With proper tech, the penalty for Mar's gravity well can be made pretty small. For example, one of the giant volcanoes on Mars sits right on the equator. It is so tall that the top is essentially in vacuum. So you can build an accelerator that throws things into Mars orbit. From low Mars orbit to Phobos you can use the Rotovator type space elevator.
Mars has advantages that loose asteroid's don't. Tectonics, internal heating, water, and other geological processes have sorted the planet into differentiated ores. But focusing on the Moon or Mars or Asteroids as if you have to choose one is as silly as focusing on only California, Minnesota, or Texas when expanding the United States. The right answer is to expand outwards in terms of difficulty, and using the fuel and supplies you can produce at one location to leverage getting to the next. The right answer is "everywhere in the Solar System", though some places will need to wait quite a while until our tech and needs demand using them.
The actual energy to reach Earth orbit, at retail electric rates, is about what Walmart sells bags of potatoes for. It costs way more than that because we basically are using weapons of war (rockets descended from ballistic missiles) to do the job. The cost of a ballistic ICBM is limited by the value of the targets it destroys, so cost was not seriously limited.
As soon as billionaires rather than governments got involved, where cost came out of their own pocket, sanity began to reign. Carrier airplanes to raise launch efficiency, using the expensive aerospace hardware more than once, etc. Launch costs have room to drop about 50-fold from today's prices, and still be well above raw energy costs, the way airplane trips are well above fuel cost.
From Earth orbit to Mars we can build a chain of "truck stops" that supply food, fuel, and other necessities, rather than launching it all from here. Physics says it makes much more sense to get your supplies from a nearby asteroid than the bottom of a deep gravity well (Earth). The particular locations would be Earth-Moon L1, Mars Cycling Transfer Orbit, and Phobos. We already know of 12,000 Near-Earth asteroids, and the region between and near Mars should have just as many. They are farther away, so our Earth-based telescopes can't spot them as easily.
Using local materials, we can gain another 50-fold price reduction for the trip. So instead of $1 billion/seat, we are looking at $400K per person, which a corporation may well finance to get people to the work location.
Not only is it very sunny, it is high altitude and cold. Less air above it means the sunlight is more intense, and solar cells are more efficient when they are cooler. The combination makes it the best place in the world for solar, aside from the fact nobody lives there and you need power lines to the coast, where people actually live.
I guess you don't have any idea how much land is disrupted when you strip mine for coal. It's a lot, and it continues as long as you need to feed the power plant. Solar is a one time installation.
It has plenty of industrial use where what you want is heat, and not electricity. You don't get the conversion losses from heat to electrons moving. A big example is the 6% of the world's CO2 emissions that come from making Portland Cement (the binder in concrete). Making that product involves heating a mix of shale/clay plus limestone to high temperatures, which changes it chemically. Today it is mostly done by burning fossil fuels, but solar would work just as well.
The proper comparison is to PV at the same installed capacity. Solar thermal started later, and therefore has had less of a learning curve. Also, heliostat mirrors are inherently cheaper than solar panels because a sheet of mirrored glass is simpler to make than a finished panel. Most of the cost comes from the steerable mount that aims the mirror at the tower, but there is a lot of room for improvement there.
> The number of birds incinerated
Could be reduced quite a bit with screens that keep them off the top of the tower. The problem is that birds like to perch on top of the tower, for the same reason they like to perch on trees and power lines. Unfortunately that is where all the mirrors point. Nobody compares the number of birds killed flying into windows or by cats (about a billion) to the number incinerated (hundreds? These plants are built in deserts, so there are not a lot of birds in the first place).
Current solar thermal plants don't use storage most of the time, since there are not enough of them to require it with the grid as a whole. For example, the 400 MW Ivanpah solar thermal plant is on the same power line as Boulder Dam. Ivanpah just displaces some of the water otherwise run through the dam, which can be used at other hours.
> Thermal energy storage doesn't work well for anything much smaller than a large industrial site.
That *used* to be true, before the development of hi-temp vacuum-powder insulation. It has about 6x lower thermal conductivity than fiberglass, and therefore lowers the relative heat loss on smaller units. It is being sold for industrial furnace insulation, which is a similar job to thermal storage.
Hot rock thermal storage is the cheapest long term option, because rock is as cheap as you can get for a storage medium. You blow air through a heat exchanger into the rock bed to store energy, then reverse the air flow to extract heat. The heat exchanger has boiler tubes to make steam. That then goes to a turbine the way most electricity is generated.
You mean photovoltaic doesn't match demand. Solar thermal with storage can meet demand whatever time you want. Not many plants with storage have been built yet, because they are not necessary. Solar is a small enough part of the grid that other sources can adjust. Once you get to about 20% penetration, you will need storage options, and they will get included.
Solar-Thermal gets the same performance as Nuclear-Thermal, except the reactor is 150 million km or more away. Both heat hydrogen gas to high temperatures, and therefore get the same exhaust velocity. Large solar concentrators are lightweight, and not hard to build in orbit. One the size of the Space Station (100 meter diameter) would generate 10 MW.
The nice thing about solar-thermal is it avoids all the issues with nuclear-anything. No Greenpeace protestors, no extra costs for nuclear security on the ground, radiation shielding, etc.
How about the same people who actually wired up rural areas, the Rural Electric Cooperatives? The TVA built dams and power plants, but the REC's did the local work. As cooperatives, they are customer-owned. The government helped them get started with loans, but those are long since paid off. The advantage of using the Electric Co-ops is they already have poles going everywhere necessary.
> Who knows about the bitcoin mining because that's all nonsense anyway.
Nobody in their right mind uses GPUs to mine bitcoin any more. They use custom mining chips (ASICs) which are about 100 times more efficient, because the calculations are done entirely in hardware, and being fairly simple, can be parallelized much more than graphics cores.
> But I'll bet their little programs that they run using $1 of electricity to get 50 cents in bitcoins
I did mine at a loss sometimes back in the day, but it was in the background, for a graphics card I was already using in this PC. So I only had to pay for the incremental electricity of the card running full bore instead lower levels. The $60 of extra electricity is worth $680 in bitcoins today. I stopped mining in mid-2013 when the custom chips started going into volume production. Not all of us are idiots.
Space solar arrays are also 2.5 times as efficient than in 1998. That's because they now use triple-layer cells, that convert more of the solar spectrum to electricity. The biggest shift will be if SpaceX can reuse their rocket stages. They are already the low-cost launch provider, and that would given them another factor of 3 or so in cost.
Reducing launch cost also will reduce satellite cost. The cost optimum is when the marginal cost of removing 1 kg from the satellite = the marginal cost of launching that kg. So cheaper launch means heavier but less expensive satellite parts.
> Private corporations may soon have more space technology than the US government.
That's already the case. NASA's share of total space industry is only 6% ($18 vs $300 billion/year). Commercial satellites have had ion thrusters for a number of years before the NASA Dawn spacecraft had them. For-profit corporations have more incentive to update their tech sooner, to get a competitive advantage.
The free market method is to offer "dead or alive" bounties on whoever dumped in your water system, and let competition sort it out. One mining company might do it once, but after that, the rest would have an object lesson.
> "...and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
This looks like an attempt to get around that provision. Sorry, FBI, you actually have to do police work.
> It does limit the functionality though since you don't get emergency calls where someone you know had to borrow a phone and such.
Those people can leave a voicemail message. Most telemarketers and robocalls don't. When I get a mystery calling number, I let it go to voicemail. If it's important they can leave a message, and I can call them back.
> I wonder what the fastest possible chemically-propelled-rocket probe is?
Slower than a Nuclear-ion probe. Nuclear in this case means a small nuclear reactor, say in the 1 MW power range. Plasma thrusters have an exhaust velocity of ~ 50 km/s, and it is reasonable to reach 3x exhaust velocity, thus 150 km/s. The mass ratio (propellant to empty mass) would be 20:1 in that case. For any kind of chemical rocket to reach that velocity, it would need a mass ratio of 10 trillion, which is seriously impractical.
150 km/s = 31.6 AU/year, therefore missions to around 300 AU would be reasonable (10 year trip time). 1 MW reactor with radiators would mass ~ 20 tons. 300 AU probe would mass ~ 5 tons. Propellant load would be 25x20 = 500 tons. Propellant flow rate is.57 grams/sec or 49 kg/day. So thrust time is 28 years, which is a bit long. It would help if the reactor could be made lighter.
> The hard part is getting up to speed, and slowing down at the destination.
The diffusion method I call "slow interstellar" doesn't require that. If you already live in the Sun's Oort Cloud, and another star gets close enough that the Oort Clouds overlap, you only have to match velocity, which is on the order of 50 km/s. After that you drift along with the other star, spreading to fill their environment, until another close stellar encounter happens. This method requires more patience than humans possess, though.
> We know (or can know) which bitcoins were "lost" in MtGox
No, we can't, because those were not block chain transactions. They were funds transactions internal to Mt. Gox's account books. Let's assume Mt. Gox had 500,000 bitcoins in "cold storage" (the private keys printed out and stored in a safety deposit box, where no hacker can get to them). Some of those 500,000 coins belong to Mt.Gox itself, from accumulated trading fees. The rest belong to customers. Who owns what is kept track on their internal database. By fiddling with the database, they can move ownership between accounts without ever touching the coins in cold storage. Being able to trace what shenanigans happened to the database depends entirely on available backups of the database *before* the shenanigans happened.
> So couldn't the top 5 or 10 players in the network, who collectively have something like 75% of the computing power, collude and simply invalidate the transactions out of MtGox?
If by that you mean transactions from a Mt.Gox owned address to one outside Mt. Gox, again no. Blocks from 9 months to 3 years ago (when Mt. Gox was presumably messing around are linked to every block afterwards (that's why it is called a "block chain"). The linkage is by including the hash value of one block as part of the data in the next block (along with new transactions). If you change an old transaction, the hash of that block will change, and no longer match the value stored in the next block. You would have to recalculate new hashes for every block after the one you want to change. This is basically impossible, as it took the whole network's combined power to generate the existing series of block hashes. If 75% of the network gave up working on new blocks, they would lose future income *and* past income, as a different set of people would get the coins generated in each recalculated block. In turn, all the people who spent all those block rewards, or parts thereof, downstream of the miners, would have their balances invalidated.
> "Inherently worthless" is the salient feature of money. When you trade things of intrinsic value you are bartering.
They are not disjoint sets. Money was whatever commodity had the most acceptability and was easiest to trade. Normally that happened to a commodity with features like durability, scarcity, divisibility, etc. The US dollar is backed almost entirely by debt, so it is not true to say it is inherently worthless. Those debts (Treasury bonds, mortgage-backed securities, and bank loans) have value because they pay interest, and you can trade a pile of dollars for any of those debts if you want to hold them directly. Paper money and coin are just convenient size trading units. A home mortgage or Treasury bond are inconvenient for day-to-day purchases.
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With proper tech, the penalty for Mar's gravity well can be made pretty small. For example, one of the giant volcanoes on Mars sits right on the equator. It is so tall that the top is essentially in vacuum. So you can build an accelerator that throws things into Mars orbit. From low Mars orbit to Phobos you can use the Rotovator type space elevator.
Mars has advantages that loose asteroid's don't. Tectonics, internal heating, water, and other geological processes have sorted the planet into differentiated ores. But focusing on the Moon or Mars or Asteroids as if you have to choose one is as silly as focusing on only California, Minnesota, or Texas when expanding the United States. The right answer is to expand outwards in terms of difficulty, and using the fuel and supplies you can produce at one location to leverage getting to the next. The right answer is "everywhere in the Solar System", though some places will need to wait quite a while until our tech and needs demand using them.
The actual energy to reach Earth orbit, at retail electric rates, is about what Walmart sells bags of potatoes for. It costs way more than that because we basically are using weapons of war (rockets descended from ballistic missiles) to do the job. The cost of a ballistic ICBM is limited by the value of the targets it destroys, so cost was not seriously limited.
As soon as billionaires rather than governments got involved, where cost came out of their own pocket, sanity began to reign. Carrier airplanes to raise launch efficiency, using the expensive aerospace hardware more than once, etc. Launch costs have room to drop about 50-fold from today's prices, and still be well above raw energy costs, the way airplane trips are well above fuel cost.
From Earth orbit to Mars we can build a chain of "truck stops" that supply food, fuel, and other necessities, rather than launching it all from here. Physics says it makes much more sense to get your supplies from a nearby asteroid than the bottom of a deep gravity well (Earth). The particular locations would be Earth-Moon L1, Mars Cycling Transfer Orbit, and Phobos. We already know of 12,000 Near-Earth asteroids, and the region between and near Mars should have just as many. They are farther away, so our Earth-based telescopes can't spot them as easily.
Using local materials, we can gain another 50-fold price reduction for the trip. So instead of $1 billion/seat, we are looking at $400K per person, which a corporation may well finance to get people to the work location.
Developers are already building solar farms in the Atacama:
http://www.bloomberg.com/news/...
Not only is it very sunny, it is high altitude and cold. Less air above it means the sunlight is more intense, and solar cells are more efficient when they are cooler. The combination makes it the best place in the world for solar, aside from the fact nobody lives there and you need power lines to the coast, where people actually live.
I guess you don't have any idea how much land is disrupted when you strip mine for coal. It's a lot, and it continues as long as you need to feed the power plant. Solar is a one time installation.
Samsung in fact does make solar panels:
http://www.samsung.com/us/busi...
It has plenty of industrial use where what you want is heat, and not electricity. You don't get the conversion losses from heat to electrons moving. A big example is the 6% of the world's CO2 emissions that come from making Portland Cement (the binder in concrete). Making that product involves heating a mix of shale/clay plus limestone to high temperatures, which changes it chemically. Today it is mostly done by burning fossil fuels, but solar would work just as well.
> It is more expensive than PV
The proper comparison is to PV at the same installed capacity. Solar thermal started later, and therefore has had less of a learning curve. Also, heliostat mirrors are inherently cheaper than solar panels because a sheet of mirrored glass is simpler to make than a finished panel. Most of the cost comes from the steerable mount that aims the mirror at the tower, but there is a lot of room for improvement there.
> The number of birds incinerated
Could be reduced quite a bit with screens that keep them off the top of the tower. The problem is that birds like to perch on top of the tower, for the same reason they like to perch on trees and power lines. Unfortunately that is where all the mirrors point. Nobody compares the number of birds killed flying into windows or by cats (about a billion) to the number incinerated (hundreds? These plants are built in deserts, so there are not a lot of birds in the first place).
Current solar thermal plants don't use storage most of the time, since there are not enough of them to require it with the grid as a whole. For example, the 400 MW Ivanpah solar thermal plant is on the same power line as Boulder Dam. Ivanpah just displaces some of the water otherwise run through the dam, which can be used at other hours.
> Thermal energy storage doesn't work well for anything much smaller than a large industrial site.
That *used* to be true, before the development of hi-temp vacuum-powder insulation. It has about 6x lower thermal conductivity than fiberglass, and therefore lowers the relative heat loss on smaller units. It is being sold for industrial furnace insulation, which is a similar job to thermal storage.
Hot rock thermal storage is the cheapest long term option, because rock is as cheap as you can get for a storage medium. You blow air through a heat exchanger into the rock bed to store energy, then reverse the air flow to extract heat. The heat exchanger has boiler tubes to make steam. That then goes to a turbine the way most electricity is generated.
You mean photovoltaic doesn't match demand. Solar thermal with storage can meet demand whatever time you want. Not many plants with storage have been built yet, because they are not necessary. Solar is a small enough part of the grid that other sources can adjust. Once you get to about 20% penetration, you will need storage options, and they will get included.
Solar-Thermal gets the same performance as Nuclear-Thermal, except the reactor is 150 million km or more away. Both heat hydrogen gas to high temperatures, and therefore get the same exhaust velocity. Large solar concentrators are lightweight, and not hard to build in orbit. One the size of the Space Station (100 meter diameter) would generate 10 MW.
The nice thing about solar-thermal is it avoids all the issues with nuclear-anything. No Greenpeace protestors, no extra costs for nuclear security on the ground, radiation shielding, etc.
How about the same people who actually wired up rural areas, the Rural Electric Cooperatives? The TVA built dams and power plants, but the REC's did the local work. As cooperatives, they are customer-owned. The government helped them get started with loans, but those are long since paid off. The advantage of using the Electric Co-ops is they already have poles going everywhere necessary.
> but the suspects can easily dispose of "evidence" (illicit drugs) in the toilet.
So it's too hard to put a bucket or stopper in the sewer line?
> Who knows about the bitcoin mining because that's all nonsense anyway.
Nobody in their right mind uses GPUs to mine bitcoin any more. They use custom mining chips (ASICs) which are about 100 times more efficient, because the calculations are done entirely in hardware, and being fairly simple, can be parallelized much more than graphics cores.
As far as bitcoin being nonsense, the New York Stock Exchange and a large bank just invested in a bitcoin company: http://blog.coinbase.com/post/..., and Microsoft accepts bitcoins: https://commerce.microsoft.com... . Evidently they don't think it is nonsense.
> But I'll bet their little programs that they run using $1 of electricity to get 50 cents in bitcoins
I did mine at a loss sometimes back in the day, but it was in the background, for a graphics card I was already using in this PC. So I only had to pay for the incremental electricity of the card running full bore instead lower levels. The $60 of extra electricity is worth $680 in bitcoins today. I stopped mining in mid-2013 when the custom chips started going into volume production. Not all of us are idiots.
Space solar arrays are also 2.5 times as efficient than in 1998. That's because they now use triple-layer cells, that convert more of the solar spectrum to electricity. The biggest shift will be if SpaceX can reuse their rocket stages. They are already the low-cost launch provider, and that would given them another factor of 3 or so in cost.
Reducing launch cost also will reduce satellite cost. The cost optimum is when the marginal cost of removing 1 kg from the satellite = the marginal cost of launching that kg. So cheaper launch means heavier but less expensive satellite parts.
> Private corporations may soon have more space technology than the US government.
That's already the case. NASA's share of total space industry is only 6% ($18 vs $300 billion/year). Commercial satellites have had ion thrusters for a number of years before the NASA Dawn spacecraft had them. For-profit corporations have more incentive to update their tech sooner, to get a competitive advantage.
The free market method is to offer "dead or alive" bounties on whoever dumped in your water system, and let competition sort it out. One mining company might do it once, but after that, the rest would have an object lesson.
Metallic foil "radiant barrier" insulation is already a thing:
http://www.amazon.com/EcoFoil-...
Just make sure to cross-connect the pieces, so they form a single ground plane.
The Fourth Amendment reads in part:
> "...and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized ."
This looks like an attempt to get around that provision. Sorry, FBI, you actually have to do police work.
> It does limit the functionality though since you don't get emergency calls where someone you know had to borrow a phone and such.
Those people can leave a voicemail message. Most telemarketers and robocalls don't. When I get a mystery calling number, I let it go to voicemail. If it's important they can leave a message, and I can call them back.
> I wonder what the fastest possible chemically-propelled-rocket probe is?
Slower than a Nuclear-ion probe. Nuclear in this case means a small nuclear reactor, say in the 1 MW power range. Plasma thrusters have an exhaust velocity of ~ 50 km/s, and it is reasonable to reach 3x exhaust velocity, thus 150 km/s. The mass ratio (propellant to empty mass) would be 20:1 in that case. For any kind of chemical rocket to reach that velocity, it would need a mass ratio of 10 trillion, which is seriously impractical.
150 km/s = 31.6 AU/year, therefore missions to around 300 AU would be reasonable (10 year trip time). 1 MW reactor with radiators would mass ~ 20 tons. 300 AU probe would mass ~ 5 tons. Propellant load would be 25x20 = 500 tons. Propellant flow rate is .57 grams/sec or 49 kg/day. So thrust time is 28 years, which is a bit long. It would help if the reactor could be made lighter.
> The hard part is getting up to speed, and slowing down at the destination.
The diffusion method I call "slow interstellar" doesn't require that. If you already live in the Sun's Oort Cloud, and another star gets close enough that the Oort Clouds overlap, you only have to match velocity, which is on the order of 50 km/s. After that you drift along with the other star, spreading to fill their environment, until another close stellar encounter happens. This method requires more patience than humans possess, though.
>English will remain the dominant language because it is so versatile and malleable.
Malleable, this language is
On the other hand, with the rise of real-time voice translation, the need to all speak the same language may go away.
> We know (or can know) which bitcoins were "lost" in MtGox
No, we can't, because those were not block chain transactions. They were funds transactions internal to Mt. Gox's account books. Let's assume Mt. Gox had 500,000 bitcoins in "cold storage" (the private keys printed out and stored in a safety deposit box, where no hacker can get to them). Some of those 500,000 coins belong to Mt.Gox itself, from accumulated trading fees. The rest belong to customers. Who owns what is kept track on their internal database. By fiddling with the database, they can move ownership between accounts without ever touching the coins in cold storage. Being able to trace what shenanigans happened to the database depends entirely on available backups of the database *before* the shenanigans happened.
> So couldn't the top 5 or 10 players in the network, who collectively have something like 75% of the computing power, collude and simply invalidate the transactions out of MtGox?
If by that you mean transactions from a Mt.Gox owned address to one outside Mt. Gox, again no. Blocks from 9 months to 3 years ago (when Mt. Gox was presumably messing around are linked to every block afterwards (that's why it is called a "block chain"). The linkage is by including the hash value of one block as part of the data in the next block (along with new transactions). If you change an old transaction, the hash of that block will change, and no longer match the value stored in the next block. You would have to recalculate new hashes for every block after the one you want to change. This is basically impossible, as it took the whole network's combined power to generate the existing series of block hashes. If 75% of the network gave up working on new blocks, they would lose future income *and* past income, as a different set of people would get the coins generated in each recalculated block. In turn, all the people who spent all those block rewards, or parts thereof, downstream of the miners, would have their balances invalidated.
> "Inherently worthless" is the salient feature of money. When you trade things of intrinsic value you are bartering.
They are not disjoint sets. Money was whatever commodity had the most acceptability and was easiest to trade. Normally that happened to a commodity with features like durability, scarcity, divisibility, etc. The US dollar is backed almost entirely by debt, so it is not true to say it is inherently worthless. Those debts (Treasury bonds, mortgage-backed securities, and bank loans) have value because they pay interest, and you can trade a pile of dollars for any of those debts if you want to hold them directly. Paper money and coin are just convenient size trading units. A home mortgage or Treasury bond are inconvenient for day-to-day purchases.