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Nano-Scale Optical Co-Axial Cables Announced
toybuilder writes "Reuters reports that scientists have published their work on nano-scale optical coax in the most recent issue of Applied Physics Letters. The coax cable is only about 300nm wide, and is able to transmit optical signals using a carbon center conductor, transmitting light at about 90% the speed of light."
The coax cable is only about 300nm wide,...
How do you plug it in?
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
The coax cable is only about 300nm wide, and is able to transmit optical signals using a carbon center conductor, transmitting light at about 90% the speed of light.
methinks the speed of light is whatever speed the light travels at.
Push Button, Receive Bacon
The "absolute" speed of light is measured in a vacuum. As soon as light travels through any material it slows down to less then the absolute speed of light.
No, apparently not.
One university in the US (New Hampshire I think) had it down to 60km/h.
I should mention that that was going through a block of sodium at -272C (near absolute zero)
With really tiny tweezers.
Help stamp out iliturcy.
The "absolute" speed of light is measured in a vacuum. As soon as light travels through any material it slows down to less then the absolute speed of light.
If you really want to be pedantic, the speed of light in a vacuum is not measured but rather defined to be 299,792,458 m/s.
Right, because the slashdot poster definitely understands the details of the physics publication in a peer-reviewed physics journal, written by experts in the field, and can clearly question its validity in the three seconds it takes to read a slashdot summary.
Here's an idea, instead of immediately trying to show how smart you are by posting minutes after an article goes up just to say "this is dumb", have a little faith in the scientific publication process and actually read the (original, peer-reviewed) article before you jump to conclusions.
That's nothing. I had it down to zero, using nothing but a block of wood.
From TFA:
"This enables the cable to carry electromagnetic signals with wavelengths bigger than its own diameter."
co = two
axial = "being or situated in line with an axis" or "around or about an axis (a link between two or more places)" or "along, or parallel to, the main axis; lengthwise, longitudinal"
The term coax has nothing to do "spefically" with conveying electric current. That just happens to be its most common use. Etymology is your friend.
There are many tongues to talk, and but few heads to think. -Victor Hugo
Coax for light?
Why?
Think processors that produce less heat, but don't look at them directly without eye protection. As speeds ramp up, heat sincs will be replaced with tinted shields.
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
Very carefully.
just curious, how do you cool something that well?
CS: It is all sink or swim...oh and did I mention there are sharks in that water?
And before anyone says anything... I should have said, co = Together; joint; jointly; mutually.
There are many tongues to talk, and but few heads to think. -Victor Hugo
Could these cables be used to space to perhaps reach something that would normally not be reachable?
And what happens to a piece of string or yarn in space? Since there is no wind, would it stick straight out or would it move freely?
The fibers are k3w1, but what I really want to know is how they got the silly things to be so much less of a "drag" than teflon. If they can extend that, it has a lot more immediate applications as a low- material than as a fast lightpipe.
Lacking <sarcasm> tags,
If time travel occurs beyond the speed of light, I've seen it at 88 miles per hour. And the earth once was spun backwards at that rotational velocity in Superman 1.
But seriously, when will we create a material that doesn't have light bounce off of it, but is reflected and bounces off of light?
Wait...Physists worked on this project. I thought they were too busy explaining Shrodinger to Peta.
Ginga no Rekshiya Mata Each page.
As soon as I read that, it occurred to me that half of the comments were going to focus on that one sentence. And what do you know? I was right.
You live and learn. At least, you live.
. . .have a little faith in the scientific publication process . . .
Well, maybe he hasn't had half his brain sucked out yet?
KFG
You have faith in the peer reviewed physics journal? You must not know any of the peers, or have any insight into the review process. Trust me, its a mess. Although I am not a physicist myself, my friends who are complain to no end at the state of affairs with the journals. Its not that everything published is wrong, its just most of it is very, very difficult to review and very very little of it is worth reading. Its never wrong to ask stupid questions, or compare new discoveries to existing models of thought on a discussion forum. Of course, in this case it answers the question in the article, but it should have been in the summary.
It was my understanding that electric fields propagate through copper at about 1/3 C.
"Prefiero morir de pie que vivir siempre arrodillado!"
The thinner the fiber, the less the digital light pulses are spread (due to reflections on the fiber shell) per unit distance, the more information can be sent through per unit time.
Thinner means more bandwidth.
Liquid helium, under reduced pressure.
If you want to go even lower, than you can use adiabatic demagnetisation (put stuff into magnetic field->Spin orientation reduces entropy->remove heat->shut off magnetic field->the new degree of freedom reduces temperture).
Alternatively, you can try laser cooling (the closesed thing to a maxwell daemon we have), or diffusion cooling (with helium 3 and 4).
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Sorry about your impending Redundant moderation.
I think the thing we need to think about is when this may be useful to us. Right now it has to cost around elevenity billion dollars to make just enough to test... I think I will stick with the current speed of light through fiber.
You put in in an Aston Martin DB9.
Physicists in Helsinki have managed to get temperatures to 1 billionth of a degree above absolute zero.
I am more curious as to how you measure something that cold.
Thank you for pointing that out. The world is a better place because of pedants like you.
I have to admit, that I've read LOTS of published articles in well known journals and conferences, that give me the creeps, I mean... I don't know how do those papers could ever be published! (Perhaps as an example of "How not to"). So, I'll give a little credit to the skeptical people that questions everything!
However, I rather think on something else: If it is coaxial, the axis is shared with? I mean, you only have one fiber inside the cable, and I don't expect that fiber to be covered by a cylindrical planar fiber. So, is it correct the use of "coax" in this cable? or on the other hand... it is "always" coax?
Rybczynski, J.; Kempa, K.; Herczynski, A.; Wang, Y.; Naughton, M. J.; Ren, Z. F.; Huang, Z. P.; Cai, D.; Giersig, M. "Subwavelength waveguide for visible light" Applied Physics Letters 2007, 90, (2), 021104. (doi: 10.1063/1.2430400).
The paper is here, although only subscribers can read the fulltext. The abstract says this:
These are extremely small structures and this leads to an interaction between the light (which is an electromagnetic wave of course) that is essentially identical to when radiofrequency EM radiation propagates down a normal (macroscopic) coax cable. Specifically, in the introduction they say:
Then they go through the details. Their device uses a multiwall carbon-nanotube (MWCNT) as the center conductor (it is a 'metallic' CNT). The MWCNT is embedded in aluminum oxide, which acts as the optically transparent 'dielectric'. The outer wrapping electrode is made of chromium.
The mere creation of these nano-sized devices is quite an accomplishment. The fact that they've demonstrated successful transmission of light through these sub-wavelength sized devices is even more impressive. I can imagine a wide range of applications in nano-scale imaging (imagine a massive array of NSOMs), lithography, or even optical computing.
In the simplest sense, light here refers to light 'waves', which are the propogating electric/magnetic fields which are solutions to Maxwell's equations given the proper boundary conditions of the coaxial cable.
Of course this particular case involves a tiny coax, so if the wavelength of light is of order or larger than the size of the coax (I'm too lazy to read the article to see what wavelengths are used), then one would probably need to consider quantum mechanics and QED, to get the full behavior of the dynamics of these propagating waves.
But anyway, even in the classical sense there's no bizarro-world phsyics going on at all, any AC signal sent down a coaxial cable is actually sending 'light'. You might not think of a measly 10 MHz signal as being 'light', but it really is, it's propagating EM waves. That's why you need to properly terminate your coax, otherwise you can get electronic reflections and signal degradation, which is the exact analog to getting reflections at an interface between optical components where indexes of refraction are mismatched (glass/air for example).
And regarding your inductance of light phenomena, look up characteristic impedance in a decent E&M text, you might want to check out what the impedance of free space is.
make world, not war
Wake me up when they announce nano-scale HDMI.
I make these: http://beatseqr.com
Was I the only one who did a double-take at that?
Yes, yes, I know that light travels at different speeds through different materials.
You must be new here, right?
First of all, if you thought the OP was the only thing he will post, then you're wrong.
5 people will point out where exactly is the original paper mistaken, then
4 people will write a post about how dare those 5 people challenge a peer reviewed journal,
the original 5 plus 15 new people will point out the flaws in that argument,
10 people will post "in soviet russia you suck vacuum" jokes, of which the first 6 will be modded redundant and the last 4 modded up to anything between +2 and +5 funny,
2 people will play grammar nazi and correct mistakes while making much bigger errors in their post and subsequently 7 others will invoke Godwin,
6 people will be actually people with physics jobs commenting with informative posts, but they'll be reduced to oblivion by 34 people in well written but totally clueless posts that will get modded up to +5,
24 other people will post only loosely connected nonsense to the topic,
1 person (me) admits that he only included the previous item to taunt grammar nazis with a proper use for loosely,
and finally 2 trolls will post the best posts, in a tie, in the entire discussion by complete accident
It takes a man to suffer ignorance and smile
Be yourself no matter what they say
In other words, this nano-coax-cable has the proper physical characteristcs such that optical frequencies of EM radiation (ie, visible light) can be transmitted without significant dissipation or dispersion .
make world, not war
There's also evaporative cooling in a magnetic field. The atoms you are cooling are placed in a magnetic trap, and the more energetic ones "boil" off, leaving the remaining atoms cooler. This combined with the laser cooling is what was used to create the Bose-Einstein condensate that Eric A. Cornell, Wolfgang Ketterle and Carl E. Wieman won the Nobel Prize for back in 2001. link
Also might add the following:
1 person finally succeeds in combining a "in soviet russia" post with grammar nazi tactics.
Did they also discover some new physics that replaces Maxwell's equations with some bazaaro world version where light causes inductance?
Not bizarre at all. Light is nothing but RF radiation. Perfectly capable of TEM propagation in a coaxial transmission line of the appropriate size and characteristic impedance.
Sorry, fresh out of mod points...
Never answer an anonymous letter. - Yogi Berra
Yes, I DO have faith in the peer review process. It's far from perfect, but it's not as bad as you make it out to be. The thing you need to know is, a lot of physicists, and scientists in general (myself included) can be really anally retentive bastards. I one got blasted for fifteen minutes over my use of the phrase "high reynolds number" when the colleague in question believed "moderate" was the appropriate adjective and "high" was misleading. These are the types of errors that get physicists steaming, and with good reason - physics is perhaps the most rigorous of the sciences, and you have to be damn careful about how you word things. People will complain, loudly, about very minor issues. Many scientists strive for absolute perfection, and fixate on the negatives in an attempt to make the process better. There's nothing wrong with this, but it's useful to keep in mind when you form opinions about the peer review process based on your friends' complaints.
When people bitch about physics journals, in my experience it's been mainly for two common reasons:
1.) Drawing large, over-arching conclusions without enough evidence to support it. This is in no way saying the bulk of the work is invalid, just that the authors got a little greedy when writing the conclusions.
2.) Disagreement with the underlying assumptions that make up the paper. This one is trickier, but again it doesn't immediately invalidate the work, just questions how relevant the results are.
In either case, the peer review process, by people well-versed in the field, is a whole HELL of a lot more trustworthy than the slashdot peanut-gallery. The OP was full of crap, and others have gone into great detail to explain why he/she is full of crap. I was merely pointing out that the knee-jerk slashdot "post early, post often" karma whoring competitions lead to a whole lot of dumbass assertions without any firm understanding of the actual facts of the discussion.
While I'll agree with your assesment that this is really cool work, (the first demonstration of a coaxial cable at optical frequencies), I'm not sure if any of the applications you list are likely.
NSOM: You really want something that's much smaller than the wavelength. This isn't.
Lithography: Optically lithography works well because you project trillions of pixels at once. Something like this could only approach maybe a million or so. And like NSOM, you want something smaller than this will ever be.
Optical computing: Maybe, but there are already plenty of ways to guide light using strictly dielectrics. If the materials could do interesting things, then maybe it could be useful.
10 people will post "in soviet russia you suck vacuum" jokes, of which the first 6 will be modded redundant and the last 4 modded up to anything between +2 and +5 funny,
I think you meant: "In Soviet Russia, vacuum sucks you".
Also might add the following:
1 person finally succeeds in combining a "in soviet russia" post with grammar nazi tactics.
I think you meant "One person invents the grammar commie."
while walking uphill!
Of course, if you REALLY want to be pedantic, the speed of light in a vacuum is measured, and the meter is defined as being the distance light travels in 1/299792458th of a second.
"I do not agree with what you say, but I will defend to the death your right to say it"
Redundant? Redundant? How could someone with an ALL YOUR BASE signature be redundant?!? That's so fresh and hip that the poster in question had a really good shot of posting something worth while to the conversation, like pointing out something everyone else glossed over and understood to be a mistake to make himself look smarter.
No, it doesn't sound like the author didn't graduate high school at all. The constant c is almost universally referred to as "the speed of light". Only rarely is the "in a vacuum" tacked onto the end. It's perfectly understood that when you refer to "the speed of light" that it means "the speed of light in a vacuum". Your nit-picking is pointless and goes against the convention used in thousands of published books, papers, articles, ad nauseum.
Kramer: Why, I've plugged in cables so small I couldn't even see them! ... Well... I guess I just assumed...!
Elaine: How did you know you plugged them in?
Kramer:
You might want to cancel the pointy wizard hat you just ordered from theprophetshop.com, the summary is only two sentences long so half of the comments focusing on the second sentence isn't particularly odd. ;)
Will someone tell me *why* they did this? Yes, it's very cool. But the whole and only point of coax, as they talk about in TFA, is that it minimizes electrical influence.
If you're using light, there *isn't* any electrical interference, either as a transmitter or a receiver. That's one of the major benefits of using light.
So it's kind of pointless to make a coax, unless you really want a two-channel transmitter where one's a funny ring-shape. In which case, why not make optical ribbon cable?
Which brings up a wholly separate question: one reason industry has moved from parallel to very-high-speed serial is that you don't have to worry about timing and synchronicity, which are primarily due to impurities in copper. Is this an issue with optical? Coz the engineering is generally easier to run ten existing lines in parallel than to make one line ten times faster, if you don't have to worry about synchronizing them.
Nostalgia's not what it used to be.
I view at +4 and didn't have time to check. You have all the time in the world though I see. Too much time.
These posts express my own personal views, not those of my employer
When not qualified the term "speed of light", to the majority of the population (except maybe a few who think they are clever for pointing out the lack of said qualification), means the speed of light in a vacuum. When one is referring to the speed of light through some other medium it is usually stated as such.
Yeah, right. And the glass spere does know nuthink about that guy. <big silent but smelly one>
Yeah. Would you choose a neurosurgeon who pokes around people's brains in his spare time? I wouldn't.
I mean, each pound of dark matter weighs over ten thousand pounds, so light moving at 90% of the speed of light seems pretty reasonable to me.
You're wrong. In fact, it never will.
17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1
What material costs $1.93 for five tons?
Good glass I've used in fiber optics only allow about 0.6C, a much higher index of refraction. If it works like fiber optics the cladding would have a index of refraction of near 1.09. I guess they would be nano-dot calbes. Triaxial micro-dot cables were bad enough. john
Yes and speed and velocity are used interchangeably, but if you're talking physics and do that you're a twit.
The nit picking as you put it isn't pointless. The point is that if you're talking science and don't get the jargon right you become much more ambiguous and it's a bad habit to form. Yes in this case it was obvious what he meant but that doesn't make it a good story submission.
These posts express my own personal views, not those of my employer
Of course, if you REALLY want to be pedantic, the speed of light in a vacuum is measured, and the meter is defined as being the distance light travels in 1/299792458th of a second.
While this is Slashdot, we still encourage pedantic comments to be correct. :)
Your definition of the metre is correct, but you may notice that it fixes the speed of light at precisely 299792458 m/s, with no room for measurement. What you actually do in modern science is measure a second with a very precise clock, and calibrate your meter bar appropriately. Any errors you make are in the length of the metre, not the speed of light.
It didn't always used to be this way; for about eighty years the meter was defined in terms of atomic transition lines, so that the speed of light was the measured value. In 1983, however, timekeeping was accurate enough that the definition of the metre changed over so that the metre was a derived quantity.
Hey motherfuckers at Monster Cable: bigger isn't always better. Those assholes have driven up the price of HDMI and DVI cables to ridiculous levels thanks to arrangements with major electronics retailers to carry or feature their cables exclusively.
Anyway, suck it.
That is not correct. Read up on QED, the most accurate description of the interaction of light and electrons ever devised (Quantum Electro-Dynamics).
Light travels at a variety of speeds in the face of interactions or when travelling through free space. What is constant is the number of times the little arrow spins in a given vector length through spacetime (watch the Feynman lectures to get this "little arrow" reference at http://www.vega.org.uk/video/subseries/8)
I was merely pointing out that the knee-jerk slashdot "post early, post often" karma whoring competitions lead to a whole lot of dumbass assertions without any firm understanding of the actual facts of the discussion.
.. stop laughing, the mod system works ... usually).
But thats what slashdot is. Its a discussion forum. It wasn't a stupid question, as you can see it was asked in other places in this subject.Its about the exchange of ideas and is what makes slashdot a *good* place. Its like instant wikipedia that has people pooling their collective areas of expertise together. Just reading a summary, I can usually guess the topics that are going to be raised and discussed because people feel free to express their knee jerk reactions. It makes the discussion richer in the end. It helps me get a sence of what other people are thinking and why they think that way. I don't want people to self sensor themselves, (thats what the mods are for (no, seriously
Well.. maybe. Or Maybe not. But Definitely not sort of.
The point you're missing is... HE DID GET THE JARGON RIGHT. I've taken plenty of physics courses, in fact all the physics courses one needs to get a PhD in physics, and I heard the qualifier "in a vaccuum" mentioned a handful of times at best. The jargon is "speed of light", no "in a vacuum needed". You'd have to be a complete twit to demand the presense of this extraneous modifier when the meaning is already understood. Saying what you mean in a clear, consise, and compact manner is much more important than jacking off about semantics. I wouldn't be the least bit surprised to have editors in a technical publication STRIP the "in a vacuum" off to save text when space is at a premium.
And for the record, using speed and velocity interchangably is perfectly acceptable, again when the context makes it clear. Luckily for those of us who actually PUBLISH in physics, very few editors would get their panties in a wad about such an easily understood distinction.
That's fine - an honest question is all well and good, and will no doubt be answered quickly. However, posting a reply with the subject "WTF" that takes on a "these people are idiots" tone in an attempt to get easy early mod points is a shining symbol of jackassitude. Acting like you are smarter than people who are experts in their field makes one look like a complete moron - that's not starting a discussion, it's flamebait and ego-stroking.
Well, if you really, really want to be pedantic, the definition of a meter (or metre for the non-US majority of the world that actually USES the SI system) seems to be changing quite frequently (on a geologic scale, anyway). It used to be one ten millionth of the distance from the equator to the north pole (line drawn through Paris, France), then it was the length between two scratch marks on a platinum-iridium bar at 0C, now defined as the distance covered by the speed of light in 1/299792458 of a second, plus there are about 5 or 6 different methods in between that I'm omitting (curious bystanders see here.
Would the real metre please stand up?
Have you ever considered piracy? You'd make a wonderful Dread Pirate Roberts.
That may be the case, but unless you're a physicist, you're still better off trusting the journals than your own pathetic knowledge. It's much like reading an article about computer security in Wired. Is it likely to be inaccurate/simplistic/stupid? Yes. Is it still better advice than what most non-techies can come up with on their own? Yes.
The journals are still far more credible than, say, Answers in Genesis, or Time Cube.
http://outcampaign.org/
Interesting. I wonder if we could make some nifty antennas out of that.
http://outcampaign.org/
Actually some of us slashdot readers have Ph.D.s in physics and have literally "done the math". But I frankly did say WTF? at first. While this won't replace optical fibers, it does have very interesting implications for phase shifting and the like.
I've also studied physics (Astronomy at Masters level). I've also published so that doesn't impress me or make you more qualified to comment than me. You demonstrate exactly the sort of elitist pig headed attitude that makes most science papers so damned unreadable. The context wasn't clear in this case at all. The only thing that made it clear was background knowledge on the subject. If you're expecting everyone who reads /. and has an interest to have taken physics classes, you're smoking wacky weed. Get a clue.
These posts express my own personal views, not those of my employer
Would the real metre please stand up?
Actually, the FIRST definition of the metre was the length of a one-second pendulum, so it was derived from time. Unfortunately, it was quickly realized that gravity varies far too much from place to place on the Earth to make this at all precise, so they switched to the fraction of a meridian. When THAT proved too imprecise, they surrendered and went to the scratches on the bar in the vault.
Now you know why grandfather clocks were the height they were -- they had a one-second (aka one-meter) pendulum.
-- John Dierdorf, Austin TX
Acting like you are smarter than people who are experts in their field makes one look like a complete moron - that's not starting a discussion, it's flamebait and ego-stroking.
but it did start a discussion. By that token everthing on the evening news is flamebait. The comment had attitude, but jeesh, do you really think he thought he was smarter than the person who wrote the article? Its subjective. You can't tell from a short comment like that what the author was thinking. I took it as a witty sacrastic comment begging for correction. Its also varies across cultural boundries as well.
Well.. maybe. Or Maybe not. But Definitely not sort of.
The Reuter's piece misses one significant fact about the work which is reported in the journal article (linked by kebes above).
The distance which light can be expected to travel though a structure like that which is described is only the order of 0.00005 meters, i.e. 2 one-thousanths of an inch, before it is absorbed due to the loss arising from the imperfectly conducting elements. That distance number is from the journal article itself. The devices which were made seem to have a length of only 0.000006 meters. That's about 6 times longer than the best related devices to date (again according to the article.)
When we're working on quantum physics and teleportation, why are we focusing on something as slow as the speed of light? If we've already teleported information via cables in the sewers beneath the Danube, why care about the speed of light, let alone anything less than it?
Actually, the speed of light in a vacuum is not constant at all, according to several current theories. Professor R.T. Cahill's process physics theory(i mention this one, cause i've had some lectures on it, but there are others) states that the speed of light is actually inconstant, and depends on the flow of space around it. I don't claim to understand it, being a humble chemist, but it's interesting stuff http://www.arxiv.org/abs/gr-qc/0203015 for a cahill paper
Kids! Bringing about Armageddon can be dangerous. Do not attempt it in your home!
Every time I try to solder a connector on a piece of 300nm-thick coax I wind up trying to strip off the shielding, but cutting off the inner conductor as well. Either that, or I forget to put the connector shell onto the cable first....
TFA starts off talking about coax and the wavelength of RF, then explains that they've made nanoscale coax (both the core and sheath are conductive), but then suddenly switches to talking about light! This makes no sense to me.
:-)
Now I know perfectly well that light is electromagnetic radiation just like RF but at a much higher frequency, but the difference between them is that an incident light wave doesn't induce a skin effect in conductors (or possibly it does but it gets cancelled out), whereas incident RF creates a very high skin effect --- that's what makes coax work. And their aluminium sheath is ordinary metal, so special tricks.
So where's the missing link in the topic/discussion? How is light at all relevant to the operation of this coax? Just because the carbon nanotube is roughly the right size to be resonant at light frequencies doesn't suddenly make the light behave differently with respect to the aluminium sheath.
Please explain.
Since the light frequency is well below the plasma resonance in the metal of the electrodes ...
Understanding the abstract of the paper hinges on understanding the term plasma resonance in respect of metals. This must be some new concept since I studied solid state physics, and I can't find any useful explanations of it in Google.
Got a definition, or a link to an open paper about it?
Then you have to deal with radio licensing and/or line of sight issues.
Thanks, I know physics as a hobby nothing more. But I know little of low energy systems, I will have to look up a few of those terms though ;)
CS: It is all sink or swim...oh and did I mention there are sharks in that water?