China Produces Nano Fibre That Can Lift 160 Elephants - and a Space Elevator? (nzherald.co.nz) 240
Slashdot reader hackingbear quotes the NZ Herald: A research team from Tsinghua University in Beijing has developed a fibre they say is so strong it could even be used to build an elevator to space. They say just 1 cubic centimeter of the fibre — made from carbon nanotube — would not break under the weight of 160 elephants, or more than 800 tonnes. And that tiny piece of cable would weigh just 1.6 grams... The Chinese team has developed a new "ultralong" fibre from carbon nanotube that they say is stronger than anything seen before, patenting the technology and publishing part of their research in the journal Nature Nanotechnology earlier this year...
The space elevator idea has remained in the realm of sci-fi, physical and mathematical models because there has been no material strong enough to make the super-light, ultra-strong cables needed... Now, the Tsinghua team, led by Wei Fei, a professor with the Department of Chemical Engineering, says their latest carbon nanotube fibre has tensile strength of 80 gigapascals [over ten times more than the 7 gigapascals strenth NASA estimated to be required for a space elevator]... Chinese and Russian space scientists, for instance, are working together to find a safe, effective way to lower a fine, feather-light cable from a high-altitude orbit to the ground.
Wei also said his team was trying to get the carbon nanotube fibre into mass production for use in defense -- or to create super fast flywheels in a mechanical battery, which would have 40 times the energy density of a lithium battery.
The space elevator idea has remained in the realm of sci-fi, physical and mathematical models because there has been no material strong enough to make the super-light, ultra-strong cables needed... Now, the Tsinghua team, led by Wei Fei, a professor with the Department of Chemical Engineering, says their latest carbon nanotube fibre has tensile strength of 80 gigapascals [over ten times more than the 7 gigapascals strenth NASA estimated to be required for a space elevator]... Chinese and Russian space scientists, for instance, are working together to find a safe, effective way to lower a fine, feather-light cable from a high-altitude orbit to the ground.
Wei also said his team was trying to get the carbon nanotube fibre into mass production for use in defense -- or to create super fast flywheels in a mechanical battery, which would have 40 times the energy density of a lithium battery.
Better Article from Ars (Score:4, Informative)
https://arstechnica.com/scienc... [arstechnica.com]
While the authors note that this work could find a home in "sports equipment, ballistic armour, aeronautics, astronautics and even space elevators," we're still a long way from any of that. Ideally, rather than synthesizing the nanotubes in centimeter-long chunks, we'd like to have some sort of continual production process. Still, the work is important in that it hints that there is a world beyond micrometer-scale nanotube fragments.
Nice to have my instinct confirmed that there would of been much more noise over this if Ultralong meant kilometers or or at least 10s of meters.
Re:Better Article from Ars (Score:5, Interesting)
there would of been much more noise over this if Ultralong meant kilometers or or at least 10s of meters.
Actually, if a single nanotube is 1 cm, that is enough. The length would be 10M times the diameter, and the Van der Waals attraction between adjacent tubes along their entire length would far exceed the strength of the covalent link between carbon atoms in a tube.
If you were building a space elevator to GEO (36,000 km), the difference is strength between using a fiber constructed from 1 cm tubes and 1 km tubes would be negligible.
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How did African elephants end up in China ? They are non migratory.
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African or Asian elephants?
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How did African elephants end up in China ? They are non migratory
With a space elevator - did you even read TFA?
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That doesn't sound right Van Der Waals forces are 1/100th or less strength of a carbon bond also you need dipole moment to generate them. Chemistry isn't my big thing, and quantum chemistry especially not but it doesn't seem likely you are going to get much in the way of dipole moment from carbon-carbon bonds.
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There seems to be a bit of controversy in what keeps graphite together and what to call the forces, some call it Van Der Waals, some call it metallic bonds ... suffice to say, graphite does keep together. So there is a force there, the same would be true for a bundle of these nanotubes.
Re:Better Article from Ars (Score:4, Interesting)
Graphite holds together, but only just. Pencils work because a tiny amount of shear force is enough to cause layers of it to come off (and that's the direction that you'd be fighting if you tried to pull two tubes apart that were stuck in this way). A child can pull a lump of graphite apart.
This has always been the problem with potential space-elevator materials. It's relatively easy to make something that's strong enough over a very short distance, but none of the proposed materials can either be synthesised in a single long chunk (yet?) or can be woven together to form a rope that maintains anything like the same tensile strength.
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The graphene layers in graphite aren't well ordered though and as the original poster said though, the ratio of the length of the fiber to it's thickness is massive ... so small forces might add up. Impossible to say without actually doing experiments (the physical models are too poor to put much faith in).
Re:Better Article from Ars (Score:5, Informative)
Let's not forget that carbon nanotubes make asbestos look like cotton candy, healthwise. In animal studies, exposure to CNTs induced sustained inflammation, fibrosis, lung cancer following long-term inhalation, and gene damage in the lung. [nih.gov]
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Of the several kinds of naturally-occurring asbestos, some already are safe. Just not the kind formerly used in applications where you want short fibers to make it easy to mold into things like brake pads, etc.
(Still recapitulating phylogeny with my first cup of coffee, don't recall which asbestos type is which.)
Re:Better Article from Ars (Score:5, Informative)
"would've been". It's a contraction of "would have been".
It would've been nice if (supposedly) bright, (supposedly) well educated people could spell....
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I would of done that two, but I don't have CDO.
what connects strong nano fibre & space elevat (Score:4, Insightful)
how was it that first use case imagined for this fibre become space elevator?
aren't there more down to earth already practicable use cases, where this fibre will replace some other fibre because it is better.
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aren't there more down to earth already practicable use cases, where this fibre will replace some other fibre because it is better?
Are there? https://www.youtube.com/watch?... [youtube.com]
Re: what connects strong nano fibre & space el (Score:2, Funny)
Yes, lifting 160 elephants.
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Well, it'd be money well-spent if it had the same marketing impact [arstechnica.com].
Nobody wanted space in the Falcon Heavy test launch mission, but after demonstrating the ability to launch heavy payloads to escape velocity SpaceX has established credibility for launching large, geostationary payloads.
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Re:what connects strong nano fibre & space ele (Score:5, Funny)
how was it that first use case imagined for this fibre become space elevator?
It wasn't; the elevator is only for the elephants and they forgot to mention the turtle,
I think it's the other way around. (Score:2)
The idea of the space elevator is constantly out there, waiting just under the surface. Any technology that seems likely to bring the space elevator closer to reality re-ignites the idea like a spark.
I actually think this makes sense, since a working space elevator has more potential to immediately make radical changes to humanity's future than most others (AI being one of the most obvious exceptions.) A lot of great stuff (and some crappy stuff, too) could come from a practical space elevator.
Re:what connects strong nano fibre & space ele (Score:5, Insightful)
Near-invisible, huh? Birds trying to fly through it, coming out in sections.. people brushing against it, losing fingers... yakuza vat-grown ninjas swinging fake thumbs about on a spool of it, cutting people in half...
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Imagine the Chinese gift for hyperbole outrunning your common sense.
Re: what connects strong nano fibre & space el (Score:3)
Chinese already did, in the Chinese sci-fi novel Three Body Problem, where the good guys construct something like that to cut a ship into pancake sections to kill the bad guys and recover something inside.
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Inquiring minds want to know (Score:4, Informative)
Asian or African elephants, laden or unladen?
Re:Inquiring minds want to know (Score:5, Funny)
Asian or African elephants, laden or unladen?
African elephants, unladen.
TFA says 160 elephants, or 800 tonnes, or 5000 kg per elephant. That is about the average weight of an African elephant. Females are about 4000 kg and males about 6000 kg, averaging to 5000 kg.
Asian elephants are considerably smaller, averaging about 4000 kg. The only way to average 5000 kg with Asian elephants would be to use all males, but the males tend to be aggressive and difficult to handle, and there is no way you are going to get 160 of them onto a scale.
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I know you guys loves you feet and inches, but this is getting silly.
- Libraries of Congress for data storage
- Football pitches (American?) for area
- Elephants for weight
Are there any other non-SI units I should be aware of?
Re: Inquiring minds want to know (Score:2)
Are there any other non-SI units I should be aware of?
AmiMoJos for density.
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Are there any other non-SI units I should be aware of?
Don't forget the thing, a substance-dependent unit of measurement used by women:
"Honey, can you pick up a thing of butter and a thing of milk on the way?"
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This thing?
https://en.wikipedia.org/wiki/... [wikipedia.org]
Maybe you meant American Football field?
Re:Inquiring minds want to know (Score:5, Funny)
Sure there is. Just apply plenty of butter for them to leave footprints in.
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But such a product might be good news for the environment, since we'd have to preserve wet lands and numerous species of turtles in order to have an assured supply of turtles to send into orbit. We don't need to breed any huge numbers of turtles at any given time mind you. Sending up an infinite number of turtles is going to take an infinite amount of time (and energy) no matter how quickly we do it, might as well
Can someone convert this to African swallows? (Score:2)
The real question is:
Do we call it Scrith, or Twing? :)
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We can only call it scrith if it screens out 50% of incoming neutrinos.
Scientists, start your detectors!
Cross sectional area ? (Score:5, Insightful)
Quoting volume for a rope is not very helpful. The cross sectional area would be much more interesting for saying how much it can carry.
Re:Cross sectional area ? (Score:5, Informative)
Quoting volume for a rope is not very helpful.
Indeed. That is one of the stupidest metrics I have seen in a while.
The cross sectional area would be much more interesting for saying how much it can carry.
Well, they do say 80 gigapascals, which means 80 billion newtons per square meter. That is 8 million newtons per square cm, which in earth's gravity is equivalent to supporting ~800,000 kg, or 800 metric tonnes. Which is roughly the weight of 160 elephants.
For a space elevator, an important metric is how much of its own length it can support. Carbon nanotubes have a density of about 2.5 gm/cc. So 800 tonnes is about 3200 km of fiber with a square cm cross section. TFA says that is enough, but that will get you only a tenth of the way to GEO.
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You assume a uniform cross-sectional area.
Re:Cross sectional area ? (Score:4, Informative)
Do note that the glass fibers in regular fiberglass have a tensile strength approaching 5 GPa [wikipedia.org]. So regular materials are within an order of magnitude of what's needed for a space elevator. Fiberglass' performance only craters when you have to use resin to hold disparate fibers together. That's the real challenge here - how to extrude a single really-long carbon nanotube, or glue a bunch of them together with minimal loss of strength. One of the reasons the use of metals is so widespread is because their crystalline grains slide against each other until they interlock, self-solving the "glue a bunch of them together" poblem.
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The strength of the material is specified in pressure units -- in this case 80 gigapascals.
A simple unit conversion can give you the cross-sectional strength in newtons: 80 billion newtons per square meter.
Space elevator in a hurricane (Score:2)
Nuff said.
Re:Space elevator in a hurricane (Score:5, Informative)
A space elevator has to be located on the equator, where there is no coriolis effect, and thus no hurricanes.
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I feel better now.
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Trying to wrap brain around what happens it you place it e.g. 45 deg north/south.
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Ideally located there
No. It MUST be located on the equator. It is tethered to a counterweight in orbit. The satellite will trace a great circle around the center-of-mass of the earth. An equatorial orbit is the only orbit that will pull directly upward for the entire orbit.
Most proposals put the base on a barge located in the equatorial Atlantic or Pacific. The barge will make it easy to access and service, and also allow it to move slightly to avoid orbital debris.
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See, this is why I always laugh when the topic of space elevators comes up. So you're going to move the giant barge tethering the end of the space elevator to avoid the 7mile/second LEO debris, huh? Even the paint chips that we can't really see?
If your space elevator isn't on the order of meters thick, it's not going to survive ablation by space debris. And if you'd like to do the math on that, now we're talking a GEO cable manufacturing facility with raw materials supplied by asteroids. Because we simply c
Space debris (Score:2)
That cable is a really small target. A better question is how long can you statistically expect it to stay viable? Whatever that answer is, you need to be able to either rebuild or replace in less than that time frame. Realistically, this implies multiple tethers in operation at all times, using tethers to make sure there is material on-hand in orbit for repair/replacement.
A bigger problem is exposure to elemental oxygen in the upper atmosphere and hard UV as you go higher.
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Other problems include needing asteroids big enough to serve as counterweights and as raw materials, oscillation and vibration dampers, the van Allen radiation belts and UV/radiation-driven material fatigue, electrostatic charge of the cable due to the solar wind, having a stable enough tether point that you can easily load cargo, dealing with the steady rain of nanotubes at the base, etc.
Space elevators are a great sci-fi invention, but they will never be practical. Rockets are already getting closer to be
Other problems (Score:2)
Well, no. No asteroids needed, thanks, although if somebody shows up with one that would be great. We'll send a starter weight up by rocket. Once the elevator is working we'll take up additional mass for building, shielding, and selling.
A stable loading area is a gimme. It will in all likelihood be inside a building at the base of the tether (if on land) or in the center of a large barge (if on water).
I don't know why there would be a steady rain of nano tubes from the tether, but it certainly will not
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We'll send a starter weight up by rocket.
No, no we won't. Go do the math on that one.
And once you realize how insane it would be to try to do that, you'll quickly realize that we'd need hundreds or thousands of really cheap, reliable rockets to get all the material up there.....which is what the whole point of the space elevator is. At that point you're fighting financial, political and engineering challenges the likes of which the world has never seen, in order to accomplish something you're already accomplishing.
The last SpaceX rocket failure wa
Well... (Score:2)
You could drop two cables to places equidistant from the equator (N and S, obviously) and have them come together at a satellite above the equator. Then one of your cables could be in a hurricane's path.
Hmm, if you put the satellite far enough past geostationary to get some additional pull, you could have the cables be of different lengths and maybe sustain the satellite north or south of the equatorial plane?
Space Elephants? (Score:2)
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Obviously, Tactical Bombardment Elephants are the secret weapon of the Space Force.
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I thought it was Sharks in Space. :)
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I dunno man. Wait until the Fithp hear about this. It won't end well.
Don't Forget (Score:5, Informative)
That even when the tech is ready:
"The Space Elevator will be built about 50 years after everyone stops laughing." - Arthur C. Clarke
Falcon Heavy cost per kilo (Score:2)
This is right now, today. Almost. $90 million launches 63800 kilos [wikipedia.org] into low earth orbit. That is $1410/kilo. Misty eyed space elevator proponents claim $500/kilo. [wikipedia.org] Eh. Putting aside for the moment the probability that that is a wild underestimate, if space elevator launch is 35% of the cost of rocket launch then the capital cost of a space elevator will never be recovered, never. Not ever.
Don't forget that any mass you hoist up this mythical elevator needs to achieve orbital velocity, just like a rocket does
Re: Falcon Heavy cost per kilo (Score:2)
Misty eyed space elevator proponents claim $500/kilo.
You picked the highest estimate from your link instead of one of the lower ones, and then still called it's proponents "misty eyed". That's droll.
Don't forget that any mass you hoist up this mythical elevator needs to achieve orbital velocity, just like a rocket does. That takes energy. Where does that come from, who pays for it?
...
This is some kind of joke, right?
The answers are: "electricity" and "the customer".
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You picked the highest estimate from your link instead of one of the lower ones
Falcon prices are *also* a high estimate for the price of future rocketry.
Different kinds of costs (Score:2)
The problem is that rockets cost tend to be heavy on 'marginal' costs, i.e., shooting twice as many rockets costs twice as much more. Space elevator costs will (theoretically, at least) be very overhead concentrated, with very low marginal costs. This means that it is cheaper to do more, so everyone does more, so the unit cost plummets.
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The problem is that rockets cost tend to be heavy on 'marginal' costs, i.e., shooting twice as many rockets costs twice as much more
There is still a lot of cost reduction that can be done to the rocket design. Right now, even the F9 rocket wastes the upper stage. If the BFR can do reusable upper stages (and the fairing), the marginal costs will come down a lot. Ultimately, if you could just refuel the rocket and launch it again, the marginal costs could be lower than the space elevator, especially for LEO.
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I'm not sure you could ever get the marginal cost of a rocket lower than an elevator because you'll use more power making the rocket fuel than you will use powering the winches on the tether.
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Electricity costs many orders of magnitude less per kWh than a rocket booster.
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If we could land the rocket booster and reuse it (crazy idea, I know) then you should compare the price of electricity with the price of the booster's fuel.
The price of the boosters should then be compared to the construction costs of the space elevator.
Re: Falcon Heavy cost per kilo (Score:2)
Correct me if I'm wrong, ( not a rocket scientist) but once you're at the top, you are in effect going the rotational speed of the Earth, all it would take is a small push after that to keep a stable orbit. A small rocket motor depending on the mass needing to be pushed , should do
Getting off early (Score:2)
That is extremely insightful. Please log in. You are improving the discussion.
35% (Score:2)
If an elevator company can get the cost to orbit down to 35% of the market-owning competitor, they will ABSOLUTELY make back their cost of capital. This is not even accounting for your comparison of LEO to GEO cost estimates. If you could demonstrate technical feasibility investors would be bum rushing you to give you money.
Even worse, much of the cost of modern rocket launches is tied to marginal costs (fuel, personnel, pad rentals, etc.) The primary marginal cost of a space elevator is electricity (to
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You might be right but it's at least equally possible that you lack vision about the changes it could make.
At the time that people start collecting the funds and building a space elevator, they must similarly lack vision regarding possible future cost improvements of rockets.
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Give me a theory on the possible cost savings then. Nuclear rockets are not an option.
Full reuse with minimal maintenance and minimal crew requirements.
Security (Score:2)
Well, THAT is insightful. You should have logged in. That's a great comment.
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The same way most elevators minimise power use? By using a counterweight, e.g. another elevator, going in the opposite direction.
Yah, um, right. How did that counterweight get up in the sky?
Re: Falcon Heavy cost per kilo (Score:2)
Why such a hard time with this? Weight is launched into orbit by rockets, cable attached by pulley is lowered to ground and anchored. Weight is propelled farther from earth so centrifugal force creates pull of many tons. Turbine on ground turns to raise things up like flagpole on cable.
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Turbine on ground turns to raise things up like flagpole on cable.
So, there's an additional cable and a pulley to hoist the load ? The problem is that carbon nanofiber is just barely strong enough to hold it's own weight. You don't have much budget for additional infrastructure mass hanging off the tether.
Not on ground (Score:2)
No, he's wrong. The power to lift is absolutely at the terminus satellite. Probably electric winches powered by solar power installation on the terminus.
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a 1cm cable of the carbon nanofibre in TFS/TFA would be capable of supporting a 5000Km length of itself at 1g.
According to Wikipedia article on space elevators:
An untapered space elevator cable would need a material capable of sustaining a length of 4,960 kilometers (3,080 mi) of its own weight at sea level to reach a geostationary altitude of 35,786 km (22,236 mi) without yielding.
Like I said, it's barely strong enough to hold its own weight.
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A "1cm cable of the carbon nanofibre" doesn't exist after the first bit of LEO space debris hits it at orbital velocity either. If you're not talking on the order of meters to survive ablation by LEO debris, you're not even engaging with reality. Then you have to figure out where that volume of cable comes from, and how it gets into orbit.
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See that word "untapered" in your quote?
Who says the space elevator cable can't be tapered? Of course it can.
Hell, with a big enough (okay, ridiculous) taper factor, you could build a space elevator out of kevlar. This stuff brings it out of the realm of ridiculous.
(Sure, the idea has all kinds of other practical problems, but you're barking up the wrong beanstalk on this one.)
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See that word "untapered" in your quote?
Yes, I was aware of that. However, it's a decent indication that the requirements are already uncomfortably close to the margin, especially considering that many real world practical problems needs to be factored in that would add more weight to the tether or that would degrade its strength.
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Did you notice that they were talking about un-tapered cables there?
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After all, there's no way they'll ever improve the on the very first ones produced in the lab.
You can't improve the theoretical strength of the carbon-carbon bond.
$500 is lifting, not accelerating (Score:2)
The acceleration to orbital velocity comes from the rotation of the Earth. As the payload rises, the tether swings backwards (westward) because the payload is moving too slowly. The lateral tilt of the tether begins to pull the payload faster. As it reaches the correct orbital velocity, the tether moves forward (eastward) and becomes vertical again. Operations will have to account for the swing and minimize oscillations.
On the other hand, this does provide some limited mechanism for the tether to 'duck'
Cubic Centimeter? (Score:5, Funny)
You are aware that stress is measured in force per area, not elephants per volume?
What on earth ... (Score:2)
... would we do with 160 elephants in space?
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Well, but they would be on earth, would they?
(Geez, some people.)
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Ah, crap. wouldn't be on earth.
Note to self: Way to ruin a joke, Al. Finish your coffee.
Will await independent verification. (Score:5, Insightful)
Lots of these Chinese "inventions" turn out to be absolute bunk and cooked results.
Will need to see it peer-reviewed by a country that doesn't reward theft and falsehood in the hard sciences.
Is it even real? (Score:2)
I wouldn't get too excited about fantastic and amazing new developments coming out of China. From my understanding replicability tends to be low.
Imagine a feasible space elevator ... (Score:3)
Price to geo-stat orbit: 300 Euros per kilogram or less. Nice. We'd just assemble a massive spaceship and the first trip to mars would be an extended luxury cruise or something like that. Very nice. We'd be casually exploring the solar system and have a permanent residence on mars. Very nice indeed.
AFAIAC China should get right to it.
It is communist China (Score:2)
And they still ... (Score:2)
Late to the party? (Score:2)
I'm fairly sure- though I can't find the reference....
This is redundant research. The creation of this sort of fiber was first done in the USA around 2000. It's the manufacturing process which has not scaled up against economics. We don't know how to make vast quantities. Yet.
Also as I remember some resources were pulled from carbon based nano-fibers to research a diamond based product.
Again- pulling this from memory.
fucking bruges (Score:2)
According to "In Bruges" 1 American = 1 Elephant.
As an American I can say (Score:2)
Almost
Re:Cue the anti-China rhetoric (Score:5, Insightful)
at lease you protecting yourselves from those caravans of migrants hundreds of miles from your borders.
The Uyghurs would like a subscription to your newsletter.
Re: Cue the anti-China rhetoric (Score:2)
here is a perfect example of what happens when a countries pours huge amounts of cash into R&D and education
What, premature claims of groundbreaking discoveries? Don't worry, the USA has those too. Maybe not quite as many as China, but still enough to be annoying.
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"Racism' to call B.S. on claims made without a shred of proof?
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Military conflict or terrorism (Score:2)
I have long believed that a space elevator is unlikely to be feasible, unless under the auspices of an international body with no nation exerting control. It is really difficult to see how it could be protected in time of war, or even when the US, say, wanted to engineer an "accident" that removed China's, say, major economic and strategic advantage.
Re: Military conflict or terrorism (Score:2)
Iâ(TM)ve always though that the only way a space elevator would work would be some sort of modular self healing system. Something where a section could be destroyed and then quickly replaced and reattached.
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No materials has the strength to contain my skid marks.