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81 Comments
- falstaff, on 10/12/2007, -0/+24Idea: A
Animation: C+
Cheesy infomercial voiceover: F-- - johnnyzero, on 10/12/2007, -0/+22Fortunately the Inner Van Allen Belt (according to wikipedia) is 700-10,000km away from the surface, this puts it pretty far away from any low or even high orbits. What is the nature of the problem with the Van Allen Belt?
Surely it would interfere with any components of the device that are not rad-hardened and would also probably wreak havoc on the photovoltaic cells (could at store battery power for periods where the cells must be closed)...
Sounds to me as if the biggest problems facing the engineers of such a magnificent device is the materials science behind the nanotubes as well as how to deal with the catastrophic event of the entire thing snapping in half and whipping the earth with the super nanotube lash... - Autrix, on 10/12/2007, -0/+21I wasn't aware that my destiny involved "...climbing a ribbon to the stars"
Yet, here we are. - inactive, on 10/12/2007, -2/+20Every time this gets to the front page (which is about once a week) someone moron points out the van allen belt, as if NASA just completely overlooked that fact.
Hmmmm, which is more plausible...that NASA simply forgot about the Van Allen Belt, or that you idiots are commenting on something when you obviously have no idea what you are talking about? As has been said...the space elevator is for CARGO, regardless of what one article suggests. - elCapitanNemo, on 10/12/2007, -1/+16"pretty cool but it must have been hard to make it" lol
- TopherT, on 10/12/2007, -0/+14It certainly would, but so would driving your car east.
- hackwrench, on 10/12/2007, -0/+14Because an objects own weight is a factor.
- Kazanoe, on 10/12/2007, -0/+11The sun will probably blow up first.
Not to mention, we'll have screwed over the enviroment by then - 8177, on 10/12/2007, -8/+19Queue porno music
- inactive, on 10/12/2007, -0/+10I'd be more worried about a spaceship built like a giant maid sucking our atmosphere out ever our leader gives them the combination to the air shield. It is about as likely as this ribbon causing any real damage to the atmosphere.
- aprice2704, on 10/12/2007, -0/+9Probably. It does require very strong material (~100GPa) whereas the strongest bulk sample of CNTs made thus far is closer to 50GPa, but 100GPa should be achieved in the next few years. It is a huge engineering challenge thereafter, but after years of study by many scientists there seems to be no fundamental reason why it should not work.
Toughest problems are:
1. Micometeoroid impact (wears the ribbon)
2. Tensional energy released when individual CNTs snap (this must not cause a chain reaction of snapping)
3. 'Fratricide' -- one ribbon failing and bringing down all the others (there would be many of them)
See http://spaceelevator.com/ for more info. - Mousse, on 10/12/2007, -0/+8Molecules from the atmosphere that move faster than the escape velocity regularly leave earth anyway. I doubt a several foot wide ribbon would have a remotely comparable effect even if it does somehow allow more atmosphere to escape than normal.
- johnnyzero, on 10/12/2007, -0/+6From the article you linked:
"They would die on the way through the radiation belts if they were unshielded,"
Certainly we would not hang on to the nanotubes and let it take us up into space without being shielded.
Furthermore, The space elevator's primary concern is to lift cargo into space, once the cargo has reached the inside of the Van Allen Belt, one would hope it could detach if it contained live passengers, then attach to some vehicle that could begin a rocket thrust through the Belt and off to greater heights.
The article you linked is full of speculation and seems to only address the concerns of one group "LiftPort" which seeks to send groups of people up the elevator. This is really not the number one priority of such a device as getting small payloads of even relatively small masses into orbit is still very very expensive, such a device could deliver small orbital packages at a fraction of the cost once completed.
Like I already said, engineering the ribbon is a much more daunting task than figuring out what to do about the radiation belt. - kingborel, on 10/12/2007, -0/+6And the power to power the lasers to lift the 20-ton vehicles vertically off the ground comes from... where?
oh, and it's asking for a tiny rock to come and pierce it. I imagine it would stop working after that - johnnyzero, on 10/12/2007, -0/+6Feasible enough for NASA to hold a yearly competition to help advance the technological building blocks
http://www.engadget.com/2006/10/23/nasas-second-annual-tether-challenge-beset-by-controversy-yiel/ - inactive, on 10/12/2007, -0/+6Also from that article is the fact that they are taling about a MUCH longer "space elevator" than NASA has pretty much ever proposed. The ones that NASA are woroking on now would not reach the Van Allen Belt.
- oskite, on 10/12/2007, -4/+9What if it snapped...
- OpCzar, on 10/12/2007, -2/+7Okay, I'm gullible... is this feasible? Anyone?
- glmory, on 10/12/2007, -0/+5"Also, Is the material a superconductor?" no, carbon nanotubes conduct electricity "ballistically" while within a nanotube there is zero resistance, However leaving the walls or ends of a nanotube causes resistance.
- treelovinhippie, on 10/12/2007, -2/+7Well most of our high-tech stuff we have today was inspired by sci-fi writers decades before... so anything is possible.
- thespinner, on 10/12/2007, -1/+6all this talk about nanotubes... there was an article in new scientist a month or so back about this same thing. their conclusion was that nanotubes will probably never be used for this ribbon since the manufacturing tolerances required to make a tube that long 100% perfect are impossible to achieve. so... interesting, but wrong.
- aprice2704, on 10/12/2007, -1/+5You remember incorrectly. Individual nanotubes have been measured at 250GPa. Reading between the lines of one paper implies 50GPa has been reached in a macroscopic sample. 100GPa is required for a useful Earth SE and most materials scientists familiar with the subject expect this to be reached within a few years.
- bocaJWho, on 10/12/2007, -1/+5weight is a factor in determining how much energy is needed to keep it all from being pulled back to earth, also effecting how much it costs to get the elevator up in the first place. I'm sure there are also numerous other reasons why thickness and weight etc. matter.
- glmory, on 10/12/2007, -0/+4If I remember the article you are talking about correctly, it is essentially using a reasonable model of defects in nanotubes and getting a theoretical strength. If we could find a way to make perfect nanotubes(or more nearly perfect ones than this article assumes) than the space elevator idea is back. Still it was shown that this won't happen tomorrow. Huge leaps in materials science need to happen to make a space elevator possible
- saifatlast, on 10/12/2007, -0/+3I have no idea how much power it would take, but maybe there could be a nuclear power plant.
/baseless, unresearched speculation - inactive, on 10/12/2007, -2/+5"Help!"?
moo. - mediaphile, on 10/12/2007, -1/+4Arthur C. Clarke has been talking about these for years, and it features prominently in his novel 3001: The Final Odyssey. I just wonder what happens when something slams into that ribbon. Maybe it won't break it, but it might put a dent in it big enough to prohibit the elevators from rolling over it. Also, how do repairs work? Do you replace the whole ribbon every time something gets messed up? Hopefully it would be possible to fix specific sections of the ribbon, though I imagine it would be at a huge cost either way.
And would this not be a target for warfare? - johnnyzero, on 10/12/2007, -0/+3certainly not by a significant enough factor as to be noticeably measurable.
- bloodriver, on 10/12/2007, -0/+2Somewhere, Osama is thinking, "How do I bring that bad boy down?"
- ohmar, on 10/12/2007, -0/+2Because, honestly, who believes a woman talking about science?
/slap - anareric, on 10/12/2007, -0/+2How long would it take for "simple electric motors" to climb 62,000 miles?
- treelovinhippie, on 10/12/2007, -4/+6Saw it mentioned a while back: http://space.newscientist.com/article/dn10520-space-elevators-first-floor-deadly-radiation.html
Basically the radiation is immense, so passing through it could be a problem for humans unless they developed some kind of light-weight, radiation chamber.
(ps for those who dugg me down, do some research... a simple "Van Allen belt space elevator" search in Google brought up the above link) - inactive, on 10/12/2007, -0/+2No one said it would be "free". But it would take FAR less power to do it this way than to do it with rockets.
- inactive, on 10/12/2007, -0/+2Just don't put it in Williamsburg...they don't need it.
http://www.boingboing.net/2005/02/01/brooklyn_residents_j.html - falstaff, on 10/12/2007, -0/+2"Ok, why doesn't the ribbon wrap itself around the Earth?"
http://en.wikipedia.org/wiki/Geosynchronous_orbit
It's further out than most satellites, but not terrible uncommon. - nonfamous, on 10/12/2007, -1/+2The ribbon would fall to earth, wrapping around it several times.
One of Kim Stanley Robinson's "Mars" books has this as a plot element, although there the elevator was a huge cable instead of a thin ribbon. Cool story. - imtigger2, on 10/12/2007, -0/+1Finally, Disney can build a theme park in space! Would the elevator have a Fastpass(tm) system?
- Filksinger, on 10/12/2007, -0/+1"How long would it take for "simple electric motors" to climb 62,000 miles?"
1. To get to geosynchronous orbit, you only need to climb 22,250 miles at most. The rest of the length is to add weight to the end, to keep the cable taut.
2. "Simple electric motors" can reach very high speeds. Even if you could only manage 60 mph, you would reach geosynchronous orbit in about 2 1/2 weeks, at a fraction of the cost of a traditional rocket. However, passenger vehicles are expected to be developed that will reach as much as 300 mph, or able to reach the station in a little over three days. - michaeljh, on 10/12/2007, -0/+1Consider what will happen if a drag force of this magnitude decreases the angular momentum of Earth over time.
- inactive, on 10/12/2007, -0/+1How about when terrorists fly a jet into it? Or pissed off nations with crazy leaders fire guided missiles at it.
I think the technical issues are only half the story - protecting its obvious huge vulnerablity is another major hurdle. - AngelCG, on 10/12/2007, -0/+1That's from Arthur C. Clarke's "The Fountains of Paradise" (1979) !!
http://en.wikipedia.org/wiki/The_Fountains_of_Paradise - gostars, on 10/12/2007, -0/+1Just how long is it going to take Digg to rehash all the years-old news that existed before Digg?
- flash200, on 10/12/2007, -0/+1I'm curious if there'd be a practical way to have a counterweight of roughly equal mass that descends while the cargo ascends, so that it would require very little force to raise the cargo to the top (as if the cargo had little or no mass).
Depending on how high the elevator goes, the weight of the descending and ascending objects would change significantly as they change in elevation, even though their mass remains constant. Not sure if this would this prevent the two from ever being evenly balanced, except for the brief moment when they're at the same elevation, or if mass is more of a factor in this than weight.
As far as how to get the counterweight mass up there in the first place, especially if the elevator would mainly be used for the one-way transportation of cargo into space (with little of it returning to the surface), I wonder if something could be engineered comparable to how trees use transpiration to lift huge amounts of water dozens or hundreds of feet above the ground--a process that uses solar power to lift a mass of water, which could then act as the counterweight for lifting the next load of cargo. Perhaps if the counterweight-water was gradually released during descent, that could help to partially compensate for the decreasing weight of the ascending cargo. - Ethion, on 06/30/2008, -0/+1Try two years ago
- RMoore08, on 10/12/2007, -0/+1thats cool ... until the ribbon breaks from wear and everyone gets floating through space.... well i guess there would be no one present to sue...=P
- xister, on 10/12/2007, -0/+1Maintenance issues aside, how on earth (no pun intended) do you deploy such a thing? From the ground or space?
- nofxjunkee, on 10/12/2007, -1/+2Ok, why doesn't the ribbon wrap itself around the Earth? It's anchored to the Earth on one end, the other is extended outwards into space. As the Earth rotates it would either drag the ribbon with it, or the ribbon would wrap itself around the Earth as the other end remained stationary.
If it would indeed move with the Earth as it revolves and rotates, then would you have to wait for this elevator to be lined up with the target before sending something up it? In that case, how fast can it move something? Can it move an object all the way to wherever it extends quickly, before the Earth moves and changes the destination?
A lot of basic things don't seem to add up, but it could just be my lack of understanding in the physics involved. - Shaggy3, on 10/12/2007, -0/+1Hey, a triforce!
- Chesterfield, on 10/12/2007, -0/+1A year ago?!
If I had to guess by the computer graphics and 'modern' music, this idea has been around since the early-80's. - johnwc723, on 10/12/2007, -0/+1What happens when a little tiny bit of asteroid, or for that matter a speck of asteroid happens to brush up against the carbon nanotube?
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