Ive been attending a tele-seminar much of the day about nanotechnology. You know, how it might impact the environment, public health, industrial hygiene, blah, blah.
What I found to be pretty cool was that carbon nanotubes may meet the material needs for the earth to space elevator.
Would you ride the elevator into space?
Really I hope that our next adminstration can get us moving forward with a cutting edge space program again.
Edited, Jul 8th 2008 8:08pm by Elinda
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Alma wrote:
I lost my post
I have read a few books that debated whether the elevators were even possible. Something to do with the mass of the string going to infinity as the elevator went up. They mentioned Carbon nanotubes as a possibility but I haven't heard much of anything since.
I would hate to be in the way of the line if it snaps. 30 miles of cable falling down would make one heck of a mess.
I would hate to be in the way of the line if it snaps. 30 miles of cable falling down would make one heck of a mess.
With the wrong materials, it is impossible. Wrong being anything currently available. Carbon nanotubes may be strong enough - I haven't done the math.
Also, there may be malignant atmospheric effects of just having anything in the upper atmosphere. Ozone isn't terribly stable.
I think the idea is to elevate to geosynchronous orbit, thus there would be no additional acceleration needed to maintain orbit. As far as living goes, geosynchronous orbit is sort of the worst of all possible worlds. Well above most of the Earth's magnetic shielding and without the Moon's gravity and materials.
As far as low earth orbit goes, the bulk of the energy is needed to propel the object around the Earth, not to lift it from the Earth to that orbit. It's roughly a 90 minute orbit, versus the 24 hour orbit of geosynchronous objects, so you can imagine that is pretty fast. The point is, a short elevator to low Earth orbit would only be a starting point, a load of some kind of energy is needed to propel anything around the Earth for it to stay there.
Low earth orbit is the 30 mile one, geosynchronous orbit is on the same order of magnitude as the radius of the Earth (6400 kilometers).
I'd love to go into space. Living there is another story.
Also, there may be malignant atmospheric effects of just having anything in the upper atmosphere. Ozone isn't terribly stable.
I think the idea is to elevate to geosynchronous orbit, thus there would be no additional acceleration needed to maintain orbit. As far as living goes, geosynchronous orbit is sort of the worst of all possible worlds. Well above most of the Earth's magnetic shielding and without the Moon's gravity and materials.
As far as low earth orbit goes, the bulk of the energy is needed to propel the object around the Earth, not to lift it from the Earth to that orbit. It's roughly a 90 minute orbit, versus the 24 hour orbit of geosynchronous objects, so you can imagine that is pretty fast. The point is, a short elevator to low Earth orbit would only be a starting point, a load of some kind of energy is needed to propel anything around the Earth for it to stay there.
Low earth orbit is the 30 mile one, geosynchronous orbit is on the same order of magnitude as the radius of the Earth (6400 kilometers).
I'd love to go into space. Living there is another story.
I think the problem with a space elevator (beyond the materials issues) is that every time you use it you need to use energy to both hold the other end of the elevator in place (there's nothing to anchor it too) and pull the object up the elevator. I wonder if there would actually be any energy savings when compared to say an efficient rocket. If you could build a solid structure fixed to the earth it would work, but that is pretty unfeasible for a number or reasons. When they talk about a space elevator it's basically a cable with a counterweight. The counterweight is going to slowly drop down with each load that is ascended without some form of propulsion.
The other issue I see, is spin. As the earth spins the cable is going to curve towards the east unless centripetal force can overcome cables mass (which will be considerable) so the cable has to be much longer than the height you want to attain.
You'll end up with one of 2 situations, either the cable will slowly fall to the earth, or the cable will rip out of the ground. You'd need one heck of a support structure anchored to something pretty damn solid to hold a 30-60km cable spinning at 1728 km/hr.
Also, what happens if there is a storm. That's quite the lightning rod.
The other issue I see, is spin. As the earth spins the cable is going to curve towards the east unless centripetal force can overcome cables mass (which will be considerable) so the cable has to be much longer than the height you want to attain.
You'll end up with one of 2 situations, either the cable will slowly fall to the earth, or the cable will rip out of the ground. You'd need one heck of a support structure anchored to something pretty damn solid to hold a 30-60km cable spinning at 1728 km/hr.
Also, what happens if there is a storm. That's quite the lightning rod.
bubspeed wrote:
I have read a few books that debated whether the elevators were even possible. Something to do with the mass of the string going to infinity as the elevator went up. They mentioned Carbon nanotubes as a possibility but I haven't heard much of anything since.
I would hate to be in the way of the line if it snaps. 30 miles of cable falling down would make one heck of a mess.
I would hate to be in the way of the line if it snaps. 30 miles of cable falling down would make one heck of a mess.
For a long and amazing description of a space elevator falling back down onto a planet (It winds up wrapped around the equator about 3 times) try Red Mars, Blue Mars, Green Mars by Kim Stanley Robinson.
Yodabunny, I don't remember all the physics of it, But the idea is to have the elevator supporting it's entire weight in orbit. There is no actual physical connection to the Earth, it's bottom end just hovers a few meters off the ground. (Within a sleeve.) Also, I think the lifts going up and down are meant to be counterbalanced for the most part, the momentum of the falling lifts helping to propel the rising lifts. There's a few variations on space elevators and skyhooks.
Yes, it would wind up being ridiculously long in length, in order to be able to suspend itself. It would also be a seriously LONG term and high-tech project. But if done, in theory it would make getting people and some materials ridiculously more easy to get out of the Earth's gravity well than they are now.
lol buckyballs
oh yeah. just to rain on parade
* An animal study from the United Kingdom found that certain carbon nanotubes can cause the same kind of lung damage as asbestos. Carbon nanotubes are among the most widely used nanomaterials.
* A coalition of consumer groups petitioned the U.S. Environmental Protection Agency to ban the sale of products that contain germ-killing nanosilver particles, from stuffed animals to clothing, arguing that the silver could harm human health, poison aquatic life, and contribute to the rise of antibiotic resistance.
* Researchers in Singapore reported that nanosilver caused severe developmental problems in zebrafish embryos — bolstering worries about what happens when those antimicrobial products, like soap and clothing, leak silver into the waste stream.
* The U.S. Department of Defense, in an internal memo, acknowledged that nanomaterials may “present… risks that are different than those for comparable material at a larger scale.†That’s an overarching risk with nanomaterials: Their tiny size and high surface area make them more chemically reactive and cause them to behave in unpredictable ways. So a substance that’s safe at a normal size can become toxic at the nanoscale.
* Australian farmers proposed new standards that would exclude nanotechnology from organic products.
* The European Union announced that it will require full health and safety testing for carbon and graphite under its strict new chemicals law, known as REACH (for Registration, Evaluation, and Authorisation of Chemical Substances). Carbon and graphite were previously exempt, because they’re considered safe in their normal forms. But the U.K. study comparing carbon nanotubes to asbestos, along with a similar report from Japan, raised new alarms about these seemingly harmless substances.
Artitficial sickle-cell anyone?
* An animal study from the United Kingdom found that certain carbon nanotubes can cause the same kind of lung damage as asbestos. Carbon nanotubes are among the most widely used nanomaterials.
* A coalition of consumer groups petitioned the U.S. Environmental Protection Agency to ban the sale of products that contain germ-killing nanosilver particles, from stuffed animals to clothing, arguing that the silver could harm human health, poison aquatic life, and contribute to the rise of antibiotic resistance.
* Researchers in Singapore reported that nanosilver caused severe developmental problems in zebrafish embryos — bolstering worries about what happens when those antimicrobial products, like soap and clothing, leak silver into the waste stream.
* The U.S. Department of Defense, in an internal memo, acknowledged that nanomaterials may “present… risks that are different than those for comparable material at a larger scale.†That’s an overarching risk with nanomaterials: Their tiny size and high surface area make them more chemically reactive and cause them to behave in unpredictable ways. So a substance that’s safe at a normal size can become toxic at the nanoscale.
* Australian farmers proposed new standards that would exclude nanotechnology from organic products.
* The European Union announced that it will require full health and safety testing for carbon and graphite under its strict new chemicals law, known as REACH (for Registration, Evaluation, and Authorisation of Chemical Substances). Carbon and graphite were previously exempt, because they’re considered safe in their normal forms. But the U.K. study comparing carbon nanotubes to asbestos, along with a similar report from Japan, raised new alarms about these seemingly harmless substances.
Artitficial sickle-cell anyone?
To my knowledge the longest nanotubes we've been able to produce have only been two centimeters long. We'd need strands of several meters to effectively braid them into a suitable rope structure. I think a Chinese made 20 cm rope currently hold the record.
Edited, Jul 10th 2008 7:35am by Allegory
Edited, Jul 10th 2008 7:35am by Allegory
Kelvyquayo wrote:
oh yeah. just to rain on parade
* An animal study from the United Kingdom found that certain carbon nanotubes can cause the same kind of lung damage as asbestos. Carbon nanotubes are among the most widely used nanomaterials.
* A coalition of consumer groups petitioned the U.S. Environmental Protection Agency to ban the sale of products that contain germ-killing nanosilver particles, from stuffed animals to clothing, arguing that the silver could harm human health, poison aquatic life, and contribute to the rise of antibiotic resistance.
* Researchers in Singapore reported that nanosilver caused severe developmental problems in zebrafish embryos — bolstering worries about what happens when those antimicrobial products, like soap and clothing, leak silver into the waste stream.
* The U.S. Department of Defense, in an internal memo, acknowledged that nanomaterials may “present… risks that are different than those for comparable material at a larger scale.†That’s an overarching risk with nanomaterials: Their tiny size and high surface area make them more chemically reactive and cause them to behave in unpredictable ways. So a substance that’s safe at a normal size can become toxic at the nanoscale.
* Australian farmers proposed new standards that would exclude nanotechnology from organic products.
* The European Union announced that it will require full health and safety testing for carbon and graphite under its strict new chemicals law, known as REACH (for Registration, Evaluation, and Authorisation of Chemical Substances). Carbon and graphite were previously exempt, because they’re considered safe in their normal forms. But the U.K. study comparing carbon nanotubes to asbestos, along with a similar report from Japan, raised new alarms about these seemingly harmless substances.
Artitficial sickle-cell anyone?
* An animal study from the United Kingdom found that certain carbon nanotubes can cause the same kind of lung damage as asbestos. Carbon nanotubes are among the most widely used nanomaterials.
* A coalition of consumer groups petitioned the U.S. Environmental Protection Agency to ban the sale of products that contain germ-killing nanosilver particles, from stuffed animals to clothing, arguing that the silver could harm human health, poison aquatic life, and contribute to the rise of antibiotic resistance.
* Researchers in Singapore reported that nanosilver caused severe developmental problems in zebrafish embryos — bolstering worries about what happens when those antimicrobial products, like soap and clothing, leak silver into the waste stream.
* The U.S. Department of Defense, in an internal memo, acknowledged that nanomaterials may “present… risks that are different than those for comparable material at a larger scale.†That’s an overarching risk with nanomaterials: Their tiny size and high surface area make them more chemically reactive and cause them to behave in unpredictable ways. So a substance that’s safe at a normal size can become toxic at the nanoscale.
* Australian farmers proposed new standards that would exclude nanotechnology from organic products.
* The European Union announced that it will require full health and safety testing for carbon and graphite under its strict new chemicals law, known as REACH (for Registration, Evaluation, and Authorisation of Chemical Substances). Carbon and graphite were previously exempt, because they’re considered safe in their normal forms. But the U.K. study comparing carbon nanotubes to asbestos, along with a similar report from Japan, raised new alarms about these seemingly harmless substances.
Artitficial sickle-cell anyone?
Alma wrote:
I lost my post
knoxsouthy wrote:
Elinda,
You can't go a single day without blaming something on the administration can you?
Quote:
Really I hope that our next adminstration can get us moving forward with a cutting edge space program again.
You can't go a single day without blaming something on the administration can you?
There really isn't any blame being placed here, and certainly not on the current administration. The Space Program kinda dropped off after the challenger thingy.
I just don't think we'll make much advancement leaving things up to the private sector.
Btw, I'm a government employee.......
Alma wrote:
I lost my post
knoxsouthy wrote:
Elinda,
Now I know why you're f*cked up.
Quote:
Btw, I'm a government employee.......
Now I know why you're f*cked up.
Alma wrote:
I lost my post
Elinda wrote:
knoxsouthy wrote:
Elinda,
Now I know why you're f*cked up.
Quote:
Btw, I'm a government employee.......
Now I know why you're f*cked up.
I don't think anyone really wants that.
Nexa
“It has always been the prerogative of children and half-wits to point out that the emperor has no clothes. But a half-wit remains a half-wit, and the emperor remains an emperor.â€
― Neil Gaiman, The Sandman, Vol. 9: The Kindly Ones
― Neil Gaiman, The Sandman, Vol. 9: The Kindly Ones
#15REDACTED,
Posted: Jul 10 2008 at 8:39 AM, Rating: Sub-Default, (Expand Post) dal1234 turn 30 degrees right vectors to aviod "elevator".........
Aripyanfar wrote:
[quote=bubspeed]But the idea is to have the elevator supporting it's entire weight in orbit. There is no actual physical connection to the Earth, it's bottom end just hovers a few meters off the ground. (Within a sleeve.)
It won't work. You couldn't maintain this level of accuracy of movement without some serious fuel and power consumption. Remember, stationary on earth isn't stationary, it's moving over 1700 km/hr. Faster the farther out you go. This would be beyond dangerous, sleeve or not.
Quote:
oh yeah. just to rain on parade
Meaning that the thing that makes them attractive also makes them dangerous?
Unfortunately these characteristics will be one reason they are more widely used.
Just as Planned.
Aripyanfar wrote:
For a long and amazing description of a space elevator falling back down onto a planet (It winds up wrapped around the equator about 3 times) try Red Mars, Blue Mars, Green Mars by Kim Stanley Robinson.
Belkira wrote:
Wow. Regular ol' Joph fan club in here.
Timelordwho wrote:
Quote:
oh yeah. just to rain on parade
Meaning that the thing that makes them attractive also makes them dangerous?
Unfortunately these characteristics will be one reason they are more widely used.
I can't really decide how likely it is that these things would reproduce and spread like a virus and become some kind of mecha-plague.. and how much worse or better it would be than a bio-epidemic or bio-warfare.
I imagine it should be easy to turn these things OFF with some kind of sweep of charge particles.. perhaps they can be programed to only respond to a certain frequency..
I dunno//
Need caffeine
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