Microsoft's licensing agreement appears to be per product line. If this is the case, all Dell has to do is re-label a line of their machines and sell them as Linux-only, thus exempting them from the Microsoft tax. Expect this as soon as another manufacturer gets into the arena, making it competitive. --
If you haven't read anything by David Brin, Lois McMaster Bujold, John Varley or Greg Bear, do so. There is a future in SF, and they are leading it. --
Some time ago, I ran into a fellow who was designing a pressure-fed upper stage. He was investigating an inflatable nozzle for the engine. According to him, the conditions well downstream from the nozzle throat are cool enough for current materials to handle, and the huge increase in expansion ratio possible with an inflatable nozzle could give a substantial boost in engine thrust with the same fuel burn. This translates to more payload. On top of this, the inflatable nozzle is very compact compared to a rigid nozzle bell. I wonder what became of this? --
Another possibility would be to grab some ice, melt it, and electrolyze H and O out of it. Use the H for a fuel cell.
This will get you exactly nowhere. Just a hint: look up "conservation of energy".
I wonder of you could make biodegradable blivets?
Things don't biodegrade on the ice sheet; it's too cold for bacteria, and there's no liquid water. Photodegradation is another matter. The researchers pack out their trash (including feces), but they pee on the ice; solar UV breaks the urea down into CO2 and NH3. I suppose you could air-drop solid fuel, like coal or wax, but this still requires someone to fly out frequently. This is not particularly safe even for professionals, and well beyond the capabilities of a group of amateurs (which was my impression of the original idea). --
There's just one thing left: find someone to go to the probe every so often, and fill it up with gas. (Nomad is gasoline-powered and cruises at about 1 MPH.)
There might be alternatives. There's a reasonable amount of wind on Antarctica, and enough sunlight during the summer months that the meteorite hunters who camp out there use solar panels to charge their laptop batteries. Running a mobile probe off this might be challenge, though. Unlike the gas-powered version you have a much smaller power supply, no waste heat for thermal control, and a host of other added constraints. Anyone trying to do this would have their work cut out for them. --
It can't get stranded in snow, because there's no snow there. Just ice. Nomad is running in an area where the ice is actually evaporating; if snow was accumulating, the meteorites would be buried and thus extremely difficult to detect. The beauty of the conditions where Nomad (and other Antarctic meteorite hunters) operate is that the sublimation of the ice sheet exposes all the things which have fallen onto it over the hundreds of miles and thousands of years before. The ice flows like a river and brings everything to that one area, like streams washing gold dust into every crevice in the stream bed. To a meteoriticist, this is just like panning for gold --
I seem to recall coverage on a legged robot called Dante, which was sent to investigate a volcanic crater in Antarctica. Could you be thinking of that? --
If information does infact become free, then no one will gather information anymore.
That's the same as saying "If software becomes free, nobody will write software anymore." And just as untrue; if information is free, people will still gather it for the use-value. Maybe it will stop people from gathering information only for the sale value, but this is probably a good thing. --
Cerulean is very unimpressive.
on
On to Mars
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· Score: 2
A first look at their web-site shows that they can do some elementary artwork, but they cannot even write at a 12th-grade level. Technical details are lacking, too; for instance, how is this boron nitride ceramic supposed to be applied to the aluminum structure, and how are the little details like aluminum's rather low softening point handled? And what about the heat load on the canopy during re-entry? A Plexiglas bubble works fine for a helicopter, but not on a Mach 3 aircraft.
If these guys were serious, they would have pictures showing details like sample panels being tested under the heat loads expected during re-entry. All they have is some moderately well-drawn art and a few equations. I'd not cite them again in support of the assertion that private parties will go to space; you're just giving people cause to dismiss the entire idea, Rotary Rocket included. --
Wy would it take ten years before we could return to the moon when it only took us seven or eight years to get there in the 60's? Do you really think NASA and space technology have gone backwards since then?
Entrenched interests and bureaucracies, in a nutshell. A concerted effort could uproot them, but without a crisis this is impossible. And what conceivable crisis requires a human visit to Mars? Now you see the nub of the problem. --
I dont think that the shuttle is capable of landing on the moon.
You're right. The Space Scuttle lands as a glider and requires a very smooth landing surface. The Moon has no atmosphere, the minimum orbital speed is about a mile per second, and even if the brakes could handle the huge increase in energy dissipation there is not a sufficient expanse of flat surface for the landing and runout anywhere on the Moon.
Which is beside the point, because the Scuttle cannot get anywhere near the Moon. It has enough OMS (Orbital Maneuvering System) fuel to get up to about 400 miles altitude with a minimal payload. This requires, IIRC, about 200 m/sec of delta-V. Going from LEO to lunar transfer orbit requires about a 2 mile/second kick; that's 3200 meters/sec, or about sixteen times the punch of the OMS packs. Forget braking to lunar orbit, landing, or taking off again; you're never going to get more than a few hundred miles from home in one of those things.
Scuttle is also about a billion bucks per launch, so it's a mighty expensive way to get anything to anywhere. Mostly it's a self-perpetuating program, going on the momentum of the political pull of the vendors. In other words, pork. To get anywhere, we need another vehicle with radically different characteristics. Since that vehicle would replace Scuttle and leave its well-connected vendors out in the cold, we're stuck. --
1. Precipitate carbonates (calcium, magnesium) from seawater.
There is not enough salt in the world to do this, but I suppose the salt could be recycled at a higher energy cost. This isn't the real problem though.
You don't do it with salt, you do it by concentration of seawater until the minerals precipitate. Or you do it electrically; there is a hint about artificial reef-building here (I've been unable to find any papers on the web). Unless I'm mistaken, pretty much all of the magnesium used in the world is "mined" by precipitation of MgCO3 from seawater.
4.Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.
This is the step that makes no sense at all. The energy requirements will be big, but probably not as much as the salt processing in your steps 1 and 2.
The energy requirements are entirely involved with producing the hydrogen (at least for the conversion to CH4); with common industrial catalysts, the reaction 4H2 + CO2 -> CH4 + 2 H2O runs all by itself.
No, the real problem is what you do with all the methanol.
You ship it to where you need energy, and you burn it. If you want to sequester the carbon you'll have to get fancy, but if you just dump the CO2 back into the air it'll replace the CO2 being consumed by the CaO and MgO you dumped.
Never mind that you would need horrific amounts of energy (probably more than the world currently produces).
Absolutely. It assumes a situation where energy is cheaper than fossil carbon. There are a number of scenarios which might bring this about, such as some of the Solar Power Satellite schemes or a breakthrough in Ocean Thermal-Electric Conversion (OTEC); one of the biggest problems with OTEC is that electrical transmission from generators in the middle of the ocean is impractical, and this converts the problem into one of transport of bulk liquids. Stiff carbon taxes would change the economics in favor of schemes like this overnight. --
Typically the statement that NADH is a co-factor in the rxn is enough to make the above clear to the audience of the New Scientist.
If you've ever read New Scientist (and especially looked at the pictures they run with their stories) you'd know that it's aimed at a very popular audience, not expected to have all that much education. A magazine like Nature would never have run a picture of a hooker's buttocks with an article on sampling and population estimating techniques; New Scientist did (and got a lot of indignant letters over it).
New Scientist does not even bother captioning most of their pictures, which is probably appropriate because few of them are very relevant to the stories in which they are placed. It is not even in the league of Scientific American in that respect. On the other hand, it is a weekly, and it is fairly thick. I've subscribed to it and found it expensive (in US$) but about as worthwhile for the money as Science News (burden of glitz outweighed by volume of coverage). --
Precipitate carbonates (calcium, magnesium) from seawater.
Roast carbonates to oxides, capture CO2.
Dump any undesired oxides back into the ocean, raising the pH, converting bicarbonate ion to carbonate ion, and helping absorb more CO2. (MgO may be worth saving for conversion to metal.)
Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.
If you have enough cheap energy, this might actually be feasible. --
THIS is the missing chemistry from the New Scientist article! Thank you, sir, for the enlightenment. (Someone ought to moderate the parent post up.) --
Don't forget 100% miscible with water. Spill the stuff and any ground water or reservoir it gets into is going to be poisonous....
Also biodegradable. There are bacteria which produce significant amounts of methanol in the process of fermenting carbohydrates. There are other bacteria which eat the methanol. No biggie, just put the right bugs to work. Besides, there are trace amounts of methanol in all kinds of things, including grape juice. Unlike carcinogens such as benzene and MTBE, it does not appear to be at all dangerous below a certain threshold. --
The article doesn't mention chemical H2, it mentions NADH. I'm assuming that NADH can be regenerated at the cathode of an electrolysis cell, but the article (and your description) still leave me in the dark as to the exact role played by NADH and how it is altered in the process. --
. He just said that the hydrogen in the fuel was itself derived via electrolysis.
I found the original post to be incoherent, but that assertion is untrue. The hydrogen used by space probes is obtained by reforming natural gas (methane, CH4) in a chemical reactor. You put CH4 and O2 in, you get CO2 and H2 out. --
The New Scientist article left a lot out, but filling in the blanks is suggestive.
Suppose you have a fuel-cell hybrid car. The fuel cells run at high pressure, so you can store the CO2 in tanks (perhaps along with the water, all dissolved as soda water). You can either dump the soda-water and buy more methanol (expensive, perhaps, if carbon taxes are imposed) OR you can hook up to the wind genny, solar panel or wave-power machine somewhere and use the CO2/NADH reaction to regenerate methanol and oxygen from the CO2 and H2O. This effectively puts the exhaust back into the fuel tank. You wouldn't necessarily have to do the regeneration in the car; you could dump the soda water into a tank at home or a station and regenerate it there.
This is equivalent to a battery-powered car, but without any effective daily-range limitation and "recharging time" of a few minutes. --
Said SO2, NO2, and H2O all combine in the atmoshere to form H2SO4 and HNO3 and promptly rain down on some forest somewhere, killing it.
One little problem for your assertion there... HNO3 dissociates in water to H+ and NO3-. NO3-, otherwise known as nitrate, is an essential nutrient for plants. It isn't plant-killer, it's plant food. (H2SO3 and H2SO4 have no real uses in that regard, save perhaps for changing the pH of excessively alkaline soils.) The real problem with NOx production is its contribution to photochemical smog.
Nitrate is also produced by lightning, and IIRC the fertilizing effect is well-known. Adding too much puts it into rivers and lakes (promoting eutrophication and algal blooms), but that's once removed from the main issue. --
Slashdot Mirror
Microsoft's licensing agreement appears to be per product line. If this is the case, all Dell has to do is re-label a line of their machines and sell them as Linux-only, thus exempting them from the Microsoft tax. Expect this as soon as another manufacturer gets into the arena, making it competitive.
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Perens is still on-target with that one.
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If you haven't read anything by David Brin, Lois McMaster Bujold, John Varley or Greg Bear, do so. There is a future in SF, and they are leading it.
--
Some time ago, I ran into a fellow who was designing a pressure-fed upper stage. He was investigating an inflatable nozzle for the engine. According to him, the conditions well downstream from the nozzle throat are cool enough for current materials to handle, and the huge increase in expansion ratio possible with an inflatable nozzle could give a substantial boost in engine thrust with the same fuel burn. This translates to more payload. On top of this, the inflatable nozzle is very compact compared to a rigid nozzle bell. I wonder what became of this?
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I believe the word is "ballute", a mix between a balloon and a parachute.
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Fortunately, that would run afoul of international treaties.
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There might be alternatives. There's a reasonable amount of wind on Antarctica, and enough sunlight during the summer months that the meteorite hunters who camp out there use solar panels to charge their laptop batteries. Running a mobile probe off this might be challenge, though. Unlike the gas-powered version you have a much smaller power supply, no waste heat for thermal control, and a host of other added constraints. Anyone trying to do this would have their work cut out for them.
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.. it's called Nomad because it wanders the ice?
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It can't get stranded in snow, because there's no snow there. Just ice. Nomad is running in an area where the ice is actually evaporating; if snow was accumulating, the meteorites would be buried and thus extremely difficult to detect. The beauty of the conditions where Nomad (and other Antarctic meteorite hunters) operate is that the sublimation of the ice sheet exposes all the things which have fallen onto it over the hundreds of miles and thousands of years before. The ice flows like a river and brings everything to that one area, like streams washing gold dust into every crevice in the stream bed. To a meteoriticist, this is just like panning for gold
--
I seem to recall coverage on a legged robot called Dante, which was sent to investigate a volcanic crater in Antarctica. Could you be thinking of that?
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If these guys were serious, they would have pictures showing details like sample panels being tested under the heat loads expected during re-entry. All they have is some moderately well-drawn art and a few equations. I'd not cite them again in support of the assertion that private parties will go to space; you're just giving people cause to dismiss the entire idea, Rotary Rocket included.
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Which is beside the point, because the Scuttle cannot get anywhere near the Moon. It has enough OMS (Orbital Maneuvering System) fuel to get up to about 400 miles altitude with a minimal payload. This requires, IIRC, about 200 m/sec of delta-V. Going from LEO to lunar transfer orbit requires about a 2 mile/second kick; that's 3200 meters/sec, or about sixteen times the punch of the OMS packs. Forget braking to lunar orbit, landing, or taking off again; you're never going to get more than a few hundred miles from home in one of those things.
Scuttle is also about a billion bucks per launch, so it's a mighty expensive way to get anything to anywhere. Mostly it's a self-perpetuating program, going on the momentum of the political pull of the vendors. In other words, pork. To get anywhere, we need another vehicle with radically different characteristics. Since that vehicle would replace Scuttle and leave its well-connected vendors out in the cold, we're stuck.
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New Scientist does not even bother captioning most of their pictures, which is probably appropriate because few of them are very relevant to the stories in which they are placed. It is not even in the league of Scientific American in that respect. On the other hand, it is a weekly, and it is fairly thick. I've subscribed to it and found it expensive (in US$) but about as worthwhile for the money as Science News (burden of glitz outweighed by volume of coverage).
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- Precipitate carbonates (calcium, magnesium) from seawater.
- Roast carbonates to oxides, capture CO2.
- Dump any undesired oxides back into the ocean, raising the pH, converting bicarbonate ion to carbonate ion, and helping absorb more CO2. (MgO may be worth saving for conversion to metal.)
- Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.
If you have enough cheap energy, this might actually be feasible.--
THIS is the missing chemistry from the New Scientist article! Thank you, sir, for the enlightenment. (Someone ought to moderate the parent post up.)
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The article doesn't mention chemical H2, it mentions NADH. I'm assuming that NADH can be regenerated at the cathode of an electrolysis cell, but the article (and your description) still leave me in the dark as to the exact role played by NADH and how it is altered in the process.
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Suppose you have a fuel-cell hybrid car. The fuel cells run at high pressure, so you can store the CO2 in tanks (perhaps along with the water, all dissolved as soda water). You can either dump the soda-water and buy more methanol (expensive, perhaps, if carbon taxes are imposed) OR you can hook up to the wind genny, solar panel or wave-power machine somewhere and use the CO2/NADH reaction to regenerate methanol and oxygen from the CO2 and H2O. This effectively puts the exhaust back into the fuel tank. You wouldn't necessarily have to do the regeneration in the car; you could dump the soda water into a tank at home or a station and regenerate it there.
This is equivalent to a battery-powered car, but without any effective daily-range limitation and "recharging time" of a few minutes.
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Nitrate is also produced by lightning, and IIRC the fertilizing effect is well-known. Adding too much puts it into rivers and lakes (promoting eutrophication and algal blooms), but that's once removed from the main issue.
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