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Comment Re:I'm totally shocked... (Score 1) 613

> Now the long slide since 2008 will continue until some disruptive element creates economic opportunity.

Personal automation in the form of machines that can make more machines, which in turn make the stuff you need. Jobs and income will go down, because stuff you make for yourself isn't counted as work or income. Despite that, production will go up and people will be better off.

For example, automated machine shop and foundry makes robot farm tractors, among other things. The tractors in turn grow food for the owners. Since the machine shop is too expensive for the average person, they would be run as cooperatives, like my power company and credit union are. When you make your own stuff using your own equipment, you get to skip all the middle-man markups and profit, and you don't pay income or sales taxes on it. You are also immune to layoffs, because you own the equipment. You don't have to work very hard for it, either, because the equipment is mostly automated. A regular farm tractor can produce food for 50 or 100 people, an automated one can do at least as well. You still need a farmer to oversee the tractors and decide when to plant and harvest, but for most people the food just shows up on a regular basis.

Comment Re:Bitcoin? Yes. TOR? NO! (Score 2) 103

Actually, Day One for Bitcoin was buying two pizzas for 10,000 BTC, and that was 18 months after the network first booted up. Until then it was just a cryptographic curiosity. The Silk Road prosecution revealed that only 4% of bitcoin transactions were used on their black market to buy drugs and other nefarious purposes. That's not much higher than the ratio of illicit drugs to GDP worldwide (3%), and is far less than the total underground economy in the US (20%). The underground economy = black market (illegal) + off the books economy (nominally legal but not reported).

Good old cash is still by far the preferred choice for illegal activity. That's why over 70% of hundred Dollar bills are overseas:

Comment Re:Sharing is a business now? (Score 2) 103

> All transactions are recorded in the block chain and supposedly available for inspection by anyone.

Yes, they are. But they only record the sending address, receiving address, and the amount being sent. No names or other personal information. Here, look at a transaction from the most recent block, and tell me anything about the people involved:

Comment Re:Other motivations (Score 2) 164

> (you could "make" more money by stuffing it under a mattress, than by using it to do something economically productive).

That's only true if the rate of deflation was greater than the nominal rate of return on other investments. Stock earnings, as measured by the S&P 500 have grown at an average of 6.6% over the last 55 years, plus paid out a few percent in cash dividends on top of that. If the dividends were re-invested, then total earnings would grow around 8.8%. If your money were deflating at 2% you would be far better off with stocks.

Comment Re:Other motivations (Score 1) 164

> Bitcoin has always been expressly designed to favor the people who got bitcoins early.

And start-ups favor the founders and early investors, so what's your point?

For the first 18 months bitcoins were worth *zero*, they were merely an interesting experiment. There was no guarantee they would ever be worth anything in real terms. Then someone bought two pizzas for 10,000 BTC, establishing a value of 0.4 cents/BTC, meaning the mining reward at the time was 20 cents. Given that there were perhaps 100 people mining at the time, the average reward was 1.2 cents an hour, hardly a get rich quick scheme.

Comment Re:Totally makes sense. Coming from a man... (Score 3, Interesting) 306

> and usually costs more energy than that thing could harvest in space).

That's incorrect. The Falcon 9 rocket has a liftoff mass of 550,000. Their website says it is 96% rocket, and 4% payload. So 24 units of rocket per unit of payload. The combustion energy of the fuel is 13 MJ/kg, and the embodied energy of the rocket hardware is in the same range. So about 312 MJ/kg is required to get the payload into orbit. 1 kg of modern space solar panels produce 175 Watts, and they last >15 years in low orbit. Duty cycle is 60% in low orbit due to the Earth's shadow. So they produce 31,556,925 seconds/year x 15 years x 60% x 175 Watts/kg = 49.7 GJ/kg. That's 160 times their launch energy. That's why satellites almost universally use solar panels instead of fuel cells or some other power source.

Comment Re:I don't even (Score 1) 306

> After we have a fully working space tether,

That's not required. A partially-built space elevator can bootstrap it's own construction and lower launch costs as it grows. By the way, "tether" is just the cable between the ends. It is no more a complete space elevator than the cable of a suspension bridge are the whole bridge.

How do you start bootstrapping the space elevator? With cheaper rockets. What does Jeff Bezos own? A rocket company working on cheaper rockets (and, which pays for the rocket stuff)

Comment Re:Night time (Score 5, Informative) 306

> Thought experiment: you use nice pretty reflectors to smelt aluminium. You now have a ball (or, more likely, an expanding cloud) of +/- 700C molten metal.

Actually, extracting Aluminum is more complicated than just heating, since most of that metal everywhere (Earth and space) is in the form of oxide minerals. However Iron in the form of metallic asteroids *is* available already reduced to metal, so I will substitute that in my discussion. You build a rotating circular crucible and throw chunks of metallic asteroid into it. Focus enough sunlight on it to melt the batch. Bits of rocky inclusions will float to the "top" (center) because they are less dense, and the molten iron will sink to the "bottom" (rim). Throw in a bit of carbon from the C-type asteroids, since Iron + Carbon = steel. The bottom of your crucible has a hole that you tap to extrude the molten metal, which then passes through cooled rollers to provide a final shape. On Earth this is called "continuous casting". The rollers can form an "H" shape for structural beams, flat sheet, or whatever else you need, by just choosing roller positions. Cooling water goes through the rollers, and out to radiator pipes. They don't have to cool to room temperature, just enough to keep the rollers from deforming. Since the radiators will be rejecting heat at a pretty high temperature, they don't have to be very large.

> I'm not saying we should shitcan the whole idea, but the "Futurist" camp really has to stop talking about how trivial things are once we get most of the way out of the gravity well,

Actual space systems engineers like myself don't trivialize the tasks. Most space enthusiasts don't even know what materials are available to work with, or what the solar flux is, or the realities of working in the space environment. But some of us do know all that stuff, collectively. I don't know everything, either, and I work in the field. Generally you need teams of specialists in different subjects to complete a project. So you won't get a complete answer in a forum comment. You get it in a study report that lots of people contributed to.

Comment Re:Really? (Score 3, Informative) 306

Bezos runs a rocket company (besides I'm sure he has people who can tell him to 3 significant figures how much energy is needed. I can too, 31.273 MJ/kg. I do space systems engineering, and it's one of the basic facts you learn. At wholesale electric rates, that comes to $0.43/kg, about what I pay for a bag of potatoes. The fact that current launch prices are at least 3,800 times higher just means *we're doing it wrong* and are terribly inefficient at it.

> the tons of raw metals and other materials that you would need for industrial operations.

Those tons are already in space, on the Moon and nearby asteroids. There is plenty of solar energy in orbit to process those materials. And you can bootstrap industry via the Seed Factory concept ( That's where you send a starter set of machines, and use them to make *more* machines out of local materials already in space. Once your production capacity is big enough, you start making products for sale.

Comment Re:Really? (Score 2) 306

Governments are irrelevant. Space industry worldwide is $324 billion/yr, and NASA represents 5.5% of that. Most of the 1250 active satellites in orbit are commercial.

And efficient transport to and from orbit is quite possible, but not the simplistic space elevator concept that is usually described in the media. That's based on Tsiolkovsky's original 1895 *thought experiment*, which isn't anything like a proper engineering design. The fact is the Earth's gravity well is too deep to span with a single cable from bottom to top.

One end point design breaks up the elevator into three sections of cable. The one in the middle hangs vertically in the Earth's gravity. The upper and lower ends rotate so as to provide sub-orbital capture at the bottom end, and transfer to higher orbits at the upper end. Because it resembles a bicycle (two rotating objects connected by a non-rotating structure), the "Bicyclevator" is a name you can use. A sub-orbital launch system meets up with the bottom section, transfers payload, then lets go and does a sub-orbital re-entry. This is much easier than conventional rockets that go all the way to orbit.

Such a transport system is an *end point* of evolution, like Atlanta's airport is the end point of 85 years of growth. Atlanta-Hartsfield didn't start out handling 100 million passengers a year. You build a small section of space elevator to start with, and use that to bootstrap the rest of the construction as increased traffic justifies it. Since each increment of construction pays its own way, you don't need government finance.

Comment Re:Really? (Score 1) 306

> The moon should be used for energy-heavy industries, though, not space.

Actually, open space is a better location. It gets sunlight 100% of the time, instead of 50% on the surface. Modern space solar panels produce ~175 W/kg, and the energy to reach Lunar orbit from the surface is 1.53 MJ. Dividing, we get 8,743 seconds for the panel to produce enough energy to lift it's own mass from the Moon to orbit. That's a bit under 2.5 hours. Over a working life of ~15 years, the panel will produce >50,000 times the energy to lift itself to orbit, but only half as much on the surface.

Typical embodied energy in products is 10 MJ/kg, or 6.5 times the launch energy. So on the surface, the panel can process 4000 times it's mass to products, while in orbit it can process 8000, which is a better answer.

Comment Re:It costs millions now... (Score 1) 306

> The closest source of raw materials in space is the moon, and that is not exactly an economical place to get anything from.

Actually, it is. Modern triple-layer space solar panels produce ~175W/kg. It takes 1.53 MJ/kg to reach a reasonable Lunar orbit. Therefore the solar panel can produce the energy to put its own mass in orbit in 8,750 seconds, or 2.4 hours. Allow for 50% night and 50% operating efficiency, and we get 10 hours. So a solar panel can put 875 times its mass in orbit in a year, and panels last ~15 years beyond LEO, so 13,000 times its mass.

How do you get stuff in orbit? The Moon is a small body with no atmosphere, so an electric centrifuge can throw loads of raw rock directly into orbit. Materials like carbon fiber are perfectly adequate for the centrifuge arm, and electric motors are not rocket science :-). You need either a small kick motor or a collection system in orbit to circularize the orbit, otherwise it comes back down to ground level one orbit later.

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