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Quantum Wires
Silverlancer writes "Room temperature superconductors have often been a hallmark of far-future science fiction. But fortunately for us, they're here today, according to MIT's Technology Review. Richard Smalley, winner of the 1996 Nobel Prize for the discovery of the buckyball, is currently heading a project to produce a prototype carbon nanotube superconductor. They've already produced some wires up to 100 meters long--the only thing left to do is figure out how to produce only a certain type of nanotube, the "5,5 armchair nanotube," that conducts so well that it can be considered a superconductor."
I'm sure that in the next 5 minutes, the "5,5 armchair nanotube" will be criticized by the armchair physicists, the Slashdot equivalent of the armchair quarterback.
100 times stronger than a normal conductor, and able to carry a thousand volts in a sinlge bound!
That out the way, this is great news. There are so many useful scientific applications for superconducting wires that this is really cool news, once you get over the ethical dilemma caused by the fact that they are making them by *cloning* the orginals. It's ok to clone wires but not people? Hypocrites.
Interestingly,Dr. Smalley talked about armchair nanotube technology at the senate Oversight hearing on sustainable, low emission, electricity generation Full Committee Hearing almost one year ago. The full text is here.
Iran captures three CIA agents
If a first post occurs via a quantum wire in an article when every bodies threshold is +1, did it really occur?
There is one type of carbon nanotube which is ideal for near superconductivity. Unfotunatley, right now only multiple types can be produced on a large scale. One of the proposed solutions is to "seed" the nanotube growth process with the desired type so essentialy the growth occurs through cloning. The cool thing about this is that if it works, it should be possible to have supercondutivity at room temperature.
"You mortals are so obtuse." -Q
A superconductor is in a different league to a conductor, even a really good one. That's all this appears to be about, a really good conductor.
great! now i have something geekish to use for bondage with girls.
This seems like a good technology for micro(or nano)-processors.
A room temp super-conductor would be a boon for great speeds with less heat.
The preceding message was based on actual events. Only the names, locations and events have been changed.
Who cares if the first post is by an AC?
Real men first post on their account.
In short, not all new technologies will help bring about the worker paradise. Scientist and their capitalist pig ways!!! Soon the proletariat will rise and all you carbon nanotube superconductor makers will find yourselves up against a brick wall...
*bang!*
How about building a Stargate instead ? If that guy can build one in Carter's basement then I would imagine this future technology is way closer than we would imagine.
What I wouldn't give to live in her basement.
.
Ooh I feel dirty
Seems like from one direction optical computing is advancing, from another we're working towards room-temperature superconductors.
So what's the future look like? Quantum processors with superconducting and optical connections? I wonder how these various technologies will actually be deployed?
While the effects are still debated, would this have any effect on radiation given off from high tension power lines? Would the electricity be carried at a higher or lower frequency?
Superconducting wires are "here today", the only left to do is to make super conducting wires.
In other news, I am now a billionaire with a super model trophy wife. The only thing left is for me to get a lot of money and a hot wife.
The article says that there is "almost no loss of energy." But real superconductors truly have zero resistance. Once you start a current in a superconducting loop it runs for years without decreasing. AFAIK a decrease has never been observed. The article is unclear about whether this actually is a super-conductor or not. Does anyone know for a fact?
So much work (and funding) is being poured into finding alternative energy sources, I wonder how much the discovery of a scaleable, inexpensive, widely deployable (as in converting the world's energy grid) superconducting power distribution system has been quantified.
I do understand that this isn't that, and that there are a million barriers to be overcome, and that fossil fuels need a replacement Real Soon Now, but I do wonder if anyone knows of any studies out there trying sort out how much energy is currently lost in the distribution of consumer power, and how much less we'd need to generate if a practical superconducting solution is found.
Factoring in a reasonable probability of success in both sides, it would be interesting to see whether the potential cost/benefit of investments in finding superconducting solutions all the way to the last mile might be as or more efficient in the long run than funding research in new power sources.
I know, it shouldn't be either or in any case, but it's just a thought...
The only acceptable defense of scientific results is to say that they were the product of the Scientific Method.
The armchair nanotube is great for those lazy electrons who put up a lot of resistance to doing work.
So if that electron in your life is giving you heat about the pressure they are under this new product from LazyBoy is the perfect gift for them!
If they could devleop this, and replace those big power lines that carry electricity from plants to cities, they could save the power loss. I dont know any figures, but I'm sure utilities would like to decrease or eliminate power loss due to transmission.
The Doormat
If you're not outraged, then you're not paying attention.
Real men are in bed fucking their wives/girlfriends instead of posting on Slashdot.
Just try and find one of them after dropping it on the floor.
And you thought your contacts were hard to find!
Never play chicken with a passive aggressive.
Someone's gotta find a way to break the $2000 mark for speaker cables that some arrogant ass will insist makes the whole sound experience worth it.
500GB of disk, 5TB of transfer, $5.95/mo
The most essential thing about a superconductor isn't the zero resistance, but the meissner effect. So if they manage to create wires with near-zero resistance, they will not have created `near-superconductors'.
For energy transportation and storage it doesn't matter all that much, cause zero resistance (even without superconductivity) would make energy transportation and storage better
There was a discussion yesterday about using LEDs to replace incandescent lights. One thing that came up was the power losses associated with stepping down the mains voltage to voltages required by LEDs.
Even if the carbon nanotubes are not technically superconductors, if their resistance is much lower than copper they might be ideal for low voltage home wiring. You could step the mains down to 5 or 12 volts in a central location in your house, and power the all your low voltage electronics without having to worry about I^2R losses.
That, and it means that electromagnetic coils can be made much more efficient, thus increasing the power output of turbines for the same mechanical power input... That is, of course, if these nanotubes have the same properties as a metal wire, and can be rolled up into a coil ;)
armchair physicists
;-)
Smalley was a chemist. He won the Nobel Prize in chemistry. Synthesizing nano-tubes is done by chemists. This ain't physics we're talking about.
Then again, what discussions have those armchair physicists not gotten themselves into.
I am defenseless. Use your button. Mod me down with all of your hatred.
We might call them "quasi-superconductors". See, the difference between carbon nanotubes and common conductors is their crystaline structure that makes electrons travel in 1-D, as opposed to 3-D in common conductors. This nullifies heat dissipation, because, if there's no friction between the electrons, there's no energy loss.
And think about this. Cold superconductivity is a temporary, artificial effect. And there's a limit on the amount of current that can flow thru a superconductor before it loses its superconductive properties (don't ask where I read it because that was years ago). But carbon nanotubes have a permanent structure.
So I'd say this is the *REAL* superconductivity, and the phenomena discovered in near-0K conditions was just an attempt to it.
Will you do it? For me?
Well then sir, what am I?
When she screames the 3rd time from orgasm I decided it was time to get off. Now shes in the shower and I'm on Slashdot.
Make sense out of that one.
I would, but I don't know what "screames" means.
You are a liar.
http://www.businessweek.com/magazine/content/05_16 /b3929120_mz018.htm
From the url:
"Even though such transistors are still in their infancy, says IBM's Avouris, "Carbon nanotubes can get around most of the problems that doom very small silicon devices." In the lab, he has backed this statement up. It took him four years to assemble his current, third-generation prototype of a carbon nanotube transistor, but in the end, the device can carry up to 1,000 times the current of the copper wires used in today's silicon chips, making it vastly more efficient."
Two years later Sheng et al demonstrated superconductivity in carbon nanotubes. The experiment was conducted below 20K and the data collected was consistent with the Bardeen-Cooper-Schreiffer (BCS) theory of superconductivity.
For practical applications one wants the superconducting phenomenon to occur at much higher temperature. A material becomes superconducting when its electrons pair up. Normally such negatively charged particles would repel each other, but in a positively charged crystal structure, vibrations called phonons help them get together. In carbon nanotubes, the frequency of these vibrations is very high, which, in theory at least, means superconductivity at higher temperatures.
But if no one reads the first post, is it really there?
Schrodinger's post, perhaps?
And this gets modded up?
At least it was modded interesting, Spy der Mann sure doesn't understand enough to be Informative.
Well, if anyone needs the visual proof that carbon nanotubes are very electrically conductive, here's a video.
So sue me. I was still light headed from an orgasm.
*Screams*
Am not.
So this is probably not some new huge breakthrough in anything like superconductivity, but a refinement of a well-known phenomenon.
Letter To Iran
You fools still don't get it. *bang!*
off-topic ? sort of,, at least mod it down with something else because it's slightly on topic :) The Stargate is a superconducting ring, the ancients build the thing, induce massive joules of energy into and it flows forever without loss. Not sure how that guy built a the equivalent in Carter's basement though :D
When electricity can be transmitted large distances with little loss than it would lead to tremendous growth in renewable energy. For instance one could cover huge areas in the Sahara desert with solar cells or one could use geothermal energy in Iceland or one could use hydroelectric power from the Hudson Bay. There are plenty of areas where cheap electric power could be generated but are too far from where that energy is needed. It would also mean that we could improve the efficiency of all electric motors as it would mean reduced heat and reduced need to rid the motor of that heat. If this technology were certain to be accomplished in even a twenty year time span it would lead to a tremendous change in our energy policies but I for one will remain skeptical.
They've already produced some wires up to 100 meters long--the only thing left to do is figure out how to produce only a certain type of nanotube, the "5,5 armchair nanotube," that conducts so well that it can be considered a superconductor."
Does the amount of conductivity depend on how you set the little lever on the side of the armchair?
To put a witty saying into 120 characters, jst rmv ll th vwls.
I'm more used to them passing out rather than screaming. Um . . . I suppose that could be the drugs.
on average around 2% of energy is lost during transmission over power lines. It'll be different in different countries. It all depends how far you are from the station.
On the other hand, convertng fuel to heat in order to generate electricity is typically around 40% efficient with a 60% loss of energy. Combined cycle power stations are closer to 60% efficient with a 40% loss of energy. The laugh is that the single largest use of electricity is to produce heat, but we're only doing it at around 40% efficiency with a 60% loss.
What we should be doing is using that 60% waste heat from the power stations to heat our houses and offices directly and using the electricity to power stuff. It's called Combined Heat and Power (CHP) or District Heating (DH). We'd then be closer to 80% -> 90% efficient.
CHP and DH systems have already been in use in northern european countries (Denmark, Finland etc) for decades, they are nothing new. I guess the UK and USA literally have money to burn.
Deleted
I suspect that if the wire is in a magnetic field it will lose it's superconductivity - thus it wouldn't work in an electric motor. If you're looking for a perpetual motion machine I understand Joseph Newman has one for sale.
Does super or ballistic conductivity do anything unusual to the B (magnetic) Field around a current carrying condutor?
In other words, are lighter, more effcient, cooler running electric motors also a potential?
And physics is an abstraction of math, right (physics laws are mathematical in nature)? And all social sciences are abstractions of biology? If you assume all of the above, you can play some interesting mind games; does the fact that math is deterministic imply human behaviour is too? :-)
There is an important distinction between superconductors and perfect conductors. These carbon nanotubes are not superconductors at all, as a few posts above almost pointed out. In a superconductor the fermions (here electrons) pair up into Cooper pairs and then Bose condense. They exibit the Meissner effect, etc. This is an entirely different ballgame than a perfect conductor, which would simply have zero resistance to electrical flow. Check out your local solid state physics book for more info.
I'm at Rice University, and I can tell you what the real situation is. Smalley has DARPA and NASA money to try to do something he calls continued growth: to take an existing carbon nanotube, and increase its length in a gas-phase chemical vapor deposition process. They are having limited success. Don't go buying your space-elevator stock yet.
Separately, Smalley and collaborators have been working on spinning fibers from ropes of nanotubes (basically short (less than 1 micron) tubes bundled together by van der waals forces). Those are the fibers that can be meters long. These fibers do not consist of meter-long tubes!
Finally, metallic nanotubes are not room temperature superconductors. In fact, they are not even ballistic over length scales larger than a micron. Smalley's habit of implying otherwise is really annoying to any physicist who knows anything about these systems.
Now, a long fiber of only metallic nanotubes would still have conductivity better than copper at much less the weight, and would therefore be very important industrially if it could be made economically. There is a huge difference between that and having no electrical resistance, though.
It won't be economically feasible to make long nanotube wires for quite a while. Tiny wires to conduct within a microchip might be more realizable.
> I suspect that if the wire is in a magnetic
> field it will lose it's superconductivity
> - thus it wouldn't work in an electric motor.
1) Superconductors only lose their superconductivity when exposed to a field strength in excess of the threshold for the material they are made of. Superconductors are, in fact, used to produce extremely strong magnetic fields for things like MRI machines. Motors and generators (some very large) _have_ been made with them and they have real advantages: they are just not cost effective in most applications.
2) We are not talking about superconductors. I see no reason why ballistic ultraconductors should not work in high magnetic fields.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
The linked article doesn't seem to say room temperature.
It's true it does say:
quantum wires could perform at least as well as existing superconductors--without the need for expensive cooling equipment.
But that is subject to multiple interpretations, and an earlier post said that his report in 1999 featured data collected at 20 Kelvin. Nitrogen liguifies at about 70K, and Oxygen at about 90K. So that probably means liquid Helium, but not extremely cold Helium. Unless this is based on something else, his idea of "expensive cooling equipment" would appear to be a lot different from mine.
There is http://www.pa.msu.edu/cmp/csc/eprint/DT153.pdf which talks about room temperature ferromagnetism (PHYSICAL REVIEW B 67, 125421 2003), but it doesn't seem to define the term, and that's not superconductivity.
I think we've pushed this "anyone can grow up to be president" thing too far.
Prisoners have been using carbon to conduct electricity for years and years, in the form of taking the graphite out of pencils, sticking it into an electrical outlet and bridging with another piece of graphite to make one hot arc so they could light their cigarettes. Maybe they'll make carbon nanotube pencils so the prisoners can start lighting their cigarettes in a more energy-efficient way.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
If you coil a superconductor into a torus, it sounds like it will loop around the torus forever with no losses. How much electricity can you feed into it? Is the size of the coil a significant factor? If there is an easy way to feed electricity into it, and later pull electricity from it, have we created a perfect battery?
How many amps can these nanotubes carry? Do they produce a magnetic field like normal wires? If so, one should be able to make an MRI scanner with nanotubes rather than superconductors.
If powerlines could have negligible resistance, then it will be viable to transmit power as DC. (At the moment, AC is used to minimize power loss during transmission.) This could mean that devices could plug into a (say) 12V DC outlet right in the wall, eliminating all the heat loss from each individual transformer, and getting rid of the bulk. Imagine, your computer wouldn't need some massive AC-DC power supply! (Obviously it'd still need a small, simple one to transform down to 5V, etc.)
I was going to post almost the exact same thing (except for the part about being at Rice).
It's kind of a standard disclaimer that I feel goes with any online posting of nanotube research. For some reason, quite a large number of people ignore the laboratory realities of carbon nanotubes.
Would this actually work? If you tried to cut a single carbon nanotube with a knife, would it cut the knife instead?
All of what dr. loser said is true, except for the part about "limited success" with continued growth. Perhaps he was being diplomatic, but the Smalley group has been trying to grow nanotubes from seeds for about 10 years, with _no_ success. They can not show that they have _ever_ successfully cut a nanotube and restarted growth. I don't know why DARPA keeps shoveling millions of dollars into that money pit.
And yes, Smalley has a habit of implying things that physicists would find outright insane. He's essentially a politician now; what do you expect?
I can't wait for these superconducting wires to hit the market. They represent the last missing parts of my doomsday machine.
-- I borrowed this SIG from a friendly neighbor
I work in a physics lab, and we synthesize nanotubes.
A lot of new work on nanotube synthesis is done by chemists (also physicists and electrical engineers). However, studying the properties of nanotubes and making devices out of them is primarily done by physicists.
That said, work on nanotubes and other kinds of molecular nanotechnology really is interdisciplinary between physics, chemistry, and electrical/materials engineering. My particular degree program is a fusion of these, and there similar programs springing up around the country.
Actually AC was originally used because it made it easy to step the voltage up and down. Transmitting at higher voltages minimises the resistance loss in the cables. Using high voltage DC is even better since it eliminates capacitive and inductive effects and reduces the peak voltage stress on insulators. With modern invertor technology it is about as efficient as a transformer, although still more complicated. Switch mode supplies as used in computers these days are an example of using a DC-DC device instead of a transformer, and the economics there are that the saving on weight and copper and iron costs will pay for the electronics.
Thanks for the pictures.
Smalley has always said that nanotech cannot work because there is no room down there for little fingers. These photos clearly show what he means.
That said, he's getting funds now for nanotech research from the NNI. Logic and consistency never were his strong point.
Most definitely my favorite molecule.
I wonder if this could be put to use in batteries and capacitors. Wihout resistance, you could a string of electrons inside the tube - the trick is sealing off the ends...
Antisource - antivirus, antispam, antispyware
Now, a long fiber of only metallic nanotubes would still have conductivity better than copper at much less the weight, and would therefore be very important industrially if it could be made economically.
I don't like the way you imply that we use copper for transmission lines.
First, I'm actually Mike Wofsey, not annonymous coward, but I can't remember my password, and the script gate won't let me through to retrieve it. Anyway ...
...
This whole thing is completely on the level. The armchair chirality nanotubes are not superconductors, but they are better conductors than any of us will ever see in our lifetimes, mainly because unlike superconductors, they don't need liquid nitrogen. These things will work at room temperature and above.
By the way, I'm a physicist grad student, and I'm working on quantum wires right now, so I think I'm right, but if I'm wrong, please insult the heck out of me, I deserve it! Here's what's happening
The single wall carbon nanotube can be made in a variety of chiralities. The chirality of a SWNT is the way the carbon atoms link up. Some chiralities produce insulating nanotubes, other produce semiconducting nanotubes, and the armchair chirality produces a conducting nanotube.
So far, it's still just a conductor. But the nanotube has something else happening. A typical 5 nanometer armchair chirality nanotube has an electron path along the surface of the tube that is essentially ONE-DIMENSIONAL! This is the so-called quantum wire, because it allows the charge carrier to go forward, to go backward, and pretty much nowhere else. Of course this is actually a quasi one-dimensional system, because the Heisenberg Uncertainty Principle necessitates three dimensional movement for the electron. But for our purposes the nanotube is essentially a quantum wire, or a one-dimensional system.
This 1-D wire now offers a dramatically improved mean path for the electron, or in other words, the average length that the electron can travel before it collides with another electron is increased significantly, because it is contained within one-dimension. Since the mean free path is increased, the electron drift velocity is correspondigly increased, which then figures into the equation for drift velocity, (currren density)=(number of charge carriers)*(charge)*(drift velocity). This shows that the current density is increased, which then figures into Ohms Law, (even if the nanotube is not Ohmic, it will still roughly follow the proportionality of Ohms Law.) And Ohms law thus says that resistance is decreased.