The problem here is that 3D printer can only be used to make a very small subset of spare parts. And these are the type that usually dont break. Seriously, radio will give out the genie 10x before the front panel cracks. Plastic parts are usually ornamental in nature, a plane will not be inoperable because there is a scratch or a crack on some plastic part. Unless the platic part is the canopy - and no 3D printer will make you one of these.

3D printer is a powerful tool for the right job. Like any tool it has its advantages and limitations. All the media hype tends to forget the limitations, or never bothers to find out about them in the first place. 90% of 3D printing related articles seem to think that any day now we will be able to download plans from pirate bay and print ourseves our very own starship Enterprise complete with photonic torpedoes - not gonna happen.

Dirt Cheap(tm) 3d printers can make you cruddy glumps of plastic that somewhat resemble 3D models you fed it, but really have no practical use

Reasonably Priced(tm) 3d printers can make plastic parts with reasonable quality that could be used in a commercial product - after further surface treatments, milling where neccesary, adding thread inserts and whatnot

Very Expencive(tm) 3d printers can make metal and plastic parts with good enough surface finish that they can be used as is in some cases, but mating surfaces still need to be milled to tolerances

And they all take forever to make a single part. One redeeming quality of 3D printing is that you can make geometries that are simply impossible with any other manufacturing method and that is the only reason why anyone uses 3D printing in proffesional setting at all. But if original part was made with conventional manufacturing methods, there is no reason to make a spare part with 3D printing.

You really think 3D printing needs less human operators than injection molding? Or is your comment aiming for "funny" raiting?

PS: obvious piece of wisdom - if a man can be replaced by a machine - the man is not worth his paycheck

"The parts include protective covers for cockpit radios and guards for power take-off shafts"

Sorry but this is simply moronic, these are cheapest possible parts in the airplane - plastic covers for stuff. It doesnt make much of a price difference if you make 100 or 200 of such plastic parts, its the first one that costs you. Once you have made all that were needed for a batch of machines (aircraft in this case) that were actually ordered, you make a little more and store them for spare parts. The main cost here is spare parts storage - something you need to have anyway. Replacting some storage space with a very expencive 3D printer (you really thought they want to use a 300$ one? think again) makes no sense, you get lower quality parts and making them takes longer than it would take for you to get the parts from storage.

When you get to printing turbine blades - then you are talking business, but for plastic parts.. makes no sense.

Theres a world of difference between trying and succeeding. Still its not bad that money is pumped into quant computing research, someone is going to crack the problem sooner or later anyway, and it will cause problems for cryptography and security anyway. But cracking crypto is hardly the only thing you can do with practical quant computer, having one would literally mean quantum jump in engineering and science research. The boost it would give world of science greatly outweighs the risk of NSA cracking your porn archive open.

Oh it'll happen sooner or later, science behind it is sound, you can practically build quantum computers and they work. The problem is that while there are plenty of prototype computers out there, they can still only do operations with few qbits and thats no good for practical applications. While developing computers with more qbits is not exactly easy, it is very much doable, its an engieneering problem now, not something that would require a novel scientific breakthrough.

Well yeah, if you need just a cpu, making it on a fpga is not that smart(unless you want to play around with cpu arhidecture). That doesnt mean there are no good reasons to add a cpu into your fpga. For example you can have one half of fpga solving time critical tasks straight in hardware logic(very, very fast) and another half would be a simple cpu that handles tasks that are not that time critical but would be unreasonably complex to solve in hardware logic, for example communications, configuration, etc. You could also have the mcu outside fpga doing much the same tasks, but thats just a compromise between PCB space, component count, fpga internal recources, io resources etc.

FPGA does not make a very good cpu, but there are plenty of reasons to have a cpu inside FPGA.

BOINC: here is a model, please calculate what the temperature in Boston is going to be tomorrow

Me: 42

BOINC: thank you for your work, here is a unit of money for you.

Yeah sure i need to actually do the work.

"any currency is a fiat currency"

Nope, fiat currency is a currency only by someones fiat: "these polished turds are currency fom now on because i say so".

Latin fiat ("let it be done", "it shall be")

fiat - An authoritative command or order to do something; an effectual decree

For example bottles of vodka work as a currency, but that does not make a bottle of vodka into fiat currency. There is noone laying down the law, there is no fiat

"but as a legitimate currency, it will be dead."

I wonder, how exactly do you go about "squashing" it? Technical attack vectors dont seem to work (do you really think someone wouldnt have broken bitcoin already if it could be done?). I guess you can always make a law "thou shall not use bitcoin", but making a law and enforcing it are very different things. How do you really prevent people from using bitcoins? This brings you back to technical attack vectors - and i havent seen one that works yet.

"BitCoin looks like it was designed as a weapon intended to damage central banking and money issuing banks, with a Libertarian political agenda in mind—to damage states ability to collect tax and monitor their citizens financial transactions,"

Nothing "looks like it" about bitcoin, it was designed as a weapon against world financial system. Highest coal of bitcoins in to eventually supersede all worlds currencies(achieving such a goal is entirely different matter tho). That pretty much means rewriting world economy. Bitcoin is designed to take control out of governments hands, the entire system is self regulatory and designed to resist tampering from governments or anyone really.

“Let me issue and control a nation's money and I care not who writes the laws.” Mayer Amschel Rothschild (1744-1812), founder of the House of Rothschild.

I wonder, what if nobody really controls money?

CPU does not make a sound. Its current consumption does however swing wildly depending on what program its currently running. Variable current, all these chokes and coils in the way - you will get vibration and thus acoustics. Look up power analysis attack vectors on cryptography. These are old news and they work. Now the novel bit here is how you get the data for power analysis, instead of direct current measurement you measure acoustics. I guess thats plenty of data.

I think a while back there were news about a project aiming to build an overprotocol to bitcoin that would affix ownership of any sort of property to some particular marked coin. Stocks, cars, houses, whatnot. So if you want to transfer ownership you just trade that coin away. The idea is to make away with all the expensive notarized paperwork that is involved in usually transferring ownership of properties and just stating whoever can present bitcoin x owns that particular property. Its more of a legal challange really that an engieneering challange.

"wait for 6 blocks" is a historic tradition and in my opinion no longer makes any sense but only slows down transactions. With 6 blocks the level of "no-takebacks" certainty is on the order of "the entire bitcoin ecosystem will explode before you can do a takeback". The tradition is from a time where almost any supercomputer could have overpowered bitcoin network to make takebacks possible, this has not been a reality for a long time. For anything less than transaction worth a fortune, id say single block is plenty of certainty.

For an altcoin to win out its not just a matter of technical superiority, the new coin would have to win out economically and thats really hard to do when bitcoin has a head start. Take a look at all the altcoins out there, i bet some of them have valid technical improvements over bitcoin, are they winning? Naah, they are worthless and are going to stay worthless because bitcoin simply got a head start. For example its worth nothing to avarage bitcoin user how large block chain is, they do however care about the value and history of their chosen currency. Between choosing bitcoin that has been around for couple of years and is actually worth quite a bit or some altcoin that is worth nothing and started last month, what choice do you really have?

Mining does not arbitarily become harder or easier on its own. It self regulates so that on avarage new block would be created every 10 minutes. Put more hashing power to the network and mining becomes harder, take some power away and it becomes easier. But regardless of difficulty new blocks are generated every 10 minutes(average).