That's why I have orbital mining and transfer habitats in the step-by-step approach above. They are in orbits between Earth and Mars, and don't move once set up. They have mass shielding and greenhouses for life support. You get the raw materials for that from asteroids already in orbits between the two planets, so the delta v to move stuff to the desired orbits is not that much.
Crew and supplies meet up with the transfer habitats when they are close to Earth, and drop off when they are close to Mars, so the time unprotected by shielding is low. You also don't have to carry food and water for the whole trip, since the Habitats supply that. You just need enough for the shorter times at each end. It ends up being way more efficient if you are doing more than a few trips.
Advanced manufacturing pays for itself on Earth, regardless of if you do anything in space, by being more efficient.
Bulk cargo delivery is a cheaper way to deliver supplies to Low Earth Orbit. Customers at first would be places like Space Station, and communications satellites (which need a lot of fuel to get to GEO). Those are existing markets.
Steps 3-6 work together. They both make it cheaper to go anywhere past LEO (electric thrusters), and provide their own fuel (mining and processing), so it's self-sustaining once it's set up. A 2 ton mining ship plus 4.5 tons of fuel is sufficient to return 200 tons of asteroid rock, which you feed into your processing plant to extract useful items. That's not really vast infrastructure, but it's enough to get started. It can grow later as needed.
There is no need for the infrastructure to all be owned by the same entity, it can be multiple separate businesses who compete with each other. In fact, I specifically note in item 2 that a cheap launcher (like a re-useable SpaceX rocket) can substitute for what I have listed. In the page I linked to I also stated "If you build in smaller steps, you have the opportunity to change direction if new developments come along, or retrofit an improvement to just the part that needs it." That is in direct opposition to the current NASA plan of building a big rocket for their Space Launch System, all of which will be wasted if a cheaper launch vehicle comes along, or something changes the mission assumptions they sized it for.
So I think your concerns are unfounded, but I have more work to do to flesh out the data to support this step by step plan, like comparing it to the cost of doing the standard NASA Mars mission they are planning.
A more complete step by step plan. Robotic/Automated/Remote controlled equipment is used throughout to prepare the way ahead of large numbers of humans:
(1) Advanced Manufacturing - Using modular automated systems that can bootstrap much of their own construction. This has a goal of lowering manufacturing cost by a large factor. It is first used on Earth to build the factories to build the first space systems, and then later used in space to leverage local energy and materials resources.
(2) Hypervelocity Launcher - This is a low development cost device for launching bulk cargo. Delicate cargo and humans still travel by conventional rockets. At the moment there is enough cost savings to justify such a launcher, but if other vehicles get cheap enough, it may not be needed.
(3) Orbital Assembly - Assemble larger space systems from smaller components launched from Earth, or later manufactured in space. Smaller components means you can use smaller launch systems from Earth, which have lower startup cost.
(4) Electric Thrusters - These have about 10 times the fuel efficiency of existing rockets, and enable highly leveraged mining and processing.
(5) Orbital Mining - Mining small asteroids in orbits close to the Earth for raw materials. The mass return ratio is so high, especially with getting fuel from the next step, it dramatically affects all subsequent cost.
(6) Processing Factory - Converts raw materials mined in space into useful inventory such as fuel, oxygen, structural parts, etc.
(7) Space Elevator - This allows using the highly efficient electric thrusters in place of rockets for much of the transport job in gravity wells, starting with the Earth's.
(8) Human Transport - This improves the methods for transporting humans and cargo which cannot withstand the high acceleration of the hypervelocity launcher.
(9) Lunar Development - With our in-space infrastructure well developed, we can now access the Moon in a robust fashion and start to use it's relatively large mass and surface area.
(10) Interplanetary Development - Transfer habitats in orbits between Earth and Mars. Since they don't move, they can have heavy shielding and greenhouses. Crews use small vehicles to get from habitat to planet orbit at each end of the trip
(11) Mars Development - Use materials from Phobos to build elevator to Mars surface, and start to build up Mars.
Reading the patent, which was granted in 2009, it seems no different than what Second Life did in 2002, so at least that much is prior art. I have not used other virtual worlds, so not sure if there are even earlier 3D virtual worlds as prior art. The patent makes no mention of Second Life that I can find, which given it's popularity as a virtual world, is a glaring omission. World of Warcraft was released in 2004, and also predates the patent.
There is no question that water is the main greenhouse gas in the Earth's atmosphere. The average temperature of the Moon is -15C, and of the Earth is +15C, and most of that 30C difference is due to water, and that difference is despite the Moon being darker and thus absorbing more of the incoming sunlight. The existing warming does not prevent CO2 from causing additional increase of around 3C. If CO2 contributes 10% of total greenhouse warming, that is 3C, so a doubling should produce another 3C.
Anyone who has been outdoors at night knows that on cloudy nights it stays warmer than on clear nights. That difference is due to more greenhouse gases above you (water vapor i.e clouds) preventing radiation to space. To the extent that CO2 prevents radiation to space, the same thing will happen. Your mention of warming the upper atmosphere is irrelevant, it's the ability of the surface to cool by radiation that matters.
A layer of paint is typically 1/8 of a millimeter thick, and is close to 100 opaque to visible light. Carbon dioxide in the atmosphere amounts to 4 kg per square meter. If condensed, it would be a layer 2.6 millimeters thick, or 20 times thicker than a paint layer. It should not be hard to understand a layer that thick being able to absorb a significant amount of infrared light. The fact that it is distributed vertically does not change the absorbing power of the molecules, you still have the same number per unit area to run into.
Expressing the numbers as percentages is a way to make them seem small, and ignores the fact that the whole atmosphere has a mass of 10.3 tons per square meter, and would be about 9 meters thick if condensed. It's fairly amazing that thickness only absorbs about 27% of total incoming sunlight.
Note that the YD debris layer covers 10% of the Earth. It is hypothesized it was caused by a comet which broke up some time before hitting Earth, so created a large number of smaller craters rather than one big one.
Instead of a binary variable, friend or not friend, 1 or 0, It should be a floating point value with a range from -1 to 1. -1 = strong enemy, 1 = strong friend, anything in between indicates strength of the connection. Default value is 0 for everyone not specifically set to another value. Then you could set levels where certain info is revealed. For example: only friends above 0.9 get to post to my wall, anyone at 0 or below does not even see the wall. etc. That would make it a much more useful social service than now, where some random company that I want to keep up with gets the same privileges as my brother.
* Elimination of atmospheric absorption and distortion. In some wavelengths, the Earth's atmosphere absorbs near 100%, so going to space is the only option there.
* Very long exposure times. Earth-based exposures are limited by how long the night is.
Drawbacks:
* Hard to modify if you have a great new instrument you want to put at the receiver end
* Very expensive
Given those circumstances, we end up with lots of big telescopes on the ground, and a few in space for tasks they are better suited for.
The entire Pirate Bay set of magnet links, descriptions, and maybe comments could fit on a flash drive. When the plane lands, update with a new version by plugging in a new drive. With magnet links, the rest is handled by the torrent network.
Did you know that all 500 of the largest corporations worldwide by sales have a larger annual revenue than the entire United States did in 1800? ($14 B in today's dollars) They are big enough to be nations, so it should be no surprise they act like them.
I'm writing a book on that subject. There are way more than gravity slingshots. That's #73 out of 83 on the list so far, and I'm only 1/3 of the way to a first draft:
Accelerating and decelerating on an interstellar trip using only fuel you start with suffers from an exponential growth of fuel vs velocity. Look up the "Rocket Equation". If you send resupply robots ahead of the main ship, who mine these nomad objects and place fuel pellets or fuel tanks in your path so you can pick them up as you go, that turns an exponential fuel problem into a linear one. Yes, it takes work to accelerate fuel pellets, but less work than accelerating an entire ship with all it's cargo and passengers.
In a simplified version, imagine you use up all your fuel to accelerate to travel velocity, and then later pick up a new fuel supply to stop with. The second batch of fuel could come from a nomad.
The name for this is "Adhocracy" - An ad hoc association of people for getting a single task done. Note that home construction and film making work that way too. They pull together construction subcontractors, or directors, actors, and tech people, for a single project, then disband. What enables them to work is some kind of social network so they can gather for the next project.
25,000 downloads a day is utterly trivial in comparison to the hundreds of millions of downloads of file sharing software from CNET alone, let alone other sites:
The amusing part of the CNET downloads, is that CNET is owned by CBS, a major media company. So any attempt by CBS to sue file sharers can be countered by the fact that they encouraged it by distributing the software on a massive scale. The same story, on not as massive scale, is true for Fileplanet, owned by IGN, which is a division of News Corp, owners of Fox:
The Earth's atmosphere is equivalent to 10.3 meters of water in mass per area. Re-entry heating gets split between the meteorite and the air it is traveling through. When the meteorite mass per area is higher than the equivalent mass per area of the atmosphere, it tends to not pick up enough heat to melt entirely or drag to stop. Asteroid density varies depending on type from near water to near steel (1 to 8). Dynamic pressure slamming into the atmosphere can definitely fragment an asteroid, but that deposits all the kinetic energy in an airburst. This size rock can generate 0.5 to 4 Megatons of equivalent energy. It either goes into the air or into the gound. Either way you get a shock wave far beyond the size of the rock.
The number of asteroids passing close to the Earth has not changed recently, but the number we know about has increased dramatically. The current statistics are around 8700 known NEO's, which is double what we knew about 5.5 years ago, 4 times that of 9.5 years ago, and 10 times that of 12.5 years ago. Therefore the number of *known* close passes will continue to go up.
In the silver lining department, the more NEO's we know about, the more chances for space mining, and the better chance we have of preventing dangerous ones from hitting us or the Moon. Lunar impacts are often neglected, but more mass can be tossed off the Moon, because it's smaller, to end up sucked into the giant gravity well nearby called Earth. You get just as dead being hit by a 1 ton Lunar fragment as by a megaton asteroid, but the deaths are more distributed in time and space.
Note that people practice voluntary eugenics every time they decide not to have a child because the genetics of the parents risks inherited disease. Few people object to that, it's the forced eugenics that is abhorrent.
"Containment" will happen because of the rising price of fossil fuels, and the declining price of renewable energy. Oil is going up because the demand for it is rising faster than production. Coal is going up because rich nations demand less pollution, and the world is getting richer on the whole. Solar and wind are going down because of economies of scale and improved technology. So we are seeing a shift in use which will become big enough this decade to become obvious to everyone:
Wind + solar added 65 GW of capacity (13 GW of average output) in 2011. That sounds like a lot, but it's only around 0.1% of the world's energy use. The thing is wind increased ten-fold in the past decade, and solar increased thirty-fold. There is every reason to think rapid growth will continue. When the addition of renewables to total energy use moves from tenths of a percent per year to percent per year, the general media will pick up on it
What part of religion is it that some atmospheric gases absorb infrared? Ever notice how on cloudy nights the temperature falls less than on clear nights? That's the greenhouse effect in action. More greenhouse gas (water) means less heat escapes to space, thus it stays warmer. Water is the main greenhouse gas, mainly because there is a lot more of it, about 1% of the atmosphere, vs 0.04% CO2. But you cannot ignore the CO2 contribution, because water vapor concentration is highly non-linear with temperature. Thus any temperature effect caused by CO2 is magnified about 3 times by added water vapor. The reason so much more vapor can get in the air is because the Earth is mostly covered in water, and even the land parts are mostly covered in wet objects (soil and plants).
The extra CO2 is demonstrably from humans, because the Carbon-13 ratio is changing along with the CO2 level. Plants have a 2% lower C-13 ratio than inorganic sources. The only source of enough plant-derived CO2 to explain the ratio shift is fossil fuels plus deforestation, i.e humans. Where is there belief in this chain of logic, rather than observation and deduction?
Yes, water is the dominant greenhouse gas, and all of them together add 30C to the Earth's average temperature. We are worried about CO2 forcing another 3-6C. The Moon, which is at the same average distance from the Sun as we are, has a global average temperature of -15C (yes, it's much hotter on the day side, but it's also much colder on the night side). The Earth has an average temperature of +15C. The difference is due to our atmosphere slowing down heat leaking out. So merely saying water is the main greenhouse gas means nothing without the context that the worry is only 10-20% *more* greenhouse effect.
Oh, and we can prove the CO2 is man-made. Plants prefer Carbon-12 to Carbon-13, because the lighter atoms participate in reactions slightly faster. Thus they have 2% less C-13 than other sources (volcanoes and carbonate rocks). The C-13 ratio in the atmosphere is changing along with the total CO2 amount. Therefore the added CO2 comes from plants. The only sources of plant-derived CO2 large enough are fossil fuels and deforestation, both man-made sources.
Don't forget to put pivoting airfoils on the lower 20km of the struts. That reduces wind loads by about a factor of ten. Also check out the reference book I'm collecting if you have time: http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods (it's about 1/4 of the way to a first draft).
Slashdot Mirror
That's why I have orbital mining and transfer habitats in the step-by-step approach above. They are in orbits between Earth and Mars, and don't move once set up. They have mass shielding and greenhouses for life support. You get the raw materials for that from asteroids already in orbits between the two planets, so the delta v to move stuff to the desired orbits is not that much.
Crew and supplies meet up with the transfer habitats when they are close to Earth, and drop off when they are close to Mars, so the time unprotected by shielding is low. You also don't have to carry food and water for the whole trip, since the Habitats supply that. You just need enough for the shorter times at each end. It ends up being way more efficient if you are doing more than a few trips.
Advanced manufacturing pays for itself on Earth, regardless of if you do anything in space, by being more efficient.
Bulk cargo delivery is a cheaper way to deliver supplies to Low Earth Orbit. Customers at first would be places like Space Station, and communications satellites (which need a lot of fuel to get to GEO). Those are existing markets.
Steps 3-6 work together. They both make it cheaper to go anywhere past LEO (electric thrusters), and provide their own fuel (mining and processing), so it's self-sustaining once it's set up. A 2 ton mining ship plus 4.5 tons of fuel is sufficient to return 200 tons of asteroid rock, which you feed into your processing plant to extract useful items. That's not really vast infrastructure, but it's enough to get started. It can grow later as needed.
There is no need for the infrastructure to all be owned by the same entity, it can be multiple separate businesses who compete with each other. In fact, I specifically note in item 2 that a cheap launcher (like a re-useable SpaceX rocket) can substitute for what I have listed. In the page I linked to I also stated "If you build in smaller steps, you have the opportunity to change direction if new developments come along, or retrofit an improvement to just the part that needs it." That is in direct opposition to the current NASA plan of building a big rocket for their Space Launch System, all of which will be wasted if a cheaper launch vehicle comes along, or something changes the mission assumptions they sized it for.
So I think your concerns are unfounded, but I have more work to do to flesh out the data to support this step by step plan, like comparing it to the cost of doing the standard NASA Mars mission they are planning.
A more complete step by step plan. Robotic/Automated/Remote controlled equipment is used throughout to prepare the way ahead of large numbers of humans:
(1) Advanced Manufacturing - Using modular automated systems that can bootstrap much of their own construction. This has a goal of lowering manufacturing cost by a large factor. It is first used on Earth to build the factories to build the first space systems, and then later used in space to leverage local energy and materials resources.
(2) Hypervelocity Launcher - This is a low development cost device for launching bulk cargo. Delicate cargo and humans still travel by conventional rockets. At the moment there is enough cost savings to justify such a launcher, but if other vehicles get cheap enough, it may not be needed.
(3) Orbital Assembly - Assemble larger space systems from smaller components launched from Earth, or later manufactured in space. Smaller components means you can use smaller launch systems from Earth, which have lower startup cost.
(4) Electric Thrusters - These have about 10 times the fuel efficiency of existing rockets, and enable highly leveraged mining and processing.
(5) Orbital Mining - Mining small asteroids in orbits close to the Earth for raw materials. The mass return ratio is so high, especially with getting fuel from the next step, it dramatically affects all subsequent cost.
(6) Processing Factory - Converts raw materials mined in space into useful inventory such as fuel, oxygen, structural parts, etc.
(7) Space Elevator - This allows using the highly efficient electric thrusters in place of rockets for much of the transport job in gravity wells, starting with the Earth's.
(8) Human Transport - This improves the methods for transporting humans and cargo which cannot withstand the high acceleration of the hypervelocity launcher.
(9) Lunar Development - With our in-space infrastructure well developed, we can now access the Moon in a robust fashion and start to use it's relatively large mass and surface area.
(10) Interplanetary Development - Transfer habitats in orbits between Earth and Mars. Since they don't move, they can have heavy shielding and greenhouses. Crews use small vehicles to get from habitat to planet orbit at each end of the trip
(11) Mars Development - Use materials from Phobos to build elevator to Mars surface, and start to build up Mars.
More details here: http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods/Combined_Systems
Reading the patent, which was granted in 2009, it seems no different than what Second Life did in 2002, so at least that much is prior art. I have not used other virtual worlds, so not sure if there are even earlier 3D virtual worlds as prior art. The patent makes no mention of Second Life that I can find, which given it's popularity as a virtual world, is a glaring omission. World of Warcraft was released in 2004, and also predates the patent.
There is no question that water is the main greenhouse gas in the Earth's atmosphere. The average temperature of the Moon is -15C, and of the Earth is +15C, and most of that 30C difference is due to water, and that difference is despite the Moon being darker and thus absorbing more of the incoming sunlight. The existing warming does not prevent CO2 from causing additional increase of around 3C. If CO2 contributes 10% of total greenhouse warming, that is 3C, so a doubling should produce another 3C.
Anyone who has been outdoors at night knows that on cloudy nights it stays warmer than on clear nights. That difference is due to more greenhouse gases above you (water vapor i.e clouds) preventing radiation to space. To the extent that CO2 prevents radiation to space, the same thing will happen. Your mention of warming the upper atmosphere is irrelevant, it's the ability of the surface to cool by radiation that matters.
A layer of paint is typically 1/8 of a millimeter thick, and is close to 100 opaque to visible light. Carbon dioxide in the atmosphere amounts to 4 kg per square meter. If condensed, it would be a layer 2.6 millimeters thick, or 20 times thicker than a paint layer. It should not be hard to understand a layer that thick being able to absorb a significant amount of infrared light. The fact that it is distributed vertically does not change the absorbing power of the molecules, you still have the same number per unit area to run into.
Expressing the numbers as percentages is a way to make them seem small, and ignores the fact that the whole atmosphere has a mass of 10.3 tons per square meter, and would be about 9 meters thick if condensed. It's fairly amazing that thickness only absorbs about 27% of total incoming sunlight.
Evidence for Younger Dryas impact: http://www.pnas.org/content/early/2012/03/01/1110614109.abstract
Note that the YD debris layer covers 10% of the Earth. It is hypothesized it was caused by a comet which broke up some time before hitting Earth, so created a large number of smaller craters rather than one big one.
We know he's a pirate because he distributes file sharing software: http://www.fileplanet.com/73/0/0/0/1/section/File_Sharing
Scroll to the bottom and note it's operated by IGN Entertainment. Then check who owns IGN: http://corp.ign.com/about/
That's right, News Corp, Murdoch's company.
Instead of a binary variable, friend or not friend, 1 or 0, It should be a floating point value with a range from -1 to 1. -1 = strong enemy, 1 = strong friend, anything in between indicates strength of the connection. Default value is 0 for everyone not specifically set to another value. Then you could set levels where certain info is revealed. For example: only friends above 0.9 get to post to my wall, anyone at 0 or below does not even see the wall. etc. That would make it a much more useful social service than now, where some random company that I want to keep up with gets the same privileges as my brother.
Some reasons for a space-based telescope:
* Elimination of atmospheric absorption and distortion. In some wavelengths, the Earth's atmosphere absorbs near 100%, so going to space is the only option there.
* Very long exposure times. Earth-based exposures are limited by how long the night is.
Drawbacks:
* Hard to modify if you have a great new instrument you want to put at the receiver end
* Very expensive
Given those circumstances, we end up with lots of big telescopes on the ground, and a few in space for tasks they are better suited for.
The entire Pirate Bay set of magnet links, descriptions, and maybe comments could fit on a flash drive. When the plane lands, update with a new version by plugging in a new drive. With magnet links, the rest is handled by the torrent network.
Did you know that all 500 of the largest corporations worldwide by sales have a larger annual revenue than the entire United States did in 1800? ($14 B in today's dollars) They are big enough to be nations, so it should be no surprise they act like them.
Swap DVD's and loaded USB drives. You can borrow as much media as you contribute to the pool, in GB.
Homeless people with pirate boxes?
http://mxp.blogs.cnn.com/2012/03/13/robin-meades-tuesday-morning-express-preview-controversial-scheme-pays-homeless-to-be-wifi-hotspots-at-sxsw/
+
http://torrentfreak.com/piratebox-takes-file-sharing-off-the-radar-and-offline-for-next-to-nothing-120311/
I'm writing a book on that subject. There are way more than gravity slingshots. That's #73 out of 83 on the list so far, and I'm only 1/3 of the way to a first draft:
http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods
Accelerating and decelerating on an interstellar trip using only fuel you start with suffers from an exponential growth of fuel vs velocity. Look up the "Rocket Equation". If you send resupply robots ahead of the main ship, who mine these nomad objects and place fuel pellets or fuel tanks in your path so you can pick them up as you go, that turns an exponential fuel problem into a linear one. Yes, it takes work to accelerate fuel pellets, but less work than accelerating an entire ship with all it's cargo and passengers.
In a simplified version, imagine you use up all your fuel to accelerate to travel velocity, and then later pick up a new fuel supply to stop with. The second batch of fuel could come from a nomad.
The name for this is "Adhocracy" - An ad hoc association of people for getting a single task done. Note that home construction and film making work that way too. They pull together construction subcontractors, or directors, actors, and tech people, for a single project, then disband. What enables them to work is some kind of social network so they can gather for the next project.
25,000 downloads a day is utterly trivial in comparison to the hundreds of millions of downloads of file sharing software from CNET alone, let alone other sites:
http://download.cnet.com/windows/p2p-file-sharing-software/?tag=mncol%3Bsort&rpp=10&sort=downloadCount+asc
The amusing part of the CNET downloads, is that CNET is owned by CBS, a major media company. So any attempt by CBS to sue file sharers can be countered by the fact that they encouraged it by distributing the software on a massive scale. The same story, on not as massive scale, is true for Fileplanet, owned by IGN, which is a division of News Corp, owners of Fox:
http://www.fileplanet.com/73/0/1/2/1/section/File_Sharing
Yes, depending what it is made of. Check out this one at the American Museum of Natural History:
http://farm3.static.flickr.com/2189/2106429655_9edb74118a.jpg
The Earth's atmosphere is equivalent to 10.3 meters of water in mass per area. Re-entry heating gets split between the meteorite and the air it is traveling through. When the meteorite mass per area is higher than the equivalent mass per area of the atmosphere, it tends to not pick up enough heat to melt entirely or drag to stop. Asteroid density varies depending on type from near water to near steel (1 to 8). Dynamic pressure slamming into the atmosphere can definitely fragment an asteroid, but that deposits all the kinetic energy in an airburst. This size rock can generate 0.5 to 4 Megatons of equivalent energy. It either goes into the air or into the gound. Either way you get a shock wave far beyond the size of the rock.
The number of asteroids passing close to the Earth has not changed recently, but the number we know about has increased dramatically. The current statistics are around 8700 known NEO's, which is double what we knew about 5.5 years ago, 4 times that of 9.5 years ago, and 10 times that of 12.5 years ago. Therefore the number of *known* close passes will continue to go up.
In the silver lining department, the more NEO's we know about, the more chances for space mining, and the better chance we have of preventing dangerous ones from hitting us or the Moon. Lunar impacts are often neglected, but more mass can be tossed off the Moon, because it's smaller, to end up sucked into the giant gravity well nearby called Earth. You get just as dead being hit by a 1 ton Lunar fragment as by a megaton asteroid, but the deaths are more distributed in time and space.
Note that people practice voluntary eugenics every time they decide not to have a child because the genetics of the parents risks inherited disease. Few people object to that, it's the forced eugenics that is abhorrent.
"Containment" will happen because of the rising price of fossil fuels, and the declining price of renewable energy. Oil is going up because the demand for it is rising faster than production. Coal is going up because rich nations demand less pollution, and the world is getting richer on the whole. Solar and wind are going down because of economies of scale and improved technology. So we are seeing a shift in use which will become big enough this decade to become obvious to everyone:
Wind + solar added 65 GW of capacity (13 GW of average output) in 2011. That sounds like a lot, but it's only around 0.1% of the world's energy use. The thing is wind increased ten-fold in the past decade, and solar increased thirty-fold. There is every reason to think rapid growth will continue. When the addition of renewables to total energy use moves from tenths of a percent per year to percent per year, the general media will pick up on it
That's funny because the greatest deniers of AGW are white evangelicals: http://www.pewforum.org/Science-and-Bioethics/Religious-Groups-Views-on-Global-Warming.aspx
What part of religion is it that some atmospheric gases absorb infrared? Ever notice how on cloudy nights the temperature falls less than on clear nights? That's the greenhouse effect in action. More greenhouse gas (water) means less heat escapes to space, thus it stays warmer. Water is the main greenhouse gas, mainly because there is a lot more of it, about 1% of the atmosphere, vs 0.04% CO2. But you cannot ignore the CO2 contribution, because water vapor concentration is highly non-linear with temperature. Thus any temperature effect caused by CO2 is magnified about 3 times by added water vapor. The reason so much more vapor can get in the air is because the Earth is mostly covered in water, and even the land parts are mostly covered in wet objects (soil and plants).
The extra CO2 is demonstrably from humans, because the Carbon-13 ratio is changing along with the CO2 level. Plants have a 2% lower C-13 ratio than inorganic sources. The only source of enough plant-derived CO2 to explain the ratio shift is fossil fuels plus deforestation, i.e humans. Where is there belief in this chain of logic, rather than observation and deduction?
Yes, water is the dominant greenhouse gas, and all of them together add 30C to the Earth's average temperature. We are worried about CO2 forcing another 3-6C. The Moon, which is at the same average distance from the Sun as we are, has a global average temperature of -15C (yes, it's much hotter on the day side, but it's also much colder on the night side). The Earth has an average temperature of +15C. The difference is due to our atmosphere slowing down heat leaking out. So merely saying water is the main greenhouse gas means nothing without the context that the worry is only 10-20% *more* greenhouse effect.
Oh, and we can prove the CO2 is man-made. Plants prefer Carbon-12 to Carbon-13, because the lighter atoms participate in reactions slightly faster. Thus they have 2% less C-13 than other sources (volcanoes and carbonate rocks). The C-13 ratio in the atmosphere is changing along with the total CO2 amount. Therefore the added CO2 comes from plants. The only sources of plant-derived CO2 large enough are fossil fuels and deforestation, both man-made sources.
Hi Geoffrey,
Don't forget to put pivoting airfoils on the lower 20km of the struts. That reduces wind loads by about a factor of ten. Also check out the reference book I'm collecting if you have time: http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods (it's about 1/4 of the way to a first draft).