I'd be VERY interested in getting a transcript of this (or even better, if it can be done legally, a copy of your tape).
> Which of these three (or something else?) would be the best material to use
> in a cable if the strength per unit weight is the only consideration (i.e.,
> with molecular nanotechnology the material is 'free'):
> - diamond
> - carbon again, but in the form of a superfullerene ( > 60 carbon atoms
> - C3N4: this crystal may be harder than diamond, but would it outperform
> diamond in terms of strength too? I gather that hardness means that the
> atoms can't be compacted further, which doesn't imply that the bonds are
> especially strong under tension (= brittleness?).
A basic material in the RPG "CyberGeneration" is Hexite, which is carbon in 11-atom fullerenes. Six or more of these can be linked to create a fantastically strong material, hence the name. Ten times the structural strength of titanium (supposedly), about 1/3 the density. Any comments on this material?
[Things are a bit more complicated than this. You'd think, for example, that the strongest fibers would be polyethylene, which is just long carbon chains. It turns out that a large part of the strength of stronger materials (e.g. nylon, Kevlar) is the side groups that keep the chains from slipping past each other. There are a lot of tensility vs shock resistance vs brittleness issues that mean that there isn't any one best, or even "strongest", material. --JoSH]