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Space Elevators Going Up
MikShapi writes "CBC is running a new piece on the Space Elevator. Nothing dramatically new, as we're all still waiting for one of the many Carbon Nanotube research centers to announce they reached the famous 100GPa red line from page 10 of the NIAC Phase 2 Report, thus obtaining 'unobtainium' [pun intended], the material necessary to build the Elevator. The report predicts this will happen during the course of the next two years or so. It's then that the fun really starts - A REAL all-out space race, open to everyone with will and a national budget, winner probably getting to own space [read last paragraph]. In the meanwhile, we can all spread the word, discuss, debate and brainstorm every nook and cranny of the program here on Slashdot, and give Edwards a shoulder by giving the program every bit of mass-exposure we can."
The Fountains of Paradise by Arthur C Clarke and Red/Green/Blue Mars by Kim Stanley Robinson. Both discuss the politics and sociology surrounding the construction and use of a space elevator. Good books, well worth a read.
Tubal-Cain smokes the white owl.
Unobtainium is a term for non-existant wonder materials. In this case carbon-nano tubes are unobtainium. As in unobtainable.
Not two years away. More like fourteen. According to the article, it would be two years away once research has produced the proper technique for creating a cable, and once someone produces 650 tons of the stuff. Earlier in the article he mused that they were 12 years away from such a thing.
I'm a physicist, and I work with carbon nanotubes. In October's Macromolecules, there was a paper put out called "Phase Behavior and Rheology of SWNTs in Superacids". It was done by a huge group of people (for a nanotech paper), including Nobel winner Richard Smalley. A press release about it was posted here somewhere.
To make a long story short:
They did it.
By finding a way to dissolve nanotubes, then slowly concentrating the solutions, they formed a liquid crystal of nanotubes. By extruding this through a syringe, they formed an aligned, macroscopic, nanotube rope.
I've seen this stuff... somewhere, and it looks just like black string.
What's left?
They used tubes grown by high pressure carbon monoxide, which leads to a lot of defects. If they switch to methane, the defects will largely be gone, but the yeild drops.
They probably need to chemically connect the tubes. You can do that with an electron beam, but that would be a pain industrially. I'm sure there's a way around it.
I'm sure that same group of people has already figured out many more problems and solutions than I can think of. I havn't seen anything out about the mechanical properties of these ropes yet, but I would expect something within a few months, and I would be surprised if it wasn't amazing.
I used to be a skeptic when it came to a space elevator, but now...
As far as countries on the equator go, Ecuador's competition consists of Colombia, Brazil, Sao Tome & Principe, Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia, Maldives, Indonesia and Kiribati. I reckon they've got a shot!
The station is not only intended for putting things in orbit or for cargo purposes, but also for experimentation. The space elevator can only get the stuff/people up into space, but without a place to put them they arn't much use. Therefore, the ISS is still just as important as it was before, maybe more so. With the ability to more cheaply and easily get experimentation materials to the station, experimentation in space will become cheaper and more widely available. Perhaps with this new space elevator students can even go beyond the "vomit comet" and actually go into space. One easily accesible space station will inevidabley lead to others, soon.
With the competition that all of this new technology is/will be producing, a commom point like the ISS is important to unite the major countries.
where are we going to find a big enough rock to attach to the other end?
According to the book, the plan is to send up a rocket with the smallest possible cable. The cable gets lowered to Earth and secured (cable also gets spooled out in the opposite direction, in order to keep the spacecraft in orbit). Then they send up a series of progressively larger robots along the ribbon. Each robot adds more material to the ribbon as it climbs, and when it gets to the top of the ribbon, it stays there to add to the mass of the counterweight. So basically we bootstrap our way up.
I don't care if it's 90,000 hectares. That lake was not my doing.
According to Strong's Concordance, the word in the original Greek is "praus" (latinized spelling) which means mildness of disposition, gentleness of spirit, or meekness. If this page doesn't load, go here, type "meek" into the first line, submit, find Matthew 5:5 and click on the number 4239. This word is close to the modern Greek "praos" which also means "meek."
In other words, Jesus was saying that the humble and mild-mannered will inherit the Earth. You can find this same word commonly translated as meek in 1st Peter 3:4. Also, if you look at the context of Matthew 5:1-13, the opening of one of Jesus's sermons, it's quite clear that he's saying that rewards await the humble and downtrodden. They "are the salt of the Earth" and there is not an aggressive or angry group among "the poor in spirit," "those who mourn," "the meek," "those who hunger for righteousness," "the merciful," "the pure of heart," or "the peacemakers."
I'd be very surprised if Strong's Concordance was wrong on the issue given the context and the modern descendant of the word. I'd love to see some evidence for your professor's claims.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
*This assumes that each section of the elevator has the same mass as any other equally long section.
Laws are horrible moral guides, moral guides make even worse laws.
While there is a difference between achieving 100 GPa over very short lengths and over 100,000 kilometers, it's not as much as you might think.
The longest individual nanotubes we can reliably produce are on the order of a couple of centimeters. But once we have nanotubes on the order of a meter long, they will probably be sufficient to produce a long ribbon with sufficient loading on the nanotubes themselves.
The limiting factor is not the length of the nanotubes in a composite (beyond a certain point, anyway), but rather how effectively the nanotubes themselves can be made to bear the load. Nanotube exteriors are slippery, like graphite, so the challenge is being able to stick them together in a substrate the transfers load effectively between them.
For this, a process known as "functionalization" comes into play. This basically means adding small appendages to the nanotubes so that they have more traction within the substrate.
LiftWatch.org carries regular space-elavator news items. Here are some recent articles on CNT advances:
No, actually the middle floor will have no gravity (geostational orbit).
The top orbit will have "gravity" in exactly the opposite direction because it's spinning faster than than the required speed to stay in orbit. It has to pull on the cable to keep it from falling down.
It is somewhat like going through the earth. As deeper you go the gravity will diminish. In the middle of the earth: None. On the other side the gravity will increase again but in the opposite direction.
Have you ever looked through the Forbes 400? "Old money" in the US is largely a myth.
The ten wealthiest individuals in America are Gates, Buffett, Paul Allen, Larry Ellison, Michael Dell, and the Walton heirs. (Steve Ballmer is 11th, incidentally.) Of these, only the Waltons inherited their money, and that not from some ancient rail baron, but from a self-made man who died in 1992.
All employees must wash hands before seeking equitable relief.