Science fiction meets real science! “Tractor beams” – fascinating invisible beams that can push and pull objects, leave science fiction domain. The idea of “tractor beam” employed in science fiction films and books to haul spaceships and capture floating capsules gains scientific focus.
It’s not just science fiction writers who are interested in this technological phenomenon. Haifeng Wang and co-workers at the A*STAR Information Storage Institute producing long term generation technologies, have now demonstrated how a tractor beam can in reality be recognized on a little scale.
These rays of light are frequently shown pulling objects towards an observer, seemingly violating the laws of physics, and of course, this kind of beams have but to be realised in the actual world.
Haifeng Wang at the A*STAR Information Storage Institute and co-employees have now demonstrated how a tractor beam can in fact be realized on a tiny scale.
“Our work demonstrates a tractor beam primarily based only on a single laser to pull or push an object of interest toward the light source,” says Wang.
In addition, the intensity that varies across a laser beam can be used to push objects sideways, and for example can be used to move cells in biotechnology applications.
Pulling an object in the direction of an observer, nevertheless, has so far verified to be elusive. In 2011, researchers theoretically demonstrated a mechanism in which light movement can be controlled utilizing two opposing light beams — though technically, this differs from the concept behind a tractor beam.
Wang and co-workers have now studied the properties of lasers with a distinct kind of distribution of light intensity across the beam, or so-referred to as Bessel beams. Generally, if a laser beam hits a tiny particle in its path, the light is scattered backwards, which in turn pushes the particle forward.
What Wang and co-workers have now shown theoretically for Bessel beams is that for particles that are sufficiently modest, the light scatters off the particle in a forward path, which means that the particle itself is pulled backwards towards the observer.
In other words, the behaviour of the particle is the direct opposite of the typical scenario. The dimension of the tractor beam force depends on parameters such as the electrical and magnetic properties of the particles.
Even though the forces are not really significant, such tractor beams do have real applications, says Wang.
“These beams are not very likely to pull a human or a auto, as this would demand a massive laser intensity that could damage the object,” says Wang. “However, they could manipulate biological cells due to the fact the force required for these doesn’t have to be large.”
This kind of applications are the driving force for long term experimental demonstrations of this kind of pulling effects.
The engineering could, for example, be used to gauge the tensile power of cells, which would be helpful to investigate regardless of whether cells have been infected. “For instance, the malaria-infected blood cell is much more rigid, and this technologies would be an easy-to-use device to measure this,” adds Wang.
“How can we help someone so powerful they can create water out of thin air?” an astonished Jabin yells in Star Trek’s Caretaker. If you are a Star Trek fan you will remember how the Kazons try to aquire technology that can create water our of thin air. This technology is no longer in the realms of science fiction. Today we can really create water out of thin air!
Sources and more information:
Who hasn’t wanted a tractor beam at one time or another? The notion that beaming a ray of light at something would allow you to bring it closer is very appealing. And, if you’re willing to settle for a particle, you could have a tractor beam in the near future according to scientists in Singapore. From the May 23, 2012 news item on…