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)."

Comments

massless photons vs black hole

[martyb]

Slightly OT question but TFA mentions that photons are massless particles. I've read that elsewhere, too.

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?

Re:massless photons vs black hole

[Anonymous Coward]

I'm no expert.

But I think it has less to do with gravity directly effecting things, and more to do with the gravity of the singularity simply bending space to the degree that things move into it. Thus, anything traveling through that warped space would be effected.

Re:massless photons vs black hole

[martyb]

Photons have no _rest mass_ or they couldn't go the speed of light. Their mass is their energy which is a function of their frequency.

Aaaaah! rest mass == massless, but because of their energy, and e=mc^2, there is, effectively, a mass, which the black hole can act upon... got it! Thanks!

Starwards the wrong cultural reference.

[BLACKMIST]

So I'm reading this, and they do the whole lightsaber thing- they explain this opens the possibility of -crystals made of light-

They have completely missed the cultural reference. Clearly this needs a Tolkien reference. This is Feanor's Silmaril. Why can't they see the obvious?

Oh, and new form of matter made of energy- there's that too. That didn't even make the title.

Seriously though, howto simerils.
_B

the summary is garbage...

[slew]

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 ;^)

Holodeck

[Tekoneiric]

This is more like holodeck matter from Star Trek or hard light holograms from Red Dwarf rather than a lightsaber.

Re:STEVEN SPIELBERG HERE !!

[K. S. Kyosuke]

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?