That's what you people in this thread fighting for?
Personally, if Zawahiri or Osama gives me a ring, I would want the NSA to know. Also the FBI, CIA, DIA, IRS, and possibly my local crossing guard.
Even if it was a wrong number.
And if you don't want your Al Qaeda calls monitored, then frankly I'd like to know what sort of private discussions you need to have with them and why.
Is that unreasonable after a trillion-dollar terrorist attack that killed 3,000 people? Am I overreacting?
Freedom of speech isn't freedom from criticism or consequences. They just booted a guy for being a right-wing neo-Nazi nut. Does the left get an exemption?
http://www.nj.com/columns/ledger/mulshine/index.ss f?/base/columns-0/1137649957316870.xml&coll=1
Frankly, I'm amazed anyone can argue against this, because it amounts to basically recording and repeating what the professors are saying. A classroom is a public domain; you can't reasonably expect political views expressed in a lecture to have some right of privacy.
Yes, but why go back? We're not dealing with any critical life-threatening shortage of Moon rocks afaik.
There's a good reason we never went back to the Moon: it's a big, airless, resourceless, useless hunk of rock that costs $100 billion to get to. We have rocks here on Earth. They cost a lot less than $100 billion to get to.
but the technical challenges we would need to overcome to build a space elevator makes it simply irresponsible to factor them into any of our realistic plans yet.)
I wouldn't disagree. We definitely shouldn't plan on having an SE. It might turn out not to be feasible.
On the other hand, if we're planning to waste $100B on an ego-boosting "been there, done that" trip to the Moon, it's probably not unreasnable to say "Hey, maybe SE research is a better use."
And it's theoretically possible that putting a billion spare parts in a box and shaking it could create a replacement for the Shuttle, but it ain't very likely
I'll forward your idea to NASA.
SEs are considerably more likely.
Rei, you've clearly done some homework. I don't think too many people are claiming it's definitely do-able, just that the justification is strong enough we should be looking at funding this research over a $100 billion ego trip to the Moon.
It's only *theoretically* possible, let alone discovered in practice, that they might be capable of getting that strong.
See? So even you admit it's possible. Maybe it'll turn out it isn't. But the potential rewards suggest it's worth finding out.
First off, CN is cyanide; please use proper terms Sheesh, what are you, the Acronym Police? I'll use whatever I please. It's not that hard to tell when I mean cyanide vs Carbon Nanotubes, unless you're an idiot.
Current designs call for half what you claim they need.
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
Second, that is a false statement. Even individual tubes aren't that strong.
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
Sorry for the repost, some of the stuff got cut off before due to my Slashdot noobness. Feel free to mod my other post out of existence.
I still see a lot of comments from naysayers that are based on outdated technology and SE specs. A lot has happened in the last year or two, guys. White papers dealing with everything from cable design (a ribbon seems to be the answer) to weather to electrical charge have been published.
There are still technical problems, some of which we probably don't even know about yet. But there is a design for a cable of 40 - 60% CN that should be strong enough. CN mass production facilities are being built. NASA is taking the concept seriously enough that their guys are writing white papers.
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
"The hurdle to date, Edwards said, has been the commercial fabrication of carbon nanotubes. Both U.S. and Japanese firms, among others, are ramping up production of carbon nanotubes, with tons of this now exotic matter soon to be available. "That quantity of material is going to be around well before five years time. It's not going to take long," he said."
Frequently Asked Questions regarding the SE endeavour, from LiftPort Group
(a LOT of very good info here, here's a couple regarding points I've seen here)
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
"The elevator would be susceptible to a terrorist attack. "
First of all, it's important to point out that there will be more than one Space Elevator. We plan to build a second one immediately (using the first to make it much cheaper) and expect that the second will immediately be used to build a third, fourth, etc. An attack on any one ribbon is unlikely because of the anchor stations' isolation and the relatively small number of casualties that would result. Terrorists are unlikely to be able to break the elevator anywhere higher than 15 km or so; it can then be simply flown back down to the anchor by moving some of the counterweight mass a bit further out and will be back in operation in a couple of days.
I see a lot of comments from naysayers that are based on outdated technology and SE specs. A lot has happened in the last year or two, guys. White papers dealing with everything from cable design (a ribbon seems to be the answer) to weather to electrical charge have been published.
There are still technical problems, some of which we probably don't even know about yet. But there is a design for a cable of 40 - 60% CN that should be strong enough. CN mass production facilities are being built. NASA is taking the concept seriously enough that their guys are writing white papers.
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
"The hurdle to date, Edwards said, has been the commercial fabrication of carbon nanotubes. Both U.S. and Japanese firms, among others, are ramping up production of carbon nanotubes, with tons of this now exotic matter soon to be available. "That quantity of material is going to be around well before five years time. It's not going to take long," he said."
Frequently Asked Questions regarding the SE endeavour, from LiftPort Group
(a LOT of very good info here, here's a couple regarding points I've seen here)
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
"The elevator would be susceptible to a terrorist attack. "
First of all, it's important to point out that there will be more than one Space Elevator. We plan to build a second one immediately (using the first to make it much cheaper) and expect that the second will immediately be used to build a third, fourth, etc. An attack on any one ribbon is unlikely because of the anchor stations' isolation and the relatively small number of casualties that would result. Terrorists are unlikely to be able to break the elevator anywhere higher than 15 km or so; it can then be simply flown back down to the anchor by moving some of the counterweight mass a bit further out and will be back in operation in a couple of days.
The first anchor will be located in the equatorial Pacific 650 kilometers from any air or shipping lanes. The ribbon would also have restricted airspace around it. The ribbon and anchor would be protected like any other valuable piece
Not true. There are new SE designs calling for 40% CN composite cables, which would be sufficiently strong.
The only challenge is developing a "cable" (actually a very thin belt) with 40% CN. Currently, the best they can do is around 10%. But this is believed to be a solvable problem.
Space elevators as a real engineering concept are still so new that not many people realize the engineering/materials hurdles are much much closer to being overcome than they were even five years ago, when you could have have stated unequivocally that a space elevator requires large amounts of unobtanium.
Five years ago, it was pixie dust. Today, it's probably a challenge more on the order of building a 3Ghz processor circa 1995.
And really, why waste all that money going to the moon? Is it supposed to make us all proud of ourselves? I'm not thrilled about being remembered as the generation that went to the moon.. again.
There isn't even really that much basic materials work that needs to be done. They just need to get the composite percentage up (iirc) from around 10% to around 50%.
I think the success of carbon nanotube companies and SpaceShipOne suggests the best way to do this is for NASA to offer large monetary rewards, perhaps in the range of $10 - $100M, for producing a workable cable and climber power source. My understanding is those two things are the major engineering hurdles right now.
Currently there is a NASA-sponsored climber competition, which I believe has a 400K reward.
Slashdot Mirror
That's what you people in this thread fighting for? Personally, if Zawahiri or Osama gives me a ring, I would want the NSA to know. Also the FBI, CIA, DIA, IRS, and possibly my local crossing guard. Even if it was a wrong number. And if you don't want your Al Qaeda calls monitored, then frankly I'd like to know what sort of private discussions you need to have with them and why. Is that unreasonable after a trillion-dollar terrorist attack that killed 3,000 people? Am I overreacting?
Freedom of speech isn't freedom from criticism or consequences. They just booted a guy for being a right-wing neo-Nazi nut. Does the left get an exemption? http://www.nj.com/columns/ledger/mulshine/index.ss f?/base/columns-0/1137649957316870.xml&coll=1
Frankly, I'm amazed anyone can argue against this, because it amounts to basically recording and repeating what the professors are saying. A classroom is a public domain; you can't reasonably expect political views expressed in a lecture to have some right of privacy.
Yes, but why go back? We're not dealing with any critical life-threatening shortage of Moon rocks afaik.
There's a good reason we never went back to the Moon: it's a big, airless, resourceless, useless hunk of rock that costs $100 billion to get to. We have rocks here on Earth. They cost a lot less than $100 billion to get to.
but the technical challenges we would need to overcome to build a space elevator makes it simply irresponsible to factor them into any of our realistic plans yet.)
I wouldn't disagree. We definitely shouldn't plan on having an SE. It might turn out not to be feasible.
On the other hand, if we're planning to waste $100B on an ego-boosting "been there, done that" trip to the Moon, it's probably not unreasnable to say "Hey, maybe SE research is a better use."
And it's theoretically possible that putting a billion spare parts in a box and shaking it could create a replacement for the Shuttle, but it ain't very likely I'll forward your idea to NASA. SEs are considerably more likely.
but there is no point in throwing space money at the basic ribbon problem.
There's even less point in going to the moon. We can hope, though, that prize money and research money might solve the SE problems sooner.
Rei, you've clearly done some homework. I don't think too many people are claiming it's definitely do-able, just that the justification is strong enough we should be looking at funding this research over a $100 billion ego trip to the Moon.
It's only *theoretically* possible, let alone discovered in practice, that they might be capable of getting that strong.
See? So even you admit it's possible. Maybe it'll turn out it isn't. But the potential rewards suggest it's worth finding out.
Please also see the NIAC paper, it has lots of answers (and uses official, correct terms, unlike my ad hoc abbreviations).
l
http://www.isr.us/Downloads/niac_pdf/contents.htm
You should also be aware most designs now call for a ribbon, as opposed to a cable.
I agree; I'm not arguing it's a fait accompli, just that it justifies some research $$$.
First off, CN is cyanide; please use proper terms
1 .htm
Sheesh, what are you, the Acronym Police? I'll use whatever I please. It's not that hard to tell when I mean cyanide vs Carbon Nanotubes, unless you're an idiot.
Current designs call for half what you claim they need.
http://science.nasa.gov/headlines/y2000/ast07sep_
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
Second, that is a false statement. Even individual tubes aren't that strong.
http://www.liftport.com/faq.php
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
That's addressed here:l
http://www.isr.us/Downloads/niac_pdf/contents.htm
Phase I NIAC Paper
See the sections on meteors and impact of breakage.
Please see:
l
http://www.isr.us/Downloads/niac_pdf/contents.htm
Phase I NIAC Paper
http://www.liftport.com/faq.php
Frequently Asked Questions regarding the SE endeavour, from LiftPort Group
Sorry for the repost, some of the stuff got cut off before due to my Slashdot noobness. Feel free to mod my other post out of existence.
.htm
/space_elevator_020327-2.html
I still see a lot of comments from naysayers that are based on outdated technology and SE specs. A lot has happened in the last year or two, guys. White papers dealing with everything from cable design (a ribbon seems to be the answer) to weather to electrical charge have been published.
There are still technical problems, some of which we probably don't even know about yet. But there is a design for a cable of 40 - 60% CN that should be strong enough. CN mass production facilities are being built. NASA is taking the concept seriously enough that their guys are writing white papers.
It ain't pixie dust anymore.
Detailed info and links below. http://science.nasa.gov/headlines/y2000/ast07sep_1
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
http://www.space.com/businesstechnology/technology
"The hurdle to date, Edwards said, has been the commercial fabrication of carbon nanotubes. Both U.S. and Japanese firms, among others, are ramping up production of carbon nanotubes, with tons of this now exotic matter soon to be available. "That quantity of material is going to be around well before five years time. It's not going to take long," he said."
http://www.liftport.com/faq.php
Frequently Asked Questions regarding the SE endeavour, from LiftPort Group
(a LOT of very good info here, here's a couple regarding points I've seen here)
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
"The elevator would be susceptible to a terrorist attack. "
First of all, it's important to point out that there will be more than one Space Elevator. We plan to build a second one immediately (using the first to make it much cheaper) and expect that the second will immediately be used to build a third, fourth, etc. An attack on any one ribbon is unlikely because of the anchor stations' isolation and the relatively small number of casualties that would result. Terrorists are unlikely to be able to break the elevator anywhere higher than 15 km or so; it can then be simply flown back down to the anchor by moving some of the counterweight mass a bit further out and will be back in operation in a couple of days.
The first anchor will be located in the equatoria
I see a lot of comments from naysayers that are based on outdated technology and SE specs. A lot has happened in the last year or two, guys. White papers dealing with everything from cable design (a ribbon seems to be the answer) to weather to electrical charge have been published.
.htm
/space_elevator_020327-2.html
There are still technical problems, some of which we probably don't even know about yet. But there is a design for a cable of 40 - 60% CN that should be strong enough. CN mass production facilities are being built. NASA is taking the concept seriously enough that their guys are writing white papers.
It ain't pixie dust anymore.
http://science.nasa.gov/headlines/y2000/ast07sep_1
"The desired strength for the space elevator is about 62 GPa. Carbon nanotubes... appear to have a theoretical strength far above the desired range for space elevator structures."
http://www.space.com/businesstechnology/technology
"The hurdle to date, Edwards said, has been the commercial fabrication of carbon nanotubes. Both U.S. and Japanese firms, among others, are ramping up production of carbon nanotubes, with tons of this now exotic matter soon to be available. "That quantity of material is going to be around well before five years time. It's not going to take long," he said."
http://www.liftport.com/faq.php
Frequently Asked Questions regarding the SE endeavour, from LiftPort Group
(a LOT of very good info here, here's a couple regarding points I've seen here)
What are some frequent Space Elevator misconceptions?
"Nothing is strong enough to make a Space Elevator."
Carbon nanotubes (CNT), discovered in 1991, are almost certainly strong enough. Theory says that they are 3-5 times as strong as we need them to be, and laboratory measurements of their strength, though very difficult to do and not yet definitive, have shown more than half the strength we need.
The longest nanotubes thus far are measured in centimeters, not kilometers, and certainly not 100,000 km.
We don't need and are not counting on individual carbon nanotube molecules running the entire length of the space elevator or any significant fraction thereof. The individual fibers in a string or rope are only a few millimeters long, yet the rope has a large fraction of the theoretical strength of the fibers. This is even more the case with MOLECULES, several orders of magnitude smaller than a fiber. A diamond is said to be the "hardest substance in the world" because of the strength of the carbon bonds that make it up, but a diamond is not a single molecule. Likewise an SE could be made with CNTs just a few centimeters or millimeters long. (In fact, a CNT several centimeters long is a wonder; they're single molecules!)
"The elevator would be susceptible to a terrorist attack. "
First of all, it's important to point out that there will be more than one Space Elevator. We plan to build a second one immediately (using the first to make it much cheaper) and expect that the second will immediately be used to build a third, fourth, etc. An attack on any one ribbon is unlikely because of the anchor stations' isolation and the relatively small number of casualties that would result. Terrorists are unlikely to be able to break the elevator anywhere higher than 15 km or so; it can then be simply flown back down to the anchor by moving some of the counterweight mass a bit further out and will be back in operation in a couple of days.
The first anchor will be located in the equatorial Pacific 650 kilometers from any air or shipping lanes. The ribbon would also have restricted airspace around it. The ribbon and anchor would be protected like any other valuable piece
Rei,
Not true. There are new SE designs calling for 40% CN composite cables, which would be sufficiently strong.
The only challenge is developing a "cable" (actually a very thin belt) with 40% CN. Currently, the best they can do is around 10%. But this is believed to be a solvable problem.
Space elevators as a real engineering concept are still so new that not many people realize the engineering/materials hurdles are much much closer to being overcome than they were even five years ago, when you could have have stated unequivocally that a space elevator requires large amounts of unobtanium. Five years ago, it was pixie dust. Today, it's probably a challenge more on the order of building a 3Ghz processor circa 1995. And really, why waste all that money going to the moon? Is it supposed to make us all proud of ourselves? I'm not thrilled about being remembered as the generation that went to the moon.. again.
There isn't even really that much basic materials work that needs to be done. They just need to get the composite percentage up (iirc) from around 10% to around 50%. I think the success of carbon nanotube companies and SpaceShipOne suggests the best way to do this is for NASA to offer large monetary rewards, perhaps in the range of $10 - $100M, for producing a workable cable and climber power source. My understanding is those two things are the major engineering hurdles right now. Currently there is a NASA-sponsored climber competition, which I believe has a 400K reward.