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Negative Refractivity for Optical Computing

michael posted more than 11 years ago | from the making-the-impossible-possible dept.

Science 125

zero_offset writes "This article in EE Times details Purdue's efforts to create a material with negative refractivity. One of the important results would be the ability to create optical computers due to the effect's tendency to amplify and focus light at wavelengths larger than the thickness of the nanowires used in the transmission system. Purdue's School of Electrical and Computer Engineering's Vladimir Shalaev says, "Using these plasmonic nanomaterials, we hope to directly manipulate light, guide it around corners with no losses and basically do all the fundamental operations we do with electronic circuits today, but with photons instead." Nanowires, surface plasmon polaritons, optical computers, nanoscale metamaterials, unnatural refractivity -- what's not to like?" We did a story on the first material known to have a negative index of refraction last year.

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http://slashdot.org/~the wipo troll (-1, Troll)

Anonymous Coward | more than 11 years ago | (#4155674)

"Whenever Mr. Malda gets bored (and who wouldnt, running a site like Slashdot all day), he roams through the user database, penis in hand, looking for people who might enjoy engaging in homosexual activities with him. How he determines this is anyones guess; but if you have a homosexual-sounding nickname, or a nick with a letter of the English alphabet in it, youre a potential candidate."

negative index of refraction (0)

Anonymous Coward | more than 11 years ago | (#4155684)

isn't the negative index of refraction called reflection?

not at all (2, Insightful)

dollargonzo (519030) | more than 11 years ago | (#4155733)

what this means is that u can bend the light BEYOND the normal. it is NOT reflecting off the surface of the material, but rather entering the material and reversing direction within it. (iMHO)

Re:not at all (1)

the way, what're you (591901) | more than 11 years ago | (#4155762)

Kind of like a weiner, which typically has a positive index of refraction. But pull it back between your legs, and you've got negative index of refraction. If you've got a stiffy pointing towards the sky, that's reflection.

My opinion as an optrician (-1, Troll)

Anonymous Coward | more than 11 years ago | (#4155690)

The Open Sores revolution is an optical illusion. If you are an open sauce coder you should probably switch to .NET now while you can.

Re:My opinion as an optrician (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155705)

Thank you for wasting your mod points on me dear slashbots.

Moore's Law (1, Troll)

RobertNotBob (597987) | more than 11 years ago | (#4155710)

Well, there goes Moore's law out the window.

I guess it has a bit of life left in it, but with the article talking about 'single molecule' focal points. I geuss we are about to run into a little wall if these ever actually make it to market.

Of course, with the computational power that will come of this, maybe we will be satisfied for a while. Somebody once said "Nobody will need more than 640 k of RAM" Right?

Re:Moore's Law (2)

Jucius Maximus (229128) | more than 11 years ago | (#4155846)

"Well, there goes Moore's law out the window."

Moore's Law [intel.com] describes an increase in transistor counts.

I hope you are referring to the idea that traditional microprocessor design would be obsolteted by 'optical computing' thus halting the advancement of traditional microelectronics, thus stopping the advancement of transistor counts as opposed to somehow having transistors being used in 'optical computing.'

Re:Moore's Law (1)

RobertNotBob (597987) | more than 11 years ago | (#4155930)

Moore's Law describes an increase in transistor counts.

I hope you are referring to the idea that traditional microprocessor design would be obsolteted .....

Well, yes.

The role transistors play will not always be performed by transistors. Just like vacume tube technology halted in the 70's and buggy-whip disigns have been stagnate (for the most part) since the 1920's.

But I think you missed part of my point. That being: weather of not you are talking about a transistor, once a single molecule is used as the focal point of a device, the count will not be rising much from there.

Don't read too much into this. I am in my early 30's and for IT people my age, Moore's Law has been darned-near the only constant in our professional lives. I was just "thinking out loud" about the possibility if it now being obsolteted.

kind of a bummer: But at least it will be around for at least a bit longer.

Re:Moore's Law (2)

CProgrammer98 (240351) | more than 11 years ago | (#4155975)

Man, that's an awful lot of typos for someone in their 30's !

(vacuum, designs, stagnant, "whether or" "of it" obsolete)

Re:Moore's Law (1)

Jucius Maximus (229128) | more than 11 years ago | (#4156005)

"But I think you missed part of my point. That being: weather of not you are talking about a transistor, once a single molecule is used as the focal point of a device, the count will not be rising much from there."

OK I get it ... and yes I did miss your point at first. Thank you.

Re:Moore's Law (2)

Junks Jerzey (54586) | more than 11 years ago | (#4155881)

Of course, with the computational power that will come of this, maybe we will be satisfied for a while. Somebody once said "Nobody will need more than 640 k of RAM" Right?

I'm not saying that more power wouldn't have many uses, but it always bothers me when people quote the "640K" line about modern computers. Imagine if Bill Gates, living in three bedroom house, had said "Nobody needs more than three bedrooms." And then now, living in a forty bedroom house, he says "Nobody needs more than forty bedrooms."

The latter, I think, rings a lot more true than the former. In most endeavors, diminishing returns can kick in after a while. It's the same reason we can't get away from the x86 architecture: There are more important issues than raw performance.

Re:Moore's Law (1)

jacoberrol (561252) | more than 11 years ago | (#4156134)

and not to mention that the "640k" quote often attributed to bill g is an urband legend [urbanlegends.com] .

Re:Moore's Law (1)

Morphine007 (207082) | more than 11 years ago | (#4156877)

and not to mention that the "640k" quote often attributed to bill g is an urband legend

yeah... sure it is.... if I had ever said something so monumentally stupid there's no way in hell that I would admit to it... you honestly think that captain doublespeak himself is any different???

Re:Moore's Law (2)

timeOday (582209) | more than 11 years ago | (#4157669)

As I see it, there are two classes of problems: 1) problems for which there's some clever, efficient algorithm (like sorting and serching), i.e. essentially easy problems and 2) problems that are not easy, where the only known option is to try all the solutions and see which work. There is a great divide between these two classes of problems.

Computers are now fast enough to do the easy problems comfortably, even on quite large datasets. These are the ones people have in mind when they say computers are "fast enough."

But computers are no where near fast enough to solve large problems of the second kind, and it doesn't seem that they ever will be in the forseeable future. A problem of this type might be, "what lossless compression/decompression algorithm under 1000K in length has the highest average compression on a given sample dataset?" It's easy to write a program to solve this problem, but awfully hard to wait for it to finish.

I think we're falling into the gap between easy and hard problems. We can do easy problems easily, but have no feasible way to approach the hard problems.

slashsludge (-1, Flamebait)

Anonymous Coward | more than 11 years ago | (#4155716)

Comments on this one are going nowhere, fast. What a dud of a story. I mean who really cares. WHO THE FUCK REALLY CARES ABOUT QUANTUM COMPUTING THROUGH A TELESCOPE OR WHATEVER the fuck this is about. sheeeet.

Remember your physics (-1, Troll)

PhysicsGenius (565228) | more than 11 years ago | (#4155723)

It seems like a negative idex of refraction would imply that light is moving faster than c through the material, but obviously this is crazy. Basically if you've ever done any electromagnetism then you'll have heard of the right-hand rule which governs the interactions of the electric and magnetic fields and the directions of their wave velocities. But for this new class of composite materials we instead get a left-hand rule, meaning that Snell's law (which governs the change of angel caused by the change of velocity of EM radiation through materials) is essentially reversed... The really unusual thing about these materials is that they exhibit negative electric permittivity and negative magnetic permeability, never seen before in any material. There are sure to be plenty of interesting applications to follow.

Re:Remember your physics (2, Interesting)

dollargonzo (519030) | more than 11 years ago | (#4155744)

wouldn't that mean you would have to FORCE electrons through the material? that seems like a bad consequence.

Re:Remember your physics (1)

photonic (584757) | more than 11 years ago | (#4155916)

NO, the surface plasmons they mention are a combination of an electromagnetic field (=light) with electrons that oscillate at the same frequency in the metal.


These are perfectly legal solutions of Maxwell's equation and only occur on the surface (hence the name) of metals.

Re:Remember your physics (2, Interesting)

Anonymous Coward | more than 11 years ago | (#4155750)

It doesn't mean the velocity is faster than 'c'. It only means the light beam is deflected towards the opposite direction ( angle of refraction > 90 deg )

Sorrrry (0)

Anonymous Coward | more than 11 years ago | (#4155861)

I'm sorry it's not > 90 deg., it's 0 deg.
I forgot the conventions of defining the angle of incidence/refraction during a braino.

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155938)

You mean 0 deg?

Re:Remember your physics (1)

n9hmg (548792) | more than 11 years ago | (#4156657)

It doesn't mean the velocity is faster than 'c'.
That's how it's negative...Thank you. I'd been beating myself around on this one. Trying how to figure out how to get a negative IR. An IR less than 1 would be big news... Oh, wait. It already was [cnn.com] .
So when it enters the material, it is going back out of the material? Ok, I think these guys have simply discovered reflection. If, at the interface from medium A to medium B, it reverses direction, it never entered medium B. If it did enter medium B, then it is moving in the positive direction in medium B, which this article says it isn't. Either medium B is non-homogenous, and is using a gradient of IR to bend the light back out the surface, it is reflection, or they're playing silly symantic games concerning the direction of time.

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155782)

I found this post more insightful when Kha0S posted it [slashdot.org] . I thought you were a different kind of troll than this Physics! *sniff*

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155823)

No.

Light travelling faster than c would imply an index of refraction less than 1.
(not less than 0 as implied above)

Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155896)

Any *normal* material has R.I. 1.

thanks to [slashdot.org]
KhaOS for the subject line.

Sorry (0)

Anonymous Coward | more than 11 years ago | (#4155912)

Any *normal* material has R.I. < 1. Light travelling faster than 'c' implies R.I. > 1.

err. I am new to /. & forgot 'Plain Old Text' implies HTML.

Re:Remember your physics (2, Informative)

dracken (453199) | more than 11 years ago | (#4155841)

Negative refractive index does not mean light is moving faster than C. According to Snell's law the refractive index of any material with respect to vacuum = velocity of light in vacuum / velocity of light in material.

So for dense thingies refractive index greater than 1. Eg glass. Now the refractive index of material A with respect to material B is Vel in B / Vel in A. So light travelling from Inside a glass slab to outside would think it encountered refractive index less than 1.

Now negative refractive index mean negative velocity ?? I dunno. Refractive index can also be calculated from Sine (incidence angle) / Sine (refracted angle). The only way to get negative refractive index is if Refracted angle greater than 180. (Remember high school trigonometry. Sine is negative only in the third and fourth quadrant). Now refracted angle greater than 180 would mean that light has suffered total internal reflection. So a negative refractive index material would behave like a mirror and not a lens. (hence giving negative velocity - velocity is a vector, has magnitude as well as direction). I smell a rat in the article.

-Dracken

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155909)

Negative refractive index would mean that light a slab of material from a vacuum bends away from the normal. In conventional (positive refractive) materials, light bends towards the normal.

Negative refractive indices are known at other wavelengths (e.g. microwave and X-ray), but what is new is discovering this phenomenon in the optical regime.

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4156116)

Light moves "away" from normal even for materials with positive refractive index (but refractive index less than 1). Light moves "towards" the normal for materials with refractive index greater than 1. Moving "away" from normal does not imply negative refractive index. For example as the post above said, light moving from a glass to air moves away from the normal - doesnt mean air (or glass) has negative refractive index. For a material to have a refractive index less than 0, the sine of the refracted angle should be greater than 180 degrees (and ofcourse less than 360 degreees).

Re:Remember your physics (1)

RobertNotBob (597987) | more than 11 years ago | (#4155848)

Actually, light CAN move through objects faster than 'C'. Researchers have made light move over 300C!

the story from CNN is here:

http://www.cnn.com/2000/TECH/space/07/20/speed.of. light.ap/

Re:Remember your physics (0)

Anonymous Coward | more than 11 years ago | (#4155884)

those are good points. However, I'd like to point out that ``c'' (constant) is the speed of light in a vacuum. If we're not in a vacuum, we can alter other conditions (packing density, refractivity index, EM raditiaon interference, etc) to increase or decrease the speed of light. Becknull's law covers the quantum variability of isotope determination, which has Snell-law implications.

Learnt a new word.... (3, Funny)

marko123 (131635) | more than 11 years ago | (#4155736)

I must have been out of the negative refractivity thread of modern physics, but I love this word...

"They had free drinks that night. Trevor was absolutely PLASMONIC. I mean... shit, man! he almost had a negative refractive index. Lucky we got him in a taxi when we did"

Re:Learnt a new word.... (1)

chef_raekwon (411401) | more than 11 years ago | (#4155772)

ahem.

dont you mean
"they had free drinks that night. Afterwards, Trevor was absolutely PLASMONIC, when he 'drove' me out of this world (in the back of the taxi)...."
ahem.

Re:Learnt a new word.... (-1, Troll)

Anonymous Coward | more than 11 years ago | (#4155837)

ahem.

don't you mean
"they had free drinks that night. Afterwards Trevor's anus was absolutely PLASMONIC, when he 'drove' my fist deep inside (in the back of the taxi)...."

Re:Learnt a new word.... (1)

Rocky (56404) | more than 11 years ago | (#4155885)

Brilliant, they transduced amplitude modulation via the concavity of that oversized beverage conveyence.

I mean, that is some clever PLASMONIC GOYVIN!

Quantum Cryptology (1)

reaperbean (453437) | more than 11 years ago | (#4155749)

Sounds like this technology could drastically improve implementing Quantum Cryptography. Imagine, long distance completely secure connections , that are provably unbreakable. Lets see Carnivore tackle that.

Re:Quantum Cryptology "The New Threat" (0)

Anonymous Coward | more than 11 years ago | (#4155780)

ok, so how long until Law Enforcement agencies decide that optical computation needs to be regulated because of the unbreakable nature of quantum cryptography? yay another clipper debacle

Re:Quantum Cryptology (2)

Abcd1234 (188840) | more than 11 years ago | (#4156760)

Umm... what does this have to do with Quantum Cryptography?

Re:Quantum Cryptology (0)

Anonymous Coward | more than 11 years ago | (#4157278)

You are a fucking karma whore!

Site's already slashdotted. Here's a mirror. (-1, Troll)

Anonymous Coward | more than 11 years ago | (#4155751)

Unnatural optics create precise photonic lens [cmpnet.com]

By R. Colin Johnson
EE Times
August 27, 2002 (5:51 a.m. EST)

WEST LAFAYETTE, Ind. -- Optical experiments using arrays of nanowires are demonstrating that the concept of a negative refractive index could be realized in practical systems. The work, done at Purdue University, attempts to reproduce results similar to those shown last year at the University of California at San Diego using microwave radiation. A negative refractive index, which is not found in nature, would allow scientists to construct new types of microscopes with unprecedented resolution and could allow the creation of novel photonic devices.

Since the first demonstration of a negative refractive index material, research groups around the world have been pursuing photonic technologies that appear to break the laws of nature. "The race is on," said Vladimir Shalaev, a professor in Purdue's School of Electrical and Computer Engineering. "We think there are about 20 other labs around the world rushing to create the first working prototypes at visible and communications wavelengths. We hope to have a prototype by early next year."

Shalaev is assisted by Viktor Podolskiy, a postdoctoral fellow at Princeton University, and Andrey Sarychev, a senior research scientist at Purdue.

A transmission medium with a negative index of refractions would enable a flat planar lens to focus light to precisions that are smaller than the wavelength of the light itself. With tunable versions of such photonic materials now being rushed into prototypes by labs worldwide, it is conceivable that not only could a "perfect" lens be created but that known electron effects could be translated into photonic operations to create sensors that could detect a single molecule.

"Conventional lenses cannot focus light in an area smaller than the wavelength of the light, but with our nanomaterials you can focus light down much smaller than its own wavelength," said Shalaev. "These metallic nanostructures might even be able to detect a single molecule of a substance, which will never be possible for conventional optics."

All materials have two fundamental electromagnetic parameters: permeability and permittivity, which respectively measure the capacities of a medium to form magnetic and electrical fields. The values of those parameters produce the characteristic bending of a light beam when it travels from one medium into another. In addition, since both parameters are always positive in nature, the electric and magnetic vector field components are directed according to the "right-hand rule," which can be represented by pointing the index finger of the right hand in the direction of propagation. The thumb and middle finger are then oriented at right angles to the index finger, showing the field vector directions.

With the photonically engineered materials, everything is reversed: The field parameters are negative, and the field vectors are described by a corresponding "left-hand rule." In addition, the electromagnetic direction bends away from the normal to the interface between two media, rather than toward the normal, as in Snell's Law.

Perfect-lens recipe

In 1968, Russian theorist Victor Veselago predicted that composite metamaterials might be engineered to have negative permeability and permittivity. Such materials, Veselago theorized, would interact with their environment in exactly the opposite way from natural materials. Using mathematical models, Veselago predicted that such metamaterials would follow a "left-hand rule," which would reverse their effect on electromagnetic radiation. One intriguing prediction was that the left-hand rule would nevertheless allow a flat lens to focus light to a point.

Veselago's prediction that such perfect lenses could be made from metamaterials lay dormant until 2000, when John Pendry, a physicist at Imperial College in London, showed that certain metals could be engineered to respond to electric fields as though the field parameters were negative. Pendry demonstrated different configurations of metal that created a left-hand rule for magnetic fields. In 2001, researchers at Imperial College and Marconi Caswell (London) announced a magnetic resonance imaging system using a magnetic metamaterial based on Pendry's design.

Last year, physicist Richard Shelby's group at the University of California-San Diego demonstrated a left-handed composite metamaterial that exhibited a negative index of refraction for microwave EM. The simple arrangement consisted of a planar pattern of copper split-ring resonators (SRRs) and wires on a thin fiber glass circuit board. The SRRs and wires were arranged into a two-dimensional structure with a repeated 5-mm lattice, with the wires located on the opposite side of the circuit board from the SRRs.

Now Salaev's group is working to scale down Shelby's 5-mm pitch to 15 nanometers so that instead of microwaves, light at visible and communications wavelengths can take advantage of negative permeability and permittivity.

To simulate their nanoscale metamaterial, Salaev's group had to model the behavior of left-handed metamaterials at the nanoscale. To do that, they had to turn to the study of nanoscale metallic structures that produce electron configurations called surface plasmon polaritons (SPPs).

SPPs are a "higher-order" object since they are part light (photons) and part plasmon. To complicate matters, plasmons are themselves higher-order objects, composed of free electrons behaving as a wave across the surface of a metal.

Optical amplification

Three years ago, Thomas Ebbesen at the NEC Research Institute in New Jersey reported that some wavelengths of light could be transmitted by a nanoscale metal grid with an efficiency of greater than one. That implied that the photons were being accelerated, rather than retarded, by the metal grid. Even stranger was the fact that the grid spacing was smaller than the wavelength of the photons, which normally would have blocked out most of the radiation. Theory said that almost no light should go through a hole smaller than its own wavelength, but Ebbesen reasoned that resonant waveforms across the surface of the grid, called surface plasmons, were performing a type of optical amplification on the incident photons.

Surface plasmons are collective oscillations of electrons at the boundary between conductors and insulators. Plasmons, themselves a collection of electrons, then meld with photons to form a new order of object, called a surface plasmon polariton. SPPs produce a reverse effect to a photonic crystal: Whereas the crystals exclude light at special wavelengths (so-called optical "bandgap" materials), SPPs enhance transmission in certain bands, creating the negative refractive index effect.

Resonant SPPs on the metal surface accumulate electromagnetic energy, operating like an antenna when the grid pitch is close to the resonant wavelength of the light. Thus, by changing the pitch of the grid, the wavelength of enhanced transmission can be tuned to a desired wavelength of light. An optical "near field" is generated when localized SPPs are excited by light. The resonating SPPs enhance the transmission of specific light wavelengths by several orders of magnitude, according to Salaev's model.

Now all the researchers have to do is build it.

"In the simulations, we took metal wires and spheres about 10 nanometers thick -- about 100 atoms wide -- and they functioned like nano-antennas for certain wavelengths," said Shalaev.

Clouds and waves

The tiny wires, 10-nm thick and as long as the wavelength of light they are tuned to enhance, were arranged in pairs parallel to each other. When the resonant wavelength of light hit the wires, they resonated, transforming a cloud of electrons into a wave (plasmon), which enhanced the transmission of light in a "left-handed" manner.

The simulations used the discrete-dipole approximation to verify that the plasmon polariton modes in tiny parallel wires were dependent on the incident-light wavelength and the direction of propagation. Verification of the existence of localized plasmon modes and their strong local-field enhancement when fabricated into composites convinced the researchers that left-handed materials in the near-infrared and visible could be built.

"Using these plasmonic nanomaterials, we hope to directly manipulate light, guide it around corners with no losses and basically do all the fundamental operations we do with electronic circuits today, but with photons instead," said Shalaev.

Shalaev's group experimented with many different nano-antenna shapes, from spheres and wires to more complex geometric configurations based on repeated fractal-like patterns. Each metallic pattern was analyzed for its ability to enhance light using SPPs responding to selected incident wavelengths. The winning designs are now being fabricated into prototypes, due out by early 2003.

And as always... (0, Troll)

Steve Franklin (142698) | more than 11 years ago | (#4155757)

Nobody has given the least thought to what they are going to do with all this peculiar junk after it gets to the end of its useful life. Just dig a big hole like any good primate and throw it in, right?

Dr. Frankenstein lives on.

Bend light=invisible? (2, Interesting)

phorm (591458) | more than 11 years ago | (#4156561)

If they can fiddle with light and directly manipulate it, does this mean they could possibly simulate some form of "invisibility". E.g. bending light completely around an object, so that the object no longer refracts light itself, but is essentially hidden within a sphere of redirected light?

I suppose the current theory applies only to light within some conduit of sorts, like fibre optics, but it would be cool if it had other such uses


I'm not a physacists, so feel free to critisize, but it's just a thought... direct manipulation of light could be a powerful thing.

-Quote-
"Using these plasmonic nanomaterials, we hope to directly manipulate light, guide it around corners with no losses and basically do all the fundamental operations we do with electronic circuits today, but with photons instead," said Shalaev.
-EndQuote-

RIAA hacked (-1, Offtopic)

back@slash (176564) | more than 11 years ago | (#4155761)

Completely offtopic but go check out the RIAA website [riaa.org] They've just been hacked.

Re:RIAA hacked (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155778)

LOL!

"Where can I find information on giant monkeys?"

Slashdotted (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155793)

Hacked and slashdotted.

They're really taking a hit!

Re:RIAA hacked (-1, Offtopic)

scott1853 (194884) | more than 11 years ago | (#4155805)

It's already back up.

Re:RIAA hacked (-1, Offtopic)

scott1853 (194884) | more than 11 years ago | (#4155810)

And it's down again. They must have at least one server working.

Re:RIAA hacked (-1, Offtopic)

Ripplet (591094) | more than 11 years ago | (#4155816)

Must be an 'aftershock' from the slashdot earthquake!

Re:RIAA hacked (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155817)

Hacked? Or DOSed?

Re:RIAA hacked (-1, Offtopic)

back@slash (176564) | more than 11 years ago | (#4155854)

It was hacked. Looks like they have shut down the site now though. You can access a mirror of it here. [scriobh.com] I'm sure this will be on the news later today.

But ... netcraft says (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155894)


The site www.riaa.org is running Microsoft-IIS/4.0 on NT4/Windows 98. FAQ

NT4/Windows 98 users include ABB Asea Brown Boveri Ltd, Arthur Andersen & Company, Gillette and British Nuclear Fuels Ltd

Microsoft-IIS is also being used by www.dellhost.com, www.datapipe.com, geotrust and Ferrari

Re:RIAA hacked (-1)

Anonymous Coward | more than 11 years ago | (#4155829)

Re:RIAA hacked (-1, Offtopic)

plarsen (579155) | more than 11 years ago | (#4155845)

ha, since when did RIAA advertise for www.babylonx.com, a new major sponsor?

RIAA Hacked (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155764)

Check it: http://riaa.org

text below->

Piracy can be beneficial to the music industry
Adult Entertainment
Wynton Marsalis Brings videos to Young People Inside RIAA with Eric Cartman
Money Matters
Where can I find information on giant monkeys?
When will you offer free movies?
Are there subscription music services up and running?

Some Claims are absurd (3, Informative)

slashnot007 (576103) | more than 11 years ago | (#4155776)

Much of what is claimed in the article and comapnion article is wrong, no doubt distorted through the prism of some "science writer" or attempt to dumb it down. For exampe, you cant focus light to a perfect point or even less that the wavelength of light.
the ways one can escape these limits in a semantic sense is that you can change the index of refration of the media so the wavelength is shorter than in vaccum, but that's not really accomnlishing the goal. Alternatively, near field or or ther diffraction effects can confine a light field to a region smaller the wavelength, but it cant propagate in vacuum/air that way.

likewise the claim you could make a perfecly flat focusing lens by combining poistive and negative materials is pretty hilarious too. You can do that right now with conventional positive only materials. (example take two plano confave lenses of high index material, and fill the space between them with water. voila!).

on the other hand you could do a lot of really interesting stuff with negative index materials that is harder to put in laymans terms. one example, the speed of light might be faster than in vacuum.

Stealth materials (1)

slashnot007 (576103) | more than 11 years ago | (#4155876)

One interesting application of this might be zero reflectivity materials. Right now the problem with (almost) all materials is that if they have any absorption at all then by defineition thay have a different index of refraction than air and consequently an inescapable reflectivity. (yes, black paint always refelcts some light!). this is bad news if you are a stealth airplane. Some ferrite materials posses an unusualy perimtivity/permiability that lets them actually have absorption yet a matched index but they are too heavy to put on an airplane. this might break open a whole new class.

Re:Stealth materials (2, Interesting)

Morphine007 (207082) | more than 11 years ago | (#4156827)

One interesting application of this might be zero reflectivity materials

now how would that work anyway... if you painted a basketball with "zero reflectivity" paint, you would no longer see the ball, because no light would bounce from it to your eyes, but you would also not be able to see anything behind it... so what would you see.. .or perceive??

Re:Stealth materials (0)

Anonymous Coward | more than 11 years ago | (#4157085)

if you painted a basketball with "zero reflectivity" paint, you would no longer see the ball, because no light would bounce from it to your eyes, but you would also not be able to see anything behind it... so what would you see.. .or perceive??


A very black ball, dummy.

Re:Stealth materials (1)

Garridan (597129) | more than 11 years ago | (#4157255)

The ball would simply be perfectly matte black. You would see no features on it, no shadows, no nothing. It would essentially look like a hole into black nothingness from any angle, no matter how much light was on it. You might see heat waves coming off of it, though, if you shine enough light on it.

Re:About that "flat" lense (0)

Anonymous Coward | more than 11 years ago | (#4156247)

All you are creating in your example is a convex water lense contained in a glass block. Your example dosen't really work.

Re:About that "flat" lense (1)

slashnot007 (576103) | more than 11 years ago | (#4157101)

Retard. of course it works, I've done similar things many times.

Re:Some Claims are absurd (1)

diablovision (83618) | more than 11 years ago | (#4156316)

one example, the speed of light might be faster than in vacuum.

No, the speed of light in the medium need only be faster than the speed of light in the surrounding medium--e.g. air.

Re:Some Claims are absurd (1)

BTO (604614) | more than 11 years ago | (#4156565)

What I find particularly absurd is the reliance on the existence of so-called "negative numbers." Puh-leez.

Obvious Troll: Some Claims are absurd (0)

Anonymous Coward | more than 11 years ago | (#4156689)

C'mon, moderators. Anyone who mentions FTL speeds regarding negative refractive index either didn't read the article or hasn't understood physics beyond a few college courses. This is hardcore solid-state optical physics and stands up to peer-reviewed scrutiny. Sheesh.

Re:Obvious Troll: Some Claims are absurd (1)

DanEsparza (208103) | more than 11 years ago | (#4156837)

I would agree. Reading Feynman's [yahoo.com] 'Six easy pieces' and actually learning a thing or two about Quantum Physics might shed some 'light' on the subject (I couldn't resist the pun). :-)

Who said anything about FTL travel? (2, Informative)

slashnot007 (576103) | more than 11 years ago | (#4157168)

No need to get technical, but it is in fact possible to have qauntum probability waves exiting a resonator before the entered it. (No i'm not making this up, it was published in Nature two years ago.) There may be not infomation content is transmitted. Recently it has been proposed that gravity waves may be faster than electromagnetic waves (i.e. light).

but in regards to the article, the final comment was sheer speculation. THe existence of a negative index suggests that it might be possible to create a composte substance with an index less than one yielding an electomagnetic propagation media with a speed faster than vacuum.

Negative R.I. for sure? (1, Interesting)

Anonymous Coward | more than 11 years ago | (#4155803)

Didn't we have a story [slashdot.org] about how skeptical [physicsweb.org] scientists were about these results.

1rst post! (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4155813)

:-P

Quantum / Optical computers (1)

joncarwash (600744) | more than 11 years ago | (#4155822)

I'm still waiting for the next big breakthrough in quantum computing, but this new optical technology will give way to some really fast stuff. Just imagine having a quantum computer cpu with optical connections to a solid-state hard drive. At least there is something to look forward to in computing nowadays.

Cool... now can you help my internet connection? (0)

Anonymous Coward | more than 11 years ago | (#4155836)

If they could build optical circuits with this stuff, could they replace my silly blue wire? Sure optical is here, but could this bring it to my house?

Hmmmm....

Plasmonic Nanomaterials (2)

geophile (16995) | more than 11 years ago | (#4155850)

Damn, that sounds cool!

Plasmonic nanomaterials

Plasmonic nanomaterials

Plasmonic nanomaterials

Now I'm sorry I went into software. I really, really wish I could tell people that I was into plasmonic nanomaterials.

Re:Plasmonic Nanomaterials (0)

Anonymous Coward | more than 11 years ago | (#4155869)

Well, you are the proud owner of some Seminiferous Tubules. How cool is that?

Wurdz... (1)

Genda (560240) | more than 11 years ago | (#4155857)

Is it just me or does "surface plasmon polaritons" sound like somebody left the StarTrek technobabble generator on overnight?

Actually way kuel stuff, SciAm had an article at length about this a few months back, and it was an awesome read... one of the other cool effects of this technology is optical microscopes that are orders of magnitude higher in resolution... visual systems that will let people look at things in optical frequecies that were limited to electron microscopy in the past (means we can see things way up close, that are still alive and kicking... or nanoscopic...)

"The future's so bright you need shades..."

This all sounds great on paper but.... (1)

Njoyda Sauce (211180) | more than 11 years ago | (#4155868)

How stable is all this going to be? I have to believe this is only working in vacuum conditions at the moment. I doubt it's going to be hitting the inside of anyone's computer in the near future. As the article says, the first applications will probably be high power microscopes. Not too much else seems feasible in the near term.

Meaning? (2)

teece (159752) | more than 11 years ago | (#4155882)

I thought the index of refraction was defined as:

n = (speed of light in vacuum)/(speed of light in medium),

or n = c/cmed

Now, convenctional wisdom and all modern science says c is always the bigger value, so n is always >= 1, but positive. How the heck does one get a negative refractivity? Niether of these quantities should be signed, let alone oppositely signed, right? What is meant by negative refractivity?

Tim

Re:Meaning? (2)

morie (227571) | more than 11 years ago | (#4156454)

It happens when the light goes backwards.... :-)

cmed < 0

Re:Meaning? (2)

Abcd1234 (188840) | more than 11 years ago | (#4156744)

The use of the term "negative" regarding a material's refractive index is really semantic. Basically, as described by Snell's Law, light bends toward the surface normal as it crosses the boundary of a material. However, materials with a "negative" refractive index have the opposite effect: they cause the light to bend away from the surface normal.

Re:Meaning? (3, Informative)

guybarr (447727) | more than 11 years ago | (#4156766)

I thought the index of refraction was defined as:

n = (speed of light in vacuum)/(speed of light in medium),


another definition, IIRC, is c/sqrt(mu*epsilon)

mu = permeability
epsilon = permittivity

both are coeeficients of the linear response of meterials to the EM field.

now, if the linear response of a material to EM fields is complex, I guess you can have negative (or imaginary) n.

imaginary means exponential decay or growth, BTW, but of course in the case of growth the material stops responding linearly at some point, thus changing the dependance.

IIAC, negative n does not really mean the speed of light reverses .

Now, convenctional wisdom and all modern science says c is always the bigger value, so n is always >= 1

AFAIK you're right in saying c is always the bigger value, however there exist superluminal photons [cerncourier.com] , which have phase velocity higher than c.

This is not, again AFAIK, related to the response medium but to other quantum phenomenas.

The universe can do some weird, convoluted vodoo ...

Re:Meaning? (2)

naasking (94116) | more than 11 years ago | (#4157750)

now, if the linear response of a material to EM fields is complex, I guess you can have negative (or imaginary) n.

If n=c/sqrt(mu * epsilon) as you suggest, then negative n would simply result from the negative roots of the sqrt. No fancy gymnastics with complex roots necessary.

Re:Meaning? (2, Informative)

wyldeling (471661) | more than 11 years ago | (#4156863)

Your definitions are correct, but incomplete. The speed of light, c, (and cmed for that matter) are defined as c^2 = e*u (electric permittivity of the substance times the magnetic permeability of the substance). In other words, the speed of light is determined by how well the substance it is travelling through can be influenced by electric and magnetic fields.


To complete the definition:


n^2 = c^2/cmed^2 = (e0 * u0)/(e * u).


(The zeroes indicate that they are in free space.)


Now to the questions: Negative refractivity should be impossible. Both e and u are positive quantities, and if they weren't, the square would make them at the minimum postive imaginary numbers. The problem is that e and u are only scalars if you are working with the prefered direction of the substance. Otherwise, they are 2nd order tensors (3x3 matrices). (e0 and u0 are always scalars.) I am not sure how this would influence the outcome w/o doing the math. But, it may allow for this type of effect.



Re:Meaning? (2)

Drakula (222725) | more than 11 years ago | (#4157628)

FYI: The real part of the refractive index for metals is, in general, less than 1.

Snell's Law (0)

Anonymous Coward | more than 11 years ago | (#4155915)

indx1*sin(a) = indx2*sin(b)

Where a is the angle of the incident ray, b is the angle of the refracted ray, indx1 is the optical density of the first medium and indx2 is the optical density of the second medium.

Speed of light (0)

Anonymous Coward | more than 11 years ago | (#4155920)

is given by sqrt(permittivity * permeability). If they're both negative, the negative signs cancel. I think what people are trying to say is that if the index of refraction drops below 1, then the speed of light will be faster than in a vacuum. Although this has been demonstrated in optical fibers in areas of anomalous dispersion [ucla.edu] , this article is not talking about that...

And when we're done.... (1)

eclectus (209883) | more than 11 years ago | (#4155921)

Gheesh. I thought we had enought problems recycling our old CRT's. I wonder what kind of issues these materials are gonna have if they make it mainstream?

I wonder what country we're gonna pollute this time. Oh! Bad American!

Re:And when we're done.... (2)

wirelessbuzzers (552513) | more than 11 years ago | (#4156430)

um... it seems they're made of metal. So, shouldn't be any more nasty to the environment than, say, a few bottle caps. Not that bottle caps are good for the environment, but wouldn't it be more effective to ban, say, styrofoam than plasmonic materials?

May be more efficient than quantum computers (0)

Anonymous Coward | more than 11 years ago | (#4156045)

Using these plasmonic nanomaterials, we hope to directly manipulate light, guide it around corners with no losses and basically do all the fundamental operations we do with electronic circuits today, but with photons instead.

This is simply astounding, folks. If this were possible, computers would be so fast that there really wouldn't be a need to build a quantum computer.

Oh, goody! (3, Funny)

KC7GR (473279) | more than 11 years ago | (#4156047)

Ha! New words to play with. Let's see here...

'Surface plasmonic polaritrons...' Nah, too long. Let's condense it down to something like this...

"Give your laundry that FRESH, SPARKLING, NEGATIVE REFRACTIVE INDEX with Maytag's NEW SURFACE PLASMONITRON!! Yes, you too can have your clothes looking like they got lost in a physics lab for a month, AND REVERSE THEIR POLARITY, all in three easy cycles!!!"

(Read all warning labels before use. Not recommended for cashmere, poodle fur, or llama wool. Batteries most definitely NOT included, minor assembly and Ph.d required. This product is not available in Pakistan).

Ok... who else wants to contribute? ;-)

Re:Oh, goody! (1)

BTO (604614) | more than 11 years ago | (#4156653)

Ok... who else wants to contribute? ;-)

Not me.

uhhh... (0, Offtopic)

goudaboy (469629) | more than 11 years ago | (#4156157)

Go Boilers!!!

Sorry, had to say it, its my alma mater

And yes! its off topic!

I tried this on Cruise. (-1, Offtopic)

Anonymous Coward | more than 11 years ago | (#4156293)

After reading Dianetics(by Lron the nut) I came to the
conclusion that all Scientologists have negative
refractivity. All you need to do is strap a really
new CLAM to a gurney and position his or
her body under the laser of any cd player.
After 10 minutes under the laser, all of the Body
Thetans will starting chiming in at a Tone +40.0.
Hopefully you remembered to put on your goggles because
the scientologist will start glowing like a lighning
bugs butt.
At this point you can start downloading ALL data into
the Body Thetans of this very willing scientologist. The
only problem is that the data does not remain stable
for more than a month. So you will need to repeat
the procedure every month, unless the CLAM gets
cleared, in which case ALL of your data will have
disappeared.
so it would be in your best interest to keep the young
budding scienos from CLEARing.

So what exactly do you get (2)

IPFreely (47576) | more than 11 years ago | (#4156350)

It sounds cool and all, but what do you get with photon logic over electron logic?
Is it faster? Cheaper? Less heat? More Compact? Some of these but not all of these? What do you lose by switching to photon?

It does sound like good stuff, but what exactly is the good?

Re:So what exactly do you get (1)

Garridan (597129) | more than 11 years ago | (#4157142)

RTFA

New words a boon to Star Trek writers! (2)

StefanJ (88986) | more than 11 years ago | (#4156701)

I figure the producers of Enterprise should be able to get five episodes worth of plot points out of the words "plasmonic" and "polariton."

Stefan

Other applications (0)

Anonymous Coward | more than 11 years ago | (#4156786)

The most important aspect is the ability to focus light to a point finer than it's wavelength. The article discusses using visible light to image individual molecules. Up until now the only way to do such a thing with visible light was with the near field effect.

Another interesting application would be telescopes. Maybe we won't have to wait
for the space interferometers to see all
the cool stuff out there.

Invisibility? (1)

Robotbeat (461248) | more than 11 years ago | (#4157363)

Negative refraction could definitely alllow you to have at least some sort of invisibility. If not the ability to make anything disappear like with some sort of "cloaking device", you could make materials that are completely invisible. They would be constructed of this material with negative refraction along with some other material, like fused quartz or something, so that you would have a composite material with a total index of refraction of zero.

I have thought about this subject before, and I did some research about different materials. Just think of glass. The only reason that pure glass reflects anything is that it has a different index of refraction as the air or vacuum or water that contacts it. If you notice clear ice that is in water, it is almost invisible since the index of refraction of ice is very close to that of liquid water.

There are many applications of this type of material. Does anybody have any ideas of some applications for a zero-refraction material? Perfectly clear windows? Practical jokes?

"unnatural" materials? (2)

iabervon (1971) | more than 11 years ago | (#4157529)

Today on slashdot, we have a nanomaterial that focuses light backwards, and also a nanomaterial that can attach to a flat, clean, dry surface well enough to support 200 lbs with a few square inches (using forces thought to only have effects at microscopic scales). The former is found only in labs and is brand new, and the latter is found in gardens and is older than humanity.

It's sort of interesting that the article refers to the negative refraction materials as "unnatural". Nature has been doing nanotech for millions of years now. It's pretty likely that, if these materials turn out to be good for anything that occurs in nature, they can be found there.

Retro Sci Fi (2)

sysadmn (29788) | more than 11 years ago | (#4157687)

plasmonic nanomaterials
Heck, that even sounds cool.

Colossal Storage Corp. ---- Patented Technology ?? (-1)

geekster_2000 (580578) | more than 11 years ago | (#4157924)

3D Volume Holographic Optical Storage NanoTechnology patented 5 years ago.

http://www.colossalstorage.net

Its amazing to see how the scientific community
makes revolutionary discoveries on known
patented technologies ??

What negative refraction means (3, Informative)

zero_offset (200586) | more than 11 years ago | (#4158060)

For those of you trying to figure out what "negative refraction" actually implies, the article at the URL below has a pretty easy-to-understand explanation of the key characteristics.

03/2001 photonics.com article [photonics.com]

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