> while space travel is largely a money pit.
Space industry worldwide is $300 billion a year, of which NASA is about 6%. Most of the money, and most of the recent technology improvements, are from satellite communications. High efficiency solar arrays and ion propulsion have been used on satellites for about 15 years now. The Dawn asteroid mission (which has electric thrusters) was 7 years later and 1/4 the mass.
The Rocket Equation gives us guidance on how to get around it. Increase exhaust velocity or reduce velocity increments. For lots more detail, see my book ( http://en.wikibooks.org/wiki/S... ), but here are a few ideas:
* Replace some of the bottom part of reaching orbit with higher efficiency engines. That can be anything from subsonic jets (Stratolaunch) to ramjets, to ground accelerators. Replace some of the top part of reaching orbit with electric thrusters transferring momentum to a fractional space elevator (only reaches part way to the ground. By reducing the velocity provided by chemical engines, and more by other methods, you lower the mass ratio.
* Mine for fuel everywhere: scoop mine our atmosphere from orbit, process asteroid rock in high orbit, mine Phobos for fuel, etc. By repeatedly fueling at each location, you reduce fuel needed to a series of linear steps, instead of an exponential. If fuel extraction has a large mass return on your capital equipment, how much you need to launch from Earth drops dramatically.
> Whereas most people in slashdot are brainwashed and gullible morons that would rather invest in the most useless and most expensive form of energy generation: photovoltaics.
I guess you think Warren Buffet is a moronic investor too:
> It reminds me of that old joke about why the Space Shuttle (and now SLS) design is influenced by the width of a horses ass.
Two horse's asses. Wagons were sized according to the width of two horses, and roads were in turn sized to fit the wagons. When underground mining got serious, the mining wagons were just converted outdoor wagons, still pulled by two horses. Then they started putting rails under the wagons, to allow moving heavier loads with less friction. Rail lines began to be used outdoors, pulled by horses at first, so the rail spacing continued to be suitable to the width of two horses. One engines replaced horses, the rails stayed the same width. Go look at train tracks today, you will see they are the right size for two horses to fit.
The Solid rocket boosters for the Space Shuttle were shipped by rail from Utah to Florida, and thus had to fit on railcars on the standard rail spacing. In turn, the size of the boosters set the lift capacity of the rocket, and thus how big the Shuttle Orbiters could be. Finally, the Space Station modules had to fit in the Orbiter, so the Space Station's design is dictated by the width of two horse's asses.
I may have been responsible for this analysis about 30 years ago at Boeing. I was both designing launch vehicles, and had a hobby interest in the history of technology. It is also possible it came up in a USENET discussion on sci.space back then. I don't remember any more.
Since this was the post office calling, the answer would be to go to the local machine shop and borrow one for a minute. Since they deliver to everyone in town anyway, just assign whichever letter carrier has that shop on their route to do it.
> Automation will destroy jobs to the extent that the people running the companies implementing the automation wish it to.
I disagree with this statement, and the assumptions behind it. First is the assumption that only big companies can have automation. That like assuming only big companies can have computers. 50 years ago that was a reasonable assumption, because computers were expensive, like industrial robots are today. But it need not be true in the future. I'm working on "MakerNets" and "Seed Factories". A MakerNet is a network of people with skills and some machines. They help each other build stuff and upgrade. Eventually you reach a level where most of the member's needs are met by automation within the network. If your housing, food, and utilites are supplied that way, most of the need for conventional jobs goes away.
A "Seed Factory" is a starter kit of machines designed to make parts for more machines to expand the factory capacity. At first, the starter kit won't make anywhere close to 100% of the new parts. Stuff will still have to be bought. But as the collection of machines grows, you can make more of your own items, and need to buy less. The engineering question is what belongs in the starter kit, and what's the best path for expansion.
The problem with corporations is the separation of ownership and labor, giving them conflicting goals. Concepts like MakerNets and Seed Factories lets the workers "grow their own" production. Then they are owners as well as workers for whatever amount of labor is still needed. Their goals are now aligned - owner-operators are not going to lay themselves off. More automation just makes them more efficient.
To a first approximation, everyone in the world has a mobile phone, and the percentage that have a smartphone is rapidly increasing. Everyone will be able to *access* an AI, just like we can access Google search. Your comment is like "the poor won't be able to afford a library", it is poorly formulated. You don't need your own full time AI, just enough access to do the things you need to do.
As a space systems engineer, I would agree. There isn't much benefit to putting humans in the Venusian clouds. It adds weight and risk to the mission. They can just as well stay in orbit, controlling a robotic exploration blimp.
> carrying out a crime while armed makes the penalty more severe.
Police are always armed when on duty. Just apply the same rules to them as to everyone else.
Essentially *all* Dollars, in a computer or in paper, are just representations of debt. When the Federal Reserve issues paper money, it's backed by Treasury bonds and mortgages. When banks make loans, the loan check is backed by the loan they just made.
> I don't believe that it is absolutely uncountefeitable. I did read the Wiki on it, but I don't think that any item digitally-based is safe. We are on
Then you don't understand the central invention in bitcoin, an accounting ledger that is public and cannot be altered. In order to counterfeit some bitcoins, you would have insert a transaction into everyone's copy of the ledger, and also have a valid checksum (hash). Without it, every copy of the software will reject the data as invalid. The huge amount of specialized hardware thrown at generating valid hashes prevents anyone else from inserting a spurious one.
> I just hope it does not become publicly accepted. Can someone help convince me that bitcoin is the way to go?
Modern money, like the US Dollar, is just how we keep track of who owes something to others, or is owed something. Mostly the tracking is via bank ledgers, but occasionally it is on paper (as in paper money). Almost every dollar in existence represents a debt, either treasury bonds, mortgages, or other bank loans. Dollars make the debt easily traded in convenient units.
Bitcoin also uses a ledger to keep track. It's a public distributed one, but rather than being based on debt, it's based on work. All the balances are positive. This discourages a government from spending money it doesn't have, and banks from leeching off the rest of us, earning money simply because they create debt, instead of actual work.
Central banks have shown time and time again that they are bad at managing their money supply. Venezuela and Russia are two current examples, but there are literally hundreds of examples through history. Bitcoin's supply is managed by a software algorithm that releases new units at a known rate. It is on automatic pilot rather than the whim of fallible humans. I trust that more.
The big drop since 2008 is because solar cell production at that point exceeded silicon ingot needs for electronics. When electronics was the main demand, it was not worth making separate plants for "solar grade" silicon. Electronics grade is much more expensive, because crystal defects make computer chips unusable. They only make solar cells a little less efficient. Nowadays silicon ingots for solar panels is the dominant market. In this graph you can even see a rise in price as silicon got in short supply, followed by the crash as new solar-grade production went into operation:
Nope. They require a considerable amount of energy to create, that of all the mining rigs combined. The energy is used to update the transaction history (block chain). One of the transactions adds 25 new bitcoins to the history, but that event can't happen without finding a hash value for the block. Finding the hash value requires all the mining rigs to search for it, using energy.
> It seems more and more investors are losing faith in the very possibility of producing energy with fusion.
[citation needed]
This recent survey of alternate fusion projects says otherwise: http://nextbigfuture.com/2014/...
If you have a procedure with 10 parameters, you probably missed some.
