabbit;38140232][IMG]http://images1.wikia.nocookie.net/__cb20090527025857/half-life/en/images/6/62/Gravity_Gun.jpg[/IMG]
Soon ?[/QUOTE]
That makes the model look really ugly.
[QUOTE=Madman_Andre;38139894]Now we just need to perfect it.
For reasons.
:v:[/QUOTE]
Look out space cows
[QUOTE=minilandstan;38140461]Look out space cows[/QUOTE]
Don't forget about space rednecks.
[QUOTE=monkey11;38140406]That makes the model look really ugly.[/QUOTE]
It is an ugly model. It's not meant to be seen up close.
[QUOTE][IMG]http://ego-maniac.com/wp-content/uploads/2012/02/WHAT-IF-WE-ARE-THE-MOST-INTELLIGENT-ONES-IN-THE-UNIVERSE-AND-ALL-THE-ALIENS-FEAR-US-Conspiracy-Keanu.jpg[/IMG][/QUOTE]
It'd be really sad and disappointing if we are the smartest in the galaxy.
Well at least at the same time we can boast about and say we're the smartest. But it would still be a bummer.
[QUOTE=smeismastger;38140775]It'd be really sad and disappointing if we are the smartest in the galaxy.[/QUOTE]
Not to mention safer.
:tinfoil:
[quote]We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Trapped objects can be moved selectively upstream or downstream along the conveyor by appropriately changing the Bessel beams' relative phase. The same methods used to project a single optical conveyor can project arrays of independent optical conveyors, allowing bidirectional transport in three dimensions.[/quote]
That abstract is surprisingly straight-forward and understandable.
On another note, the rate of human advancement is pretty staggering when you think about it. Things that were considered complete fiction are becoming fact in just a handful of generations.
Beam Me Up, Scotty
[QUOTE=monkey11;38140406]That makes the model look really ugly.[/QUOTE]
[img]http://www.wallpaperfo.com/thumbnails/detail/20120429/video%20games%20halflife%20artwork%20gravity%20gun%201920x1200%20wallpaper_www.wallpaperfo.com_45.jpg[/img]
Better?
the gravity gun used dark energy and zero point energy though
[QUOTE=smeismastger;38140775]It'd be really sad and disappointing if we are the smartest in the galaxy.[/QUOTE]
And maybe the other civilizations developed differently and will have something new to share. Maybe they invented advanced robotics before going for paper money or teleportation before space exploration. Or maybe they have developed a richer spirituality which can fill the empty voids that we try to cover with technology.
[QUOTE=Splash Attack;38139946]umm[/QUOTE]
The "illusion" is that it's not actually pulling it towards the source, but pushing the back of the particle towards the source.
[QUOTE=Appolox;38139942]Just thinking of all applicable ways to use tractor beams make my head explode.[/QUOTE]
a shelf of electronics
only your electronics hover in place
So we beat the Vulcans to Tractor technology?
Cool.
So the Chinese did it first?
[QUOTE=laserguided;38144182]So the Chinese did it first?[/QUOTE]
[img]http://sae.tweek.us/static/images/emoticons/emot-ssh.gif[/img]
I have to do more research on this story before I start celebrating.
[QUOTE=smeismastger;38140775]It'd be really sad and disappointing if we are the smartest race in the galaxy.[/QUOTE]So far it looks that way. I don't have much of a problem with, it doesn't change anything.
Kill me now fuck I got the wrong part of the film.
Anyway, this is pretty sweet. Does just immensely remind me of Austin Powers though.
[QUOTE=sphinxa279;38145731]Kill me now fuck I got the wrong part of the film.
Anyway, this is pretty sweet. Does just immensely remind me of Austin Powers though.[/QUOTE]
Wait what? Tractor beams remind you of Austin Powers?
[QUOTE=Pierrewithahat;38146088]Wait what? Tractor beams remind you of Austin Powers?[/QUOTE]
There's a tractor beam scene:
[media]http://www.youtube.com/watch?v=EFkIZ-Zf32Y[/media]
There are other ways tractor beams can work. A surface with a reflectivity of over 0.3 can be pushed towards the source of the light if the light comes in at an angle of over 45 degrees from the surface normal, due to radiation pressure.
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