[Solaren corporate spokesperson Marshall] said the agreement called for 800 gigawatt-hours of electricity to be provided during the first year of operation, and 1,700 gigawatt-hours for subsequent years.
1700 GWh in an 8700 hour year is just under 2MW. 200MW is enough power for 100,000 homes at 2KW each (a low average), so even their math that 1700GWh is "the annual consumption of 250,000 average homes" is wrong. I think their quoting the numbers in the contract is more reliable than their arithmetic.
I'm not sure what you mean. How does the cosine of the angle from the base station to the satellite state efficiency? The beam travels obliquely through more air than if directly overhead, but the beam is supposed to be tuned to avoid absorption.
Is it geostationary? The article I read says "over the equator", which almost always means geosynchronous. At 35Km high, the Earth is a tiny dot whose shadow blocks the Sun for maybe a few hours a year (out of 8700 hours in a year).
How about I convince you they're planning to deliver only 2MW, not 200MW.
They say they'll reach a 17GWh:y delivery once the platform is stable. There's 8765.81277 hours in a year, so that's 17 billionWh / 8765.81277h = 1.9393524 million watts.
The solar "constant" in geosync Earth orbit (about 35Km elevation) is 1366W:m^2. That's 1419.73089m^2, or 0.00141973089Km^2, significantly less (0.709865445%) than 0.2Km^2.
Buying desert land isn't "astronomically expensive". It's about the cheapest land there is. There happens to be huge deserts of dirt-cheap (cheaper: sand-cheap) land all around California. Besides, this 2MW satellite probably doesn't even need more than about 25m^2 to receive its beam at 5x solar density. If they wanted to be really safe, they probably could diffuse it over 2500m^2, for 5W:m^2, which doesn't hurt anyone.
The efficiency here is the 30% extra incoming solar power that is otherwise lost in the atmosphere (minus some small lost amount they're tuning the beam to minimize), times the 24/7 uptime instead of about 25% terrestrial due to night/weather/seasons. That's a starting point of 520%. But the other advantage is the much larger area that thin collector sheets can cover in space. Launching costs money per mass, but the collectors can unfurl across kilometers. And the maintenance costs in microgravity/femtopressure are much lower over years, despite the remoteness. After the large initial costs, the ongoing costs per watt are extremely low.
2MW would require only about 40x40m collectors. A square kilometer collector would bring 1.3GW. The geosync satellite beaming to Fresno could receive from collectors in all kinds of other orbits pointing at the hub. This infrastructure could conceivably bring all 17TW of Earth's energy consumption into a series of ground stations from only about 114*114 Km of collectors. A few score hubs around the equator each using a few dozen GW lasers could replace all the coal currently burned for stationary power. The sky is literally the limit.
It's not the deviation distance that matters. It's the duration the beam spends on a sensitive target, sending its 2MW at it. 250ms is 500j, if the RF beam is snapped over to a new target until shutdown. The beam could be something like 24m^2 wide, if at 5x solar density. That kind of accident could indeed fry some electronics, but not much more.
The real problem in shortening the delay is that the satellite is probably about 35Km up, in geosynchronous orbit. That's about 195s as the photon flies, with about 45ms left for electronics processing to shut the beam down if the failsafe signal doesn't arrive on target.
These beaming systems have interlocks pointed back from the ground receiver to the satellite. If the two get out of alignment, the satellite immediately loses the ground signal, and immediately stops transmitting.
Besides, the beamed power density doesn't have to be very high per square meter. If it's just concentrated 5x from its density in space, it's 6.5KW:m^2. At this system's 2MW transmission rate, is only 308m^2, or a square 17.5m on a side. If it's really RF, even if the interlock failsafe failed, the beam wouldn't do much except fry some unshielded electronics in the way until something else shut it down. I'm sure the multiple layers of government regulators will ensure a lot of "deadman switches" to stop the only thing that everyone guesses could go wrong.
Sunspots have practically nothing to do with "Global Warming", or rather, practically nothing to do with climate change. If humans stopped producing too much Greenhouse pollution, climate change could slow or reverse as we returned to our inherited equilibrium. Continuing to emit too much Greenhouse pollution, regardless of sunspots or other natural activity, ensures we're changing the climate too much for our civilization to survive the effects.
Planting that many trees would make lumber prices plunge. Housing and packaging and other products could return to using wood instead of plastic. The total amount of wood "in use" would increase, especially as population increases, while the amount of Greenhouse-polluting plastic would decrease. And a lot of the used and abused wood could go into landfills or scrubbed furnances, producing soot that's buried or mixed with animal/human excrement for fertilizer (that replaces petroleum fertilizer, reducing more Greenhouse pollution).
Yes, some fraction of the increased forests and their products will return to the air. But the total carbon sequestered in forests and in use in products at any given time will be a lot larger. And therefore a lot less in the atmosphere. The carbon sequestration programmes getting popular now that pump gaseous CO2 into old cracks in the Earth are risky (ground chemistry and leaks back into the surface air). But indeed burying shredded or charcoaled trees in those cracks would indeed be safe forever. And much later on, they'd produce coal and oil, or the feedstock for it, if our descendants want it.
Evidently, the amount of Greenhouse pollution spewed by the average new car these days is the same as the amount of CO2 that a half-acre of trees sucks up into growth.
If every new car sold came with a certificate that an acre of trees was planted and maintained somewhere, cars would be responsible for slowing and then reversing the Greenhouse.
Getting the trees to grow back seems a lot safer and less stupid than continuing to pretend we can mess with the complex and sensitive atmosphere like we know what we're doing, which is what got us into this mess.
I don't know why we bother to whine about MP3 prices. If we don't like the prices, they're all available free for download somewhere else. Conversely, Apple and the labels shouldn't whine about people downloading them free, when so many people are volunteering to pay these ridiculously high and profitable prices to download them from iTunes.
CDDL is GPL incompatible. So by that do you mean that Sun killed a Solaris/Debian platform that can run both Linux and Solaris apps by putting OpenSolaris under CDDL?
Much as GMail is an interesting mail platform, I don't like the idea of Google getting all of my email to look thru, along with my entire contact list and traffic records with them. Even if GMail received and sent only encrypted messages, the metadata would be private. And Google already has my entire search history, as well as a lot of my click trail (REFERER incoming to searches, cached/PDF-to-HTML docs, YouTube, whatever might even run across a Google backbone). I don't need one filthy rich entity with cross-referenced records of my entire online activity.
If the GMail server were downloadable to my own server or independent ISP, I'd use it. I'd love it as software. But as service, it seems too tempting for Google to be evil.
Indeed, I do mean that Ord's work (and work like it) will make sense to only advanced mathematicians. But those people have crossed the border from order in the universe to sense in a human mind. Those people can influence scientists and engineers, who in turn inspire artists, which is when most people get a chance to see it make sense. Between art and products (and the very fuzzy boundary between them), eventually our culture encodes that sense. The math is the watershed, and we might already be across it. Discussions like this one on Slashdot are part of the followthrough.
If the people in the picture are younger than the age at which they can legally consent to having that picture taken, then that picture is illegal. If it's a picture of sex or nudity, then it's child pornography.
It's an easy question if the law protects the subject of the picture. Protects them from the original event, where they're having sex or being naked in a way that exploits them. And protects them from the damage to their reputation and self image that distribution of the picture does. Easy question, simply the age and pose of the subject.
If you're making a law that punishes sinners for lusting after a child, then it's a hard question. You've got to make the law prohibit depictions of children who don't exist, like in comic books. You've got to prohibit pictures of adults (un)dressed like children. And probably all kinds of other things, chasing the perversion in the minds of perverts, notoriously non-uniform in what's in their minds to prohibit.
That kind of question should be hard, because it's a waste of time. The government's business isn't policing sin, but protecting children. That legit business is mercifully much easier, while still hard enough that it needs to be done by professionals when parents fail.
Subsidies mean we spent money on the ISS that Russia doesn't have to recoup in prices for vacation flights there.
Russia's home economy has all kinds of other subsidies, not least the energy costs in their huge and devastatingly abusive energy industry.
I'm all for the competition, the growth of tourism, the publicity. I don't even envy Simonyi - I wish there were many more of him, and eventually me, too once they've brought all the prices (and risks) down. I'm just annoyed that I'm subsidizing Russia's benefits, when Russia is doing me no favors (and in fact is still the perennial existential threat to the US, and to its own people). And it's showing no signs of driving down prices the US pays our own contractors for space services. So I'm going to complain until this whole "virtuous cycle" gets around to doing something for me, after the years I've been doing something for it.
It's a monopoly. Without competition, there's no "choice". Market monopolies don't require necessities for consumption to abuse their control of their market. They don't even need to be the only vendor in the market to abuse it, just domination.
An old Canadian friend's brother turned out to be a mathematical physicist working at a Canadian university researching fractal spacetime. Garnet Ord's work supposedly reconciles the notoriously conflicting relativity and quantum mechanical models of spacetime. It seems that the time axis used to be treated as an integer variable, when in fact it's a fractional dimension: a fractal.
I'd say that making relativity and QM interoperate is a good way to "make sense of the quantum world".
I'm sure glad the US spent all that money subsidizing Russia's contributions to the ISS, so that Russia's space programme could make money off rich Americans taking vacations up there. After all, Russia is our friend, has no money or means to make it, and the US government has money to burn, no need to collect any more from our rich citizens.
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TFA's math is wrong. TFA says specifically
1700 GWh in an 8700 hour year is just under 2MW. 200MW is enough power for 100,000 homes at 2KW each (a low average), so even their math that 1700GWh is "the annual consumption of 250,000 average homes" is wrong. I think their quoting the numbers in the contract is more reliable than their arithmetic.
I'm not sure what you mean. How does the cosine of the angle from the base station to the satellite state efficiency? The beam travels obliquely through more air than if directly overhead, but the beam is supposed to be tuned to avoid absorption.
Is it geostationary? The article I read says "over the equator", which almost always means geosynchronous. At 35Km high, the Earth is a tiny dot whose shadow blocks the Sun for maybe a few hours a year (out of 8700 hours in a year).
As usual, Arthur C. Clarke got there sooner, finished it faster, and was more probably correct :).
How about I convince you they're planning to deliver only 2MW, not 200MW.
They say they'll reach a 17GWh:y delivery once the platform is stable. There's 8765.81277 hours in a year, so that's 17 billionWh / 8765.81277h = 1.9393524 million watts.
The solar "constant" in geosync Earth orbit (about 35Km elevation) is 1366W:m^2. That's 1419.73089m^2, or 0.00141973089Km^2, significantly less (0.709865445%) than 0.2Km^2.
Yes, that's why we've never launched a satellite for longterm duty. That's why we never power our satellites with solar panels.
Buying desert land isn't "astronomically expensive". It's about the cheapest land there is. There happens to be huge deserts of dirt-cheap (cheaper: sand-cheap) land all around California. Besides, this 2MW satellite probably doesn't even need more than about 25m^2 to receive its beam at 5x solar density. If they wanted to be really safe, they probably could diffuse it over 2500m^2, for 5W:m^2, which doesn't hurt anyone.
The efficiency here is the 30% extra incoming solar power that is otherwise lost in the atmosphere (minus some small lost amount they're tuning the beam to minimize), times the 24/7 uptime instead of about 25% terrestrial due to night/weather/seasons. That's a starting point of 520%. But the other advantage is the much larger area that thin collector sheets can cover in space. Launching costs money per mass, but the collectors can unfurl across kilometers. And the maintenance costs in microgravity/femtopressure are much lower over years, despite the remoteness. After the large initial costs, the ongoing costs per watt are extremely low.
2MW would require only about 40x40m collectors. A square kilometer collector would bring 1.3GW. The geosync satellite beaming to Fresno could receive from collectors in all kinds of other orbits pointing at the hub. This infrastructure could conceivably bring all 17TW of Earth's energy consumption into a series of ground stations from only about 114*114 Km of collectors. A few score hubs around the equator each using a few dozen GW lasers could replace all the coal currently burned for stationary power. The sky is literally the limit.
It's not the deviation distance that matters. It's the duration the beam spends on a sensitive target, sending its 2MW at it. 250ms is 500j, if the RF beam is snapped over to a new target until shutdown. The beam could be something like 24m^2 wide, if at 5x solar density. That kind of accident could indeed fry some electronics, but not much more.
The real problem in shortening the delay is that the satellite is probably about 35Km up, in geosynchronous orbit. That's about 195s as the photon flies, with about 45ms left for electronics processing to shut the beam down if the failsafe signal doesn't arrive on target.
These beaming systems have interlocks pointed back from the ground receiver to the satellite. If the two get out of alignment, the satellite immediately loses the ground signal, and immediately stops transmitting.
Besides, the beamed power density doesn't have to be very high per square meter. If it's just concentrated 5x from its density in space, it's 6.5KW:m^2. At this system's 2MW transmission rate, is only 308m^2, or a square 17.5m on a side. If it's really RF, even if the interlock failsafe failed, the beam wouldn't do much except fry some unshielded electronics in the way until something else shut it down. I'm sure the multiple layers of government regulators will ensure a lot of "deadman switches" to stop the only thing that everyone guesses could go wrong.
Sunspots have practically nothing to do with "Global Warming", or rather, practically nothing to do with climate change. If humans stopped producing too much Greenhouse pollution, climate change could slow or reverse as we returned to our inherited equilibrium. Continuing to emit too much Greenhouse pollution, regardless of sunspots or other natural activity, ensures we're changing the climate too much for our civilization to survive the effects.
Planting that many trees would make lumber prices plunge. Housing and packaging and other products could return to using wood instead of plastic. The total amount of wood "in use" would increase, especially as population increases, while the amount of Greenhouse-polluting plastic would decrease. And a lot of the used and abused wood could go into landfills or scrubbed furnances, producing soot that's buried or mixed with animal/human excrement for fertilizer (that replaces petroleum fertilizer, reducing more Greenhouse pollution).
Yes, some fraction of the increased forests and their products will return to the air. But the total carbon sequestered in forests and in use in products at any given time will be a lot larger. And therefore a lot less in the atmosphere. The carbon sequestration programmes getting popular now that pump gaseous CO2 into old cracks in the Earth are risky (ground chemistry and leaks back into the surface air). But indeed burying shredded or charcoaled trees in those cracks would indeed be safe forever. And much later on, they'd produce coal and oil, or the feedstock for it, if our descendants want it.
Evidently, the amount of Greenhouse pollution spewed by the average new car these days is the same as the amount of CO2 that a half-acre of trees sucks up into growth.
If every new car sold came with a certificate that an acre of trees was planted and maintained somewhere, cars would be responsible for slowing and then reversing the Greenhouse.
Getting the trees to grow back seems a lot safer and less stupid than continuing to pretend we can mess with the complex and sensitive atmosphere like we know what we're doing, which is what got us into this mess.
I don't know why we bother to whine about MP3 prices. If we don't like the prices, they're all available free for download somewhere else. Conversely, Apple and the labels shouldn't whine about people downloading them free, when so many people are volunteering to pay these ridiculously high and profitable prices to download them from iTunes.
CDDL is GPL incompatible. So by that do you mean that Sun killed a Solaris/Debian platform that can run both Linux and Solaris apps by putting OpenSolaris under CDDL?
Does it run Solaris apps? Or recompiled Debian/Linux apps? Or only its own apps?
Whatever happened to the project to make a Debian distro using the OpenSolaris kernel instead of the Linux kernel?
Much as GMail is an interesting mail platform, I don't like the idea of Google getting all of my email to look thru, along with my entire contact list and traffic records with them. Even if GMail received and sent only encrypted messages, the metadata would be private. And Google already has my entire search history, as well as a lot of my click trail (REFERER incoming to searches, cached/PDF-to-HTML docs, YouTube, whatever might even run across a Google backbone). I don't need one filthy rich entity with cross-referenced records of my entire online activity.
If the GMail server were downloadable to my own server or independent ISP, I'd use it. I'd love it as software. But as service, it seems too tempting for Google to be evil.
Indeed, I do mean that Ord's work (and work like it) will make sense to only advanced mathematicians. But those people have crossed the border from order in the universe to sense in a human mind. Those people can influence scientists and engineers, who in turn inspire artists, which is when most people get a chance to see it make sense. Between art and products (and the very fuzzy boundary between them), eventually our culture encodes that sense. The math is the watershed, and we might already be across it. Discussions like this one on Slashdot are part of the followthrough.
If the people in the picture are younger than the age at which they can legally consent to having that picture taken, then that picture is illegal. If it's a picture of sex or nudity, then it's child pornography.
It's an easy question if the law protects the subject of the picture. Protects them from the original event, where they're having sex or being naked in a way that exploits them. And protects them from the damage to their reputation and self image that distribution of the picture does. Easy question, simply the age and pose of the subject.
If you're making a law that punishes sinners for lusting after a child, then it's a hard question. You've got to make the law prohibit depictions of children who don't exist, like in comic books. You've got to prohibit pictures of adults (un)dressed like children. And probably all kinds of other things, chasing the perversion in the minds of perverts, notoriously non-uniform in what's in their minds to prohibit.
That kind of question should be hard, because it's a waste of time. The government's business isn't policing sin, but protecting children. That legit business is mercifully much easier, while still hard enough that it needs to be done by professionals when parents fail.
Subsidies mean we spent money on the ISS that Russia doesn't have to recoup in prices for vacation flights there.
Russia's home economy has all kinds of other subsidies, not least the energy costs in their huge and devastatingly abusive energy industry.
I'm all for the competition, the growth of tourism, the publicity. I don't even envy Simonyi - I wish there were many more of him, and eventually me, too once they've brought all the prices (and risks) down. I'm just annoyed that I'm subsidizing Russia's benefits, when Russia is doing me no favors (and in fact is still the perennial existential threat to the US, and to its own people). And it's showing no signs of driving down prices the US pays our own contractors for space services. So I'm going to complain until this whole "virtuous cycle" gets around to doing something for me, after the years I've been doing something for it.
It's a monopoly. Without competition, there's no "choice". Market monopolies don't require necessities for consumption to abuse their control of their market. They don't even need to be the only vendor in the market to abuse it, just domination.
An old Canadian friend's brother turned out to be a mathematical physicist working at a Canadian university researching fractal spacetime. Garnet Ord's work supposedly reconciles the notoriously conflicting relativity and quantum mechanical models of spacetime. It seems that the time axis used to be treated as an integer variable, when in fact it's a fractional dimension: a fractal.
I'd say that making relativity and QM interoperate is a good way to "make sense of the quantum world".
Thanks for offering me conclusive evidence that a nice chat about books we both liked is not going to happen in this thread.
Goodbye.
I'm sure glad the US spent all that money subsidizing Russia's contributions to the ISS, so that Russia's space programme could make money off rich Americans taking vacations up there. After all, Russia is our friend, has no money or means to make it, and the US government has money to burn, no need to collect any more from our rich citizens.
That ISS is the best investment we ever made.
With almost 200 members, practically every country in the world, what else could it be but fools? That's all the world has to offer itself.