[Balgair]

FYI for all the readers here: Carbon nanotubes won't work, the phonon effects (lattice interactions) in that very large crystal usually add up to break them after a few cm. Think of it like like a very narrow and very long tube half filled with water. There are vibrations along the length of it, some big and some small in amplitude. When those random waves in the water tube interact, they can add up, sometimes so much so that they break the tube. I know that is now totally correct, but that's the gist.

http://www.ruf.rice.edu/~rau/phys600/p273.pdf

Many more here:

https://scholar.google.com/scholar?q=carbon+nanotubes+phonon...

[avmich]

Is it not possible to dampen phonons before they will break the thread? You probably don't need to have vary long monomolecular threads, you can have many shorter ones weaved in a thicker rope.

[Balgair]

Good question. I am not an expert in this in any way. I'd think that you have to have dampners in the lattice of the crystal. The only way that works is to dope the lattice with either another 4 valence element, like silicon, or to dope the carbon itself with something. The only think I can think of is to modify the isotopes to be VERY heavy which is obviously therefore radioactive and would need to be replaced a lot. If you used silicon dope then you'd reduce the interatomic strength and therefore make the rope possibly too weak to be used.

I thought that the whole point of carbon nanotubes was that they are the only thing with the 'pull strength' (forgetting the term here) that could withstand the tension. If you weaved them, then you would rely on the Van Der Waal forces to keep the tubes together which is much weaker. Also you have to contend with the phonon interactions, anything tangential to that 'plane' has no effect on the strength, you have to be a part of the lattice to effect things.

Then again, I don't do research in this area.