Because the mining reward is only given out once per 10 minutes. If your hardware is an insignificant fraction of the network computation power, you will not win a block in a reasonable time. For example, my graphics card, which I stopped mining with in mid-2013, is 42 MHash/s. The network as a whole is 1.1 million TeraHash/s today. So my expected time to win a block is 500,000 years. I could mine faster if I bought custom mining chips, but it would still be ~500 years per block. By joining a pool, you get a fractional share of each block. Smaller rewards, but more steady.
"Mining farms" just take this to an extreme. They fill a server room full of mining chips, and win blocks often enough to make a business out of it. Each block reward these days is ~$10,000, and there's 144 blocks per day, so mining as a whole is about $500 million/year.
You misunderstand how the Bitcoin Network works. New transactions are *relayed* across the network in seconds. Each network node validates the transaction before passing it on, especially comparing the transaction inputs against the existing blockchain, to make sure the sender had funds to send. If another transaction arrives later, attempting to spend the same funds a second time, it gets rejected. As long as your soda machine is well-connected to the network (talks to a well-connected node), there is a very low chance (about one in ten thousand) the transaction will turn out to be invalid. That's comparable to the rate of fake coins going into the slot, and quite acceptable for a soda machine.
Bitcoin miners gather up a bunch of transactions, and try to find a hash value that meets a difficult test, based on the contents. That's what a "block" is. Blocks also include the hash from the *previous* block as data. If anyone tries to change the contents of a block (add or change a transaction), it no longer will match the published hash value, so you know it is wrong. If it's an older block, the hash stored in the next block won't match any more. This prevents tampering with past transaction data. Since finding hashes takes significant computational work, the older the block is, the more work would be required to find a new valid hash for a changed block *and every one after it*. Otherwise at some point the contents and hash would disagree, and you would know something is wrong.
So if you are selling a house for bitcoin, then wait an hour or two for 6-12 blocks piled on top of your transaction. That way you can be sure to a really high probability the payment is final. And closing a house sale takes that long anyway for the rest of the paperwork. But for a soda, meh, 99.99% is good enough.
The 1 MB limit was originally a temporary measure to prevent spam transactions, in the days when actual volume was 10 KB/block or less, and people mined on their home computers. Today we have 1 MB/block of real transactions, and most mining happens on custom chips designed for it. Unfortunately, the people handling the original code implementation have stubbornly delayed any increase.
Blocks are solved on average every 10 minutes, so at most 1 MB generates 13,333 bps of incoming data, less than a 24 year old 14.4K phone modem could handle. Bandwidth is not the limiting factor, disk space and processing speed to verify a block are. If Bitcoin got much more popular, you would need servers in data centers with big Xeon CPUs, hard drive arrays, and some custom mining chips to verify the transaction stream. Since that's more than home hardware, people could subscribe to a Bitcoin network node on a shared basis to split the cost. As long as there were many such server nodes, with different owners, it would still be decentralized and not subject to central control or attack.
Beyond beefier network nodes, there are a number of approaches to offloading transactions off the main Bitcoin blockchain. Most of these are not ready for use yet, but people are working on it. The one that is ready is companies like Coinbase, who supports customer wallets and currency exchanging. Any transactions between customers don't have to go on the Bitcoin chain, it's just internal to Coinbase. What you lose then is decentralization. Coinbase can refuse you service or otherwise mess with your transaction, and they have, if they suspect your Bitcoins are from a shady source.
> Why not reduce the target from 10 minutes per block to 5 minutes per block, instead, however?
Because each block generates new bitcoins as an incentive to miners to mine. If you shorten the interval, you either have to halve the generation amount, or change the total number of coins which will be generated. This is a big enough change to the "planned money supply" that many people would object. Making blocks bigger was the original plan. The 1 MB limit was only supposed to be temporary.
With modern currency scanners, you can read the serial numbers off each paper bill. The bank then knows who it hands cash to, and later who it comes back from. That's not full traceability, but it sure narrows down the search problem if you know the endpoints.
> I believe (but I may be wrong) that the common commercial panels these days use three-layer cells.
Only in space, where the efficiency gain is worth a lot more. Terrestrial panels are typically multi-crystalline silicon, which is cheaper to make than mono-crystalline. Some places use mono-crystalline, because it has a bit higher efficiency, and therefore higher output when space is limited, such as on a rooftop. You can track the best "research cell" efficiencies at http://www.nrel.gov/ncpv/image... (the chart is frequently updated). Between research and mass production at the lowest cost there is a variable time delay, usually years.
I worked for Boeing in the early 1980's, and our division supplied the carbon-fiber structure for Hubble. Hubble's optics and instruments were new, but the *spacecraft* (all the other parts) were derived substantially from spy satellites. When our guys visited Lockheed during the spacecraft integration, they saw *four* high-bay clean rooms, one of which was being used by Hubble. One of our engineers asked if they (Lockheed) had done this before, and the Lockheed guys just smiled and didn't say anything. Obviously they couldn't, because it was super-secret.
Note on the carbon fiber truss: This is what held the main mirror, secondary mirror, and the science instruments in place. They didn't want them to move when the telescope came in and out of the Earth's shadow. Carbon fiber has a negative thermal expansion coefficient (it shrinks when it gets warmer), and the epoxy matrix has a positive expansion coefficient. With the right percentage of each, you could get nearly zero expansion. But "nearly" wasn't good enough. So we made a bunch of truss pieces, measured each one, then put together a set whose "nearly zeros" cancelled out. That trick worked out great. Somewhere I've got one of the scrapped pieces as space memorabilia.
> The vast majority only deliver ONE THIRD of their pretended maximum power (a lot even less)
No, the "nameplate capacity" is their actual maximum power, the most they will deliver under the right circumstances. Just like every other electrical device, the maximum power rating matters for the power lines they are connected to, whether it's a wind farm or your stove at home. The term you are searching for is "capacity factor", the percentage of maximum power delivered over the course of a year. For wind it's about 34%, and for Hydro it's about 42%, not much higher.
What you and a lot of other people forget is that *demand* varies by time of day and season. Since the grid has to be able to meet peak demand, it will always have a lot more capacity than average use. And since no power source is 100% reliable, you also need a capacity margin *above* peak demand to handle random plant outages.
> Regardless, if wind power production keeps growing this quickly (it likely will because windows power is so cheap--nuclear isn't), then its average production will probably overtake nuclear sooner rather than later. I'm not saying that's good or bad; it's just how it is.
I know it's bad form to introduce facts into this kind of discussion, but here is US Net generation by source:
Since 2005, total US utility generation has remained roughly constant at about 4,100 TeraWatt-hours. As of the 12 months ending November 2015, Coal supplied 1,391; Natural Gas = 1,314; Nuclear = 801, Hydro = 250, Wind = 183, Wood = 42.5 and Photovoltaic = 22.6.
The change since 2005 was Nuclear +20, Hydro -20, Wind +165, and Photovoltaic +22.6. It will take a while for wind to pass nuclear, but Wind+Photovoltaic will pass Hydro in a couple of years. The really big shift in the last decade is Coal -622 and Natural Gas +553. Coal is on it's way out.
The simple answer is just cut out the middle-men, and have the research institutions organize their own publications. The academic departments can do the review and editing, and the libraries can do the archiving and access.
> So why do these authors publish their papers through expensive journals instead of just uploading to slideshare.net or scribd? Flag as Inappropriate
Because it affects their career track. Keeping your job, or getting promoted depends not just on publishing, but publishing in "high-impact" journals. Impact is the number of other papers that reference the ones in a given journal. The theory is that important and useful papers get referenced a lot. Prestigious journals like Science and Nature get to pick and choose what they publish, because everyone wants to get in them. Therefore they tend to maintain their "high impact" status. So an given author that gets published a lot in high impact journals is assumed to be doing better work than one that isn't. It's not a true measure of quality, but a statistical one that's easy to calculate, like a GPA. So long as their careers depend on it, they have a strong incentive to keep going to these journals.
That said, many authors make their papers available online *in addition* to publishing in a journal, and I have had good luck just emailing a paper's author and just asking for a copy. There is also a growing rebellion/boycott of the giant publishing houses that charge ridiculous prices for their journals.
Bitcoins (the accounting token) is backed by the Bitcoin Network of nodes, software, mining hardware, and all the other stuff that makes it useful. Without the network, bitcoins are just entries in an un-editable database.
This is similar to UPS shipping labels, which by themselves are just sticky paper with some stuff printed on them, of no inherent value. But they are backed by a network of shipping terminals, trucks, and other stuff that makes the labels useful for moving packages, so people are willing to trade money for the labels.
Instead of packages, the Bitcoin Network moves monetary value from place to place, and it does this very well. In one test, it moved some bitcoins halfway around the world, six times, in an hour, for a few cents in fees. The usefulness is why people will trade other money for some units of the accounting token.
Transactions only contain the sending and destination addresses, and the amount of bitcoin being transferred. They don't contain any personal information. As long as you don't leak your identity by activity *around* a transaction, they can be anonymous. For example, Coinbase is a company that sells bitcoins to individuals, and you can link your checking or credit card to fund the purchase. So Coinbase knows which coins you bought. But if you buy them in a private transaction from an individual for cash, less info can be revealed.
Easter Island gets 1,147 mm of rain a year, Mauna Kea Observatory gets 187. It's a better site for lots of other reasons (altitude, stability of the air, etc.)
> A group of native Hawaiians object on the grounds that the land has historic and spiritual significance.
It doesn't. The top of Mauna Kea was used by the natives as a *rock quarry* for stone tools. There is literally tons of archeological evidence of that:
Eminent domain isn't relevant in this case. The land already belongs to the State of Hawaii, under their Department of Land and Natural Resources. Basically the entire upper half of the Big Island by altitude is a nature reserve. The very top of Mauna Kea is a science reserve managed by the University of Hawaii (another state institution). It includes archaeological sites where natives used it as a *rock quarry* for stone tools, and the area where the telescopes are set up.
Nobody has ever lived up there, because there is not enough rainfall to support farming, and it gets quite cold at 14,000 ft. So there was nobody to kick out. Once westerners brought metal tools, they replaced the stone tools, so even the native quarry shut down.
> We have no business as a society stopping building on the basis of blasphemy anyway.
Except the top of Mauna Kea was never a holy site. It was a rock quarry, there is evidence all over the top of the mountain. Before Westerners brought metal tools, the natives used stone ones, and the lava that erupted up there during an ice age cooled quickly, making it chip-resistant. So they set up mining camps and dug up the mountain top. They didn't live up there, not enough rainfall to grow things. That's also the reason it is a good telescope site. So the natives commuted from lower altitudes, dug up stone tools, and went back down. Not exactly a religious pilgrimage.
> "The planned construction site is on land considered sacred by some Native Hawaiians."
What the *modern* natives fail to mention is that the *pre-western* natives used the top of the mountain as a rock quarry. It wasn't sacred at all. Turns out that lava erupted during an ice age, when there were glaciers on top, hardened rapidly, preventing crystal growth. Crystals fracture more easily, so the lack made for excellent stone tools, which the natives used before westerners brought metal tools.
The top of the mountain wasn't habitable for the same reason it makes an excellent telescope site - very little rain. The altitude also means it's cold, and it is high enough to induce altitude sickness if you are acclimated to sea level. So the natives didn't live up there, but rather set up mining camps to extract the rock, then took them back down. There is literally tons of archaeological evidence all over the Mauna Kea Science Reserve, the area on top of the mountain that the University of Hawaii controls. The astronomers are careful about not putting a telescope in archeology areas. There's rock debris, partial tools, shelters, etc. up there.
If it was originally an industrial site, I see no reason not to use it now for a scientific site. It's not like they are knocking down the Parthenon to build a telescope.
> Bitcoin is all the hype, but the blockchain has flaws, in that it isn't as anonymous as one would hope for — you can track past transactions.
Bitcoin transactions record sending and receiving addresses, and the amount sent, and that's it. Privacy depends on how careful you are outside the transaction itself. For example, if you buy something physical online, and give a delivery name and address, the store knows who those bitcoins came from. But compared to a credit card or paper check, which have your name printed on them, bitcoin transactions have the *possibility* of privacy. Cash is no longer anonymous, by the way. Banks and ATMs can scan serial numbers when cash goes out and comes in. Depending how many hand-to-hand transactions happen in between, they can figure out what you were doing.
> Rumors of Bitcoin showing cracks are popping up and also there are quite a few alternatives out there.
The Bitcoin Network is still running fine. They are getting close to a limit in the code originally intended to stop spam transactions. That limits the size of "blocks" of transactions to 1 MB. The current arguments are over how and when to raise that cap. A majority of the network has to upgrade to raise the limit. Yes, there are lots of alternatives, because all it takes is to fork the code and slap a new name on it (it's open source). But as this table ( http://coinmarketcap.com/ ) shows, Bitcoin is 7/8 of the market, and only three others have significant market capitalization and trading volume. Building a network of users, apps, etc. for an ecosystem is a lot harder than releasing a new cryptocoin.
> Is getting into dealing with crypto currency worthwhile already?
It was for me, but I started in mid-2011 (from an article on Slashdot, in fact). If it is worthwhile for *you* depends on a lot of things. If you send money to family in another country, or international wire transfers, it may be very worthwhile, because of the very high fees from the other methods. If you are an average US consumer with credit and debit cards and want to shop on Amazon, not so much.
> become easily trackable once NSA and the likes adapt their systems to doing exactly that?
The NSA can download a copy of the blockchain, just like everyone else. What they have, that the rest of us don't, is all the other data collection that can correlate a Bitcoin transaction to a person or place. Like if you are using a smartphone app to send bitcoins, they know who owns the phone and where you were at the time
> What digital currency has the technical and mind-share potential to supersede bitcoin?
What social network is going to replace MySpace?:-). What OS is going to replace Windows? Predicting the future is hard, especially before it happens
> Are there feasible cryptocurrencies that have the upsides of Bitcoin (such as a mathematical limit to their amount) but are fully anonymous in transactions?
Bitcoin can be anonymous, but you have to use it properly for that to happen. As I said above, data leakage *around* a transaction is how you de-anonymize it. The same would be true of alt-coins (the general name for cryptocurrencies besides Bitcoin). If you use them to buy something, the seller may leak your info.
> What do the economists and digi-currency nerds here have to contribute on that?
Economists in general don't have the software chops to understand how cryptocurrencies work, and have religious beliefs on how economies and money *should* work. Not all of them, but a lot of them. My own opinion is bitcoin is the most developed cryptocurrency, with the most users, apps, mining hardware, etc. The direction in the future won't be replacing bitcoin with another coin, but building layers on top of Bitcoin. It's a communication protocol for scriptable transaction messages, and people have barely figured out how to make use of that. As such, it is similar to the IP protocol stack.
Two reasons. First, the insane competition to mine bitcoins is a temporary phenomenon. We will hit 75% of the 21 million total this July. At that point the reward for mining a block will drop in half, and so will the incentive to mine. Every 4 years half the remaining coins will be mined, and the reward will drop in half again. It was set up this way to encourage early adopters for the initial distribution of coins. Eventually transaction fees, which are ~1% of miner income today, will be the only income. Most miners will give up because it will be unprofitable, or they will get way more efficient. Either way the energy use will go down.
Second, there are half a million bank buildings around the world. Some of them are the largest skyscrapers in town. How much total energy do you think that consumes? Bitcoin mining doesn't use more energy for more transactions. It uses more energy when more people compete for the reward (25 BTC x $370 today, or $9,250 per block, $1.3 million per day, $486 million/year). Network bandwidth and disk space go up with more transactions, but they are not as energy intensive. A world that uses a lot of bitcoin transactions instead of bank branches actually would use less energy in total.
My reason is making money by expanding civilization into the Solar System. There are huge amounts of untapped energy and material resources out there. For a description of how the "mining and manufacturing based space program" would work, see:
Slashdot Mirror
Because the mining reward is only given out once per 10 minutes. If your hardware is an insignificant fraction of the network computation power, you will not win a block in a reasonable time. For example, my graphics card, which I stopped mining with in mid-2013, is 42 MHash/s. The network as a whole is 1.1 million TeraHash/s today. So my expected time to win a block is 500,000 years. I could mine faster if I bought custom mining chips, but it would still be ~500 years per block. By joining a pool, you get a fractional share of each block. Smaller rewards, but more steady.
"Mining farms" just take this to an extreme. They fill a server room full of mining chips, and win blocks often enough to make a business out of it. Each block reward these days is ~$10,000, and there's 144 blocks per day, so mining as a whole is about $500 million/year.
You misunderstand how the Bitcoin Network works. New transactions are *relayed* across the network in seconds. Each network node validates the transaction before passing it on, especially comparing the transaction inputs against the existing blockchain, to make sure the sender had funds to send. If another transaction arrives later, attempting to spend the same funds a second time, it gets rejected. As long as your soda machine is well-connected to the network (talks to a well-connected node), there is a very low chance (about one in ten thousand) the transaction will turn out to be invalid. That's comparable to the rate of fake coins going into the slot, and quite acceptable for a soda machine.
Bitcoin miners gather up a bunch of transactions, and try to find a hash value that meets a difficult test, based on the contents. That's what a "block" is. Blocks also include the hash from the *previous* block as data. If anyone tries to change the contents of a block (add or change a transaction), it no longer will match the published hash value, so you know it is wrong. If it's an older block, the hash stored in the next block won't match any more. This prevents tampering with past transaction data. Since finding hashes takes significant computational work, the older the block is, the more work would be required to find a new valid hash for a changed block *and every one after it*. Otherwise at some point the contents and hash would disagree, and you would know something is wrong.
So if you are selling a house for bitcoin, then wait an hour or two for 6-12 blocks piled on top of your transaction. That way you can be sure to a really high probability the payment is final. And closing a house sale takes that long anyway for the rest of the paperwork. But for a soda, meh, 99.99% is good enough.
The 1 MB limit was originally a temporary measure to prevent spam transactions, in the days when actual volume was 10 KB/block or less, and people mined on their home computers. Today we have 1 MB/block of real transactions, and most mining happens on custom chips designed for it. Unfortunately, the people handling the original code implementation have stubbornly delayed any increase.
Blocks are solved on average every 10 minutes, so at most 1 MB generates 13,333 bps of incoming data, less than a 24 year old 14.4K phone modem could handle. Bandwidth is not the limiting factor, disk space and processing speed to verify a block are. If Bitcoin got much more popular, you would need servers in data centers with big Xeon CPUs, hard drive arrays, and some custom mining chips to verify the transaction stream. Since that's more than home hardware, people could subscribe to a Bitcoin network node on a shared basis to split the cost. As long as there were many such server nodes, with different owners, it would still be decentralized and not subject to central control or attack.
Beyond beefier network nodes, there are a number of approaches to offloading transactions off the main Bitcoin blockchain. Most of these are not ready for use yet, but people are working on it. The one that is ready is companies like Coinbase, who supports customer wallets and currency exchanging. Any transactions between customers don't have to go on the Bitcoin chain, it's just internal to Coinbase. What you lose then is decentralization. Coinbase can refuse you service or otherwise mess with your transaction, and they have, if they suspect your Bitcoins are from a shady source.
> Why not reduce the target from 10 minutes per block to 5 minutes per block, instead, however?
Because each block generates new bitcoins as an incentive to miners to mine. If you shorten the interval, you either have to halve the generation amount, or change the total number of coins which will be generated. This is a big enough change to the "planned money supply" that many people would object. Making blocks bigger was the original plan. The 1 MB limit was only supposed to be temporary.
With modern currency scanners, you can read the serial numbers off each paper bill. The bank then knows who it hands cash to, and later who it comes back from. That's not full traceability, but it sure narrows down the search problem if you know the endpoints.
Hillary's ex-son-in-law was a Goldman-Sachs investment banker (he and Chelsea divorced). You don't get much more global elite than that.
> I believe (but I may be wrong) that the common commercial panels these days use three-layer cells.
Only in space, where the efficiency gain is worth a lot more. Terrestrial panels are typically multi-crystalline silicon, which is cheaper to make than mono-crystalline. Some places use mono-crystalline, because it has a bit higher efficiency, and therefore higher output when space is limited, such as on a rooftop. You can track the best "research cell" efficiencies at http://www.nrel.gov/ncpv/image... (the chart is frequently updated). Between research and mass production at the lowest cost there is a variable time delay, usually years.
I worked for Boeing in the early 1980's, and our division supplied the carbon-fiber structure for Hubble. Hubble's optics and instruments were new, but the *spacecraft* (all the other parts) were derived substantially from spy satellites. When our guys visited Lockheed during the spacecraft integration, they saw *four* high-bay clean rooms, one of which was being used by Hubble. One of our engineers asked if they (Lockheed) had done this before, and the Lockheed guys just smiled and didn't say anything. Obviously they couldn't, because it was super-secret.
Note on the carbon fiber truss: This is what held the main mirror, secondary mirror, and the science instruments in place. They didn't want them to move when the telescope came in and out of the Earth's shadow. Carbon fiber has a negative thermal expansion coefficient (it shrinks when it gets warmer), and the epoxy matrix has a positive expansion coefficient. With the right percentage of each, you could get nearly zero expansion. But "nearly" wasn't good enough. So we made a bunch of truss pieces, measured each one, then put together a set whose "nearly zeros" cancelled out. That trick worked out great. Somewhere I've got one of the scrapped pieces as space memorabilia.
> The vast majority only deliver ONE THIRD of their pretended maximum power (a lot even less)
No, the "nameplate capacity" is their actual maximum power, the most they will deliver under the right circumstances. Just like every other electrical device, the maximum power rating matters for the power lines they are connected to, whether it's a wind farm or your stove at home. The term you are searching for is "capacity factor", the percentage of maximum power delivered over the course of a year. For wind it's about 34%, and for Hydro it's about 42%, not much higher.
What you and a lot of other people forget is that *demand* varies by time of day and season. Since the grid has to be able to meet peak demand, it will always have a lot more capacity than average use. And since no power source is 100% reliable, you also need a capacity margin *above* peak demand to handle random plant outages.
> Regardless, if wind power production keeps growing this quickly (it likely will because windows power is so cheap--nuclear isn't), then its average production will probably overtake nuclear sooner rather than later. I'm not saying that's good or bad; it's just how it is.
I know it's bad form to introduce facts into this kind of discussion, but here is US Net generation by source:
https://www.eia.gov/electricit... and https://www.eia.gov/electricit...
Since 2005, total US utility generation has remained roughly constant at about 4,100 TeraWatt-hours. As of the 12 months ending November 2015, Coal supplied 1,391; Natural Gas = 1,314; Nuclear = 801, Hydro = 250, Wind = 183, Wood = 42.5 and Photovoltaic = 22.6.
The change since 2005 was Nuclear +20, Hydro -20, Wind +165, and Photovoltaic +22.6. It will take a while for wind to pass nuclear, but Wind+Photovoltaic will pass Hydro in a couple of years. The really big shift in the last decade is Coal -622 and Natural Gas +553. Coal is on it's way out.
> Wind capacity factor is about 25%.
In the US, in 2014, it was:
Coal 61%
Natural Gas Combined Cycle 48.3%
Nuclear 91.7%
Hydro 37.3%
Wind 34.0%
Photovoltaic 25.9%
Geothermal 74%
Source: https://www.eia.gov/electricit... and https://www.eia.gov/electricit...
> very modest subscription fees
$45,000 for a public library isn't modest.
The simple answer is just cut out the middle-men, and have the research institutions organize their own publications. The academic departments can do the review and editing, and the libraries can do the archiving and access.
> So why do these authors publish their papers through expensive journals instead of just uploading to slideshare.net or scribd?
Flag as Inappropriate
Because it affects their career track. Keeping your job, or getting promoted depends not just on publishing, but publishing in "high-impact" journals. Impact is the number of other papers that reference the ones in a given journal. The theory is that important and useful papers get referenced a lot. Prestigious journals like Science and Nature get to pick and choose what they publish, because everyone wants to get in them. Therefore they tend to maintain their "high impact" status. So an given author that gets published a lot in high impact journals is assumed to be doing better work than one that isn't. It's not a true measure of quality, but a statistical one that's easy to calculate, like a GPA. So long as their careers depend on it, they have a strong incentive to keep going to these journals.
That said, many authors make their papers available online *in addition* to publishing in a journal, and I have had good luck just emailing a paper's author and just asking for a copy. There is also a growing rebellion/boycott of the giant publishing houses that charge ridiculous prices for their journals.
> and who will bring this to you? at&t"
Given that AT&T is my ISP, in fact they *are* bringing it to me.
Bitcoins (the accounting token) is backed by the Bitcoin Network of nodes, software, mining hardware, and all the other stuff that makes it useful. Without the network, bitcoins are just entries in an un-editable database.
This is similar to UPS shipping labels, which by themselves are just sticky paper with some stuff printed on them, of no inherent value. But they are backed by a network of shipping terminals, trucks, and other stuff that makes the labels useful for moving packages, so people are willing to trade money for the labels.
Instead of packages, the Bitcoin Network moves monetary value from place to place, and it does this very well. In one test, it moved some bitcoins halfway around the world, six times, in an hour, for a few cents in fees. The usefulness is why people will trade other money for some units of the accounting token.
Transactions only contain the sending and destination addresses, and the amount of bitcoin being transferred. They don't contain any personal information. As long as you don't leak your identity by activity *around* a transaction, they can be anonymous. For example, Coinbase is a company that sells bitcoins to individuals, and you can link your checking or credit card to fund the purchase. So Coinbase knows which coins you bought. But if you buy them in a private transaction from an individual for cash, less info can be revealed.
Easter Island gets 1,147 mm of rain a year, Mauna Kea Observatory gets 187. It's a better site for lots of other reasons (altitude, stability of the air, etc.)
> A group of native Hawaiians object on the grounds that the land has historic and spiritual significance.
It doesn't. The top of Mauna Kea was used by the natives as a *rock quarry* for stone tools. There is literally tons of archeological evidence of that:
http://www.mauna-a-wakea.info/...
https://photos1.blogger.com/bl...
Eminent domain isn't relevant in this case. The land already belongs to the State of Hawaii, under their Department of Land and Natural Resources. Basically the entire upper half of the Big Island by altitude is a nature reserve. The very top of Mauna Kea is a science reserve managed by the University of Hawaii (another state institution). It includes archaeological sites where natives used it as a *rock quarry* for stone tools, and the area where the telescopes are set up.
Nobody has ever lived up there, because there is not enough rainfall to support farming, and it gets quite cold at 14,000 ft. So there was nobody to kick out. Once westerners brought metal tools, they replaced the stone tools, so even the native quarry shut down.
> We have no business as a society stopping building on the basis of blasphemy anyway.
Except the top of Mauna Kea was never a holy site. It was a rock quarry, there is evidence all over the top of the mountain. Before Westerners brought metal tools, the natives used stone ones, and the lava that erupted up there during an ice age cooled quickly, making it chip-resistant. So they set up mining camps and dug up the mountain top. They didn't live up there, not enough rainfall to grow things. That's also the reason it is a good telescope site. So the natives commuted from lower altitudes, dug up stone tools, and went back down. Not exactly a religious pilgrimage.
> "The planned construction site is on land considered sacred by some Native Hawaiians."
What the *modern* natives fail to mention is that the *pre-western* natives used the top of the mountain as a rock quarry. It wasn't sacred at all. Turns out that lava erupted during an ice age, when there were glaciers on top, hardened rapidly, preventing crystal growth. Crystals fracture more easily, so the lack made for excellent stone tools, which the natives used before westerners brought metal tools.
The top of the mountain wasn't habitable for the same reason it makes an excellent telescope site - very little rain. The altitude also means it's cold, and it is high enough to induce altitude sickness if you are acclimated to sea level. So the natives didn't live up there, but rather set up mining camps to extract the rock, then took them back down. There is literally tons of archaeological evidence all over the Mauna Kea Science Reserve, the area on top of the mountain that the University of Hawaii controls. The astronomers are careful about not putting a telescope in archeology areas. There's rock debris, partial tools, shelters, etc. up there.
If it was originally an industrial site, I see no reason not to use it now for a scientific site. It's not like they are knocking down the Parthenon to build a telescope.
> Bitcoin is all the hype, but the blockchain has flaws, in that it isn't as anonymous as one would hope for — you can track past transactions.
Bitcoin transactions record sending and receiving addresses, and the amount sent, and that's it. Privacy depends on how careful you are outside the transaction itself. For example, if you buy something physical online, and give a delivery name and address, the store knows who those bitcoins came from. But compared to a credit card or paper check, which have your name printed on them, bitcoin transactions have the *possibility* of privacy. Cash is no longer anonymous, by the way. Banks and ATMs can scan serial numbers when cash goes out and comes in. Depending how many hand-to-hand transactions happen in between, they can figure out what you were doing.
> Rumors of Bitcoin showing cracks are popping up and also there are quite a few alternatives out there.
The Bitcoin Network is still running fine. They are getting close to a limit in the code originally intended to stop spam transactions. That limits the size of "blocks" of transactions to 1 MB. The current arguments are over how and when to raise that cap. A majority of the network has to upgrade to raise the limit. Yes, there are lots of alternatives, because all it takes is to fork the code and slap a new name on it (it's open source). But as this table ( http://coinmarketcap.com/ ) shows, Bitcoin is 7/8 of the market, and only three others have significant market capitalization and trading volume. Building a network of users, apps, etc. for an ecosystem is a lot harder than releasing a new cryptocoin.
> Is getting into dealing with crypto currency worthwhile already?
It was for me, but I started in mid-2011 (from an article on Slashdot, in fact). If it is worthwhile for *you* depends on a lot of things. If you send money to family in another country, or international wire transfers, it may be very worthwhile, because of the very high fees from the other methods. If you are an average US consumer with credit and debit cards and want to shop on Amazon, not so much.
> become easily trackable once NSA and the likes adapt their systems to doing exactly that?
The NSA can download a copy of the blockchain, just like everyone else. What they have, that the rest of us don't, is all the other data collection that can correlate a Bitcoin transaction to a person or place. Like if you are using a smartphone app to send bitcoins, they know who owns the phone and where you were at the time
> What digital currency has the technical and mind-share potential to supersede bitcoin?
What social network is going to replace MySpace? :-). What OS is going to replace Windows? Predicting the future is hard, especially before it happens
> Are there feasible cryptocurrencies that have the upsides of Bitcoin (such as a mathematical limit to their amount) but are fully anonymous in transactions?
Bitcoin can be anonymous, but you have to use it properly for that to happen. As I said above, data leakage *around* a transaction is how you de-anonymize it. The same would be true of alt-coins (the general name for cryptocurrencies besides Bitcoin). If you use them to buy something, the seller may leak your info.
> What do the economists and digi-currency nerds here have to contribute on that?
Economists in general don't have the software chops to understand how cryptocurrencies work, and have religious beliefs on how economies and money *should* work. Not all of them, but a lot of them. My own opinion is bitcoin is the most developed cryptocurrency, with the most users, apps, mining hardware, etc. The direction in the future won't be replacing bitcoin with another coin, but building layers on top of Bitcoin. It's a communication protocol for scriptable transaction messages, and people have barely figured out how to make use of that. As such, it is similar to the IP protocol stack.
The solution is to require a long term contract for high power uses. You want 10 MW? OK, you will have to sign a 5 year contract for it.
Two reasons. First, the insane competition to mine bitcoins is a temporary phenomenon. We will hit 75% of the 21 million total this July. At that point the reward for mining a block will drop in half, and so will the incentive to mine. Every 4 years half the remaining coins will be mined, and the reward will drop in half again. It was set up this way to encourage early adopters for the initial distribution of coins. Eventually transaction fees, which are ~1% of miner income today, will be the only income. Most miners will give up because it will be unprofitable, or they will get way more efficient. Either way the energy use will go down.
Second, there are half a million bank buildings around the world. Some of them are the largest skyscrapers in town. How much total energy do you think that consumes? Bitcoin mining doesn't use more energy for more transactions. It uses more energy when more people compete for the reward (25 BTC x $370 today, or $9,250 per block, $1.3 million per day, $486 million/year). Network bandwidth and disk space go up with more transactions, but they are not as energy intensive. A world that uses a lot of bitcoin transactions instead of bank branches actually would use less energy in total.
My reason is making money by expanding civilization into the Solar System. There are huge amounts of untapped energy and material resources out there. For a description of how the "mining and manufacturing based space program" would work, see:
https://en.wikibooks.org/wiki/... (part 1), and
https://en.wikibooks.org/wiki/... (part 2)