Can someone please explain why everyone and their dog are all so fixated with carbon dioxide when methane is an order of magnitude worse as a greenhouse gas?
While each molecule of methane causes much more warming than CO2, there has been much, much more CO2 released during the industrial revolution, so the warming component of CO2 gas is still larger (60% according to
here, which is also a source for the other Methane facts I say here) than the component from CH4. Also, the increase in methane levels mainly comes from the increased scale of our agriculture as our population grows, and most of that comes from our cattle farming. Large developing countries like India and China have already begun industrializing in a way which rapidly raises their CO2 levels on par with the West, however they are showing little indication of adopting the Western diet anywhere near the level that would cause their CH4 production to match that of the US, so it looks like in the near future the CO2 production will outpace methane production by an even greater extent.
Additionally, methane is a useful fuel source, that means that there is an economic incentive to capture it, so that is the sort of thing the private market will take care of by itself as the techniques arise to do so, and this has already begun to happen. New landfills have systems to capture the produced methane, and there are even people experimenting with ways to capture cow farts. There is no money in sequestering carbon in a free economy, and as long as the global and societal costs of burning carbon are not transferred to the market as a financial cost then those methods of energy production will remain cheaper than cleaner methods for the foreseeable future, meaning that that is where our political (to apply those costs) and technological (to lower the costs of the alternatives) efforts need to go.
Lastly and most importantly Methane only persists in the atmosphere for around a dozen years, while CO2 remains for centuries. That means that we canafford to hold off on addressing methane while we work on CO2, since all of the CO2 we produce will stay in the atmosphere basically indefinitely, unless we recapture it at enormous expense, we need to get a grip on it as soon as possible. Once CO2 has started down the road towards sustainability we can address Methane (if it still needs to be addressed), then watch the environment scrub that out naturally within a generation.
I've been saying this for years but every time I bring it up the point is just laughed down. Recycling paper = Green = Good has just been so ingrained into people's head that even intelligent people can't seem to bring themselves to question it.
We are supposed to recycle paper in order to "save the trees" but if we really wanted more trees we would use more paper so that the current tree farms couldn't keep up with the demand and more would need to be planted. The analogy I like to make is that if you wanted to "save the Potatoes" you would eat as many french fries as you could. If the entire nation stopped eating french fries tomorrow all of the Potato farmers would switch to other crops and you wouldn't see any potatoes any more.
The biggest stopping point I see is that most people just flat out don't believe that lumber and paper comes from tree farms. They imagine that forests are being clear cut and not replaced, not realizing that if that was really how it worked we would have been out of forest long ago. When I mention that I generally get a reply like "well I know that's not sustainable, and the corporations know that it's not sustainable, but they care too much about this quarter's profit to actually plant more trees." I appreciate the sentiment, and the short-shortsightedness of corporations is true in many cases, but it's just not true here. The biggest problem with this thought line (besides making it impossible to actually think through pros and cons of recycling) is that it also masks the actual problems of having large sections of "forests" all made out of a single species of tree of a fairly young age, which pretty much turns any normal forest ecosystem upside down.
Now I'm not saying that non-recycled paper is definitely better from a CO2 standpoint, I'm just saying that there is a really good chance that it is better. Say that T is the amount of carbon sequestered in the new paper, R is the amount of Carbon released when processing used paper into recycled paper, and N is the amount of carbon released processing trees into new paper. I readily admit that N > R, but whether R > N - T is the real question. I don't have the ability to answer that question, but I'm sure someone out there has data on the processed mass of paper and energy requirements of various paper mills, and I would love to see those numbers. Preferably in addition to a comparison of secondary environmental costs, like the types and amounts of dyes, bleaching, etc involved in each process.
How does any of the above change the fact that *some* things in the bible are rational and well informed? Lets say you have a thousand year old book on sailing that says the earth is flat and that you will fall off the edge if you travel too far from land. Do you throw out the rational lessons on navigating using the sun and stars just because the flat earth thing appears in the same book?
What I would do in that situation is take the parts that were useful out of that book, strip out all of the useless parts, and replace them with more current models and the useful applications that those observations have. Then I could publish the second edition of the sailing book that is far superior to the first edition, and everybody could use that edition without all of the hang ups and deficiencies of the first book.
An alternative would be to classify all of the useful parts of the book as "literal truth" and the obsolete parts as "metaphorical truth" then every week I would indoctrinate children with undeveloped logical reasoning on how God said the Earth was flat because of his unbending sense of justice, and that people sailing off the end of the world if they went too far away from land represented the moral fall of people that strayed too far from his divine message.
And Zombies are a HORID placeholder. There give a preconceived notion of a specific reasons and that leads to people taking preparations towards a specific respond instead of a set of possible disaster types.
So you are saying that when I read that preparing for a zombie pandemic would prepare you for other types of disasters I shouldn't have just bought a shotgun and three thousand pounds of shells?
That's almost as bad as spending one dollar out of every four on the military, then telling people on Social Security and Medicare we need to cut their programs.
Parent:
And yet, the CIA world factbook lists US military expenditures at 4% of the GDP. As they list the GDP as 14.66 trillion, that's 595 billion dollars annually. That matches what the wikipedia says, that the US spent over 600 billion on the military in 2008.
You are quoting different numbers there, and they can both be correct. GP is saying that 25% of Government expenditures are on the military, and CIA world factbook is saying that 4% of the total national income is spent on the military.
Assuming that federal government expenditures in 2008 were 16% of the GDP then both of those numbers match up. That seems a little low though, and I'm guessing that GP's numbers are closer to accurate, due to different budget shenanigans that Congress does to hide apparent costs. One of the big ways is to provide big lump sums to programs throughout the course of the year in addition to their budget. When you go to look up the budget of the program by finding that year's budget that Congress voted in you miss out on all of the spending later in the year.
Please someone correct me if I'm wrong but I was under the impression that we've never seen any of the light reflected by a planet outside of our solar system. I thought the only methods of planet detection we currently have were to see the light it blocks from its host star, or to see the pull it has on its host star.
Only a few planets have actually been imaged through reflected light, the first in 2008, but it has been done.
The two alternative methods you mention have been going on for longer though, and have found many more planets than the imaging method.
There are actually physical barriers that make the 2020 deadline important, although the article sadly didn't mention them. One of them is the attitude control system, the Russian portion of the spacecraft uses thrusters to maintain attitude. When the US portion is responsible for maintaining the attitude it uses Control Moment Gyroscopes. However at the current rate those CMGs will become saturated shortly before 2020. Once this occurs there are a handful of options, all very expensive.
The simplest is to retire them and begin using only the Russian attitude jets, but this will significantly increase the IS fuel use and necessary resupply frequency. It's also possible to unsaturate such a system using external torques. The Russian attitude system isn't nearly powerful enough to do this effectively, however it should theoretically be possible to have a docked vehicle help with this maneuver, just like docked ships routinely assist with the ISS reboost. I'm guessing that this is impractical though, though I don't have the information on their saturation momentum or the other numbers I'd need to guess how many Soyuz/Progress/ATV/HTV trips would be necessary for such a maneuver, assuming the ISS was designed to handle it.
By the way, the Soyuz, Progress, ATV, and HTV are Russian, Russian, European Union, and Japanese ISS resupply ships... go USA?
The last option is to just replace them. We've already replaced two of them before, for excess vibrating and other mechanical breakdowns, why can't we replace these? Funny story there. First of all we only ever made two spares and have used both of them, I'm guessing starting another production run would be pretty expensive. More importantly the Space Shuttle was the only thing large enough to take them up to the ISS.
This info comes from my senior design project, which was to design a commercial Space Shuttle replacement. While the ability to carry a CMG was not a requirement, it was strongly advised. My last 20 minutes of googling wasn't able to recover the sources I found for that project, once I get home tonight I'll read through my paper again and post some citations.
This is very true, but the GP is also underrating the importance of a free oxidizer. From Wikipedia the specific energies of Liquid Hydrogen and Jet A aviation fuel are 143 and 42.8 MJ/kg ignoring the mass of their oxidizers. Once you account for the mass of the LOX that a rocket engine would need the specific energy of the LH/LO rocket fuel goes down to 8.4 MJ/kg, five times less than jet fuel and its free oxidizer. (Also note that the proposed engine for Skylon actually runs off of Hydrogen in the air-breathing mode, not jet fuel. And LH/LOX engines are very high performing rocket engines, I didn't pick a weak combination.) Add in the L/D (the concord had a L/D ratio of 7) benefit that you mention and you have a launch vehicle that has many advantages over a normal rocket.
It's not without it's flaws to overcome, however. Once it actually gets into space it's lugging around wings, landing gear, jet engines, and other stuff that does it no good whatsoever. It seems unlikely that the spaceplane's other advantages would offset this increased cost, though it's possible. IMO what you really want is the aircraft to operate as the first stage, releasing the rest of the rocket mid-flight. The Pegasus already operates this way, albeit at subsonic speeds. Back in undergrad I was part of a group that did some research into this, however supersonic release of a payload that threatened to outmass its carrier was a problem that we weren't able to satisfactorily address.
The Skylon solution may very well succeed without the staging however. They have a very, very stripped down aircraft as far as the flight characteristics are concerned, and their proposed engine is a combination rocket/air-breathing engine, when most other looks at this form of launch vehicle have assumed that two entirely separate propulsion systems would be needed. It's definitely a technology to watch, and I wish them the best of luck.
The idea that the brain is instructing your body to increase caloric intake in response to visual stimuli of exercise is intriguing. I hope they follow this up with a study comparing reading a neutral topic (the control), playing a soccer game, watching a soccer game, and then less active tv and video game media. Say playing Civilization and watching a romantic comedy.
If the grandparent's hypothesis is correct than playing the soccer video game and watching a soccer game would both cause increased caloric intake, while the other videogame and television show wouldn't.
Wait, so by some fantastic cosmic coincidence, plants only absorb energy at 2 out of the 3 wavelengths that human beings can actually see? That's the best argument I've heard yet for semi-intelligent yet strangely half-assed design!
It's a good argument for Evolution as well. The wavelengths that reach the Earth's surface in the greatest amount are those that are the most useful for both energy generation and vision.
I read the blog post the climber made when he first posted this video. According to him tethering yourself at every step is recommended, but not mandatory. Most of the climbers do not tether themselves at every step because the extra hooking/unhooking process makes it take significantly longer to get to the top, and is much more tiring, which in turn makes the process longer and more mistake prone.
Not to mention that the budget the politicians hand down with their decrees is never enough, and every four to eight (recently eight) years a new politician comes around and throws out half of your funding for the old to-do list and gives you a new to-do list.
There's a reason NASA has only been successful at (comparatively) cheap probe missions lately. They aren't as sexy or popular so they can go through development with much less political "help".
The existence of other bodies that don't have life doesn't nullify his point in any way. If you could point to a body and say "hey look, that body has 20% Oxygen, 3 %C02, and the rest Nitrogen. The atmosphere is much thicker than Earth's, and the equator isn't offset from the ecliptic by as much. The average temperature is the same as Earth's, but because of the above factors the temperature doesn't deviate in any one location over time very much. It also has a nice big salty ocean and plenty of fresh water! However even though we have this planet that you say should be better for life than Earth doesn't have any life at all." then you could comfortably call him a moron (not that that would further the debate, but at least you'd have a chance at being accurate).
Instead you pointed at the Moon and said "Hey look! That body's equator is offset from the ecliptic by the exact same amount as Earth's! Its orbit around the sun is identical to Earth's too! In addition its atmosphere is thinner (non-existent) and it's slower rotation makes absolutely enormous day/night temperature differentials. So in two of the things you mentioned it's identical, and in the other two it's way worse. It's also tremendously worse in things like water and oxygen content which you didn't specify, but because you were talking about secondary conditions useful to life that Earth lacked it was implied that there were more important primary conditions that Earth did have. So I can comfortably assume that you would look at the moon as an unlikely location for life, but I'm going to ignore that and call you a moron anyways."
Alternatively could you spend an hour a day lying down in 4g gravity, then spend the other 23 in 0g and be fine in the long term? That sort of thing could scale better with large populations, even though there is a lot more speed involved the fact that your machinery only has to support 1/24 of your population at once could make it better off.
Hopefully our next space station will be large enough to have something that could start getting data on that sort of circumstance. There was some talk a decade or two ago of trying to get an apparatus up to the ISS that could spin a single astronaut at a few g's, but there were always higher priorities. Now without the Space Shuttle I really doubt that we'll ever see anything of that scope on the ISS.
According to this paper the specific impulse of this new fuel is actually lower than that of LOX and LH, and comparable to other rocket fuels, It is the density impulse which is 20-30% better. This means that the propellant mass wouldn't increase, although making a smaller, denser fuel source would lead to a smaller rocket overall, with mass and cost savings for the structure. Additionally it's lack of Chlorine would make it more environmentally (and worker) friendly than some of the propellant options, which is always nice. Unfortunately that paper doesn't go into production costs, or any possible issues with storing it (This paper looks like it may have more information along those lines, but I don't have a subscription). I don't know if it can sit in a tank at room temperature like Hydrazine, or needs special care like Oxygen (due to its molecular weight I'm guessing the former.) All in all it does seem like a nice stepping stone between the high functionality of LOX LH, and the economy and convenience of some of the other liquid fuels, but it doesn't appear to be a serious game changer in any way.
As far as your suggestion to launch from buildings, mountains, or balloons, that doesn't actually offer substantial benefits either. While launching from high up would result in lower drag losses, that helps less than you'd expect because a ground launched rocket travels through the densest part of the atmosphere at it's slowest speeds. By the time a rocket is going fast enough that drag would really start to slow it down it is already at a pretty high altitude. If you are trying to make a cheaper rocket you really want to increase it's starting speed much more than its height. The math works out this way because of the fact that our starting radius is 6378 km. As big and impressive at Mount Everest seems to us it's really just a tiny pimple compared to the radius of the earth (brings you to 6386 km), and our entire atmosphere isn't much better.
However neither Person 1 or Person 2 should win a Nobel peace prize. In your story the Nobel Peace Prize should go to Person 3 in that other city who is spreading awareness for the problem, paying for rabies shots for poor people's pets, etc etc.
I'll leave the orbital mechanics to the astrophysicists.
I'll take a shot at it.
While you are right in saying that their orbital speeds are very close, that doesn't necessarilly mean that their velocities will be that close together. Even when you are just working in 2 dimensions the difference in speed between 30 km/s and 31 km/s could lead to a difference in velocity from 1 to 61 km/sec.
In addition that just gives you the V-inifinite, or the velocity when the mechanics switch over to predominantly be a two body problem between the asteroid and the Earth instead of a two-body problem between the Asteroid and the sun. At this point the asteroid has maximum potential energy. As the asteroid approaches the Earth it will continue to speed up until it is as close as it is going to get, at which point the relative velocities will be at their highest. As the asteroid leaves Earth's influence it will once again reach the speed of V-inf with respect to Earth, although it's speed with respect to the rest of the solar system will have changed. That's the basis of a slingshot maneuver.
Anyways, the Impact Risk Summary that the Near Earth Orbit Program made back in October 2009 estimated a V-infinity of 5.87 km/s and an impact velocity of 12.59 km/sec. The latest estimates have V-inf at 5.84 km/sec and the maximum relative speed at 7.42 km/s.
Let's say that we need 5 km/s to capture Apophis in our desired orbit. With a specific impulse of 450 s (similar to the space shuttle main engines) we'd need more than 3 times the mass of Apophis in propellant. Apophis has a mass of 2.7E10kg. We'd need more than 3 million space shuttle missions to lift all the propellant into lower-earth orbit.
Slashdot Mirror
Can someone please explain why everyone and their dog are all so fixated with carbon dioxide when methane is an order of magnitude worse as a greenhouse gas?
While each molecule of methane causes much more warming than CO2, there has been much, much more CO2 released during the industrial revolution, so the warming component of CO2 gas is still larger (60% according to here, which is also a source for the other Methane facts I say here) than the component from CH4. Also, the increase in methane levels mainly comes from the increased scale of our agriculture as our population grows, and most of that comes from our cattle farming. Large developing countries like India and China have already begun industrializing in a way which rapidly raises their CO2 levels on par with the West, however they are showing little indication of adopting the Western diet anywhere near the level that would cause their CH4 production to match that of the US, so it looks like in the near future the CO2 production will outpace methane production by an even greater extent.
Additionally, methane is a useful fuel source, that means that there is an economic incentive to capture it, so that is the sort of thing the private market will take care of by itself as the techniques arise to do so, and this has already begun to happen. New landfills have systems to capture the produced methane, and there are even people experimenting with ways to capture cow farts. There is no money in sequestering carbon in a free economy, and as long as the global and societal costs of burning carbon are not transferred to the market as a financial cost then those methods of energy production will remain cheaper than cleaner methods for the foreseeable future, meaning that that is where our political (to apply those costs) and technological (to lower the costs of the alternatives) efforts need to go.
Lastly and most importantly Methane only persists in the atmosphere for around a dozen years, while CO2 remains for centuries. That means that we canafford to hold off on addressing methane while we work on CO2, since all of the CO2 we produce will stay in the atmosphere basically indefinitely, unless we recapture it at enormous expense, we need to get a grip on it as soon as possible. Once CO2 has started down the road towards sustainability we can address Methane (if it still needs to be addressed), then watch the environment scrub that out naturally within a generation.
I've been saying this for years but every time I bring it up the point is just laughed down. Recycling paper = Green = Good has just been so ingrained into people's head that even intelligent people can't seem to bring themselves to question it.
We are supposed to recycle paper in order to "save the trees" but if we really wanted more trees we would use more paper so that the current tree farms couldn't keep up with the demand and more would need to be planted. The analogy I like to make is that if you wanted to "save the Potatoes" you would eat as many french fries as you could. If the entire nation stopped eating french fries tomorrow all of the Potato farmers would switch to other crops and you wouldn't see any potatoes any more.
The biggest stopping point I see is that most people just flat out don't believe that lumber and paper comes from tree farms. They imagine that forests are being clear cut and not replaced, not realizing that if that was really how it worked we would have been out of forest long ago. When I mention that I generally get a reply like "well I know that's not sustainable, and the corporations know that it's not sustainable, but they care too much about this quarter's profit to actually plant more trees." I appreciate the sentiment, and the short-shortsightedness of corporations is true in many cases, but it's just not true here. The biggest problem with this thought line (besides making it impossible to actually think through pros and cons of recycling) is that it also masks the actual problems of having large sections of "forests" all made out of a single species of tree of a fairly young age, which pretty much turns any normal forest ecosystem upside down.
Now I'm not saying that non-recycled paper is definitely better from a CO2 standpoint, I'm just saying that there is a really good chance that it is better. Say that T is the amount of carbon sequestered in the new paper, R is the amount of Carbon released when processing used paper into recycled paper, and N is the amount of carbon released processing trees into new paper. I readily admit that N > R, but whether R > N - T is the real question. I don't have the ability to answer that question, but I'm sure someone out there has data on the processed mass of paper and energy requirements of various paper mills, and I would love to see those numbers. Preferably in addition to a comparison of secondary environmental costs, like the types and amounts of dyes, bleaching, etc involved in each process.
My favourite was ~3 years ago when all the jobs I was applying for were demanding 3+ years experience with Windows Server 2008...
Companies have to do that because it's illegal to actually ask you if you're a Time Lord.
My favorite example is teenage girls being charged with distributing child porn for sending pictures of themselves to friends.
Is that actually true, or just another urban myth?
Yes it has actually happened. Slashdot covered it at the time: http://news.slashdot.org/story/09/03/30/1249237/Is-That-Sexting-Pic-Illegal-A-Scientific-Test
Well duh that's not reasonable, you didn't allot for enough fuel to slow down again once we arrived!
How does any of the above change the fact that *some* things in the bible are rational and well informed? Lets say you have a thousand year old book on sailing that says the earth is flat and that you will fall off the edge if you travel too far from land. Do you throw out the rational lessons on navigating using the sun and stars just because the flat earth thing appears in the same book?
What I would do in that situation is take the parts that were useful out of that book, strip out all of the useless parts, and replace them with more current models and the useful applications that those observations have. Then I could publish the second edition of the sailing book that is far superior to the first edition, and everybody could use that edition without all of the hang ups and deficiencies of the first book.
An alternative would be to classify all of the useful parts of the book as "literal truth" and the obsolete parts as "metaphorical truth" then every week I would indoctrinate children with undeveloped logical reasoning on how God said the Earth was flat because of his unbending sense of justice, and that people sailing off the end of the world if they went too far away from land represented the moral fall of people that strayed too far from his divine message.
And Zombies are a HORID placeholder. There give a preconceived notion of a specific reasons and that leads to people taking preparations towards a specific respond instead of a set of possible disaster types.
So you are saying that when I read that preparing for a zombie pandemic would prepare you for other types of disasters I shouldn't have just bought a shotgun and three thousand pounds of shells?
That's almost as bad as spending one dollar out of every four on the military, then telling people on Social Security and Medicare we need to cut their programs.
Parent:
And yet, the CIA world factbook lists US military expenditures at 4% of the GDP. As they list the GDP as 14.66 trillion, that's 595 billion dollars annually. That matches what the wikipedia says, that the US spent over 600 billion on the military in 2008.
You are quoting different numbers there, and they can both be correct. GP is saying that 25% of Government expenditures are on the military, and CIA world factbook is saying that 4% of the total national income is spent on the military.
Assuming that federal government expenditures in 2008 were 16% of the GDP then both of those numbers match up. That seems a little low though, and I'm guessing that GP's numbers are closer to accurate, due to different budget shenanigans that Congress does to hide apparent costs. One of the big ways is to provide big lump sums to programs throughout the course of the year in addition to their budget. When you go to look up the budget of the program by finding that year's budget that Congress voted in you miss out on all of the spending later in the year.
Please someone correct me if I'm wrong but I was under the impression that we've never seen any of the light reflected by a planet outside of our solar system. I thought the only methods of planet detection we currently have were to see the light it blocks from its host star, or to see the pull it has on its host star.
Only a few planets have actually been imaged through reflected light, the first in 2008, but it has been done. The two alternative methods you mention have been going on for longer though, and have found many more planets than the imaging method.
Good thing you posted AC, or we'd know who had the logical IQ of a crustacean.
You should have posted AC. Now we all know who to WOOOSH.
There are actually physical barriers that make the 2020 deadline important, although the article sadly didn't mention them. One of them is the attitude control system, the Russian portion of the spacecraft uses thrusters to maintain attitude. When the US portion is responsible for maintaining the attitude it uses Control Moment Gyroscopes. However at the current rate those CMGs will become saturated shortly before 2020. Once this occurs there are a handful of options, all very expensive.
The simplest is to retire them and begin using only the Russian attitude jets, but this will significantly increase the IS fuel use and necessary resupply frequency. It's also possible to unsaturate such a system using external torques. The Russian attitude system isn't nearly powerful enough to do this effectively, however it should theoretically be possible to have a docked vehicle help with this maneuver, just like docked ships routinely assist with the ISS reboost. I'm guessing that this is impractical though, though I don't have the information on their saturation momentum or the other numbers I'd need to guess how many Soyuz/Progress/ATV/HTV trips would be necessary for such a maneuver, assuming the ISS was designed to handle it.
By the way, the Soyuz, Progress, ATV, and HTV are Russian, Russian, European Union, and Japanese ISS resupply ships... go USA?
The last option is to just replace them. We've already replaced two of them before, for excess vibrating and other mechanical breakdowns, why can't we replace these? Funny story there. First of all we only ever made two spares and have used both of them, I'm guessing starting another production run would be pretty expensive. More importantly the Space Shuttle was the only thing large enough to take them up to the ISS.
This info comes from my senior design project, which was to design a commercial Space Shuttle replacement. While the ability to carry a CMG was not a requirement, it was strongly advised. My last 20 minutes of googling wasn't able to recover the sources I found for that project, once I get home tonight I'll read through my paper again and post some citations.
No, the sun is a very, very large system that is much too powerful to be perturbed in a meaningful way by a collision of that size.
This is very true, but the GP is also underrating the importance of a free oxidizer. From Wikipedia the specific energies of Liquid Hydrogen and Jet A aviation fuel are 143 and 42.8 MJ/kg ignoring the mass of their oxidizers. Once you account for the mass of the LOX that a rocket engine would need the specific energy of the LH/LO rocket fuel goes down to 8.4 MJ/kg, five times less than jet fuel and its free oxidizer. (Also note that the proposed engine for Skylon actually runs off of Hydrogen in the air-breathing mode, not jet fuel. And LH/LOX engines are very high performing rocket engines, I didn't pick a weak combination.) Add in the L/D (the concord had a L/D ratio of 7) benefit that you mention and you have a launch vehicle that has many advantages over a normal rocket.
It's not without it's flaws to overcome, however. Once it actually gets into space it's lugging around wings, landing gear, jet engines, and other stuff that does it no good whatsoever. It seems unlikely that the spaceplane's other advantages would offset this increased cost, though it's possible. IMO what you really want is the aircraft to operate as the first stage, releasing the rest of the rocket mid-flight. The Pegasus already operates this way, albeit at subsonic speeds. Back in undergrad I was part of a group that did some research into this, however supersonic release of a payload that threatened to outmass its carrier was a problem that we weren't able to satisfactorily address.
The Skylon solution may very well succeed without the staging however. They have a very, very stripped down aircraft as far as the flight characteristics are concerned, and their proposed engine is a combination rocket/air-breathing engine, when most other looks at this form of launch vehicle have assumed that two entirely separate propulsion systems would be needed. It's definitely a technology to watch, and I wish them the best of luck.
However, there will be no lascivious thoughts because that sort of nastiness just doesn't happen in Heaven.
More evidence that they are actually describing hell.
The idea that the brain is instructing your body to increase caloric intake in response to visual stimuli of exercise is intriguing. I hope they follow this up with a study comparing reading a neutral topic (the control), playing a soccer game, watching a soccer game, and then less active tv and video game media. Say playing Civilization and watching a romantic comedy.
If the grandparent's hypothesis is correct than playing the soccer video game and watching a soccer game would both cause increased caloric intake, while the other videogame and television show wouldn't.
Does anyone actually believe this?
If you do, I've got a terrorist-proof bridge to sell you.
Why the heck would I pay extra for a terrorist-proof bridge now that we've won the war on terror?!
Do you have any of the normal bridges?
Wait, so by some fantastic cosmic coincidence, plants only absorb energy at 2 out of the 3 wavelengths that human beings can actually see? That's the best argument I've heard yet for semi-intelligent yet strangely half-assed design!
It's a good argument for Evolution as well. The wavelengths that reach the Earth's surface in the greatest amount are those that are the most useful for both energy generation and vision.
I read the blog post the climber made when he first posted this video. According to him tethering yourself at every step is recommended, but not mandatory. Most of the climbers do not tether themselves at every step because the extra hooking/unhooking process makes it take significantly longer to get to the top, and is much more tiring, which in turn makes the process longer and more mistake prone.
Not to mention that the budget the politicians hand down with their decrees is never enough, and every four to eight (recently eight) years a new politician comes around and throws out half of your funding for the old to-do list and gives you a new to-do list.
There's a reason NASA has only been successful at (comparatively) cheap probe missions lately. They aren't as sexy or popular so they can go through development with much less political "help".
The existence of other bodies that don't have life doesn't nullify his point in any way. If you could point to a body and say "hey look, that body has 20% Oxygen, 3 %C02, and the rest Nitrogen. The atmosphere is much thicker than Earth's, and the equator isn't offset from the ecliptic by as much. The average temperature is the same as Earth's, but because of the above factors the temperature doesn't deviate in any one location over time very much. It also has a nice big salty ocean and plenty of fresh water! However even though we have this planet that you say should be better for life than Earth doesn't have any life at all." then you could comfortably call him a moron (not that that would further the debate, but at least you'd have a chance at being accurate).
Instead you pointed at the Moon and said "Hey look! That body's equator is offset from the ecliptic by the exact same amount as Earth's! Its orbit around the sun is identical to Earth's too! In addition its atmosphere is thinner (non-existent) and it's slower rotation makes absolutely enormous day/night temperature differentials. So in two of the things you mentioned it's identical, and in the other two it's way worse. It's also tremendously worse in things like water and oxygen content which you didn't specify, but because you were talking about secondary conditions useful to life that Earth lacked it was implied that there were more important primary conditions that Earth did have. So I can comfortably assume that you would look at the moon as an unlikely location for life, but I'm going to ignore that and call you a moron anyways."
If the trend continues, we're going to be a nation of absolute scaredy-cats who are afraid of our own shadows in just a couple more generations.
Aren't we are already there?
Alternatively could you spend an hour a day lying down in 4g gravity, then spend the other 23 in 0g and be fine in the long term? That sort of thing could scale better with large populations, even though there is a lot more speed involved the fact that your machinery only has to support 1/24 of your population at once could make it better off.
Hopefully our next space station will be large enough to have something that could start getting data on that sort of circumstance. There was some talk a decade or two ago of trying to get an apparatus up to the ISS that could spin a single astronaut at a few g's, but there were always higher priorities. Now without the Space Shuttle I really doubt that we'll ever see anything of that scope on the ISS.
According to this paper the specific impulse of this new fuel is actually lower than that of LOX and LH, and comparable to other rocket fuels, It is the density impulse which is 20-30% better. This means that the propellant mass wouldn't increase, although making a smaller, denser fuel source would lead to a smaller rocket overall, with mass and cost savings for the structure. Additionally it's lack of Chlorine would make it more environmentally (and worker) friendly than some of the propellant options, which is always nice. Unfortunately that paper doesn't go into production costs, or any possible issues with storing it (This paper looks like it may have more information along those lines, but I don't have a subscription). I don't know if it can sit in a tank at room temperature like Hydrazine, or needs special care like Oxygen (due to its molecular weight I'm guessing the former.) All in all it does seem like a nice stepping stone between the high functionality of LOX LH, and the economy and convenience of some of the other liquid fuels, but it doesn't appear to be a serious game changer in any way.
As far as your suggestion to launch from buildings, mountains, or balloons, that doesn't actually offer substantial benefits either. While launching from high up would result in lower drag losses, that helps less than you'd expect because a ground launched rocket travels through the densest part of the atmosphere at it's slowest speeds. By the time a rocket is going fast enough that drag would really start to slow it down it is already at a pretty high altitude. If you are trying to make a cheaper rocket you really want to increase it's starting speed much more than its height. The math works out this way because of the fact that our starting radius is 6378 km. As big and impressive at Mount Everest seems to us it's really just a tiny pimple compared to the radius of the earth (brings you to 6386 km), and our entire atmosphere isn't much better.
However neither Person 1 or Person 2 should win a Nobel peace prize. In your story the Nobel Peace Prize should go to Person 3 in that other city who is spreading awareness for the problem, paying for rabies shots for poor people's pets, etc etc.
I'll leave the orbital mechanics to the astrophysicists.
I'll take a shot at it.
While you are right in saying that their orbital speeds are very close, that doesn't necessarilly mean that their velocities will be that close together. Even when you are just working in 2 dimensions the difference in speed between 30 km/s and 31 km/s could lead to a difference in velocity from 1 to 61 km/sec.
In addition that just gives you the V-inifinite, or the velocity when the mechanics switch over to predominantly be a two body problem between the asteroid and the Earth instead of a two-body problem between the Asteroid and the sun. At this point the asteroid has maximum potential energy. As the asteroid approaches the Earth it will continue to speed up until it is as close as it is going to get, at which point the relative velocities will be at their highest. As the asteroid leaves Earth's influence it will once again reach the speed of V-inf with respect to Earth, although it's speed with respect to the rest of the solar system will have changed. That's the basis of a slingshot maneuver.
Anyways, the Impact Risk Summary that the Near Earth Orbit Program made back in October 2009 estimated a V-infinity of 5.87 km/s and an impact velocity of 12.59 km/sec. The latest estimates have V-inf at 5.84 km/sec and the maximum relative speed at 7.42 km/s.
Let's say that we need 5 km/s to capture Apophis in our desired orbit. With a specific impulse of 450 s (similar to the space shuttle main engines) we'd need more than 3 times the mass of Apophis in propellant. Apophis has a mass of 2.7E10kg. We'd need more than 3 million space shuttle missions to lift all the propellant into lower-earth orbit.