The World's Longest Carbon Nanotube 142
Roland Piquepaille writes "As you probably know, carbon nanotubes have very interesting mechanical, electrical and optical properties. The problem, currently, is that they're too small (relatively speaking) to be of much use. Now, researchers at the University of Cincinnati (UC) have developed a process to build extremely long aligned carbon nanotube arrays. They've been able to produce 18-mm-long carbon nanotubes which might be spun into nanofibers. Such electrically conductive fibers could one day replace copper wires. The researchers say their nanofibers could be used for applications such as nanomedicine, aerospace and electronics."
One more step toward a space elevator? (Score:3, Interesting)
Carbon fibre (Score:4, Interesting)
The real killer commercial application (Score:2, Interesting)
Then we will really see what Arthur C was talking about.
The applications for "diamond" fibre are enormous.
Re:Wow (Score:5, Interesting)
Ted Stevens actually being prophetic, rather than just wrong.
You know, Stevens gets a totally bad rap on that whole thing. Exactly what is wrong with that analogy? Even UNIX uses the analogy with pipes; Ritchie* could have just easily called them tubes rather than pipes. And yes, the "tubes" of the Internet CAN get clogged up if there's too much flowing through them.
I've never understood why he took such a beating about it. I guess some people are just determined to believe the worst about people, as though the guy though the Internet was literally air-filled tubes.
Re:One more step toward a space elevator? (Score:5, Interesting)
The problem with rockets has never been the mass of the rocket, but the mass of the fuel. There's only so much oomph you can get out of a million litres of hydrogen and oxygen chemically, and it's only marginally more than the power it takes to lift a million litres off the surface and into space. Sure, a lighter fuel tank, and lighter payload will help, but not significantly.
No, if we want cheap access to space, we either go nuclear [nuclearspace.com], or build some sort of space elevator. While we may just be at the threshold of being able to make materials with the tensile strength needed for a beanstalk, we have the tech to make gas core nuclear rockets right now.
Re:Wow (Score:3, Interesting)
Re:Come again (Score:3, Interesting)
That puts it in the area of useable length for macro-sized application.
Obviously we've got a long ways to go then.
The other thing they mentioned was that given a mathematically perfect carbon nanotube structure, the highest building we could build before it would collapse on itself is something like 90 miles; and we need
Of course both of these are hearsay so take them with a grain of salt, but the important thing I remember is that whatever the max height of a carbon nanotube structure that we could build is, the height required for a space elevator/cable is several orders of magnitude greater.
So why were we funding this stuff again?
Re:Carbon fibre (Score:3, Interesting)
Note that nanotubes != CF.
That said, people are already starting to incorporate nanotubes in composite materials. The two hard parts are that they're really slippery and it's hard to get the matrix to stick to them, and that they tend to clump up a lot. The increased length helps with the first problem -- slippery is less of a problem if there's more surface to stick to. I don't know about the dispersion.
Nanotube composites are already impressive. You can get things with 30-50% more stiffness, 50-200% more thermal conductivity, lower thermal expansion, and other useful properties. Metal matrix composites are also impressive. Think aluminum with nanotubes added. You can get double the strength, more than double the stiffness, and double or more the thermal conductivity in something as machinable as aluminum by adding only 1-2% nanotubes. This is a *rapidly* advancing field, and it's poised to seriously change high end materials science in the very near future.
Re:Wow (Score:3, Interesting)
The analogy isn't too terrible. It conveys the notion that Internet bandwidth is a shared resource. However, Ted Stevens demonstrated very clearly that he has no idea what he's talking about. He seems to think that when somebody downloads a movie, the entire movie gets put into the 'tube' and all other data gets in line behind it. He thinks an e-mail he got several days after it was sent arrived late because too many movies were coming through the tubes. Not only that, but he referred to the e-mail as "an internet."
He doesn't realize that data is divided into packets, where a limited amount are in transit at one time for each transfer. This fact is very important. It means that bandwidth is shared roughly evenly between all the users of a 'tube' at any given moment, and that e-mails can always be delivered just a quickly as a few packets of a movie would be delivered. His e-mail could only have been delayed by a messed up mailserver, but he didn't know enough about the Internet to realize that.
Re:Wow (Score:3, Interesting)
I think its kinda dangerous to assume that he's stupid, because you fail to realize just how much of a cold, calculating demon he is. Believe me, I know people who used to be former interns of his... they're all hoping he'll die soon, but from what I've heard, his physical health is like that of a 30-year old.
Oh well, as long as his party doesn't get control back, we should be relatively safe.