Nanotubes Start to Show their Promise 329
Rei writes "Researchers at the University of Texas at Dallas have developed the highest quality nanotube sheets to date (the team previously set strength records with polymer-nanotube composites). Producable at a rate comparable to commercial wool spinning, the transparent cloth has exceedingly high conductivity, flexibility, has huge surface area to volume ratios, can potentially be made into very effective OLEDs and thin-film photovoltaic cells, and outperforms even our best bulk materials (such as Mylar and Kevlar) at strength normalized to weight. It strongly absorbs microwaves for localized heating (leading to applications in seamless microwave welding of sections and even windshield warming), changes conductivity little over a wide temperature range (very useful in sensors), and is expected to be used in commercial applications very soon. The research should even be expandable to artificial muscles! To head people off, while the exact tensile strength is not listed, it sounds like it is still far from the >100 GPa needed for a space elevator. Anyways, here's to process advancements!"
How about... (Score:5, Interesting)
I know tfa says that it will be efficient, but does that take the cost into perspective? It's not unusual to hear about a new idea that is totally ground braking in several fields, then the research on the commercial fades out, because they find out that it's too pricey. A lot of products was that way in the beginning. Just look at LCD screens etc.
Well. That being said. This sound awesome, I'd like to see it developed...
Re:flexible screens..? (Score:1, Interesting)
Also.. (Score:2, Interesting)
Stealth material? (Score:5, Interesting)
Space elevators will never work (Score:2, Interesting)
A space elevator is going to require a truly civilisation shaking level of investment by a country. Then, once it's built that investment has to be amortized over it's lifetime, but wait, it only has two end points and it takes a certain amount of time to load and unload a vehicle of cargo and passengers, it takes a certain amount of time to travel the distance up to orbit. These two fundamental physical limitations will mean that a space elevator will never be able to pay back the investment. It's always going to be cheaper to load a cargo on top of a rocket booster and fire it up.
Sounds great... (Score:3, Interesting)
Re:Let's hope it's safe to use (Score:1, Interesting)
I suppose there is the possibility of other dangers unlike any seen before, but if we halted advancement for every risk, we would not exist, as even without technology life is full of risk (some would say more without all of our technology).
Re:Space elevators (Score:3, Interesting)
It's taken a very long time to get here (I was just a kid at the time), and I pretty much have always dismissed the idea of space elevators, but it's kinda neat to see that the concept is evolving along the same vein as over two decades ago.
*(CSSS merged with the L5 society in the early 1980's.)
Not science fiction according to IEEE Spectrum (Score:5, Interesting)
Re:Still lot of carbon... (Score:1, Interesting)
You are right... if your space is asymptoticaly flat. In an arbitrary space it is not necessarily true.
Re:Space elevators (Score:1, Interesting)
Since they're scientists at heart, and need to retain a bit of credibility they can't claim that the applications will work (they might not) and so they qualify every little statement they make. The journalist knows too little about science to correct the resulting bad writing.
Re:Space elevators will never work (Score:3, Interesting)
There is a big difference between an up-only cable and an up-down cable - up-down allows for easy energy exchange, better utilization of cable bearing strength, and lower capital costs (than two separate cables), but needs to be a small amount larger, is slightly harder to build, and most significantly, requires many launches of small elevators instead of few launches of large elevators for effective power exchange.
To understand why having both up and down utilize the tether better, picture the strains on each part of the tether if you have one starting at the bottom and the other starting at the top. Start the one on the top first - once it has enough acceleration to go without pulling on the tether, start the bottom one. They pass each other at a point less than 0.5g. The one that was at GEO lands on earth braking slowly while the other elevator largely drifts, and once it touches down, the Earth elevator brakes as fast as it wants to and arrives at GEO.
You'll notice that these two elevators could be carrying a full payload, and put little more stress on the tether than just an up-only climber with equivalent payload at any given point.
Adding in more elevators decreases this benefit somewhat (although still keeps minimal strain on the critical bottom part of the tether at any given time - it's easier to reinforce the further up you get, because reinforcements have to be supported all the way back to GEO), but allows for power transfer. With just two elevators at a time, power transfer isn't realistic (unless the tether superconducts or you can afford the mass of thousands-of-miles-long superconductor, the resistance is too great for long distance transmission; furthermore, the battery mass to store energy for several days of power accumulation is not realistic. Storing several hours worth, however, is realistic, as is transferring that much power in a couple minutes time in a "passing zone")
Shuttle Tank 1st, then elevator OK? (Score:2, Interesting)