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#121
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Questions about "The High Frontier"
Damien Sullivan wrote: Lofstrom launch loop. 2000 km long, 80 km high. Can rise pretty straight, and above the atmosphere. No supervelocity needed. Mind you it needs the total GDP of a country for a year or two to build., and the effect of the winds of the jet stream on its support structure would be interesting to see. :-D Pat |
#122
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Questions about "The High Frontier"
Johnny1a wrote: That doesn't make the effort totally wasted, it's fun, and it might contribute something eventually to what actually does get built. For an example, consider the early days of trans-atlantic air travel. An idea that kept getting floated (literally) was to build artificial islands in the midst of the ocean, to make air travel between North America and Europe viable, since the planes could use them to refuel. It never actually got built, because technology advanced to the point that non-stop trans-Atlantic flight was viable without the islands. But some of the thinking that went into that idea eventually went into aircraft carriers. Made of ice, no less: http://en.wikipedia.org/wiki/Project_Habakkuk Pat |
#123
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Questions about "The High Frontier"
Johnny1a wrote: By which I mean: is the best comparison for an operational O'Neill Hab a city, or a ship? Ships at sea, for ex, are not and can not be run democratically. The ship's master _might_, depending on the situation, take the wishes of the crew into account in his decisions, but that isn't democracy in the political sense. Considering how these things seem to be geared toward the best and the brightest...not to mention wealthiest... in Libertarian pipe dreams, maybe a cruise ship might be a closer analogy. There's all the lads thinking deep thoughts while the hired help under the strict command of the captain actually does the dirty work that keeps the whole thing running. Jules Verne came up with a idea somewhat like this in his story "Propellor Island"; a huge ship full of rich people that is a nation unto itself. Unfortunatly, a social breakdown occurs as the inhabitants break down into two opposing groups: http://www.fantasticfiction.co.uk/v/...ler-island.htm I think he hit that right on the nose also...the people who would love to move into a space habitat would be a bunch of individulists and dreamers, and that would make for the biggest mess you ever saw, as no one would want to be told what to do by anyone else. A army made up entirly of generals. I could imagine various social arrangements that _might_ work on an O'Neill Hab other than dictatorship or strict military regimentation, but I can't see any way to avoid the necessity for a very strong executive and a state that can override individual wishes pretty firmly and quickly. There wouldn't be much margin for error. There could be a _lot_ that could go wrong on one of those things. Pat |
#124
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Questions about "The High Frontier"
Johnny1a wrote: By which I mean: is the best comparison for an operational O'Neill Hab a city, or a ship? Ships at sea, for ex, are not and can not be run democratically. The ship's master _might_, depending on the situation, take the wishes of the crew into account in his decisions, but that isn't democracy in the political sense. Considering how these things seem to be geared toward the best and the brightest...not to mention wealthiest... in Libertarian pipe dreams, maybe a cruise ship might be a closer analogy. There's all the lads thinking deep thoughts while the hired help under the strict command of the captain actually does the dirty work that keeps the whole thing running. Jules Verne came up with a idea somewhat like this in his story "Propeller Island"; a huge ship full of rich people that is a nation unto itself. Unfortunately, a social breakdown occurs as the inhabitants break down into two opposing groups: http://www.fantasticfiction.co.uk/v/...ler-island.htm I think he hit that right on the nose also...the people who would love to move into a space habitat would be a bunch of individualists and dreamers, and that would make for the biggest mess you ever saw, as no one would want to be told what to do by anyone else. A army made up entirely of generals. I could imagine various social arrangements that _might_ work on an O'Neill Hab other than dictatorship or strict military regimentation, but I can't see any way to avoid the necessity for a very strong executive and a state that can override individual wishes pretty firmly and quickly. There wouldn't be much margin for error. There could be a _lot_ that could go wrong on one of those things. Pat |
#125
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Questions about "The High Frontier"
Johnny1a wrote:
I don't think an O'Neill Habitat would _have_ to be a fascist state. It would not, however, lend itself well to the dreamy visions of participatory democracy that have too often been coupled to it. One interesting question about an O'Neill Habitat: is it a place, or is it a vehicle? By which I mean: is the best comparison for an operational O'Neill Hab a city, or a ship? Ships at sea, for ex, are not and can not be Dreams of the Culture notwithstanding, large habitats probably won't be changing orbits very often or very quickly, so I think you can make a case for "more like a climate controlled place". run democratically. The ship's master _might_, depending on the situation, take the wishes of the crew into account in his decisions, but that isn't democracy in the political sense. Why *can't* ships be run democratically? Especially as pirate ships apparently were often pretty democratic. There's an executive who has to be obeyed in combat, but is otherwise quite answerable to the ship's assembly. http://a4a.mahost.org/pirates.html quoting _Raiders and Rebels_ says they didn't just elect captains, but subjected most decisions to referendum. And it's not the only source. If actual ships could run on such lines, I see no reason an O'Neill colony couldn't be run via New England town meetings -- the early models are just the right size for it, too. -xx- Damien X-) |
#126
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Questions about "The High Frontier"
Johnny1a wrote:
I would like to see experiments done to establish just what levels of gravitational attraction (or the equivalent) are necessary for Human health, and what durations are dangerous. We just don't have the data to make anything but WAGs on the subject as matters stand. Agreed. Even more importantly, human tolerance to angular velocity (revolutions per minute) needs to be determined. Centrifugal force is w^2 * r, w being angular velocity and r being radius. A 4-fold increase in w could mean a 16-fold decrease in radius. Hop |
#127
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Questions about "The High Frontier"
Hop David wrote:
Agreed. Even more importantly, human tolerance to angular velocity (revolutions per minute) needs to be determined. Centrifugal force is w^2 * r, w being angular velocity and r being radius. That's centripetal/centrifugal acceleration, not force. -- Erik Max Francis && && http://www.alcyone.com/max/ San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis It's hard to say what I want my legacy to be when I'm long gone. -- Aaliyah |
#128
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Questions about "The High Frontier"
Eivind Kjorstad wrote:
Hop David skreiv: However small orbital hotels with artificial gravity may be possible. If lunar gravity is sufficient to maintain health, the rotating hab radius need only be 1/6 of the radius necessary for earth gravity. Nyrath has mentioned recent research on tolerance to angular velocity. It indicates humans can tolerate higher rpms if transition is gradual. 4 as opposed to 1 rpm would mean a sixteen fold difference in radius length. So much smaller and less expensive rotating habs may be possible. High-rpm-low-radius habs have a different problem though, the apparent gravity inside them has a sharp gradient, and coriolis would be a bitch. Early research had indicated sharp gradients and coriolis made high-rpm-low-radius environments intolerable for workers. Nyrath (an occasional RASS poster) has said recent research indicates higher tolerance can be acquired if transition to a high rpm environment is gradual. Wouldn't it be easier to hang the hotel on a tether, with a counter-mass on the other end, and spin it ? (the counter-mass can be a second hotel if desired) Indeed that's one of the structures I imagine. I call this a "bolo". Another is two habs connected by a rigid length, I call this a "baton". I expect most early rotating habs to be either bolos or batons. Zubrin proposed a bolo for his Mars missions. Critics charged Zubrin hadn't demonstrated a tether between a hab and a spent fuel tank would be controllable. Waves and harmonics along the tether were a concern. I believe a short tether would be easier to control. A shorter tether would also be less expensive than a long tether. A baton with a central airlock and rigid connecting lengths thick enough to accomodate workers would be less of a problem to dock with than a bolo. And in this case, short connecting lengths would certainly be less expensive. Hop |
#129
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Questions about "The High Frontier"
Matthias Warkus wrote:
People have held out in zero-g space stations for more than one year without serious health problems AFAIK. Yes and no. Long-term stays require extensive exercise while in orbit (on the order of 2 hours a day). If we start to build SPS and the like, almost certainly some form of rotating stations (or at least sleeping quarters) will be built. I'd think it cheaper to let people live in zero-g and put two hours of mandatory daily exercise into their contracts. There are other health problems associated with weightlessness that exercise doesn't help: http://en.wikipedia.org/wiki/Weightl...Health_effects You also seem to be assuming rotating habs would be more expensive than non-rotating habs. I've mentioned some factors that may make small rotating habs workable. Do you have a reason to believe rotating habs would be a lot more expensive? Hop |
#130
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Questions about "The High Frontier"
Pat Flannery wrote:
Mike Combs wrote: Seems to suggest that Winkler was being overly-conservative when he insisted that anything over 1 RPM would be a mistake. NASA did a study on this to determine the minimum diameter of a rotating station where the crew wouldn't feel dizziness as they moved around in it due to the perception of what "up" was, particularly in regards to their inner ear. IIRC, it was around 400 feet diameter for a 1g station. Pat 400 feet = 122 meters, so the radius would be 61 meters. w^2 * 61 meters = 9.8 meters/sec^2 w^2 = 9.8/61sec^2 w = .4 radians/sec = 3.8 RPM Hop |
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