destinyland writes "A Vermont city once proposed a one-mile dome over its 7,000 residents. (They paid $4 million a year in heating bills, and HUD seriously considered funding their proposal.) The city's architectural concept included supporting the Dome with air pressure slightly above atmospheric pressure. (Buckminster Fuller warned their biggest challenge would be keeping it from floating away...) There would be no more heating bills, fly-fishing all year, and no more snow shoveling. And to this day, the former city planner insists that 'Economically it's a slam dunk.'"
I saw a Discovery channel special on mega-engineering and the plans to cover Houston with a dome [discovery.com] were quite a shock to me (here's a brief non-flash writeup [greenpacks.org]). I'll bet you're wondering what those panels are made of:
But the answer comes from German city of Bremen, from a company dubbed Vector Foil. Vector Foil manufactures an innovative strong, lightweight, transparent polymer known as ethylene tetra fluoro ethylene (ETFE). At just one percent of glass, ETFE is described as 99 percent nothing. And considering that it can withstand winds of 180 miles per hour, it could be the breakthrough for the Houston Dome.
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt. At least it's a long long way off if they follow through.
You can't do this without outlawing combustion. While it's a nice theory to say that you'll be able to blow enough air through it, in practice the airflow in a dome is not like the airflow without a dome. And anyone who has been to Houston knows just how bad the air quality is, in fact, it is some of the worst in the USA [nasa.gov]. If you could remove Chinese pollution from the Jet Stream, it probably WOULD be the worst. Then again, if you put a dome over it, the city's residents could just gas each other to death, which would effectively stop them from polluting.
The town from TFA was about 7,000 people. They said they would just use electric cars. Or a monorail.
That's nice. I'm talking about Houston, which has a lot more than 7,000 people... Although it probably wouldn't if they put a dome on it. Please try to keep up. In any case, there are numerous combustion sources besides internal combustion engines. Also, heavier-than-air combustion gases of all types (e.g. from cooking on the stove... there is no way I'm moving to Electric) would congregate in low places without winds to redistribute air. So now, you'll need air circulation fans installed on every street corner, as big as wind turbines; or they'll need to be installed in every house, and engineered to actually produce airflow instead of leaving dead pockets like most central air systems do. And unless you're planning to outlaw all combustible gases (like butane and propane, welding torches, et cetera) those fans had better be explosion-proof.
It's a fucking stupid idea on any scale. It would work on Mars, because you can reasonably outlaw combustible gases. You won't want to use them anyway, because you will have a limited supply of oxygen for the foreseeable future. It won't work here on Earth, at least not until we grow up a little more, and develop power storage technologies which can actually rival chemical fuels.
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. When the greenhouse is too hot, the air is just vented outside. Convection will draw air through the house, and the greenhouse can act as a particulate filter (and a CO2 scrubber/oxygen plant.) Periodic water washes (a rain system would be ideal) cleanse the dust from the plants; if it's soft-set on dirt then mycelium can handle fixing toxics captured this way. This doesn't get you away from weather, but it can dramatically cut heating costs in certain environments. It's not a one-size-fits-all fix, but nothing is.
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. [...]
I don't really know but it seems to me that if you put a greenhouse underneath another building then not much sunlight would make it into the greenhouse.
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. [...]
Pot growers have been already been testing this for decades. You use HPS for overheads and fluorescents on the side. Solar panels on the roof. See, this certain crop isn't exactly "legal" in most states yet.
It would work on Mars, because you can reasonably outlaw combustible gases.
But, wouldn't you want to test it out on earth first before you built one on mars?
Sorry, I meant downslope. I used "beneath" to mean "at a lower elevation."
By the way, I also advocate replacing roofs with greenhouses. Even polycarbonate panels (let alone fiberglass ones) can last better than ten years at a cost dramatically lower than "traditional" truss-and-shingle roofing, and with a lower replacement cost when viewed from almost any angle, including shipping, labor, and materials. Using bare-root aeroponics keeps weight to an absolute minimum and solar panels and their associated equipment (both for water heat and electrical generation) can be mounted over load-bearing exterior walls. These walls could as easily be the walls of a currently standing house as they could be made of straw bales, rammed earth, earth bags, adobe, or some other highly durable minimum-energy material.
In tropical climates you can put a little (okay, a lot) more effort into load-bearing in the roof, and implement a "green roof" with soil. So long as no deep-root crops are grown (careful weeding may be required!) food can be produced here. But this is a substantially higher-maintenance option and probably not really advisable for most of the Western world even where the climate permits.
If you are constructing the entire dwelling, in many parts of the world it is also possible to gather most or even all of your yearly water needs in a sub-floor cistern with the same footprint as your house, collected solely from roof runoff. If you are building with adobe or rammed earth, this can be achieved at relatively little additional cost.
The issue of local food production is only going to become more relevant to all of us interested in eating nourishing food as time goes by. And even if it were not necessary, it would be wise to implement some or all of these means to simply reduce the environmental cost of food production.
A real "nerd" would recognize that the distinction between city and town is essentially a nebulous one, and do more research to determine what the distinction would be before calling something an "elementary mistake" or labeling people they don't know a "sensationalist manipulator".
For example, in the US, the designation of "city" is controlled by state laws, and as such is determined by any of a number of factors, such as type of government or incorporation status of the community. Vermont has nine cities, the smallest of which has fewer than 3000 people.
Precisely. The Town of Gilbert, in Arizona, has nearly 200,000 people. Some think the name is quaint, but the real reason it is still a town is that towns have different government structures than cities. Basically, it allows a small group of mostly Mormons to control the entire "city" without facing the same election process as a city.
For most of New England, perhaps. In New Hampshire, (from my High School civics 1982), City means there are elected officials running the government. Town have town meetings where *everyone* votes on the issues.
See also http://en.wikipedia.org/wiki/New_England_town#Cities [wikipedia.org] "Most cities are former towns that changed to a city form of government because they grew too large to be administered by a town meeting."
FWIW, I'm originally from Lebanon, NH which is on the border with Hartford, VT.
by Anonymous Coward
on Monday November 09, @09:20AM (#30032248)
Are all of you finished making up problems? When was the last time people suffocated because the oxygen level in skyscrapers without openable windows got too low? What, they actually live in there? Blimey! They must be using magic to ensure a constant supply of fresh air!
It's not absurd for people to point it out as a possible problem.
True. And it's the most obvious problem with a fairly simple solution. It's the not so obvious problems, like the effect of sealing in plants that are dependant upon migratory pollenators and sealing out predators that feast on insects. What's going to happen to the ladybug population, for example?
A couple of buildings in the Beijing olympic park (Bird's nest, water cube) uses ETFE as roof and/or wall covering. It's pretty much as they state, very light, very clear (if you want it to) and it shrinks in close proximity of severe heat, like fires, so it'll retreat itself away from a flame, so it doesn't light up in a fire.
The Eden project [wikipedia.org] in Cornwall, England contains the world's largest greenhouse (panorama) [wikipedia.org], and it's made in a buckminsterfullerene-like way with ETFE.
It's definitely worth seeing if you're in south west England (relative to the rest of England it's quite remote area).
So did Walt Disney. The original plans for EPCOT [economicexpert.com] in Disney World included a massive translucent dome covering the "community" and its twenty thousand residents.
EPCOT "would be a testbed for city planning and organization. A giant dome was to have covered the community, so as to regulate its climate (this idea was later seen in the 1998 movie The Truman Show). The community was to have been built in the shape of a circle, with businesses and commercial areas at its center, community buildings and schools and recreational complexes around it, and residential neighborhoods along the perimeter. Transportation would have been provided by monorails and People Movers (like the one in the Magic Kingdom's Tomorrowland). Automobile traffic would be kept underground, leaving pedestrians safe above-ground."
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt.
I just get a blank page when I click on the link, so I'm not sure what the physical footprint of the town is, but when you consider modern sports stadia the ability to cover an area say 1 km across doesn't seem out of place. Modern materials are incredibly strong, and I would expect this dome would be designed as something like a kevlar rope net with panels in the holes to seal it. The internal atmospheric pressure will then keep the net under tension, and everything is good.
There is one big problem with it, which is that any failure is a catastrophic failure, albeit a catastrophe in slow motion. Unexpectedly high snow load, hurricane force winds, rocks falling from the sky and human error can all take structures of this kind down. I've seen two soccer domes fail under snow load (one was patchable and reinflatable) and know of another that was in the general vicinity of a tornado (nothing remained, although it was not actually hit by the tornado, it was just in the general area.)
As every engineer knows, if something can fail, it will. Domes like this can fail, therefore this one will. If the mean time between failure can be made long enough, it could still be worth-while, but I'd want to be sure that there was a re-inflation drill once a year or so (which policy would last for about a decade until some idiot in a suit realized they could pay themselves more today by leaving the people of tomorrow unprepared.)
There's also an interesting ecological twist: the ecosystem under the dome obviously can't be the local one, so you would have to replace a lot of vegetation with stuff that can survive without winter, and since the dome would inevitably become home to various exotic plants and animals it would be a continual source of invaders into the local ecosystem (which wouldn't survive the winter, but which would make every spring and summer a new surprise.)
I'm not a mechanical engineer, but I have built most of an airplane and studied a lot of aerodynamics in the process. The one thing I can say for certain is that ETFE cannot withstand a wind of 180mph, nor can any other "material". Materials don't withstand forces. Structures do. I can stick a cube of this stuff on the nose of an SR-71 and claim it survives Mach 4.5. Or I can make a sheet so thin that it comes apart in a slight breeze.
The statement you quoted is quite as meaningless as you surmised.
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt. At least it's a long long way off if they follow through.
Thats what people thought about powered flight. Maybe you should leave this sort of thing to the engineers.
If they were planning to keep the inside air warmer than the outside air, then they'd find themselves covered by the top half of a hot-air balloon.
The outside air can change temperature very quickly. In winter it can shift by more than 20C between day and night here in Finland, and New England could be similar. Balancing the thermal buoyancy of the air with the mass of the dome would need some skill and unreasonably fast temperature controls to prevent lift-off or collapse. It's feasible for smaller domes, but at the kilometer scale it would be a real challenge. Buckminster Fuller was right - it would need good tethering to keep it down at times. The membrane tensions might also be quite large in places, with interesting dynamics, so that the mechanical design near tethers would also be interesting.
Your comment Gothmolly is ambiguous. So I should reply to both. As I am exactly the kind of engineer this sort of task requires.
On the surface it's good advice. Don't build something that can suffocate everyone who lives underneath it without some serious engineering.
On the other hand it's terrible advice. As an engineer, I want people who will share data (like the link from the poster) for everything they related thing they can find. I WANT them to share all their worries. As an engineer it's my job to prepare a list, and address each of them. There are lives at stake in these designs, and these worries should be addressed with math, not hubris.
The early history of powered flight is littered with the corpses of the brave. Perhaps some of them were uninterested in comments too...
I'm not sure that going from heating a few thousand little boxes to heating one giant dome really qualifies as "no heating bills". Similarly, while shoveling snow off your driveway kind of sucks, it sure beats having snow build up on your habidome until the whole mess comes crashing down.
TFA suggests that it would be held up by air pressure. That means that, not only do you have to worry about snow, but there's also the problem that if enough panels break to lower the interior pressure the dome could collapse. Or in a high-wind scenario the Bernoulli effect could burst it. You're also right that obviously the surface area of the dome would result in truly absurd heating costs and I suspect really terrible AC costs in the summer (greenhouse effect!); Vermont really does get a lot of summer.
Actually the dome would have less surface area than the town. Take all the surface area of all the buildings and add it up. You will find that at makes a pretty good heat exchanger compared to a nice smooth dome. Rain water? What a great resource. You would catch it falling all the dome and and use it. I could even be used for the drinking water. Same for the snow melt from the dome. If nothing else it could be used for irrigation. Air Quality? Yes you would should ban cars from inside the city as well as fire places. You might not need to but it would probably be for the best if you did. For the dome to work you would want to have some pretty powerful air blowers to keep it pumped up. That should provide enough airflow for the air quality to be as good as a none domed town. Us air to air heat exchangers to allow for even more air flow when needed.
The one huge danger I see is fire. What is a building catches on fire? Is the dome fire proof? That risk could be reduced but if you are doing to dome an existing town you would have a lot of older buildings that may not be as fire safe as you would like.
The heating costs wouldn't be as bad because you get a lot of thermal energy stored in the ground from the sun during the day.
Effectively you are just manually replicating the greenhouse effect.
It's something I've experimented with my greenhouse (as I live in the UK and grow tropical plants which must be kept at a minimum of 15c all year around). It's suprising how effective storage of heat in the ground and such actually is and I also now keep water cooler sized bottles of water around the greenhouse walkway and under the staging through the winter to hold sun during the day which is then released through the night, it's not a massive change, but it has certainly made a measurable difference to my electric heating costs- my thermostat based electric heaters now need to come on for much less time through the night.
I'm sure there's actually probably a better substance than water for the purpose, but this was really just a small experiment. I can certainly see though from this how harnessing natural heat storage of pavements, ponds, roads, rivers, outer walls of buildings and so on could all hold heat built up during the day from the sun to drastically help heat such a dome through the night.
If the dome is thin enough, and the ambient temperature is above freezing, snow would not collect. it would merely melt and run off.
The snow would melt, in that case, by transferring heat out of the dome. This negates the energy benefit, and will result in a giant ring of ice surrounding the dome. It also assumes that the snow will melt faster than it falls. VT can get a lot of snow all at once, a blizzard would still encase the dome, melted and refrozen ice on the bottom, snow on top.
The bigger problem, I think, is still getting water (for plants) and air into the dome, and pollutants from combustion out. Even if it is structurally possible, the additional logistical costs will outweigh the benefits enough that there is no net gain to a dome.
i think it's not so much about the need to heat the whole dome, but rather the fact that the dome would trap all the heat (and pollutants) inside the dome. The lack of air exchange would trap alot of the heat, pretty much exactly how a greenhouse works.
Frankly, I encourage these people to complete their dome. It'll reveal insight into how bad (or maybe good too?) the idea is and what can go wrong with them. Also, it'll be good practice for when/if we decide to colonize extra-terran bodies. I don't think anyone has tried a larger-scale enclose ecosystem like this before (yes I know it won't be entirely enclosed.. but gotta start somewhere).
If you want to make little science, occasionally you have to break some beakers.
Similarly, while shoveling snow off your driveway kind of sucks, it sure beats having snow build up on your habidome until the whole mess comes crashing down.
If the outside surface temperature never drops below freezing, due to above square-cube law... Also it seems no great challenge at all, to design buildings, even domes, that don't collapse under heavy snow loads.
And how much will it cost when ALL their water needs for lawns and parks and such need to be piped in? Not to mention that many plants need some of the water to fall on the leaves not just the roots.
What about insects and pollinators? Birds that fly south?
Why would they have to pipe all the water in? You can just as well channel it through the dome? Even channel it throught at night.
What about insects and pollinators? They live fine in greenhouses. Why shouldnt they live in a dome. And who cares about migrating birds for such a small area?
Remember, it is still raining, just above the dome. It should be trivial to put collectors at teh base of the dome. I would hazzard a guess that it would provide the city with more water than they have currently.
My concern would be the long-term durability of the "glass". After 20 years, will it yellow? Will it be so scratched up that everything outside will be a blur? Who is going to climb up there and clean all the bird poop off of it?
large cisterns collecting water runoff at the perimeter would solve the issue of sourcing the water. piping it into the dome could be gravity feed. Then all you need pumps for is the lift to the sprinklers.
Insects could be brought in as needed. Birds could be supported as well. Migratory birds would be excluded; or, simply stay as they do here in south-east Virginia now that they've found the artificially warmed climate to be to their liking. (plenty of Ducks and Geese can't be bothered to fly south here)
I think this is one of those things that look good on paper, but...
There are so many ways this could go wrong. It might be a way to breed viruses into an entire city, or keep carcinogens trapped for all to breathe. The Biosphere II [wikipedia.org] was a fairly disastrous small scale experiment along these lines. Just imagine having an "oops" moment for a city of 5.7 million.
There's a cool book out by Bill Fawcett called "It Looked Good On Paper" that gives a lot of good (and generally unpublicized) information on Biodome II. Some of the issues:
- Failing air supply (almost immediate). Some outside air had to be pumped in. The levels reached 14% 02 enough to cause brain damage. - Food shortages. - Animal extinction: 19 of the 25 vertebrae species became extinct in the BDII. - Infighting among the crew.
According to Fawcett, the scientists "acknowledged making 10,000 mistakes."
You should check out the book. It's a highly entertaining read that covers disastrous designs from a wide number of areas.
Given that I actually live about 5 miles from where the whole Winooski Dome was planned to go this is all pretty well trodden territory here in this part of Vermont. The real killer problems are twofold. One is just that nobody has ever done it before and who wants to be first? In theory its a great idea, but its always the problem you didn't consider that bites you in the end. The second and more practical problem was always snow load. As anyone that has lived in Vermont can tell you, we get plenty of snow. Now pile it up a few feet deep on top of that dome, it adds up real fast. Nobody was ever sure exactly what would happen with all that snow or how long it would stay up there, etc. Roofs regularly collapse around here from snow load. You REALLY don't want to have that happen to your dome. That brings up what was the real final issue. What happens if something goes wrong? Its not just like you wasted a bunch of money. Having that dome come down on top of a whole town? That would be a big mess indeed...
Basically if the concept is ever going anywhere someone needs to build one way out in the middle of nowhere and figure out the basic problems first. Winooski residents wisely decided that being guinea pigs maybe isn't such a great idea.
You have a dome with a bunch of air in it, right? It has to be exchanged with fresh air, right? Now the city can tax the air their citizens people breath.
It is brilliant, really. They've finally found a way to tax the air we breathe!!
keep in mind that the heat of the warm air rising in the dome would be sufficient to maintain it well above freezing. therefore, snow would not collect.
Absolutely not true. Here in Quebec, the roof of the Olympic Stadium is a similar deal, and huge hot-air guns are needed to try to melt the snow - and when it's not fast enough, it has to be removed mechanically, or the roof fails (and then they have to get out these huge mechanical "clothespins" to hold the edges together until it can be fixed.
Go by any ice rink in the summer and look at the pile of snow outside from the Zamboni... snow just doesn't melt as fast as you think, even in 80 degree heat. Also, snow's a half-decent insulator (trapped air), so good luck melting a foot of snow.
Houston Has Similar Plans (Score:5, Interesting)
But the answer comes from German city of Bremen, from a company dubbed Vector Foil. Vector Foil manufactures an innovative strong, lightweight, transparent polymer known as ethylene tetra fluoro ethylene (ETFE). At just one percent of glass, ETFE is described as 99 percent nothing. And considering that it can withstand winds of 180 miles per hour, it could be the breakthrough for the Houston Dome.
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt. At least it's a long long way off if they follow through.
Re:Houston Has Similar Plans (Score:5, Insightful)
You can't do this without outlawing combustion. While it's a nice theory to say that you'll be able to blow enough air through it, in practice the airflow in a dome is not like the airflow without a dome. And anyone who has been to Houston knows just how bad the air quality is, in fact, it is some of the worst in the USA [nasa.gov]. If you could remove Chinese pollution from the Jet Stream, it probably WOULD be the worst. Then again, if you put a dome over it, the city's residents could just gas each other to death, which would effectively stop them from polluting.
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
Then again, if you put a dome over it, the city's residents could just gas each other to death, which would effectively stop them from polluting.
Your ideas intrigue me and I wish to subscribe to your newsletter.
--Heinrich Himmler Jr.
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
The town from TFA was about 7,000 people. They said they would just use electric cars. Or a monorail.
Monorail!
Mono ... duh!
Parent
Re:Houston Has Similar Plans (Score:5, Interesting)
The town from TFA was about 7,000 people. They said they would just use electric cars. Or a monorail.
That's nice. I'm talking about Houston, which has a lot more than 7,000 people... Although it probably wouldn't if they put a dome on it. Please try to keep up. In any case, there are numerous combustion sources besides internal combustion engines. Also, heavier-than-air combustion gases of all types (e.g. from cooking on the stove... there is no way I'm moving to Electric) would congregate in low places without winds to redistribute air. So now, you'll need air circulation fans installed on every street corner, as big as wind turbines; or they'll need to be installed in every house, and engineered to actually produce airflow instead of leaving dead pockets like most central air systems do. And unless you're planning to outlaw all combustible gases (like butane and propane, welding torches, et cetera) those fans had better be explosion-proof.
It's a fucking stupid idea on any scale. It would work on Mars, because you can reasonably outlaw combustible gases. You won't want to use them anyway, because you will have a limited supply of oxygen for the foreseeable future. It won't work here on Earth, at least not until we grow up a little more, and develop power storage technologies which can actually rival chemical fuels.
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. When the greenhouse is too hot, the air is just vented outside. Convection will draw air through the house, and the greenhouse can act as a particulate filter (and a CO2 scrubber/oxygen plant.) Periodic water washes (a rain system would be ideal) cleanse the dust from the plants; if it's soft-set on dirt then mycelium can handle fixing toxics captured this way. This doesn't get you away from weather, but it can dramatically cut heating costs in certain environments. It's not a one-size-fits-all fix, but nothing is.
Parent
Re:Houston Has Similar Plans (Score:5, Insightful)
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. [...]
I don't really know but it seems to me that if you put a greenhouse underneath another building then not much sunlight would make it into the greenhouse.
Parent
Re:Houston Has Similar Plans (Score:5, Informative)
There is a similar idea which actually carries some currency, though; put a greenhouse below a house and vent it into the house, then vent the exhaust from the house through a chimney. [...]
Pot growers have been already been testing this for decades. You use HPS for overheads and fluorescents on the side. Solar panels on the roof. See, this certain crop isn't exactly "legal" in most states yet.
It would work on Mars, because you can reasonably outlaw combustible gases.
But, wouldn't you want to test it out on earth first before you built one on mars?
Parent
Re:Houston Has Similar Plans (Score:4, Interesting)
Sorry, I meant downslope. I used "beneath" to mean "at a lower elevation."
By the way, I also advocate replacing roofs with greenhouses. Even polycarbonate panels (let alone fiberglass ones) can last better than ten years at a cost dramatically lower than "traditional" truss-and-shingle roofing, and with a lower replacement cost when viewed from almost any angle, including shipping, labor, and materials. Using bare-root aeroponics keeps weight to an absolute minimum and solar panels and their associated equipment (both for water heat and electrical generation) can be mounted over load-bearing exterior walls. These walls could as easily be the walls of a currently standing house as they could be made of straw bales, rammed earth, earth bags, adobe, or some other highly durable minimum-energy material.
In tropical climates you can put a little (okay, a lot) more effort into load-bearing in the roof, and implement a "green roof" with soil. So long as no deep-root crops are grown (careful weeding may be required!) food can be produced here. But this is a substantially higher-maintenance option and probably not really advisable for most of the Western world even where the climate permits.
If you are constructing the entire dwelling, in many parts of the world it is also possible to gather most or even all of your yearly water needs in a sub-floor cistern with the same footprint as your house, collected solely from roof runoff. If you are building with adobe or rammed earth, this can be achieved at relatively little additional cost.
The issue of local food production is only going to become more relevant to all of us interested in eating nourishing food as time goes by. And even if it were not necessary, it would be wise to implement some or all of these means to simply reduce the environmental cost of food production.
Parent
Re:Houston Has Similar Plans (Score:4, Funny)
Is there a chance the track could bend?
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
Not a chance my Hindu friend
Parent
Re:Houston Has Similar Plans (Score:5, Informative)
Not on your life my Hindu friend.
Parent
Re:Houston Has Similar Plans (Score:5, Informative)
A real "nerd" would recognize that the distinction between city and town is essentially a nebulous one, and do more research to determine what the distinction would be before calling something an "elementary mistake" or labeling people they don't know a "sensationalist manipulator".
For example, in the US, the designation of "city" is controlled by state laws, and as such is determined by any of a number of factors, such as type of government or incorporation status of the community. Vermont has nine cities, the smallest of which has fewer than 3000 people.
Parent
Re:Houston Has Similar Plans (Score:4, Insightful)
Precisely. The Town of Gilbert, in Arizona, has nearly 200,000 people. Some think the name is quaint, but the real reason it is still a town is that towns have different government structures than cities. Basically, it allows a small group of mostly Mormons to control the entire "city" without facing the same election process as a city.
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
Parent
Re:Wrong. (Score:4, Informative)
For most of New England, perhaps. In New Hampshire, (from my High School civics 1982), City means there are elected officials running the government. Town have town meetings where *everyone* votes on the issues.
NH has 13 cities: Berlin, Claremont, Concord, Dover, Franklin, Keene, Laconia, Lebanon, Manchester, Nashua, Portsmouth, Rochester, Somersworth.
See also http://en.wikipedia.org/wiki/New_England_town#Cities [wikipedia.org] "Most cities are former towns that changed to a city form of government because they grew too large to be administered by a town meeting."
FWIW, I'm originally from Lebanon, NH which is on the border with Hartford, VT.
Parent
Re:Houston Has Similar Plans (Score:5, Insightful)
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
Are all of you finished making up problems? When was the last time people suffocated because the oxygen level in skyscrapers without openable windows got too low? What, they actually live in there? Blimey! They must be using magic to ensure a constant supply of fresh air!
Parent
Re:Houston Has Similar Plans (Score:5, Insightful)
True. And it's the most obvious problem with a fairly simple solution. It's the not so obvious problems, like the effect of sealing in plants that are dependant upon migratory pollenators and sealing out predators that feast on insects. What's going to happen to the ladybug population, for example?
Parent
Re:Houston Has Similar Plans (Score:5, Informative)
Parent
Re:Houston Has Similar Plans (Score:5, Informative)
The Eden project [wikipedia.org] in Cornwall, England contains the world's largest greenhouse (panorama) [wikipedia.org], and it's made in a buckminsterfullerene-like way with ETFE.
It's definitely worth seeing if you're in south west England (relative to the rest of England it's quite remote area).
Parent
Re:Houston Has Similar Plans (Score:5, Funny)
At just one percent of glass, ETFE is described as 99 percent nothing.
Then why didn't they name it "Congress"?
Parent
Re:Houston Has Similar Plans (Score:5, Insightful)
At just one percent of glass, ETFE is described as 99 percent nothing.
Then why didn't they name it "Congress"?
Because unlike Congress ETFE is transparent.
Parent
Re:Houston Has Similar Plans (Score:4, Insightful)
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Re:Houston Has Similar Plans (Score:4, Interesting)
EPCOT "would be a testbed for city planning and organization. A giant dome was to have covered the community, so as to regulate its climate (this idea was later seen in the 1998 movie The Truman Show). The community was to have been built in the shape of a circle, with businesses and commercial areas at its center, community buildings and schools and recreational complexes around it, and residential neighborhoods along the perimeter. Transportation would have been provided by monorails and People Movers (like the one in the Magic Kingdom's Tomorrowland). Automobile traffic would be kept underground, leaving pedestrians safe above-ground."
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Re:Houston Has Similar Plans (Score:5, Interesting)
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt.
I just get a blank page when I click on the link, so I'm not sure what the physical footprint of the town is, but when you consider modern sports stadia the ability to cover an area say 1 km across doesn't seem out of place. Modern materials are incredibly strong, and I would expect this dome would be designed as something like a kevlar rope net with panels in the holes to seal it. The internal atmospheric pressure will then keep the net under tension, and everything is good.
There is one big problem with it, which is that any failure is a catastrophic failure, albeit a catastrophe in slow motion. Unexpectedly high snow load, hurricane force winds, rocks falling from the sky and human error can all take structures of this kind down. I've seen two soccer domes fail under snow load (one was patchable and reinflatable) and know of another that was in the general vicinity of a tornado (nothing remained, although it was not actually hit by the tornado, it was just in the general area.)
As every engineer knows, if something can fail, it will. Domes like this can fail, therefore this one will. If the mean time between failure can be made long enough, it could still be worth-while, but I'd want to be sure that there was a re-inflation drill once a year or so (which policy would last for about a decade until some idiot in a suit realized they could pay themselves more today by leaving the people of tomorrow unprepared.)
There's also an interesting ecological twist: the ecosystem under the dome obviously can't be the local one, so you would have to replace a lot of vegetation with stuff that can survive without winter, and since the dome would inevitably become home to various exotic plants and animals it would be a continual source of invaders into the local ecosystem (which wouldn't survive the winter, but which would make every spring and summer a new surprise.)
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Re:Houston Has Similar Plans (Score:5, Interesting)
I'm not a mechanical engineer, but I have built most of an airplane and studied a lot of aerodynamics in the process. The one thing I can say for certain is that ETFE cannot withstand a wind of 180mph, nor can any other "material". Materials don't withstand forces. Structures do. I can stick a cube of this stuff on the nose of an SR-71 and claim it survives Mach 4.5. Or I can make a sheet so thin that it comes apart in a slight breeze.
The statement you quoted is quite as meaningless as you surmised.
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Unpowered flight (Score:4, Interesting)
I'm not a mechanical engineer nor did any of my college coursework overlap with that but my gut feeling was pure skepticism and doubt. At least it's a long long way off if they follow through.
Thats what people thought about powered flight. Maybe you should leave this sort of thing to the engineers.
If they were planning to keep the inside air warmer than the outside air, then they'd find themselves covered by the top half of a hot-air balloon.
The outside air can change temperature very quickly. In winter it can shift by more than 20C between day and night here in Finland, and New England could be similar. Balancing the thermal buoyancy of the air with the mass of the dome would need some skill and unreasonably fast temperature controls to prevent lift-off or collapse. It's feasible for smaller domes, but at the kilometer scale it would be a real challenge. Buckminster Fuller was right - it would need good tethering to keep it down at times. The membrane tensions might also be quite large in places, with interesting dynamics, so that the mechanical design near tethers would also be interesting.
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Re:Houston Has Similar Plans (Score:5, Insightful)
Your comment Gothmolly is ambiguous. So I should reply to both. As I am exactly the kind of engineer this sort of task requires.
On the surface it's good advice. Don't build something that can suffocate everyone who lives underneath it without some serious engineering.
On the other hand it's terrible advice. As an engineer, I want people who will share data (like the link from the poster) for everything they related thing they can find. I WANT them to share all their worries. As an engineer it's my job to prepare a list, and address each of them. There are lives at stake in these designs, and these worries should be addressed with math, not hubris.
The early history of powered flight is littered with the corpses of the brave. Perhaps some of them were uninterested in comments too...
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So... (Score:5, Interesting)
Re:So... (Score:5, Insightful)
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Re:So... (Score:5, Insightful)
Actually the dome would have less surface area than the town. Take all the surface area of all the buildings and add it up. You will find that at makes a pretty good heat exchanger compared to a nice smooth dome.
Rain water? What a great resource. You would catch it falling all the dome and and use it. I could even be used for the drinking water. Same for the snow melt from the dome. If nothing else it could be used for irrigation.
Air Quality? Yes you would should ban cars from inside the city as well as fire places. You might not need to but it would probably be for the best if you did. For the dome to work you would want to have some pretty powerful air blowers to keep it pumped up. That should provide enough airflow for the air quality to be as good as a none domed town. Us air to air heat exchangers to allow for even more air flow when needed.
The one huge danger I see is fire. What is a building catches on fire? Is the dome fire proof? That risk could be reduced but if you are doing to dome an existing town you would have a lot of older buildings that may not be as fire safe as you would like.
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Re:So... (Score:5, Interesting)
The heating costs wouldn't be as bad because you get a lot of thermal energy stored in the ground from the sun during the day.
Effectively you are just manually replicating the greenhouse effect.
It's something I've experimented with my greenhouse (as I live in the UK and grow tropical plants which must be kept at a minimum of 15c all year around). It's suprising how effective storage of heat in the ground and such actually is and I also now keep water cooler sized bottles of water around the greenhouse walkway and under the staging through the winter to hold sun during the day which is then released through the night, it's not a massive change, but it has certainly made a measurable difference to my electric heating costs- my thermostat based electric heaters now need to come on for much less time through the night.
I'm sure there's actually probably a better substance than water for the purpose, but this was really just a small experiment. I can certainly see though from this how harnessing natural heat storage of pavements, ponds, roads, rivers, outer walls of buildings and so on could all hold heat built up during the day from the sun to drastically help heat such a dome through the night.
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Re:So... (Score:5, Insightful)
If the dome is thin enough, and the ambient temperature is above freezing, snow would not collect. it would merely melt and run off.
The snow would melt, in that case, by transferring heat out of the dome. This negates the energy benefit, and will result in a giant ring of ice surrounding the dome. It also assumes that the snow will melt faster than it falls. VT can get a lot of snow all at once, a blizzard would still encase the dome, melted and refrozen ice on the bottom, snow on top.
The bigger problem, I think, is still getting water (for plants) and air into the dome, and pollutants from combustion out. Even if it is structurally possible, the additional logistical costs will outweigh the benefits enough that there is no net gain to a dome.
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Re:So... (Score:5, Insightful)
i think it's not so much about the need to heat the whole dome, but rather the fact that the dome would trap all the heat (and pollutants) inside the dome. The lack of air exchange would trap alot of the heat, pretty much exactly how a greenhouse works.
Frankly, I encourage these people to complete their dome. It'll reveal insight into how bad (or maybe good too?) the idea is and what can go wrong with them.
Also, it'll be good practice for when/if we decide to colonize extra-terran bodies. I don't think anyone has tried a larger-scale enclose ecosystem like this before (yes I know it won't be entirely enclosed.. but gotta start somewhere).
If you want to make little science, occasionally you have to break some beakers.
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Re:So... (Score:5, Insightful)
I'm not sure that going from heating a few thousand little boxes to heating one giant dome really qualifies as "no heating bills".
Study up on the square-cube law and get back to us.
http://en.wikipedia.org/wiki/Square-cube_law [wikipedia.org]
Similarly, while shoveling snow off your driveway kind of sucks, it sure beats having snow build up on your habidome until the whole mess comes crashing down.
If the outside surface temperature never drops below freezing, due to above square-cube law... Also it seems no great challenge at all, to design buildings, even domes, that don't collapse under heavy snow loads.
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Stephen King (Score:3, Interesting)
Rain? Insects? Birds? (Score:5, Interesting)
And how much will it cost when ALL their water needs for lawns and parks and such need to be piped in? Not to mention that many plants need some of the water to fall on the leaves not just the roots.
What about insects and pollinators? Birds that fly south?
This is not very well thought out.
Re:Rain? Insects? Birds? (Score:5, Funny)
Birds that fly south?
Ah, the gentle thud of the returning swallows....
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Re:Rain? Insects? Birds? (Score:5, Funny)
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Re:Rain? Insects? Birds? (Score:5, Insightful)
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Re:Rain? Insects? Birds? (Score:5, Interesting)
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Re:Rain? Insects? Birds? (Score:4, Insightful)
large cisterns collecting water runoff at the perimeter would solve the issue of sourcing the water. piping it into the dome could be gravity feed. Then all you need pumps for is the lift to the sprinklers.
Insects could be brought in as needed. Birds could be supported as well. Migratory birds would be excluded; or, simply stay as they do here in south-east Virginia now that they've found the artificially warmed climate to be to their liking. (plenty of Ducks and Geese can't be bothered to fly south here)
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Dupe! (Score:5, Funny)
Lessons From Biosphere II (Score:5, Interesting)
I think this is one of those things that look good on paper, but...
There are so many ways this could go wrong. It might be a way to breed viruses into an entire city, or keep carcinogens trapped for all to breathe. The Biosphere II [wikipedia.org] was a fairly disastrous small scale experiment along these lines. Just imagine having an "oops" moment for a city of 5.7 million.
Re:Lessons From Biosphere II (Score:5, Informative)
There's a cool book out by Bill Fawcett called "It Looked Good On Paper" that gives a lot of good (and generally unpublicized) information on Biodome II. Some of the issues:
- Failing air supply (almost immediate). Some outside air had to be pumped in. The levels reached 14% 02 enough to cause brain damage.
- Food shortages.
- Animal extinction: 19 of the 25 vertebrae species became extinct in the BDII.
- Infighting among the crew.
According to Fawcett, the scientists "acknowledged making 10,000 mistakes."
You should check out the book. It's a highly entertaining read that covers disastrous designs from a wide number of areas.
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There are actually some serious issues with this. (Score:5, Insightful)
Given that I actually live about 5 miles from where the whole Winooski Dome was planned to go this is all pretty well trodden territory here in this part of Vermont. The real killer problems are twofold. One is just that nobody has ever done it before and who wants to be first? In theory its a great idea, but its always the problem you didn't consider that bites you in the end. The second and more practical problem was always snow load. As anyone that has lived in Vermont can tell you, we get plenty of snow. Now pile it up a few feet deep on top of that dome, it adds up real fast. Nobody was ever sure exactly what would happen with all that snow or how long it would stay up there, etc. Roofs regularly collapse around here from snow load. You REALLY don't want to have that happen to your dome. That brings up what was the real final issue. What happens if something goes wrong? Its not just like you wasted a bunch of money. Having that dome come down on top of a whole town? That would be a big mess indeed...
Basically if the concept is ever going anywhere someone needs to build one way out in the middle of nowhere and figure out the basic problems first. Winooski residents wisely decided that being guinea pigs maybe isn't such a great idea.
Cheaper solution (Score:5, Insightful)
Just cover all the streets with linear roofs
Re:what about high winds? (Score:5, Funny)
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Simple, tax the air (Score:5, Funny)
You have a dome with a bunch of air in it, right? It has to be exchanged with fresh air, right? Now the city can tax the air their citizens people breath.
It is brilliant, really. They've finally found a way to tax the air we breathe!!
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Re:I dunno, man. Snow is heavy (Score:5, Informative)
Absolutely not true. Here in Quebec, the roof of the Olympic Stadium is a similar deal, and huge hot-air guns are needed to try to melt the snow - and when it's not fast enough, it has to be removed mechanically, or the roof fails (and then they have to get out these huge mechanical "clothespins" to hold the edges together until it can be fixed.
Go by any ice rink in the summer and look at the pile of snow outside from the Zamboni ... snow just doesn't melt as fast as you think, even in 80 degree heat. Also, snow's a half-decent insulator (trapped air), so good luck melting a foot of snow.
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