No, mining is "proof-of-work" to enable reaching consensus on the order of transactions. This is necessary to prevent spending a balance multiple times. Only the first spending event counts. It is done by searching for hard to find hashes for a block of transactions + the hash of the previous block + a random number you insert until you meet the hard-to-meet condition (a low hash value). Using the hash of the previous block as part of the data for the current block puts the blocks in sequence, so you can know the order of transaction events. Attempting to change any block contents, such as altering transaction values or adding another transaction will change the hash, so it no longer matches the value stored in the next block. If you attempt to find a matching hash for your altered block, now the second block will no longer match the value in the third block. You end up having to find hashes for every block after the altered one up to the last one.
By making finding hashes so hard that the entire mining network can only succeed every ten minutes, you force everyone to collaborate on the search, leaving no computing power to generate an alternate history of transactions. The longest chain of blocks had the most work put into it, and thus represents the consensus of events.
If you can figure out another way to ensure digital transaction data isn't altered, great, you can become famous. Nakamoto's big invention is chaining hashes + requiring work to find the hashes, so that altering the data would require even more work. As long as a majority of the network is honest, a hacker can never catch up.
Unless you consider PayPal and Western Union to be pyramid schemes, then no, neither is the Bitcoin Network. All three are in the business of moving money from one place to another. The Bitcoin Network happens to use it's own internal accounting unit, the "bitcoin" unit, which is transferable once purchased. But if you buy some bitcoin units in the US with dollars, and send them to someone in Poland who exchanges them to Zloty, it looks just like PayPal or Western Union: money goes in one end, money comes out the other. Oh, and the Bitcoin Network is distributed, and the fees are lower than the competition.
So if you think it's a pyramid scheme, what's the false promise that was made? Making lots of money because you were an early adopter or investor is normal for technology business.
I found mutiple errors in the first paragraph of the paper. That does not engender trust in the quality of the authors work. The first paragraph of the paper states:
> Every four years the number of bitcoins created is scheduled to be cut in half until 2040
The correct date is approximately 2140 AD. The reward per block started at 50 BTC and is cut in half every 210,000 blocks, which nominally takes about 4 years. After ~130 years you have done 33 halvings, so the reward is 50 / (2^33) = 0.58 Satoshi, where 100 million Satoshi = 1 bitcoin. Since the smallest unit in the bitcoin transaction system is 1 Satoshi, the reward becomes too small to measure, and thus mining for new coins stops.
> Mining is done by volunteers who operate servers running bitcoin software.
Three errors in one sentence. Most miners do it for income, not volunteering. They earn a share of the block reward by participating in mining pools. They don't use servers, they used to use graphics cards until that became too difficult, and now mostly use custom hardware (ASICs). Neither are servers in the client-server sense, they are nodes in a peer-to-peer network, because they have to receive new transactions and send completed blocks to the other nodes. Miners generally don't run "bitcoind", the default client, or other wallet software. They run custom mining software for the kind of mining hardware they use.
> How long will it remain feasible to create new alt-coins, and what does this do to the existing alt-coin economy?
Nothing prevents me from creating an auction website either. But eBay will still be the dominant site because of the network effect.
Bitcoin has brand recognition, a whole ecosystem of software, apps, custom hardware, 35,000 merchants, 1.6 million online wallets + plus some number of PC wallets. A new altcoin can't reproduce that, it only has the default mining program that bitcoin started with 5 years ago. Because of the network effect, the most utility resides in the network with the most users.
The landscape is heavily tilted to the biggest digital currencies, and will remain that way.
The older cryptocurrencies are open-source, so you just download the source code from the repository, make a few changes (like the mining algorithm and reward schedule) and send it off. Litecoin is literally made that way, they just tweaked a few parameters and substituted a different hashing function.
I'm mining Protoshares, because it actually brings something new, and not just tweaking the source code. A stream of business concepts will be forked off the prototype shares, with each one having shares issued in proportion to the holdings of protoshares. Think of it like a venture capital fund, except the capital is created by mining, rather than gathering piles of dollars from investors. Once issued, the forked shares will trade on their own chain. Their value will depend on the strength of the business ideas and execution, thus directing investment value when the various shares are sold for fiat currencies.
> BTC doesn't have the general acceptance as a store of value
Bitcoin was designed as a payment network, not a store of value. If you want to store value, trade your bitcoins for gold or real estate or shares of Disney stock. The Block Chain records only transactions, i.e. value in motion. If you want a "storage coin" then buy a bunch of assets, whatever is calculated to be a stable mix, and issue shares of that at a level comparable to dollars or euro.
That's pretty much what we do with any securitized asset or investment fund, but Wall Street imposes lots of friction on trading such things. A block chain database that recorded ownership of asset-backed coins would be as mobile as bitcoin, and a better store of value. The problem is how to verify transactions, if there is no incentive for "mining" like bitcoin has.
> I would add that ideally, the amount of Bitcoin needed to increase to reflect the amount of transactions being undertaken in Bitcoin. Bitcoin does not do this.
The amount of bitcoin value increased by a factor of 60 in 2013, is that not enough? It just did it mostly by increasing the value of each unit, instead of the number of units in the system. Since bitcoin was designed as a *payment network* and not a *long term store of value*, it doesn't matter what the value per unit is, software takes care of the conversion in real time. If the demand for bitcoin transaction volume goes down, so will the value per unit, by simple supply and demand, so there is always just the right amount. Money supply is number of units in circulation x value per unit. You are just used to the left hand term varying, but mathematically the right hand term can do the varying while the left one stays fixed.
Note: the number of bitcoins in circulation is about 12 million, and it's capped at 21 million, with a known rate of increase. So far the demand to use it has grown far faster than the number of units, but at some point demand will saturate and the value per unit will be more stable.
> What happens if a powerful government declares this software fork is the legal bitcoin software, not the current software?
The same thing that happens when they declare that file sharing is illegal - people will ignore them. The only way to change the software is to get a majority of the users and miners to accept the change. They won't do it if there is the potential for a central authority to debase the system by handing out extra coins, it would devalue the ones they already have. Those have value because they are scarce.
At best, a government can create it's own competing cryptocurrency. Canada is trying something like this with their MintChip stored value digital signature devices, but it has not been deployed yet in real use. Bitcoin has at least 1.6 million users just in the top two online wallets (Blockchain.info's MyWallet and Coinbase), plus an unknown number of other users that run it on their PC's, so it's way ahead on user count.
What rises to become a currency, neglecting government mandates, is usually the most easily traded and accepted good, whatever that is, because that is the most useful in trade. Russia is full of smokers and drinkers, so everyone knows they can trade cigarettes and vodka pretty much anywhere to somebody. Bitcoin is very easily traded, assuming you have internet access, and acceptance is rising, though still small. It really should be considered a transferable commodity at this point, since it has not reached general acceptance, even within the online community. But in a few years it may have wide enough acceptance to be considered a full currency.
Fiat is a Latin word meaning "Let this be", as in the Biblical "Fiat Lux" - let there be light. It's a command. So a fiat currency is one commanded to be a currency by some authority. But if the currency is badly managed, people will no longer accept it and look for something else. I'm old enough to remember the high inflation in the US around 1980, when everyone was looking for an "inflation hedge", i.e. something that didn't lose value at 1% a month.
> therefore all cryptocurrencies have no actual reason to have a value
This is incorrect, because you are only looking at the currency, and not the network it is part of.
The Bitcoin Network consists of software, apps, websites, a big database, relay nodes, and custom hardware. Collectively this network enables fast and cheap transfer of value from one place to another, with a number of other nice features. This has value to people because it is useful, and creates a demand to use it. Since the only way to use the network is by controlling a balance in the database (so that you can send it to someone else), those balances also have value. The balances, which are measured in units called "bitcoins" and "Satoshi" have no value in and of themselves, but then neither do the numbers in a bank's computer that represent your checking balance. It's only in the context of the whole Bitcoin Network, or the whole conventional banking network, that you can perform the useful function of sending value to another person.
The reason the total value of all bitcoins, which is $9.9 billion right now ( $812/BTC x 12.212M BTC) is much larger than all the other cryptocurrencies combined is it has by far the most developed network, and the largest number of merchants and users using the network. Thus it has the most demand and utility. Bitcoins can be spent for a large and increasing number of things, while Kanyecoins will have nearly nobody who uses it at first.
Metcalfe's Law says the value of a network rises as the square of the number of users, which means the largest network tends to dominate. Unless a new cryptocurrency has much better features than the original, bitcoins are likely to continue dominating the digital currency arena. That also adds to its value - bitcoins you buy now are likely to still have uses for some time into the future.
Actually, I heard direct from a Biospherian (one of the people who lived in the the thing), that the reason they ran short of oxygen was:
(a) as scientists, they didn't include a healthy design margin like an engineer would, they cut things too close (b) Mount Pinatubo erupted, throwing dust into the upper atmosphere, and lowering available sunlight (c) They didn't think about carbonation of the concrete, a process that removes CO2 and mineralizes it. Effectively that is an oxygen sink.
If they had to do it over, they could have overcome these deficiencies.
For a Mars base, however, with enough power, you can extract oxygen from the CO2 in the atmosphere, so even if your food growing doesn't supply enough, you can make it up with a chemical process plant.
> What I don't understand is the people saying they shouldn't even try.
I'm not saying they shouldn't try, merely that they have a rational technical approach. I'm working on self-expanding automation ( http://en.wikibooks.org/wiki/Seed_Factories ) as an enabler for big space projects. We can't afford to haul entire factories to the asteroids or Mars, so it makes sense to bring a starter kit, and use that to build more equipment, until you have whatever industrial capacity you need.
But instead of trying to go to Mars as the first step, I'm planning to build prototypes for *Earth* production first. This would be self-financing, like most advanced automation will be. Then in steps you go to more difficult locations like the oceans, deserts, and ice caps, and finally you go into orbit. By that time you will have plenty of experience with the technology and worked out a lot of the bugs. Not only that, but each generation of factory helps you build the next generation.
I think my approach is more sensible in the long run.
For example, they want to land the modules 5-10 km away from the base location, because that's the landing error circle for current technology, and the landing rockets can do serious damage if you land too close. Then supposedly a rover will pick up this several ton module, and drive it over unimproved natural terrain to the base site. How do you test the route with an unloaded rover? You can't because you don't have a load heavy enough to make sure you don't fall into a sandpit. What if there is a ridge somewhere along the way bigger than the rover wheels? On Earth we send in a bulldozer and make a path. These rovers are too light to do serious earth moving even if you include a digging arm or front blade.
I could go on, but you get the idea. There's a whole lot of thinking needed to make a project like this work, and they haven't got enough of the right talent to even get started.
Supposedly they are going to start training the astronauts in 2015, i.e. 12-24 months from now. The training site is supposed to have a simulation of their Mars base and equipment to train on. But they only just picked a couple of aerospace companies to do a *conceptual design* of the *precursor unmanned lander*. Conceptual design is the earliest stage of aerospace proejcts.
They haven't even started design of the human capsules. As far as I know they also don't have a site selected for the training. You can't just drop a few mobile homes in the desert and call it a training site. You need simulators capable of giving the crew a reasonable analog of real operations, and trainer operators to give them problems to solve, and all that takes time to design.
They are so far away from a real program it's not even funny.
Visit the Andes and the Himalayas. The people who live there have different genes from low-landers *and* from each other, that make them better adapted to high altitudes. Unless you want to postulate that God is a trickster who wants to fool us into thinking evolution is happening, it's hard to explain how different adaptions to the same problem have happened. Not being able to breathe is such a strong selection factor, that these changes have happened over just a few thousand years. It's the fastest known evolutionary change in humans.
It's an accounting token in a big database of transactions. Demand to move money from place to place using the Bitcoin Network creates demand for the tokens. Because there are a limited number of tokens, when demand goes up, so does their unit price. But the tokens themselves are not a separate entity. They have no function without the database and network of which they are a part. Seen as a whole, the Network takes in money from a user at one end, and delivers money to someone else at the other end. ATM's with dollar bill readers could do the same thing. That the dollar amounts are converted to electronic transmissions and data entries on the way between ATM's doesn't affect how the network as a whole functions.
You can branch block chains off the central bitcoin one, and then use local transactions on the side chains. Assuming the side chains are evenly distributed, their size grows as the square root of the total number of transactions. You only need to store chains that you have any balance on.
Alternately, people can subscribe to servers hosting the block chain and doing nothing else. As long as there are a sufficient number of these distributed servers checking each other, you don't rely on a centralized trustee.
I'm surprised so many Slashdot readers get this wrong. The Bitcoin Network (or BitNet for short) is designed to deliver payment transactions quickly and cheaply. It is made up of user software, mobile apps, a big database, P2P nodes that relay transactions, and custom hardware that verifies blocks of transactions. It was not designed to store value over long periods, so it is not surprising that it doesn't perform that function.
The number of accounting tokens in the database (which people refer to as bitcoins) is finite for sound mathematical reasons. As demand goes up and down for payment transactions, the price of one token will go up and down too. As long as it does not change much between when someone buys a token and the person at the other end sells it, it has performed it's job of delivering a payment between them.
You are right that the tokens themselves have no intrinsic value, they are just accounting units. The value comes from the BitNet being cheaper and faster than alternatives like Western Union or PayPal in delivering payments. That creates demand to use the network, and in turn demand for the tokens as part of how the network functions. By analogy, imagine that UPS had a limited number of reusable shipping labels. As demand for shipping goes up, the price of a label would be driven up by supply and demand. But the labels only have value because UPS has a network of trucks and distribution terminals that can deliver packages. The labels don't have intrinsic value by themselves.
Bitcoin tokens will only have value until the BitNet is superceded by something better. For a "reserve of wealth", i.e. the store of value function of money, you want something which doesn't depend on the velocity of transactions, which by their nature are variable. You want something that people want and need under any circumstances as backing for a currency. I am not an economist, so I don't know what the best option would be, but for example, land certificates redeemable in land would seem to be a pretty solid store of value. It's not like they are making more of it, and everyone has to live *somewhere*.
> where is the system that keeps up with how much, and where?
The whole bitcoin network (BitNet) performs this function. You start with a private cryptographic key, and an address derived from that key, like mine is 1Hfxy1j4uJknLzAKhjrNPXpCGmzPGX3PPQ. My private key allows me to sign a transaction that sends some amount of bitcoins from my address to someone else. The transaction goes across a peer-to-peer network to everyone else. Each node in the network looks up past transactions for my address, and makes sure I had enough bitcoins to make the transaction, and also verifies the digital signature matches the address. If it's a good transaction it gets passed along, if not, it's ignored.
Certain people on the network, called "miners", gather incoming transactions, and try to find a hard to find hash value which is a checksum of the included transactions. How hard it is to find is adjusted so the whole set of miners can only do it on average every ten minutes. The incentive to look for it is if you find it first, you get to include a transaction that creates new bitcoins which are sent to yourself. You send off this gathered set of transactions (called a block) and the hash to the network, who adds it to the growing set of all past transactions. Blocks also include the hash value from the previous block as part of their data. Thus each block is linked to a parent block, and the whole forms a chain we call the "block chain". The block chain is an unambiguous history of the order of transactions, from when a given bitcoin is created, to all subsequent transactions up to the present.
Because of the amount of work that goes into creating each block (proof of work), and that each block is linked to the next one which contains the hash that verifies it's contents, no past entry can be changed without redoing all the hash searching. Since the whole network was required to do the job the first time, there is no available processing power larger enough to redo it, thus the history is un-alterable. Since everyone has a full copy of the whole transaction history, everyone can verify new transactions are valid on their own, without the need to trust any third party.
The current balance on any address is simply the sum of all past transactions into and out of that address. Figuring that out is basically a database query on the block chain, then adding up all the found transactions. Thus the answer to your question is "everyone keeps up with how much, on their own independent copy of the bitcoin account books (the Block Chain)". We don't have to trust anyone else, because we all check for ourselves.
Roads and Sewers - Apparently you have never seen a subdivision or shopping center where the developer puts in those features.
Police - I guess you have never heard of private security either
Fire Departments - If insurance companies didn't get a free ride from government funded fire departments reducing their losses, they would pay for them themselves. It ends up being a shift in how the firefighters get paid, but they would still be around.
Parks - See developers again, or charitable fundraising to buy land and build a park.
See, what people like you forget is that if there are less government taxes, there is more money available for people to buy what they want, including private versions of the public "services". If it turns out people don't want to pay for something when given the choice, that means the government was actually working against the public will.
Slashdot Mirror
> Mining seems to just waste energy,
No, mining is "proof-of-work" to enable reaching consensus on the order of transactions. This is necessary to prevent spending a balance multiple times. Only the first spending event counts. It is done by searching for hard to find hashes for a block of transactions + the hash of the previous block + a random number you insert until you meet the hard-to-meet condition (a low hash value). Using the hash of the previous block as part of the data for the current block puts the blocks in sequence, so you can know the order of transaction events. Attempting to change any block contents, such as altering transaction values or adding another transaction will change the hash, so it no longer matches the value stored in the next block. If you attempt to find a matching hash for your altered block, now the second block will no longer match the value in the third block. You end up having to find hashes for every block after the altered one up to the last one.
By making finding hashes so hard that the entire mining network can only succeed every ten minutes, you force everyone to collaborate on the search, leaving no computing power to generate an alternate history of transactions. The longest chain of blocks had the most work put into it, and thus represents the consensus of events.
If you can figure out another way to ensure digital transaction data isn't altered, great, you can become famous. Nakamoto's big invention is chaining hashes + requiring work to find the hashes, so that altering the data would require even more work. As long as a majority of the network is honest, a hacker can never catch up.
Unless you consider PayPal and Western Union to be pyramid schemes, then no, neither is the Bitcoin Network. All three are in the business of moving money from one place to another. The Bitcoin Network happens to use it's own internal accounting unit, the "bitcoin" unit, which is transferable once purchased. But if you buy some bitcoin units in the US with dollars, and send them to someone in Poland who exchanges them to Zloty, it looks just like PayPal or Western Union: money goes in one end, money comes out the other. Oh, and the Bitcoin Network is distributed, and the fees are lower than the competition.
So if you think it's a pyramid scheme, what's the false promise that was made? Making lots of money because you were an early adopter or investor is normal for technology business.
I found mutiple errors in the first paragraph of the paper. That does not engender trust in the quality of the authors work. The first paragraph of the paper states:
> Every four years the number of bitcoins created is scheduled to be cut in half until 2040
The correct date is approximately 2140 AD. The reward per block started at 50 BTC and is cut in half every 210,000 blocks, which nominally takes about 4 years. After ~130 years you have done 33 halvings, so the reward is 50 / (2^33) = 0.58 Satoshi, where 100 million Satoshi = 1 bitcoin. Since the smallest unit in the bitcoin transaction system is 1 Satoshi, the reward becomes too small to measure, and thus mining for new coins stops.
> Mining is done by volunteers who operate servers running bitcoin software.
Three errors in one sentence. Most miners do it for income, not volunteering. They earn a share of the block reward by participating in mining pools. They don't use servers, they used to use graphics cards until that became too difficult, and now mostly use custom hardware (ASICs). Neither are servers in the client-server sense, they are nodes in a peer-to-peer network, because they have to receive new transactions and send completed blocks to the other nodes. Miners generally don't run "bitcoind", the default client, or other wallet software. They run custom mining software for the kind of mining hardware they use.
Isn't that what the too big to fail banks and the Federal Reserve do?
> How long will it remain feasible to create new alt-coins, and what does this do to the existing alt-coin economy?
Nothing prevents me from creating an auction website either. But eBay will still be the dominant site because of the network effect.
Bitcoin has brand recognition, a whole ecosystem of software, apps, custom hardware, 35,000 merchants, 1.6 million online wallets + plus some number of PC wallets. A new altcoin can't reproduce that, it only has the default mining program that bitcoin started with 5 years ago. Because of the network effect, the most utility resides in the network with the most users.
The landscape is heavily tilted to the biggest digital currencies, and will remain that way.
The older cryptocurrencies are open-source, so you just download the source code from the repository, make a few changes (like the mining algorithm and reward schedule) and send it off. Litecoin is literally made that way, they just tweaked a few parameters and substituted a different hashing function.
I'm mining Protoshares, because it actually brings something new, and not just tweaking the source code. A stream of business concepts will be forked off the prototype shares, with each one having shares issued in proportion to the holdings of protoshares. Think of it like a venture capital fund, except the capital is created by mining, rather than gathering piles of dollars from investors. Once issued, the forked shares will trade on their own chain. Their value will depend on the strength of the business ideas and execution, thus directing investment value when the various shares are sold for fiat currencies.
> BTC doesn't have the general acceptance as a store of value
Bitcoin was designed as a payment network, not a store of value. If you want to store value, trade your bitcoins for gold or real estate or shares of Disney stock. The Block Chain records only transactions, i.e. value in motion. If you want a "storage coin" then buy a bunch of assets, whatever is calculated to be a stable mix, and issue shares of that at a level comparable to dollars or euro.
That's pretty much what we do with any securitized asset or investment fund, but Wall Street imposes lots of friction on trading such things. A block chain database that recorded ownership of asset-backed coins would be as mobile as bitcoin, and a better store of value. The problem is how to verify transactions, if there is no incentive for "mining" like bitcoin has.
> I would add that ideally, the amount of Bitcoin needed to increase to reflect the amount of transactions being undertaken in Bitcoin. Bitcoin does not do this.
The amount of bitcoin value increased by a factor of 60 in 2013, is that not enough? It just did it mostly by increasing the value of each unit, instead of the number of units in the system. Since bitcoin was designed as a *payment network* and not a *long term store of value*, it doesn't matter what the value per unit is, software takes care of the conversion in real time. If the demand for bitcoin transaction volume goes down, so will the value per unit, by simple supply and demand, so there is always just the right amount. Money supply is number of units in circulation x value per unit. You are just used to the left hand term varying, but mathematically the right hand term can do the varying while the left one stays fixed.
Note: the number of bitcoins in circulation is about 12 million, and it's capped at 21 million, with a known rate of increase. So far the demand to use it has grown far faster than the number of units, but at some point demand will saturate and the value per unit will be more stable.
> What happens if a powerful government declares this software fork is the legal bitcoin software, not the current software?
The same thing that happens when they declare that file sharing is illegal - people will ignore them. The only way to change the software is to get a majority of the users and miners to accept the change. They won't do it if there is the potential for a central authority to debase the system by handing out extra coins, it would devalue the ones they already have. Those have value because they are scarce.
At best, a government can create it's own competing cryptocurrency. Canada is trying something like this with their MintChip stored value digital signature devices, but it has not been deployed yet in real use. Bitcoin has at least 1.6 million users just in the top two online wallets (Blockchain.info's MyWallet and Coinbase), plus an unknown number of other users that run it on their PC's, so it's way ahead on user count.
What rises to become a currency, neglecting government mandates, is usually the most easily traded and accepted good, whatever that is, because that is the most useful in trade. Russia is full of smokers and drinkers, so everyone knows they can trade cigarettes and vodka pretty much anywhere to somebody. Bitcoin is very easily traded, assuming you have internet access, and acceptance is rising, though still small. It really should be considered a transferable commodity at this point, since it has not reached general acceptance, even within the online community. But in a few years it may have wide enough acceptance to be considered a full currency.
Fiat is a Latin word meaning "Let this be", as in the Biblical "Fiat Lux" - let there be light. It's a command. So a fiat currency is one commanded to be a currency by some authority. But if the currency is badly managed, people will no longer accept it and look for something else. I'm old enough to remember the high inflation in the US around 1980, when everyone was looking for an "inflation hedge", i.e. something that didn't lose value at 1% a month.
> therefore all cryptocurrencies have no actual reason to have a value
This is incorrect, because you are only looking at the currency, and not the network it is part of.
The Bitcoin Network consists of software, apps, websites, a big database, relay nodes, and custom hardware. Collectively this network enables fast and cheap transfer of value from one place to another, with a number of other nice features. This has value to people because it is useful, and creates a demand to use it. Since the only way to use the network is by controlling a balance in the database (so that you can send it to someone else), those balances also have value. The balances, which are measured in units called "bitcoins" and "Satoshi" have no value in and of themselves, but then neither do the numbers in a bank's computer that represent your checking balance. It's only in the context of the whole Bitcoin Network, or the whole conventional banking network, that you can perform the useful function of sending value to another person.
The reason the total value of all bitcoins, which is $9.9 billion right now ( $812/BTC x 12.212M BTC) is much larger than all the other cryptocurrencies combined is it has by far the most developed network, and the largest number of merchants and users using the network. Thus it has the most demand and utility. Bitcoins can be spent for a large and increasing number of things, while Kanyecoins will have nearly nobody who uses it at first.
Metcalfe's Law says the value of a network rises as the square of the number of users, which means the largest network tends to dominate. Unless a new cryptocurrency has much better features than the original, bitcoins are likely to continue dominating the digital currency arena. That also adds to its value - bitcoins you buy now are likely to still have uses for some time into the future.
Actually, I heard direct from a Biospherian (one of the people who lived in the the thing), that the reason they ran short of oxygen was:
(a) as scientists, they didn't include a healthy design margin like an engineer would, they cut things too close
(b) Mount Pinatubo erupted, throwing dust into the upper atmosphere, and lowering available sunlight
(c) They didn't think about carbonation of the concrete, a process that removes CO2 and mineralizes it. Effectively that is an oxygen sink.
If they had to do it over, they could have overcome these deficiencies.
For a Mars base, however, with enough power, you can extract oxygen from the CO2 in the atmosphere, so even if your food growing doesn't supply enough, you can make it up with a chemical process plant.
> What I don't understand is the people saying they shouldn't even try.
I'm not saying they shouldn't try, merely that they have a rational technical approach. I'm working on self-expanding automation ( http://en.wikibooks.org/wiki/Seed_Factories ) as an enabler for big space projects. We can't afford to haul entire factories to the asteroids or Mars, so it makes sense to bring a starter kit, and use that to build more equipment, until you have whatever industrial capacity you need.
But instead of trying to go to Mars as the first step, I'm planning to build prototypes for *Earth* production first. This would be self-financing, like most advanced automation will be. Then in steps you go to more difficult locations like the oceans, deserts, and ice caps, and finally you go into orbit. By that time you will have plenty of experience with the technology and worked out a lot of the bugs. Not only that, but each generation of factory helps you build the next generation.
I think my approach is more sensible in the long run.
As author of a space systems engineering textbook ( http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods ) and formerly working for Boeing on the Space Station project, it's obvious to me they really have not thought through reliability and logistics.
For example, they want to land the modules 5-10 km away from the base location, because that's the landing error circle for current technology, and the landing rockets can do serious damage if you land too close. Then supposedly a rover will pick up this several ton module, and drive it over unimproved natural terrain to the base site. How do you test the route with an unloaded rover? You can't because you don't have a load heavy enough to make sure you don't fall into a sandpit. What if there is a ridge somewhere along the way bigger than the rover wheels? On Earth we send in a bulldozer and make a path. These rovers are too light to do serious earth moving even if you include a digging arm or front blade.
I could go on, but you get the idea. There's a whole lot of thinking needed to make a project like this work, and they haven't got enough of the right talent to even get started.
Supposedly they are going to start training the astronauts in 2015, i.e. 12-24 months from now. The training site is supposed to have a simulation of their Mars base and equipment to train on. But they only just picked a couple of aerospace companies to do a *conceptual design* of the *precursor unmanned lander*. Conceptual design is the earliest stage of aerospace proejcts.
They haven't even started design of the human capsules. As far as I know they also don't have a site selected for the training. You can't just drop a few mobile homes in the desert and call it a training site. You need simulators capable of giving the crew a reasonable analog of real operations, and trainer operators to give them problems to solve, and all that takes time to design.
They are so far away from a real program it's not even funny.
No, pop-up net. Free drone.
Or to be more subtle, your own local transmitter to override the remote controller.
Soon to be a reality show: Drone Dynasty.
Visit the Andes and the Himalayas. The people who live there have different genes from low-landers *and* from each other, that make them better adapted to high altitudes. Unless you want to postulate that God is a trickster who wants to fool us into thinking evolution is happening, it's hard to explain how different adaptions to the same problem have happened. Not being able to breathe is such a strong selection factor, that these changes have happened over just a few thousand years. It's the fastest known evolutionary change in humans.
It's an accounting token in a big database of transactions. Demand to move money from place to place using the Bitcoin Network creates demand for the tokens. Because there are a limited number of tokens, when demand goes up, so does their unit price. But the tokens themselves are not a separate entity. They have no function without the database and network of which they are a part. Seen as a whole, the Network takes in money from a user at one end, and delivers money to someone else at the other end. ATM's with dollar bill readers could do the same thing. That the dollar amounts are converted to electronic transmissions and data entries on the way between ATM's doesn't affect how the network as a whole functions.
You can branch block chains off the central bitcoin one, and then use local transactions on the side chains. Assuming the side chains are evenly distributed, their size grows as the square root of the total number of transactions. You only need to store chains that you have any balance on.
Alternately, people can subscribe to servers hosting the block chain and doing nothing else. As long as there are a sufficient number of these distributed servers checking each other, you don't rely on a centralized trustee.
I'm surprised so many Slashdot readers get this wrong. The Bitcoin Network (or BitNet for short) is designed to deliver payment transactions quickly and cheaply. It is made up of user software, mobile apps, a big database, P2P nodes that relay transactions, and custom hardware that verifies blocks of transactions. It was not designed to store value over long periods, so it is not surprising that it doesn't perform that function.
The number of accounting tokens in the database (which people refer to as bitcoins) is finite for sound mathematical reasons. As demand goes up and down for payment transactions, the price of one token will go up and down too. As long as it does not change much between when someone buys a token and the person at the other end sells it, it has performed it's job of delivering a payment between them.
You are right that the tokens themselves have no intrinsic value, they are just accounting units. The value comes from the BitNet being cheaper and faster than alternatives like Western Union or PayPal in delivering payments. That creates demand to use the network, and in turn demand for the tokens as part of how the network functions. By analogy, imagine that UPS had a limited number of reusable shipping labels. As demand for shipping goes up, the price of a label would be driven up by supply and demand. But the labels only have value because UPS has a network of trucks and distribution terminals that can deliver packages. The labels don't have intrinsic value by themselves.
Bitcoin tokens will only have value until the BitNet is superceded by something better. For a "reserve of wealth", i.e. the store of value function of money, you want something which doesn't depend on the velocity of transactions, which by their nature are variable. You want something that people want and need under any circumstances as backing for a currency. I am not an economist, so I don't know what the best option would be, but for example, land certificates redeemable in land would seem to be a pretty solid store of value. It's not like they are making more of it, and everyone has to live *somewhere*.
> where is the system that keeps up with how much, and where?
The whole bitcoin network (BitNet) performs this function. You start with a private cryptographic key, and an address derived from that key, like mine is 1Hfxy1j4uJknLzAKhjrNPXpCGmzPGX3PPQ. My private key allows me to sign a transaction that sends some amount of bitcoins from my address to someone else. The transaction goes across a peer-to-peer network to everyone else. Each node in the network looks up past transactions for my address, and makes sure I had enough bitcoins to make the transaction, and also verifies the digital signature matches the address. If it's a good transaction it gets passed along, if not, it's ignored.
Certain people on the network, called "miners", gather incoming transactions, and try to find a hard to find hash value which is a checksum of the included transactions. How hard it is to find is adjusted so the whole set of miners can only do it on average every ten minutes. The incentive to look for it is if you find it first, you get to include a transaction that creates new bitcoins which are sent to yourself. You send off this gathered set of transactions (called a block) and the hash to the network, who adds it to the growing set of all past transactions. Blocks also include the hash value from the previous block as part of their data. Thus each block is linked to a parent block, and the whole forms a chain we call the "block chain". The block chain is an unambiguous history of the order of transactions, from when a given bitcoin is created, to all subsequent transactions up to the present.
Because of the amount of work that goes into creating each block (proof of work), and that each block is linked to the next one which contains the hash that verifies it's contents, no past entry can be changed without redoing all the hash searching. Since the whole network was required to do the job the first time, there is no available processing power larger enough to redo it, thus the history is un-alterable. Since everyone has a full copy of the whole transaction history, everyone can verify new transactions are valid on their own, without the need to trust any third party.
The current balance on any address is simply the sum of all past transactions into and out of that address. Figuring that out is basically a database query on the block chain, then adding up all the found transactions. Thus the answer to your question is "everyone keeps up with how much, on their own independent copy of the bitcoin account books (the Block Chain)". We don't have to trust anyone else, because we all check for ourselves.
> When you absolutely, positively got to cut every motherf***ing blade of grass
These things exist. They are called "Bat Wing Mowers", and are powered by farm tractors:
http://www.purplewaveauction.com/a/2010/20100427oktx/6732.JPG
Pretty much any task you can think of for the yard or garden, there is a farm implement that is bigger and scarier.
> But when the NSA says they can't tie a phone number to a specific caller, they're liars and evil.
Hey, can I borrow your cell phone?
Yes, it's even labeled:
https://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX
And since it's a known address, people are pranking it by sending tiny amounts with messages attached.
Roads and Sewers - Apparently you have never seen a subdivision or shopping center where the developer puts in those features.
Police - I guess you have never heard of private security either
Fire Departments - If insurance companies didn't get a free ride from government funded fire departments reducing their losses, they would pay for them themselves. It ends up being a shift in how the firefighters get paid, but they would still be around.
Parks - See developers again, or charitable fundraising to buy land and build a park.
See, what people like you forget is that if there are less government taxes, there is more money available for people to buy what they want, including private versions of the public "services". If it turns out people don't want to pay for something when given the choice, that means the government was actually working against the public will.