I always thought that if you were a billionaire, like Bill Gates, a good use for your money would be to develop a suit of armor to duplicate that of Iron Man, as closely as possible. I mean, a lot of it is feasible, with ten figures to back R&D. What else are you going to do with your friggin' money? Cure cancer? World hunger?
I wasn't wild about many things in the BBC TV series (e.g., Zaphod's sleepy extra puppet head), but I'll amplify what the other reply said. The animated excerpts from the guide, which I think were taken verbatim from the book, were quite enjoyable. I could sit and watch hours of just those at a sit.
I did some more poking around. While radiation from the van Allen belts is of concern, there seem to be many possible engineering solutions as I suggested. Wikipedia has an entire section on the Space Elevator in its coverage of the van Allen belts.
Furthermore, since the problematic radiation is high-energy protons, the shielding need not be so heavy (apparently some light-weight plastics are pretty effective against protons).
Finally, if you stay in low Earth orbit (LEO), below the inner belt, this is not a problem at all. You could build an orbiting space dock for human space missions. Think about shuttle missions. The astronauts can safely stay for a week in orbit because they're typically UNDER the belts. Just being able to get humans to LEO cheaply would satisfy a lot of goals for humans in space.
In terms of practical everyday benefits, I think weather and communications satellites are awesome advances, and technological improvements allow us to upgrade them but currently only at large expense. As an astronomer, space has benefits that cannot be matched from the ground (e.g., observing in X-rays or the ultraviolet); because of the expense, space telescopes are few and far between. Personally, I'd also like to be a space tourist someday, and that requires ways of getting stuff to orbit cheaply.
This is with a moment's thought. I'm sure there's a webpage somewhere titled "What space can do for you" where there's an exhaustive list of benefits the average person enjoys and may not be fully aware of.
The observation bias of not being able to see dwarf ellipticals is clear. There's also a statistical bias, related to what you're talking about, in that you're looking at a small part of space. The thing is, however, on larger scales, you're going to start coming across *rarer* objects (e.g., very luminous galaxies). So if you're interested in the most common objects, you need to look locally. To get a complete picture, including the rarest objects, you must look deeply and remotely.
Look far enough away, and you will start to see evolutionary effects, sure. But look at a field of distant galaxies, you'll notice all the bright ones. But I guarantee there will be lots more little, faint, overlooked galaxies.
Astronomers quantify this as the galaxy luminosity function. It's difficult to get the faintest end, and the brightest end, for the reasons discussed above. You do the best you can.
No, the study was a few hundred thousand. A few people for a few years. It's public, in a popular and a techincal version. Look for The Space Elevator by Edwards and Westling on amazon or similar.
Elevators/tethers can be built from orbit. We have the technology to lift the weight of an elevator/tether ribbon into Earth orbit. From there you can sling material to any part of the solar system without much trouble.
This is only a pipe dream if one has no imagination and no quantitative reasoning skills. Luckily people forged on ahead when heavier-than-air flight, rockets in space, and other engineering no-brainers were proposed despite obviously silly, but excessively vocal objections.
"In order to visit another gravity well (planet), we need vehicles with the capacity to leave that gravity well. A space elevator may make it cheaper to get out of this one. It won't help you at your destination."
Actually, this is one of the BEST arguments for the elevator. You can build orbiting, rotating tethers with the same technology that can pick up vehicles on one planet, launch them to another, catch them there, and set them down, at very little cost. There's a whole theory built up around this, and if a space elevator is technologically feasible, space tethers are to, and they're no dead end. They're the solution to cheap transport all over the solar system. See http://www.scorpiusdigital.com/teasers/vikings_x.h tml for a fictional account of this idea by G. David Nordley, who worked as an astronautical engineer for the Air Force.
You might be able to get it down from a week, but even a week isn't so long. People in the past traveled for months to get places, even for vacations. You could just put people in cubicles with an internet link to slashdot and they could spend all their time arguing about how long it was going to take.
Material science in this area has been progressing quickly, and we're apparently within factors of a few of the required properties. There's no brick wall at this point, and optimists believe this problem will be solved on the timescale of just a few years. It's certainly worth supporting that basic material research.
The comparison to "Star Wars" isn't such a good one. This would actually be much cheaper than that is costing us. And if it doesn't work in the end, well, neither has "Star Wars" technology.
That's a good point. There are ways to shield from radiation other than mass (as long as we're talking charged particles, as we are in the belts, not gamma rays). Human-carrying climbers would have to be actively shielded and go faster than cargo climbers. I expect the first SEs to be for cargo, but I don't see this engineering challenge adding so much to the cost or danger that a SE would ultimately fail in comparison to chemical rockets. We've been at rockets for many decades now, and the cost and fatality rate both remain very high.
Of course that point is literally ridiculous -- I took it to be a socio-political-economic "shadow." But that might explain the following comment about "changing weather patterns" that didn't make any sense to me. The space elevator will be long, but it won't be big by any substantial measure.
It reduces cost to orbit to dollars per kilogram, orders of magnitude down from current costs, and could reliably and regularly put large amounts of material in space. Other benefits include easy and efficient launches to other parts of the solar system, space tourism, etc. Basically, imagine if you could drive to space. That's what this would give the world.
The material being discussed would be more like a ribbon, maybe a centimeter wide, a few molecules thick, rather than a one-dimensional wire.
It is a single point of failure. If any one of the millions of potential problems with a space cable turns out to be a show-stopper, the whole investment is lost.
It's possible to "prove" the space shuttle can't fly based on the number of parts and the failure rate in those parts. Yet it flies. It isn't like we've spent a fraction of the GNP on it. This argument comes down to "I don't think it will work because it seems complicated." It's actually much simpler than riding a bomb into space which is what astronauts currently do.
The benefits are small. The energy needed to shift a payload from the bottom to the top remains the same with or without the structure. The amount of money and energy spent on building the structure needs to be recovered in improved efficiency, and that seems unlikely.
This is just wrong. The benefits are huge! This would reduce cost to orbit by orders of magnitude. When you put material into space, you're not paying for the energy. It actually doesn't take all that much energy to put something into space. The calculation is easy. It's about 60 million Joules per kg (1/2 mv^2 with v=escape velocity). You can take a day to lift (which is 86400 seconds). That gives you about 700 J/s (which is the same as 700 Watts). It's the same energy you need to run 7 100 Watt light bulbs for 24 hours.
All of the investment is up front. There is no incremental benefit to this - the elevator does not become useful until it's complete. Any return on investment (including to governments in the form of kudos or re-election benefit) is delayed until long after completion of the project.
This objection is correct, but trivial. Edwards and Westling, the only ones who have done a realistic design study, put the cost at around $10 billion. That's less than the NASA budget for 1 year. That's much less than building a successor to the shuttle. That's factors of several less than the defunct superconducting supercolidor, and similarly less than the space station. Heck, Bill Gates could in theory build it for fun. Given the international nature of the problem, issues about security, the need for some additional bits of engineering/research, it is a government project. But not an outrageously expensive one.
I agree with much of what you say, except the thing about "changing weather patterns in the region" where it is built. I don't get that. Care to elaborate?
Edwards and Westling quote a figure of 8000 objects being tracked by U.S. Space Command. There are about 100,000 additional objects with diameters between 1 and 10 cm to worry about. The worst altitude is LEO at 500 to 1700 km. These numbers would suggest an impact on average every 250 days or so.
The solution is two-fold. You build the ribbon wider in this region, which reduces the chances of a catastrophic hit. Second, you go ahead and track ALL such objects and give the ribbon a small wiggle to avoid them. This is, apparently, feasible. It's an engineering challenge, not a show-stopper.
Yes, this is a big issue with space elevator designs. For this reason, you taper the cable, for instance. And supporting its own weight is the reason ridiculous strength/weight ratios are required (which are being approached by new nanosubstances). Designs call for widths around a centimeter or so, with multiple layers glued together, if I recall correctly. The material issue is probably the biggest theoretical problem still to be overcome, but the fact that we're so close so fast with nanotubes suggest that it's not long now. Many engineering and political problems, too, but those are at least theoretically solvable.
Re:Have they considered terrorism?
on
Space Elevator Update
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· Score: 2, Insightful
Since the cost is probably in the 10 billion dollar range, it would be a catastrophe, but one on order of a space shuttle blowing up. Once it's done, building more won't be so hard (assuming an intrinsic flaw didn't cause the first catastrophe).
The bottom line for me is, however, if you ever decide not to build something because it could be a terrorist target, that means they have won. [Really, instead of the trite crap that gets associated with that phrase.] But that's a whole other topic.
Humans could and would travel on such an elevator. It would probably be much safer than sitting on top of a bomb that is a rocket, and much, much cheaper. It wouldn't be the most pleasant ride, but there's no reason it couldn't or shouldn't be done.
You pick up orbital speed, slowly, as you move up the elevator. Think about it this way. There is a geostationary point the elevator passes through, at very high altitude. Altitudes lower than this, the rigid rotation of the space elevator is below orbital speed. Altitudes above it, it is above orbital speed. This effect means the gravity changes as you ride it, and, in fact, you can use the top end of it to lauch space craft.
I've got a space elevator in my new novel (under revision). Arthur C. Clarke features on in Fountains of Paradise. Kim Stanley Robinson and Charles Sheffield also have them in novels. If you want more than novels, there are some technical nonfiction books out there, eg., The Space Elevator by Edwards and Westling.
I just ended my Friday lecture on the local group of galaxies. They're the best measure of the frequency of galaxies out there in the universe, since many dwarf ellipitcals (very common in the local group) are difficult or impossible to see at greater distances.
Slashdot Mirror
I always thought that if you were a billionaire, like Bill Gates, a good use for your money would be to develop a suit of armor to duplicate that of Iron Man, as closely as possible. I mean, a lot of it is feasible, with ten figures to back R&D. What else are you going to do with your friggin' money? Cure cancer? World hunger?
I wasn't wild about many things in the BBC TV series (e.g., Zaphod's sleepy extra puppet head), but I'll amplify what the other reply said. The animated excerpts from the guide, which I think were taken verbatim from the book, were quite enjoyable. I could sit and watch hours of just those at a sit.
I did some more poking around. While radiation from the van Allen belts is of concern, there seem to be many possible engineering solutions as I suggested. Wikipedia has an entire section on the Space Elevator in its coverage of the van Allen belts.
Furthermore, since the problematic radiation is high-energy protons, the shielding need not be so heavy (apparently some light-weight plastics are pretty effective against protons).
Finally, if you stay in low Earth orbit (LEO), below the inner belt, this is not a problem at all. You could build an orbiting space dock for human space missions. Think about shuttle missions. The astronauts can safely stay for a week in orbit because they're typically UNDER the belts. Just being able to get humans to LEO cheaply would satisfy a lot of goals for humans in space.
In terms of practical everyday benefits, I think weather and communications satellites are awesome advances, and technological improvements allow us to upgrade them but currently only at large expense. As an astronomer, space has benefits that cannot be matched from the ground (e.g., observing in X-rays or the ultraviolet); because of the expense, space telescopes are few and far between. Personally, I'd also like to be a space tourist someday, and that requires ways of getting stuff to orbit cheaply.
This is with a moment's thought. I'm sure there's a webpage somewhere titled "What space can do for you" where there's an exhaustive list of benefits the average person enjoys and may not be fully aware of.
"...build the rest out as your demand for bandwidth (groan) increases..."
Yeah, it's a groaner, but I LOVE it! Bandwidth...!
Wow, you've got issues.
I get good teaching evaluations. I am successful in research. My novel writing provides a way to communicate scientific ideas to the general public.
I don't have a problem. Why don't you do your job instead of posting on slashdot ever, ever again?
Just wow.
The observation bias of not being able to see dwarf ellipticals is clear. There's also a statistical bias, related to what you're talking about, in that you're looking at a small part of space. The thing is, however, on larger scales, you're going to start coming across *rarer* objects (e.g., very luminous galaxies). So if you're interested in the most common objects, you need to look locally. To get a complete picture, including the rarest objects, you must look deeply and remotely.
Look far enough away, and you will start to see evolutionary effects, sure. But look at a field of distant galaxies, you'll notice all the bright ones. But I guarantee there will be lots more little, faint, overlooked galaxies.
Astronomers quantify this as the galaxy luminosity function. It's difficult to get the faintest end, and the brightest end, for the reasons discussed above. You do the best you can.
No, the study was a few hundred thousand. A few people for a few years. It's public, in a popular and a techincal version. Look for The Space Elevator by Edwards and Westling on amazon or similar.
Ditto!!!
Elevators/tethers can be built from orbit. We have the technology to lift the weight of an elevator/tether ribbon into Earth orbit. From there you can sling material to any part of the solar system without much trouble.
This is only a pipe dream if one has no imagination and no quantitative reasoning skills. Luckily people forged on ahead when heavier-than-air flight, rockets in space, and other engineering no-brainers were proposed despite obviously silly, but excessively vocal objections.
"In order to visit another gravity well (planet), we need vehicles with the capacity to leave that gravity well. A space elevator may make it cheaper to get out of this one. It won't help you at your destination."
h tml for a fictional account of this idea by G. David Nordley, who worked as an astronautical engineer for the Air Force.
Actually, this is one of the BEST arguments for the elevator. You can build orbiting, rotating tethers with the same technology that can pick up vehicles on one planet, launch them to another, catch them there, and set them down, at very little cost. There's a whole theory built up around this, and if a space elevator is technologically feasible, space tethers are to, and they're no dead end. They're the solution to cheap transport all over the solar system. See http://www.scorpiusdigital.com/teasers/vikings_x.
You might be able to get it down from a week, but even a week isn't so long. People in the past traveled for months to get places, even for vacations. You could just put people in cubicles with an internet link to slashdot and they could spend all their time arguing about how long it was going to take.
Material science in this area has been progressing quickly, and we're apparently within factors of a few of the required properties. There's no brick wall at this point, and optimists believe this problem will be solved on the timescale of just a few years. It's certainly worth supporting that basic material research.
The comparison to "Star Wars" isn't such a good one. This would actually be much cheaper than that is costing us. And if it doesn't work in the end, well, neither has "Star Wars" technology.
Just finding the broken cable would likely be quite difficult!
That's a good point. There are ways to shield from radiation other than mass (as long as we're talking charged particles, as we are in the belts, not gamma rays). Human-carrying climbers would have to be actively shielded and go faster than cargo climbers. I expect the first SEs to be for cargo, but I don't see this engineering challenge adding so much to the cost or danger that a SE would ultimately fail in comparison to chemical rockets. We've been at rockets for many decades now, and the cost and fatality rate both remain very high.
Of course that point is literally ridiculous -- I took it to be a socio-political-economic "shadow." But that might explain the following comment about "changing weather patterns" that didn't make any sense to me. The space elevator will be long, but it won't be big by any substantial measure.
It reduces cost to orbit to dollars per kilogram, orders of magnitude down from current costs, and could reliably and regularly put large amounts of material in space. Other benefits include easy and efficient launches to other parts of the solar system, space tourism, etc. Basically, imagine if you could drive to space. That's what this would give the world.
The material being discussed would be more like a ribbon, maybe a centimeter wide, a few molecules thick, rather than a one-dimensional wire.
Your objections are very leaky.
It is a single point of failure. If any one of the millions of potential problems with a space cable turns out to be a show-stopper, the whole investment is lost.
It's possible to "prove" the space shuttle can't fly based on the number of parts and the failure rate in those parts. Yet it flies. It isn't like we've spent a fraction of the GNP on it. This argument comes down to "I don't think it will work because it seems complicated." It's actually much simpler than riding a bomb into space which is what astronauts currently do.
The benefits are small. The energy needed to shift a payload from the bottom to the top remains the same with or without the structure. The amount of money and energy spent on building the structure needs to be recovered in improved efficiency, and that seems unlikely.
This is just wrong. The benefits are huge! This would reduce cost to orbit by orders of magnitude. When you put material into space, you're not paying for the energy. It actually doesn't take all that much energy to put something into space. The calculation is easy. It's about 60 million Joules per kg (1/2 mv^2 with v=escape velocity). You can take a day to lift (which is 86400 seconds). That gives you about 700 J/s (which is the same as 700 Watts). It's the same energy you need to run 7 100 Watt light bulbs for 24 hours.
All of the investment is up front. There is no incremental benefit to this - the elevator does not become useful until it's complete. Any return on investment (including to governments in the form of kudos or re-election benefit) is delayed until long after completion of the project.
This objection is correct, but trivial. Edwards and Westling, the only ones who have done a realistic design study, put the cost at around $10 billion. That's less than the NASA budget for 1 year. That's much less than building a successor to the shuttle. That's factors of several less than the defunct superconducting supercolidor, and similarly less than the space station. Heck, Bill Gates could in theory build it for fun. Given the international nature of the problem, issues about security, the need for some additional bits of engineering/research, it is a government project. But not an outrageously expensive one.
I agree with much of what you say, except the thing about "changing weather patterns in the region" where it is built. I don't get that. Care to elaborate?
Edwards and Westling quote a figure of 8000 objects being tracked by U.S. Space Command. There are about 100,000 additional objects with diameters between 1 and 10 cm to worry about. The worst altitude is LEO at 500 to 1700 km. These numbers would suggest an impact on average every 250 days or so.
The solution is two-fold. You build the ribbon wider in this region, which reduces the chances of a catastrophic hit. Second, you go ahead and track ALL such objects and give the ribbon a small wiggle to avoid them. This is, apparently, feasible. It's an engineering challenge, not a show-stopper.
Yes, this is a big issue with space elevator designs. For this reason, you taper the cable, for instance. And supporting its own weight is the reason ridiculous strength/weight ratios are required (which are being approached by new nanosubstances). Designs call for widths around a centimeter or so, with multiple layers glued together, if I recall correctly. The material issue is probably the biggest theoretical problem still to be overcome, but the fact that we're so close so fast with nanotubes suggest that it's not long now. Many engineering and political problems, too, but those are at least theoretically solvable.
Since the cost is probably in the 10 billion dollar range, it would be a catastrophe, but one on order of a space shuttle blowing up. Once it's done, building more won't be so hard (assuming an intrinsic flaw didn't cause the first catastrophe).
The bottom line for me is, however, if you ever decide not to build something because it could be a terrorist target, that means they have won. [Really, instead of the trite crap that gets associated with that phrase.] But that's a whole other topic.
Humans could and would travel on such an elevator. It would probably be much safer than sitting on top of a bomb that is a rocket, and much, much cheaper. It wouldn't be the most pleasant ride, but there's no reason it couldn't or shouldn't be done.
You're wrong.
You pick up orbital speed, slowly, as you move up the elevator. Think about it this way. There is a geostationary point the elevator passes through, at very high altitude. Altitudes lower than this, the rigid rotation of the space elevator is below orbital speed. Altitudes above it, it is above orbital speed. This effect means the gravity changes as you ride it, and, in fact, you can use the top end of it to lauch space craft.
I've got a space elevator in my new novel (under revision). Arthur C. Clarke features on in Fountains of Paradise. Kim Stanley Robinson and Charles Sheffield also have them in novels. If you want more than novels, there are some technical nonfiction books out there, eg., The Space Elevator by Edwards and Westling.
The parent is a joke. A space elevator connects the ground to space (or vice versa).
I just ended my Friday lecture on the local group of galaxies. They're the best measure of the frequency of galaxies out there in the universe, since many dwarf ellipitcals (very common in the local group) are difficult or impossible to see at greater distances.