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Scientists Create New "Lightsaber-Like" Form of Matter
First time accepted submitter loftarasa writes "A group of scientists led by Harvard Professor of Physics Mikhail Lukin and MIT Professor of Physics Vladan Vuletic have developed a form of matter by binding massless photons together in a special kind of medium to create 'photonic molecules', effectively bringing us a bit closer to a world with lightsabers. 'The discovery, Lukin said, runs contrary to decades of accepted wisdom about the nature of light. Photons have long been described as massless particles which don't interact with each other – shine two laser beams at each other, he said, and they simply pass through one another. "Photonic molecules," however, behave less like traditional lasers and more like something you might find in science fiction – the light saber.' The work is described in Nature (paywalled)."
Street justice can get pretty rough.
Oh yeah.
Oh, yeah, it's not easy to pad these out to 120 characters.
As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.
These are not photons in free space being described. These are photons which have excited electron orbitals in some material.
I've also heard that black holes are so massive that the force of gravity does not let anything escape including light.
So, if photons have no mass, how do black holes keep the photons from escaping?
Good thing that lightsaber quote isn't getting out of hand.
Science is cool enough without ridiculous hyperbole.
That is all.
....... the number of accidental amputees is going to skyrocket.
File under 'M' for 'Manic ranting'
That's right...'accidental'.
Everyone knows photons were meant to be shot out of phasers, not for dueling with lasers.
Hokey religions and ancient weapons are no match for a good blaster at your side, kid.
They can take my LifeAlert pendant when they pry it from my cold dead fingers.
These are not the photons you are looking for.....
Faster! Faster! Faster would be better!
Use the force Harry!
-Gandalf
Most people, I would expect, would not intentionall dismember themselves.
File under 'M' for 'Manic ranting'
From what I can tell, they are simply creating a system of quantum-mechanically entangled photons, not a "molecule" of photons...
Apparently trick is that they created a medium (a laser cooled "gas" of rubidium atoms), and excited it with photons from a laser at a frequency that created a condition for the formation of a Rydberg state in the gas. This state is basically kind-of a pseudo-atom (i.e., a group of atoms that behave somewhat like a "scaled-up" atom). The gas made up of the pseudo-atom has a different apparent index of refraction than the unexcited medium looks to the first photon but it can effectively keep a second photon nearby the first photon in a type of quantum entanglement
This is what is described as a photon "molecule". Of course the energy levels required to create a similar Rydberg state in air (at room-temperature) would be slightly different orders of magnitude because you are pumping in enough energy into the air so that hyper-energized pseudo-molecules of air are resisting your opponent's light sabre... Not so sure you want to be actually holding a device that does that ;^)
The journalist could not say their finding will cure cancer or obesity in several decades, therefore they sold it as a potential path to lightsabers!
We would probably not accept such bold tactics from politicians, why do we accept it from scientific journalists?
If it wasn't his nickname before.....
Remember kids: What's right isn't as important as what's profitable.
Science?? Not everyone has a paid subscription to Nature. Without that there is hardly anything to miss!
This is more like holodeck matter from Star Trek or hard light holograms from Red Dwarf rather than a lightsaber.
*It's not what you can do for the Dark Side but what the Dark Side can do for you!*
http://xkcd.com/895/
Everyone knows that Star Wars started off as a cooperative writing project between Robert Heinlein and Issac Asimov
Do you also love the part of the movie where Hari Seldon uses psychohistory to predict where the engineers would have put the most vulnerable spot, and then personally blows up the Death Star with a proton torpedo?
Ezekiel 23:20
This is happening in a non-linear medium where photons interact: it can't happen in free air. Photons hardly interact on most transparent media, but there are materials with non-linear electric properties that can be used to generate harmonics ( see for example http://en.wikipedia.org/wiki/Second-harmonic_generation ). This is used to convert red light into green in some green laser light pointers. At high power levels, the refractive index increases in more normal materials, which is a nuisance in high-power lasers as light in NdYg glass laser elements can self-focus and damaage the apparatus if the power gets too great.
Hardly "contrary to decades of accepted wisdom about the nature of light" if you can find it in a green laser pointer. Meh.
In a sense. They excite the individual rubidium atoms and then get re-emitted in a form identical to the original at the quantum level.
Calling it a form of matter is a bit of a stretch as is imagining that an advanced form of it could ever be lightsaber like. Unless all saber fights will take place in a rarefied environment consisting of super cold rubidium.
It would have actually made perfect sense if Obi-Wan had said "fly, you fools!" to our heroes on the ramp of the Millenium Falcon. It flies, see?
Ezekiel 23:20
What a terrible article summary.
Light is not self interacting at the tree level. This means there is no scattering of light in the classical sense, only through virtual particles (quantum loop corrections). Did this group of experimenters prove otherwise? No.
This is the most clear statement from TFA
"It's a photonic interaction that's mediated by the atomic interaction," Lukin said. "That makes these two photons behave like a molecule, and when they exit the medium they're much more likely to do so together than as single photons."
http://phys.org/news/2013-09-scientists-never-before-seen.html
What the experiment did do was place another particle in the theory, the electron, with which the light may interact. So the light continuously scattering off of electrons keeps the two light beams spatially near each other. This is not new physics. The sun does the same thing. How long does it take a photon to escape from the sun? Typically a few million years.
What is significant about this experiment is the level of control the experimenters have over the scattering proximity of the light. Unlike the sun, whereby a very large volume is effectively trapping the light, this is a tabletop experiment.
A proper summary would be that a breakthrough in experimental techniques allowed for controlling photon scattering to a higher degree than before achieved.
I was going to reply with a "citation needed" to this one but, on second thought, if this is true then I really don't need to know.
Happy people make bad consumers.