Graphene: The Wonder Substance
richannel.org
richannel.org
From what I understand, it is very difficult to make large sections of pure graphene or long CNTs. As long as they're pure, they remain strong, and therein lies the difficulty of graphene and CNT production. Like you said, the impurities do weaken CNTs and graphene. The impurities can be contaminants which occupy a carbon location, or missing carbon atoms, forcing the lattice to reconstruct. According to [1], this can lower the tensile strength of a carbon nanotube by up to 85%. The problem with manufacturing long CNTs and large areas of graphene is that it is thermodynamically impossible to, on a large scale, have a perfect lattice. The imperfections will weaken the entire structure. So yes, as you go up in scale, the incredible/fantastic properties will just become impressive.
[1] http://en.wikipedia.org/wiki/Carbon_nanotube
*I currently study materials science and can produce literature upon request. Also this is from the top of my head so it may contain some errors.
It's interesting to note that much of the tradition of western rocketry is descended from captured and reverse-engineered Mysorean rockets. And most of the rest of the western tradition of rocketry is descended from half-crazed Russian mystics and Egyptian ceremonial magicians. But that's another story entirely...
I find it hard to believe. Any references?
India wasn't as backwards as you might suppose, there were lots of areas of technology they were very good at such as chemistry and metalurgy. After the Battle of Plassey, I believe, the British captures a number of Indian cannons and found that they were better than the guns that the British had. Of course, they all had different bores and it was too logistically difficult to keep that many different kinds of ammunition, so the British just destroyed them. Which, I think, goes a long way towards illustrating the actual reasons the British ended up ruling India.
http://duckduckgo.com/?q=hastol+tether
So long as you don't require the tether to be stationary and to meet up with a stationary point on the ground, you can have a space elevator with materials we already have.
You didn't actually say what materials are strong enough for this (that we can actually produce without bankrupting whole countries).
Apparently, you didn't read. The tether rendezvous is with a pod carried by a hypersonic spaceplane, not the ground. The tether can be spun, to make the ground speed of the tether-end even slower. Rendezvous slows down the spinning tether and lowers its orbit, but it can be boosted between rendezvous using very high ISP motors like ion thrusters, which dramatically lowers the amount of fuel to be lifted.
You didn't actually say what materials are strong enough for this (that we can actually produce without bankrupting whole countries).
Spectra and Kevlar have the required tensile strength for many proposed configurations. There is the added complication of dealing with ions, free radicals, and radiation, however.