There have been attempts to smelt metals in space, and in fact such efforts may even be beneficial for terrestrial applications. So successful that it may even be possible to suggest an economic role for shipping ores and elemental feed stocks from the Earth into orbit, perform the smelting and manufacturing in space, and then shipping finished products back to the Earth again for use here.
That you might be able to extract those elements in space even cheaper than you can ship them up from the surface of the Earth seems to be icing on the cake. Certainly whole new classes of materials are likely going to be created in space simply because a major factor that influences all manufacturing process here on the Earth will be removed.
As far as finding materials and devices that can work in space, of course it is something that takes time to discover and to work out all of the issues. It should be pointed out that we as a species has been working and doing stuff in space for more than 50 years, and that materials as well as equipment to be working in space has been developed. This isn't even really new technology in a great many cases.
The largest problem seems to be simply somebody having the will to go up and bother trying. Luckily there are severaldifferentcompanies who are willing to put up or shut up on the prospect as well. They are putting their money where their mouth is at and really try. I would even dare to suggest that other companies are going to show up eventually with this emerging industrial sector.
The largest problem they are facing right now is that these places in space are on the frontier of human endeavors. This means they are still trying to design the tools which make the tools producing the tools needed for those environments. Those working toward developing the resources in space still need to design the things that are the equivalent of the machine screw, lathe, and drill press that are so necessary for making so many other kinds of tools and being able to harvest resources in an extra-terrestrial setting.
Still, I agree with your basic premise that the best way to open up the Solar System and get humanity out there is to simply turn people loose and to let them try thousands or even millions of different ideas and let the successful ideas come forward as well as forget the millions of mistakes that didn't work. Trying to force everything through some sort of committee who is going to make a grand plan for how everything will work and get clearance before even acting is real silly.
Then again, for some time I've suggested that CNN will cover NASA astronauts landing on Mars for the first time by having one of their reporters on site filming the landing and interviewing the astronauts when they arrive.
How do you square this statement with your "nobody has even bothered to find out..." claim? Longitudinal studies are far more difficult because it requires being able to keep nonhuman life forms alive in zero or low gravity for years. IMHO, the physical infrastructure for that hasn't existed until the ISS though it probably would have been possible to convert MIR or Skylab over to such an experiment.
I guess what I find wrong with the situation is seemingly intentional and deliberate ignorance on the topic yet pronouncing policies based upon this ignorance. It is one thing to make a conjecture and to suggest some sort of experiment to test the idea, but it is completely different to be setting policy or to be suggesting that people going to a place like Mars need to be sterilized before going.
The other thing is that non-human life forms have been kept alive for years in zero gravity. There are experiments that have indeed tested a variety of physiological effects of not just people but of a great many other things. Sex, unfortunately, is taboo even if it involves just a bunch of mice of different genders hanging out with each other. This is what I can't understand and needs to be pointed out.
The physical equipment is in place, and certainly has been there for more than a decade. We aren't talking science fiction here in terms of a space station that doesn't exist or rockets that have never been built which can put people into orbit. There is a "permanently" manned space station in orbit right now that has cost taxpayers billions of dollars to put up there, and I think this question as to if children can be reared in space or a low-gravity environment is something that is of critical importance to learn about as it does lead to a great many long terms policy questions.
If (human or otherwise) children can only be born on the Earth, it significantly transforms the entire debate about the exploitation of resources in space, about extraterrestrial real estate claims, and the whole issue of robotic vs. manned space exploration. The opposite is also very much true as well.
I am offering a conjecture that in a low gravity environment (aka Lunar or Martian gravity environments.... substantial enough that you notice the gravity but less than what you get on the Earth) that the impact will be minimal and in fact many of the issues of a microgravity environment (free fall in LEO or even on a body like Phobos) will be mitigated while in at least some kind of gravity environment.
That there will be some negative effects, no doubt. It isn't like being on an African savannah in a gravity field of 9.8 m/s^2. There are a whole bunch of places that aren't like an African savannah, yet we've adapted and developed technologies that have allowed us as a species to be able to survive and even thrive in those places. I don't see why Mars or the Moon is really all that different, but we will need to know what we are going to get into before we get there... especially if trying to find out is trivial in cost and within practical reach if only somebody would be permitted to perform that kind of research.
I'm sure that there will be thousands of volunteers from both sexes, but the problem is that we don't know what the effect of lowered gravity, etc on pregnancy, growing children, or even the decades long affect on adult humans. I can't begin to describe the ethical, legal and moral problems presented by such a venture, a careful scientist would have 20 years of animal studies in such an environment alone before trying to gestate/raise a human child under such conditions. Oh wait.
Considering that serious proposals are being drawn up at the moment to send people to Mars and significant policy plans are being made for sending people to Mars that amount in the range of billions of dollars, it seems sad that over all of the years that the ISS has been orbiting around this Earth that nobody has even bothered to find out what impacts upon any mammals of any kind might have in a reduced or zero gravity environment.
I guessing that there will be virtually no impacts at all, but the sad thing is that such research is unlikely to happen until it involves a human child. Sad because there have been numerous opportunities including sending creatures like mice and rabbits into space that could be used for such a study in the first place. Using such animals not only might be able to add some protein for the diets of the astronauts, but it could also provide generational studies as well to identify how such creatures may eventually adapt to non terrestrial environments.
The "don't know" of this issue is purely political, not the ability to find out. That doesn't even touch the artificial gravity module that was a part of the original ISS design that eventually was cancelled and never flew on the Space Shuttle.
Yes, I've seen the "studies" of things somewhat like this, but none of them were longitudinal studies, with the longest such experiment being a rat that was already pregnant when she flew into space... but gave birth in space. That was on a SpaceLab module and only lasted two weeks. Some other studies have happened in "simulated microgravity" but didn't even happen in space. Serious studies on trying to find out what happens with fetal development in space simply has not been done.
When the board was originally set up, the loyalty to Jimmy Wales was unquestioned. At this point, however, I don't think it is so axiomatic that they will go along with anything that Jimmy Wales would propose even though obviously it would be seriously considered and he can directly participate in board meetings.
The appointed board members supposedly are "specialists" who have a specific skill (legal, public relations, technical, or something like that) which can benefit the foundation and the projects. There have been a few changes from the original appointments where their loyalty is more to the board as a whole than to Jimmy Wales in particular. While I don't see them getting rid of Jimmy Wales or rocking the boat too much, they also won't blindly follow him to the ends of the Earth either.
There are also some pretty strong limits in terms of what Jimmy Wales can do, and has crossed the line more than a few times such as when he tried to delete "porn" on the Wikimedia Commons. His days of arbitrarily acting without community support is certainly over, even though I think if he raises a major issue it would be seriously considered.
Jimmy Wales gave up his authority and rights to the Wikipedia domain name, trademark and server farm when he set up the Wikimedia Foundation. While he still holds a seat on the board of trustees, he is but one of a nine member board and is no longer even the chair of that board.
There was an earlier little tiff where several members of the community tried to strip Jimmy Wales of his "founder" status so far as having any sort of access to administrator tools on the Wikimedia projects. Even on stuff like that, he has pretty much lost that authority although I think he still retains bureaucrat rights on the English language edition of Wikipedia.
In theory, his only real authority on Wikipedia is the same as another user. As a practical matter, he still has a pretty strong following of supporters who will back him up on some major issues, and if he proposes some changes to policies, his opinions will be heard and have some significant backers of his proposed changes. Jimmy Wales will also be otherwise highly considered since he was around since the beginning of the project and his involvement dates back to the Nupedia days.
Other than that "moral authority" and ability to influence discussions through his fans, he really lacks authority to make many changes. That is quite a bit of political power as it were, but he doesn't hold any god-king type authority to arbitrarily make changes to the project and make them stick. If he said "let's pull the plug and stop Wikipedia", the members of the community would say "thank you for your service, have a nice day" and ignore him from that point forward.
Wikipedia airs their dirty laundry in public because of the collaborative nature of the project and general transparency of the discussion forums. Most other similar organizations do this kind of discipline much more in private and certainly not while "deliberations" are going on to decide upon a course of action or even to consider if the issue is relevant and should be addressed.
If that makes the whole process seem like a house of disorder, that is by design. Committees are rarely neat and tidy.
I think it is incredibly slimy when Jimmy Wales' personal user talk page is made into a policy discussion forum.... as if Jimmy Wales has any real authority on Wikipedia any more. His talk page tends to be the last bastion of the trolls who aren't getting their way in other places and think that somehow Wales will bless their viewpoint and take action on something.
My experience when Jimmy Wales actually does something is that it is usually violating existing policies and often acts first and explains later... if ever. There are enough Wales fanbois to follow behind that the policies often change to rationalize the actions. Rarely the community pushes back, especially on English Wikipedia itself. The non-English projects seem to avoid that kind of cult-like following, so I think it is something unique to mostly en.wikipedia. On the other hand, when he weighs in on a controversial topic in the regular community forums by talking first and mostly leaving the actual implementation of the idea to others, his input is usually much more appreciated and considerably less damaging.
Back when Jimmy Wales actually owned the server farm running Wikipedia and the developers running that server farm were on his personal payroll, it might have made some sense to give him a little bit of extra authority on getting things done. That hasn't been the case for many years yet somehow the notion that he is "in charge" persists.
The first commercial orbital launch provider technically was Space Services Inc. which built the Conestoga rocket family. Unfortunately for them, NASA so totally destroyed their market that they bailed on even trying to fix the engineering problems in their rockets and instead decided to get into secondary services in the space industry instead. They never sent a commercial payload into orbit, but they were the first provider, discounting ORTAG that had even tougher problems than simply having NASA undercut their price.
I'll grant that Arianespace was one of the first to actively get into the commercial spaceflight business and actually perform a successful flight into orbit. Calling it a commercial launch provider is sort of stretching the envelope a bit as it is owned by national governments of Europe, but I suppose you could say the same thing about other European companies like Airbus that seem to have similar kinds of ownership patterns.
The first actual commercial space launch though has the honor of going to AT&T with its Telstar I satellite, that needed a special act of the U.S. Congress just to be permitted to go into space. The first launch happened in 1962, which is what I call the real beginning of commercial spaceflight.
yeah, missing the X-37 was a mistake of mine. I caught it after I hit the "submit" buttom.... but I figured that the gist of the conversation was apparent.
Regardless, it is in America where the most diversity of ideas are coming from in terms of crewed spaceflight vehicles is coming from. Two different reusable shuttle designs are coming from private industry, including the Lynx, being built by XCor and Dream chaser being built by Sierra Nevada.
I don't know what India might be doing along the same lines, but it doesn't appear to be just America either.
Perhaps NASA knows better than these other guys and that this really is a dead end technology. Then again NASA administrators are all in on the SLS program that seems to be adopting the worst aspects of the Shuttle Program and none of its advantages.
I should note that there certainly have been several different kinds of follow upprojects which have been proposed, including a couple of projects put forward by the U.S. Air Force that started with NASA participation and the USAF simply took over the projects altogether.
If it was such a bad idea, why have repeated efforts been done to extend the technology? It is being abandoned by the Manned Spaceflight Office, but it certainly hasn't been proven to be a bad idea... or rather there are several people who think it is still a good idea that needs to only be reworked and tweaked. The USAF is certainly going in one direction, while NASA is going in a completely different direction by instead looking back to the Saturn V and trying to act as though the last 40 years never happened.
Well the problem, at the moment, is that manned space flight IS mostly useless. There is very little being done that couldn't be done by machines, while spending money that could be better spent doing new things.
That may be true, but that seems to be a NASA management issue than necessarily a critique of manned spaceflight. I'd agree that the manned spaceflight program is horribly mismanaged.
Still, I'd like to point out that having Harrison Schmitt on the Moon performed far more science and accomplished more positive things that has helped with our understanding of the Solar System than almost all of the robotic probes sent even to the Moon but also everywhere else in the Solar System.... combined. The sad part was that his trip was only a weekend camping trip and should have had some follow up study as well to build upon that science he made.
I'm not saying that robotic probes are useless, but there does reach a point that you need to send people on the ground to the field if you want to advance the science. NASA actually got to that point in the 1960's, and there was also some very real engineering research going on with the Apollo program too.
As for the travesty that became the Space Shuttle program, I'd agree that the return on investment for that was much more paltry and much harder to justify. The two dozen or so alternative vehicle programs that have been developed and thrown away since the Space Shuttle program (currently with the multi billion dollar boondoggle known as SLS in particular) is an even larger waste of money as nobody even got to fly on those rockets. Constellation, with nearly $20 billion spent, only sent up a dummy rocket that was really nothing more than a Space Shuttle SRB with a fancy nose cone attached to the top that never even the journey into orbit.
It isn't that enough money is being thrown toward NASA, as NASA seems to have plenty of money. It just isn't being spent efficiently and certainly not rationally. Noting there hasn't been a new manned spacecraft developed under NASA contracts since the 1970's (and arguably the Shuttle program was even started in the 1960's... depending on when you want to say that idea was originally started), I'd say that is a pretty huge condemnation of NASA in general. The robotic programs certainly seem to have a much better record, which is why perhaps the robotic programs seem to have a better value... something is at least happening in that part of NASA.
There is more than enough food on the Earth to feed everybody with plenty to spare. If you took all of humanity and put them into an area roughly the size of Texas, you could not only house everybody and be able to provide for factories and such, but you could even have space for farms and almost everything else that we need as people. That could even leave the rest of the Earth available as a wilderness area.
I'm not saying I would enjoy living in such high density housing, but it is possible.
Even today, the largest impediments to getting food to people involve a combination of logistics and politics getting in the way that prevents the food getting to those people who need it the most. It has almost nothing to do with the capacity of the Earth being able to feed that many people. It isn't even an issue with money as there are plenty of "relief agencies" and people who have excess money and resources willing to send food to those who are less fortunate.
It is a problem when you have tyrants as the head of countries who deliberately wish to starve portions of their country for political purposes... usually because they have withheld their support for that tyrant and reject the soul crushing lack of freedom that comes from such leaders. Define tyranny how ever you want, but you can't feed yourself if you are a slave that isn't permitted to eat and kept from doing that at the point of a gun.
OSCAR satellites are still being launched and monitored, with a wide variety of people who are taking part in their operation and development. Most of the current interest in non-commercial private satellites (aka stuff being done by hobbyists rather than for a commercial purpose) involved development of Cubesats that allow you to literally just start to buy parts from several different component manufacturers and to build your own satellite on a shoestring budget (on the order of a few thousand dollars).
There are even companies that act like a travel agent who will find space for satellites built this way on an upcoming launch... where they take care of all of the paperwork and flight approval so the only thing you need to really do is just sign the check to get it all to happen. Since these cube sats are small and relatively lightweight (just a couple of kilograms at most), launch costs aren't even that expensive either... a few tens of thousands of dollars at most. Certainly well within the budget for a university professor and his research lab or for a amateur radio club to be able to pool their money together and purchase one of these satellites.
There were private efforts to buy a Shuttle, including several investors that wanted to simply be permitted to have Rockwell International (the company who built the Space Shuttle) to simply keep the production line going to make a couple Space Shuttles for private industry.
NASA wouldn't even let it happen. They controlled the design and it couldn't be used for anything but government work.
That those investors were lucky because it ended up costing way more to actually fly the Shuttle than NASA was originally advertising, the fact that private efforts to get into space had been happening at all should have been a sign that there were better ways to get things like that done.
There were a few astronauts who flew on the Space Shuttle that could be seen as from outside of the traditional NASA astronaut corps recruitment process. At least one Saudi prince and an Israeli engineer flew on the Space Shuttle, as well as a few NASA contractors has some of their personnel go up too. Serious proposals to send private citizens on their own dime were proposed, but didn't happen and in particular after the loss of the Challenger all such proposals were openly dismissed.
It really should be seen as a sad statement of the state of American spaceflight where the first private commercial spaceflight crews were launched with equipment designed by a Communist country.
So there just wasn't any other way to get this stimulative effect besides the Apollo program? Manned spaceflight as a whole seems like a bust too me. Way too expensive for far too little gain. Probes (and robots) have done so much more and cost so much less. Someday maybe it will be more economical to send a man to Mars. Until then, why the rush?
I wish that Carl Sagan had not stuck his head out and spread this blatant lie.
Remote probes and robots do have a role to play in the exploration of space, particularly because they are cheaper and can go to places that are hard or even impossible for people to be at. Don't mistake the rest of what I say as dismissing robotic exploration, as I think it is a good thing. The problem is with having robots be the only way to get stuff done in space and it sort of misses the whole point of why it is being done.
The point of a probe is to do the initial reconnaissance and to do general surveys. I should point out that is also being done here on the Earth. There reaches a point where the probes no longer really get the job done and the initial reconnaissance is done. I would even go out on a limb and say that the Curiosity rover is about as good as it gets with current technology. The next step to go further is to send people to Mars to at the very least control the robots from orbit around Mars or perhaps to even land on Mars and leverage their efforts by controlling the robots locally.
It also helps to have somebody on site to be able to do things like repair a wheel or to simply push a little bit when things get stuck.
None of this even begins to touch what impact having people living on other worlds can have for the range of human experience that will help enable new thoughts and thought processes that can in turn be used to reflect upon other problems that humanity is facing. Very frequently knowledge gained in one field of endeavor can be applied in a completely different field and be used to solve problems that were previously thought to be unsolvable.
To suggest that we may need to do more robotic missions or to be more intelligent about how those robotic missions are being performed, I'd have to agree. To suggest that the manned spaceflight program as a whole needs to be nuked and all of the "money" being dumped on that manned spaceflight effort should be redirected to robotic missions.... please don't get started. You are living in a fantasy land if you think that is going to happen in more ways I can count.
That makes as much sense as oceanographers who think that eliminating NASA is going to somehow increase their ocean research budgets. I've even heard that argument expressed before by oceanographers.
Powerful fairy god-senators and other people in high places. It seems like that was one of the last things Hillary Clinton did before she resigned from the U.S. Senate to become Secretary of State, and some other high profile people also had a significant role in getting the vehicle assigned to NYC.
Another consideration for NYC was also that it was in the center of a very large portion of the American population, where nearly a hundred million people were within a few hours drive of the museum that is housing the Shuttle.
That may not be the best reason for why it is there, but it is a reason.
The problem with the Space Shuttle wasn't the vehicle itself or even having it built. The problem is that it became a dead end technology because nothing was built upon the engineering learned from building it. The engineers who designed the Space Shuttle are now retired, and the follow on projects have also been canceled. If there has been a "Shuttle Mark 2" or some other follow up vehicle that largely did the same thing but using more modern materials, learned from engineering mistakes, and avoided some of the compromises that crippled the original Shuttle design.... it could have been amazing.
Instead, NASA threw it all away and essentially went back to the Saturn V, saying it was a mistake to abandon that line of technology 40 years ago. Well, sort of, as they still are using some of the rougher parts of the Shuttle technology such as the solid rocket boosters.
As for transcending spacecraft, if SpaceX ever gets their Falcon XX rocket built (capable of sending a fully loaded 747 into orbit complete with passengers, crew, baggage, fuel, and even oxygen tanks) it will transform the space launch industry in a huge way and make kids dream about the future in a huge way. The only problem is trying to find a customer that would need that kind of lift. The Falcon Heavy is a good spacecraft though, and will be capable of sending a spacecraft to the Moon. Not many people have done that and certainly no private spaceflight efforts have done anything like that yet.
I would say being patent and license free (aka it can be incorporated into a GPL'd application) would be pretty far down the list
You seem to miss the fact that licence costs are alse important for any commercial program that is suppost do encode data using the codec, as it is important for manufacturers of devices that are expected to use the codec. If a company has to pay licence fees for each smartphone or tablet it builds a new format will not take off. If it is free adoption is only a matter of programming to include the codec in the own product.
I've done plenty of software development for commercial development (including "all rights reserved" proprietary licenses) that I know this not to be true... in general. If the license cost is prohibitively high it becomes an issue, but to license something like the Dolby AC-3 or the MP3 codecs (to name a couple) it really is a trivial licensing cost for most software. Most of the reason you would use those codecs is because the boss (usually a clueless CEO who happened to attend a computer convention or saw a snazzy advertisement.... or because a competitor is using that codec) has told you that is the codec you will be using. Rarely have I seen even a technical evaluation of the quality of a codec, if that is audio or video, unless it becomes a very serious issue.
If the software is being developed on a shoestring budget, perhaps license costs are a bit more of an issue. Otherwise I have seen companies simply buy a fatter network pipe that carries more bandwidth rather than trying to become more efficient.
Low-end consumer electronics might be an issue for expensive licenses, but that isn't where you get market share either. I know it sounds weird, but it is the early adopters who get to set which codecs become popular. If there is a new technology or some other kind of gizmo that is just getting developed that has some "gee whiz" features (something like the original iPhone/iPad or really innovative like the Nintendo Wii), those are the devices that establish standards. DVD-Video made MPEG-2 a pervasive A/V codec and is the reason that codec has been used by HD-television in America.
The problem is that you really don't know ahead of time which of these kind of devices is going to be the hot consumer device. Companies like Apple and Microsoft are "safe bets" on mass consumer products, but even that isn't a guarantee.
Oh, it is possible to have at least some of the time a longer block chain than the rest of the network. We are dealing with probabilities here and not just pure deterministic algorithms with Bitcoin. Perhaps only 10% of the time that the cartel would have a longer chain than the rest of the network.... but if the cartel was organized properly it could get more than their "share" of the newly minted coins and transaction fees.
This is sort of a rework of the prisoner's dilemma if you want to know the category of mathematical problems it belongs under.
Sure you can. It does take a large portion of the network, and in fact it gets easier to do this if you have multiple competing cartels (including some "cartel" members in multiple cartels).
I've performed empirical simulations to see if this works and it seems to work as promised, although it hasn't been rigorously investigated as I would hope to give some specific numbers.
Yes, you need a longer block chain than the rest of the network. The point is once you have a longer chain then you can keep the longer chain going for awhile.
I've mentioned this on the Bitcoin forums before and it has been poked and prodded to death including several people who know quite a bit about the protocol who have supported this assertion. As a conjecture, I have suggested that the minimum size to execute such a cartel and be successful is to collude with about a third of the network.
You also can't be so greedy with this kind of attack as to prevent anybody else from taking blocks, as it does take some dumb luck as well, and you risk losing some blocks by trying to be greedy. You can skew some things to your favor by rejecting some competing blocks or slightly delay competing blocks. If a cartel can be two or more blocks ahead of the rest of the network and stay that far ahead, they have pretty much captured the network for a time.
One way to stop this kind of attack is to have the network reject new blocks that seem to have a skewed time stamp that seems substantially off from the current date-time stamp. That isn't a perfect solution though because the network protocol assumes that there isn't any central time server and that individual clients may have their clocks off by quite a bit. Apparently Satoshi anticipated this kind of attack after a fashion, but even he acknowledged that the lack of an authenticated "current time" schema in the Bitcoin protocol prevented this kind of attack from being completely stopped.
1 - Ten minutes max, usually. 2 - Not true, there are several wallet tools now that don't hold the blockchain locally.
The ten minutes is the typical amount of time that Satoshi established for generating a block chain. It could be longer or much shorter before a transaction is incorporated. In theory the next block may take even days to be generated, but as a practical matter you are correct that about ten minutes is typical and longer than a half hour is almost unheard of. I have seen two blocks generated less than ten seconds apart, and some that take much longer to be processed.
If you don't bother including any transaction fee in a transaction, it may get passed over until somebody who is generous decides to incorporate your transaction into the block. Most block processors are greedy little capitalists though that will process even the most minor and insignificant transaction with the least bit of a transaction fee, so including some sort of transaction fee is almost always guaranteed to get that transaction included into the next block. Most client software won't even let you inject a transaction without a fee, but it is still possible to send them into the network.
It is hard for the government of any country to know how many Bitcions you may have, as they can be stored in a "private" hash key that can only be known to you and recorded somewhere that a government can't discover. If there are laws of this nature that you must live under, it is up to you as if you want to comply with those laws voluntarily or not.
As for how to verify how many Bitcoins you may have or not have without the government discovering that quantity, that may be a bit harder. Not impossible as you could in theory even perform the verification "by hand" without a computer, or with a computer you are 100% certain has no spyware and no government agent would be able to view the calculations, but presumably a determined government might eventually figure a way out in terms of discovering the hash code necessary to find your current Bitcoin balance. It couldn't happen through a "brute force attack" (at least not until the heat death of the universe or the development of large scale quantum computers with thousands of qubits linked together) but a "TEMPEST" type attack on your computer system might be able to find the hash key necessary to investigate the current balance.
I could say the same thing about gold, but you need to take the gold and hide it in your basement or trade it in the "black market" where records aren't kept.
Don't worry. Until about the mid 1970's it was illegal for most Americans to even own gold bullion in large quantities without explicit government licenses and extensive record keeping. Your country isn't alone in idiotic laws of that nature. It wouldn't surprise me to see legislators and parliament members coming up with insane laws that prohibit transactions in Bitcoins and arresting people simply for having the software on their computer... even if from a virus or malware.
Anonymity is not guaranteed with Bitcoin, and it is wrong to suggest that it is. There is some partial anonymity built into the system, but built into the protocol is a way to track where each coin has been spent, so far as what hash addresses it has gone to and where those "Bitcoins" eventually were spent. It is possible to trace each and every bitcoin to the block where the "coin" was generated.
Public hash codes such as something published on a website (including a Slashdot signature) or posted in a public place and has other information associated with that hash code certainly does not preserve any sort of anonymity.
This said, you can move stuff around from a public hash code to a private one rather easily, or do something like move your bitcoins in and out of one of the various exchanges to hide your tracks if that is what you want to do. The real headaches with Bitcoins happen when you try to convert them from one currency to another, and seems to be where most of the actual fraud happens as well.
Not quite. There still is the "Cartel attack" that doesn't require 50% of the computing power of the network in order to become an actor. It is the one kind of attack that could succeed.
The attack goes something like this:
You have a "cartel" that represents a significant fraction of the network (but not 50%). Among themselves they calculate and publish among themselves successful hashes and develop chains of blocks that attempt to out compete the network as a whole. Only when a "competing" chain might overtake the cartel's internal chain would that internal chain need to be published.
The main advantage of the "Cartel attack" is that the cartel is able to capture a large number or even most of the newly minted Bitcoins and transaction fees. On the other hand, there is a risk that the cartel could lose out on a number of those opportunities as well.
As for a single computing facility or "actor" being able to capture 50% of the computing power of the whole network.... I find that highly unlikely. There have been huge server farms that have tried including significant malware bot nets that have tried. The U.S. government as a whole, if it really tried, might be able to get that to happen. It would also require the cooperation of so many bureaucrats that it wouldn't be worth the effort. You would be surprised at how many computers are calculating the hash blocks now.
Hash codes can still be sent around on "sneaker net" and other ways to ensure that Bitcoins can be transmitted to each other.
You don't need a 24/7 internet connection, all you really need is the ability to get your transactions processed eventually on the global network. Eventually means just that... it just has to be incorporated into the larger chain when it becomes convenient. As long as everybody acting locally agrees upon the values being exchanged there isn't even a loss of value among the bitcoins being exchanged. About the only thing "lost" is the ability to "coin" new Bitcoins and to receive payments for processing transactions as that sub-net will not be participating with the global network until it reconnected.
It is also possible to set up a "local network" that would be processing the payments between users using the regular Bitcoin system. It would need to be noted that such a local network would be in effect a different "bitcoin" currency though in terms of coining new bitcoins and payments received. That is something to keep in mind too.... there can be more than one Bitcoin network. In fact, there is a "test network" that has a different "root block" which is being used only for testing the Bitcoin network ideas and isn't really taken seriously by the rest of the developers as having value. You can set up your own "root block" if you care to only transmit values between close friends. Good luck on getting your own private Bitcoin accepted by anybody else though. In an extreme situation such private Bitcoin currencies certainly could be created (such as an independent Bitcoin network on Mars). There would obviously be an exchange rate between the alternate Bitcoin and the main "Earth" or "global" Bitcoin, but such alternate currencies certainly could be created.
Double spending can't happen because the subsequent attempts at making a purchase (or rather transferring the Bitcions) would be invalidated and wouldn't actually happen. The person "receiving" the Bitcoins might be pissed, but that is between you and the person who thought they were getting paid and didn't. Verification that the 2nd person didn't receive the Bitcoins is public knowledge, as it is in the Bitcoin chain itself and can be verified.
As for how to transmit information about transactions for eventual incorporation into the global transaction chains, you could use a system similar to RFC 1149. This system has been implemented in the past, and certainly could be used for transmitting transaction information instead of just Internet Protocol packets instead.
All of this of course would take somebody who knows the Bitcoin protocol very well, but it isn't impossible.
It is also possible to "print" Bitcoins as paper currency, but that is a whole other subject.
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There have been attempts to smelt metals in space, and in fact such efforts may even be beneficial for terrestrial applications. So successful that it may even be possible to suggest an economic role for shipping ores and elemental feed stocks from the Earth into orbit, perform the smelting and manufacturing in space, and then shipping finished products back to the Earth again for use here.
That you might be able to extract those elements in space even cheaper than you can ship them up from the surface of the Earth seems to be icing on the cake. Certainly whole new classes of materials are likely going to be created in space simply because a major factor that influences all manufacturing process here on the Earth will be removed.
As far as finding materials and devices that can work in space, of course it is something that takes time to discover and to work out all of the issues. It should be pointed out that we as a species has been working and doing stuff in space for more than 50 years, and that materials as well as equipment to be working in space has been developed. This isn't even really new technology in a great many cases.
The largest problem seems to be simply somebody having the will to go up and bother trying. Luckily there are several different companies who are willing to put up or shut up on the prospect as well. They are putting their money where their mouth is at and really try. I would even dare to suggest that other companies are going to show up eventually with this emerging industrial sector.
The largest problem they are facing right now is that these places in space are on the frontier of human endeavors. This means they are still trying to design the tools which make the tools producing the tools needed for those environments. Those working toward developing the resources in space still need to design the things that are the equivalent of the machine screw, lathe, and drill press that are so necessary for making so many other kinds of tools and being able to harvest resources in an extra-terrestrial setting.
Still, I agree with your basic premise that the best way to open up the Solar System and get humanity out there is to simply turn people loose and to let them try thousands or even millions of different ideas and let the successful ideas come forward as well as forget the millions of mistakes that didn't work. Trying to force everything through some sort of committee who is going to make a grand plan for how everything will work and get clearance before even acting is real silly.
Then again, for some time I've suggested that CNN will cover NASA astronauts landing on Mars for the first time by having one of their reporters on site filming the landing and interviewing the astronauts when they arrive.
How do you square this statement with your "nobody has even bothered to find out..." claim? Longitudinal studies are far more difficult because it requires being able to keep nonhuman life forms alive in zero or low gravity for years. IMHO, the physical infrastructure for that hasn't existed until the ISS though it probably would have been possible to convert MIR or Skylab over to such an experiment.
I guess what I find wrong with the situation is seemingly intentional and deliberate ignorance on the topic yet pronouncing policies based upon this ignorance. It is one thing to make a conjecture and to suggest some sort of experiment to test the idea, but it is completely different to be setting policy or to be suggesting that people going to a place like Mars need to be sterilized before going.
The other thing is that non-human life forms have been kept alive for years in zero gravity. There are experiments that have indeed tested a variety of physiological effects of not just people but of a great many other things. Sex, unfortunately, is taboo even if it involves just a bunch of mice of different genders hanging out with each other. This is what I can't understand and needs to be pointed out.
The physical equipment is in place, and certainly has been there for more than a decade. We aren't talking science fiction here in terms of a space station that doesn't exist or rockets that have never been built which can put people into orbit. There is a "permanently" manned space station in orbit right now that has cost taxpayers billions of dollars to put up there, and I think this question as to if children can be reared in space or a low-gravity environment is something that is of critical importance to learn about as it does lead to a great many long terms policy questions.
If (human or otherwise) children can only be born on the Earth, it significantly transforms the entire debate about the exploitation of resources in space, about extraterrestrial real estate claims, and the whole issue of robotic vs. manned space exploration. The opposite is also very much true as well.
I am offering a conjecture that in a low gravity environment (aka Lunar or Martian gravity environments.... substantial enough that you notice the gravity but less than what you get on the Earth) that the impact will be minimal and in fact many of the issues of a microgravity environment (free fall in LEO or even on a body like Phobos) will be mitigated while in at least some kind of gravity environment.
That there will be some negative effects, no doubt. It isn't like being on an African savannah in a gravity field of 9.8 m/s^2. There are a whole bunch of places that aren't like an African savannah, yet we've adapted and developed technologies that have allowed us as a species to be able to survive and even thrive in those places. I don't see why Mars or the Moon is really all that different, but we will need to know what we are going to get into before we get there... especially if trying to find out is trivial in cost and within practical reach if only somebody would be permitted to perform that kind of research.
I'm sure that there will be thousands of volunteers from both sexes, but the problem is that we don't know what the effect of lowered gravity, etc on pregnancy, growing children, or even the decades long affect on adult humans. I can't begin to describe the ethical, legal and moral problems presented by such a venture, a careful scientist would have 20 years of animal studies in such an environment alone before trying to gestate/raise a human child under such conditions. Oh wait.
Considering that serious proposals are being drawn up at the moment to send people to Mars and significant policy plans are being made for sending people to Mars that amount in the range of billions of dollars, it seems sad that over all of the years that the ISS has been orbiting around this Earth that nobody has even bothered to find out what impacts upon any mammals of any kind might have in a reduced or zero gravity environment.
I guessing that there will be virtually no impacts at all, but the sad thing is that such research is unlikely to happen until it involves a human child. Sad because there have been numerous opportunities including sending creatures like mice and rabbits into space that could be used for such a study in the first place. Using such animals not only might be able to add some protein for the diets of the astronauts, but it could also provide generational studies as well to identify how such creatures may eventually adapt to non terrestrial environments.
The "don't know" of this issue is purely political, not the ability to find out. That doesn't even touch the artificial gravity module that was a part of the original ISS design that eventually was cancelled and never flew on the Space Shuttle.
Yes, I've seen the "studies" of things somewhat like this, but none of them were longitudinal studies, with the longest such experiment being a rat that was already pregnant when she flew into space... but gave birth in space. That was on a SpaceLab module and only lasted two weeks. Some other studies have happened in "simulated microgravity" but didn't even happen in space. Serious studies on trying to find out what happens with fetal development in space simply has not been done.
When the board was originally set up, the loyalty to Jimmy Wales was unquestioned. At this point, however, I don't think it is so axiomatic that they will go along with anything that Jimmy Wales would propose even though obviously it would be seriously considered and he can directly participate in board meetings.
The appointed board members supposedly are "specialists" who have a specific skill (legal, public relations, technical, or something like that) which can benefit the foundation and the projects. There have been a few changes from the original appointments where their loyalty is more to the board as a whole than to Jimmy Wales in particular. While I don't see them getting rid of Jimmy Wales or rocking the boat too much, they also won't blindly follow him to the ends of the Earth either.
There are also some pretty strong limits in terms of what Jimmy Wales can do, and has crossed the line more than a few times such as when he tried to delete "porn" on the Wikimedia Commons. His days of arbitrarily acting without community support is certainly over, even though I think if he raises a major issue it would be seriously considered.
Jimmy Wales gave up his authority and rights to the Wikipedia domain name, trademark and server farm when he set up the Wikimedia Foundation. While he still holds a seat on the board of trustees, he is but one of a nine member board and is no longer even the chair of that board.
There was an earlier little tiff where several members of the community tried to strip Jimmy Wales of his "founder" status so far as having any sort of access to administrator tools on the Wikimedia projects. Even on stuff like that, he has pretty much lost that authority although I think he still retains bureaucrat rights on the English language edition of Wikipedia.
In theory, his only real authority on Wikipedia is the same as another user. As a practical matter, he still has a pretty strong following of supporters who will back him up on some major issues, and if he proposes some changes to policies, his opinions will be heard and have some significant backers of his proposed changes. Jimmy Wales will also be otherwise highly considered since he was around since the beginning of the project and his involvement dates back to the Nupedia days.
Other than that "moral authority" and ability to influence discussions through his fans, he really lacks authority to make many changes. That is quite a bit of political power as it were, but he doesn't hold any god-king type authority to arbitrarily make changes to the project and make them stick. If he said "let's pull the plug and stop Wikipedia", the members of the community would say "thank you for your service, have a nice day" and ignore him from that point forward.
Wikipedia airs their dirty laundry in public because of the collaborative nature of the project and general transparency of the discussion forums. Most other similar organizations do this kind of discipline much more in private and certainly not while "deliberations" are going on to decide upon a course of action or even to consider if the issue is relevant and should be addressed.
If that makes the whole process seem like a house of disorder, that is by design. Committees are rarely neat and tidy.
I think it is incredibly slimy when Jimmy Wales' personal user talk page is made into a policy discussion forum.... as if Jimmy Wales has any real authority on Wikipedia any more. His talk page tends to be the last bastion of the trolls who aren't getting their way in other places and think that somehow Wales will bless their viewpoint and take action on something.
My experience when Jimmy Wales actually does something is that it is usually violating existing policies and often acts first and explains later... if ever. There are enough Wales fanbois to follow behind that the policies often change to rationalize the actions. Rarely the community pushes back, especially on English Wikipedia itself. The non-English projects seem to avoid that kind of cult-like following, so I think it is something unique to mostly en.wikipedia. On the other hand, when he weighs in on a controversial topic in the regular community forums by talking first and mostly leaving the actual implementation of the idea to others, his input is usually much more appreciated and considerably less damaging.
Back when Jimmy Wales actually owned the server farm running Wikipedia and the developers running that server farm were on his personal payroll, it might have made some sense to give him a little bit of extra authority on getting things done. That hasn't been the case for many years yet somehow the notion that he is "in charge" persists.
The first commercial orbital launch provider technically was Space Services Inc. which built the Conestoga rocket family. Unfortunately for them, NASA so totally destroyed their market that they bailed on even trying to fix the engineering problems in their rockets and instead decided to get into secondary services in the space industry instead. They never sent a commercial payload into orbit, but they were the first provider, discounting ORTAG that had even tougher problems than simply having NASA undercut their price.
I'll grant that Arianespace was one of the first to actively get into the commercial spaceflight business and actually perform a successful flight into orbit. Calling it a commercial launch provider is sort of stretching the envelope a bit as it is owned by national governments of Europe, but I suppose you could say the same thing about other European companies like Airbus that seem to have similar kinds of ownership patterns.
The first actual commercial space launch though has the honor of going to AT&T with its Telstar I satellite, that needed a special act of the U.S. Congress just to be permitted to go into space. The first launch happened in 1962, which is what I call the real beginning of commercial spaceflight.
yeah, missing the X-37 was a mistake of mine. I caught it after I hit the "submit" buttom.... but I figured that the gist of the conversation was apparent.
Regardless, it is in America where the most diversity of ideas are coming from in terms of crewed spaceflight vehicles is coming from. Two different reusable shuttle designs are coming from private industry, including the Lynx, being built by XCor and Dream chaser being built by Sierra Nevada.
I don't know what India might be doing along the same lines, but it doesn't appear to be just America either.
Perhaps NASA knows better than these other guys and that this really is a dead end technology. Then again NASA administrators are all in on the SLS program that seems to be adopting the worst aspects of the Shuttle Program and none of its advantages.
I should note that there certainly have been several different kinds of follow up projects which have been proposed, including a couple of projects put forward by the U.S. Air Force that started with NASA participation and the USAF simply took over the projects altogether.
If it was such a bad idea, why have repeated efforts been done to extend the technology? It is being abandoned by the Manned Spaceflight Office, but it certainly hasn't been proven to be a bad idea... or rather there are several people who think it is still a good idea that needs to only be reworked and tweaked. The USAF is certainly going in one direction, while NASA is going in a completely different direction by instead looking back to the Saturn V and trying to act as though the last 40 years never happened.
Well the problem, at the moment, is that manned space flight IS mostly useless. There is very little being done that couldn't be done by machines, while spending money that could be better spent doing new things.
That may be true, but that seems to be a NASA management issue than necessarily a critique of manned spaceflight. I'd agree that the manned spaceflight program is horribly mismanaged.
Still, I'd like to point out that having Harrison Schmitt on the Moon performed far more science and accomplished more positive things that has helped with our understanding of the Solar System than almost all of the robotic probes sent even to the Moon but also everywhere else in the Solar System.... combined. The sad part was that his trip was only a weekend camping trip and should have had some follow up study as well to build upon that science he made.
I'm not saying that robotic probes are useless, but there does reach a point that you need to send people on the ground to the field if you want to advance the science. NASA actually got to that point in the 1960's, and there was also some very real engineering research going on with the Apollo program too.
As for the travesty that became the Space Shuttle program, I'd agree that the return on investment for that was much more paltry and much harder to justify. The two dozen or so alternative vehicle programs that have been developed and thrown away since the Space Shuttle program (currently with the multi billion dollar boondoggle known as SLS in particular) is an even larger waste of money as nobody even got to fly on those rockets. Constellation, with nearly $20 billion spent, only sent up a dummy rocket that was really nothing more than a Space Shuttle SRB with a fancy nose cone attached to the top that never even the journey into orbit.
It isn't that enough money is being thrown toward NASA, as NASA seems to have plenty of money. It just isn't being spent efficiently and certainly not rationally. Noting there hasn't been a new manned spacecraft developed under NASA contracts since the 1970's (and arguably the Shuttle program was even started in the 1960's... depending on when you want to say that idea was originally started), I'd say that is a pretty huge condemnation of NASA in general. The robotic programs certainly seem to have a much better record, which is why perhaps the robotic programs seem to have a better value... something is at least happening in that part of NASA.
There is more than enough food on the Earth to feed everybody with plenty to spare. If you took all of humanity and put them into an area roughly the size of Texas, you could not only house everybody and be able to provide for factories and such, but you could even have space for farms and almost everything else that we need as people. That could even leave the rest of the Earth available as a wilderness area.
I'm not saying I would enjoy living in such high density housing, but it is possible.
Even today, the largest impediments to getting food to people involve a combination of logistics and politics getting in the way that prevents the food getting to those people who need it the most. It has almost nothing to do with the capacity of the Earth being able to feed that many people. It isn't even an issue with money as there are plenty of "relief agencies" and people who have excess money and resources willing to send food to those who are less fortunate.
It is a problem when you have tyrants as the head of countries who deliberately wish to starve portions of their country for political purposes... usually because they have withheld their support for that tyrant and reject the soul crushing lack of freedom that comes from such leaders. Define tyranny how ever you want, but you can't feed yourself if you are a slave that isn't permitted to eat and kept from doing that at the point of a gun.
OSCAR satellites are still being launched and monitored, with a wide variety of people who are taking part in their operation and development. Most of the current interest in non-commercial private satellites (aka stuff being done by hobbyists rather than for a commercial purpose) involved development of Cubesats that allow you to literally just start to buy parts from several different component manufacturers and to build your own satellite on a shoestring budget (on the order of a few thousand dollars).
There are even companies that act like a travel agent who will find space for satellites built this way on an upcoming launch... where they take care of all of the paperwork and flight approval so the only thing you need to really do is just sign the check to get it all to happen. Since these cube sats are small and relatively lightweight (just a couple of kilograms at most), launch costs aren't even that expensive either... a few tens of thousands of dollars at most. Certainly well within the budget for a university professor and his research lab or for a amateur radio club to be able to pool their money together and purchase one of these satellites.
There were private efforts to buy a Shuttle, including several investors that wanted to simply be permitted to have Rockwell International (the company who built the Space Shuttle) to simply keep the production line going to make a couple Space Shuttles for private industry.
NASA wouldn't even let it happen. They controlled the design and it couldn't be used for anything but government work.
That those investors were lucky because it ended up costing way more to actually fly the Shuttle than NASA was originally advertising, the fact that private efforts to get into space had been happening at all should have been a sign that there were better ways to get things like that done.
There were a few astronauts who flew on the Space Shuttle that could be seen as from outside of the traditional NASA astronaut corps recruitment process. At least one Saudi prince and an Israeli engineer flew on the Space Shuttle, as well as a few NASA contractors has some of their personnel go up too. Serious proposals to send private citizens on their own dime were proposed, but didn't happen and in particular after the loss of the Challenger all such proposals were openly dismissed.
It really should be seen as a sad statement of the state of American spaceflight where the first private commercial spaceflight crews were launched with equipment designed by a Communist country.
So there just wasn't any other way to get this stimulative effect besides the Apollo program? Manned spaceflight as a whole seems like a bust too me. Way too expensive for far too little gain. Probes (and robots) have done so much more and cost so much less. Someday maybe it will be more economical to send a man to Mars. Until then, why the rush?
I wish that Carl Sagan had not stuck his head out and spread this blatant lie.
Remote probes and robots do have a role to play in the exploration of space, particularly because they are cheaper and can go to places that are hard or even impossible for people to be at. Don't mistake the rest of what I say as dismissing robotic exploration, as I think it is a good thing. The problem is with having robots be the only way to get stuff done in space and it sort of misses the whole point of why it is being done.
The point of a probe is to do the initial reconnaissance and to do general surveys. I should point out that is also being done here on the Earth. There reaches a point where the probes no longer really get the job done and the initial reconnaissance is done. I would even go out on a limb and say that the Curiosity rover is about as good as it gets with current technology. The next step to go further is to send people to Mars to at the very least control the robots from orbit around Mars or perhaps to even land on Mars and leverage their efforts by controlling the robots locally.
It also helps to have somebody on site to be able to do things like repair a wheel or to simply push a little bit when things get stuck.
None of this even begins to touch what impact having people living on other worlds can have for the range of human experience that will help enable new thoughts and thought processes that can in turn be used to reflect upon other problems that humanity is facing. Very frequently knowledge gained in one field of endeavor can be applied in a completely different field and be used to solve problems that were previously thought to be unsolvable.
To suggest that we may need to do more robotic missions or to be more intelligent about how those robotic missions are being performed, I'd have to agree. To suggest that the manned spaceflight program as a whole needs to be nuked and all of the "money" being dumped on that manned spaceflight effort should be redirected to robotic missions.... please don't get started. You are living in a fantasy land if you think that is going to happen in more ways I can count.
That makes as much sense as oceanographers who think that eliminating NASA is going to somehow increase their ocean research budgets. I've even heard that argument expressed before by oceanographers.
Powerful fairy god-senators and other people in high places. It seems like that was one of the last things Hillary Clinton did before she resigned from the U.S. Senate to become Secretary of State, and some other high profile people also had a significant role in getting the vehicle assigned to NYC.
Another consideration for NYC was also that it was in the center of a very large portion of the American population, where nearly a hundred million people were within a few hours drive of the museum that is housing the Shuttle.
That may not be the best reason for why it is there, but it is a reason.
The problem with the Space Shuttle wasn't the vehicle itself or even having it built. The problem is that it became a dead end technology because nothing was built upon the engineering learned from building it. The engineers who designed the Space Shuttle are now retired, and the follow on projects have also been canceled. If there has been a "Shuttle Mark 2" or some other follow up vehicle that largely did the same thing but using more modern materials, learned from engineering mistakes, and avoided some of the compromises that crippled the original Shuttle design.... it could have been amazing.
Instead, NASA threw it all away and essentially went back to the Saturn V, saying it was a mistake to abandon that line of technology 40 years ago. Well, sort of, as they still are using some of the rougher parts of the Shuttle technology such as the solid rocket boosters.
As for transcending spacecraft, if SpaceX ever gets their Falcon XX rocket built (capable of sending a fully loaded 747 into orbit complete with passengers, crew, baggage, fuel, and even oxygen tanks) it will transform the space launch industry in a huge way and make kids dream about the future in a huge way. The only problem is trying to find a customer that would need that kind of lift. The Falcon Heavy is a good spacecraft though, and will be capable of sending a spacecraft to the Moon. Not many people have done that and certainly no private spaceflight efforts have done anything like that yet.
I would say being patent and license free (aka it can be incorporated into a GPL'd application) would be pretty far down the list
You seem to miss the fact that licence costs are alse important for any commercial program that is suppost do encode data using the codec, as it is important for manufacturers of devices that are expected to use the codec.
If a company has to pay licence fees for each smartphone or tablet it builds a new format will not take off. If it is free adoption is only a matter of programming to include the codec in the own product.
I've done plenty of software development for commercial development (including "all rights reserved" proprietary licenses) that I know this not to be true... in general. If the license cost is prohibitively high it becomes an issue, but to license something like the Dolby AC-3 or the MP3 codecs (to name a couple) it really is a trivial licensing cost for most software. Most of the reason you would use those codecs is because the boss (usually a clueless CEO who happened to attend a computer convention or saw a snazzy advertisement.... or because a competitor is using that codec) has told you that is the codec you will be using. Rarely have I seen even a technical evaluation of the quality of a codec, if that is audio or video, unless it becomes a very serious issue.
If the software is being developed on a shoestring budget, perhaps license costs are a bit more of an issue. Otherwise I have seen companies simply buy a fatter network pipe that carries more bandwidth rather than trying to become more efficient.
Low-end consumer electronics might be an issue for expensive licenses, but that isn't where you get market share either. I know it sounds weird, but it is the early adopters who get to set which codecs become popular. If there is a new technology or some other kind of gizmo that is just getting developed that has some "gee whiz" features (something like the original iPhone/iPad or really innovative like the Nintendo Wii), those are the devices that establish standards. DVD-Video made MPEG-2 a pervasive A/V codec and is the reason that codec has been used by HD-television in America.
The problem is that you really don't know ahead of time which of these kind of devices is going to be the hot consumer device. Companies like Apple and Microsoft are "safe bets" on mass consumer products, but even that isn't a guarantee.
Oh, it is possible to have at least some of the time a longer block chain than the rest of the network. We are dealing with probabilities here and not just pure deterministic algorithms with Bitcoin. Perhaps only 10% of the time that the cartel would have a longer chain than the rest of the network.... but if the cartel was organized properly it could get more than their "share" of the newly minted coins and transaction fees.
This is sort of a rework of the prisoner's dilemma if you want to know the category of mathematical problems it belongs under.
Sure you can. It does take a large portion of the network, and in fact it gets easier to do this if you have multiple competing cartels (including some "cartel" members in multiple cartels).
I've performed empirical simulations to see if this works and it seems to work as promised, although it hasn't been rigorously investigated as I would hope to give some specific numbers.
Yes, you need a longer block chain than the rest of the network. The point is once you have a longer chain then you can keep the longer chain going for awhile.
I've mentioned this on the Bitcoin forums before and it has been poked and prodded to death including several people who know quite a bit about the protocol who have supported this assertion. As a conjecture, I have suggested that the minimum size to execute such a cartel and be successful is to collude with about a third of the network.
You also can't be so greedy with this kind of attack as to prevent anybody else from taking blocks, as it does take some dumb luck as well, and you risk losing some blocks by trying to be greedy. You can skew some things to your favor by rejecting some competing blocks or slightly delay competing blocks. If a cartel can be two or more blocks ahead of the rest of the network and stay that far ahead, they have pretty much captured the network for a time.
One way to stop this kind of attack is to have the network reject new blocks that seem to have a skewed time stamp that seems substantially off from the current date-time stamp. That isn't a perfect solution though because the network protocol assumes that there isn't any central time server and that individual clients may have their clocks off by quite a bit. Apparently Satoshi anticipated this kind of attack after a fashion, but even he acknowledged that the lack of an authenticated "current time" schema in the Bitcoin protocol prevented this kind of attack from being completely stopped.
1 - Ten minutes max, usually.
2 - Not true, there are several wallet tools now that don't hold the blockchain locally.
The ten minutes is the typical amount of time that Satoshi established for generating a block chain. It could be longer or much shorter before a transaction is incorporated. In theory the next block may take even days to be generated, but as a practical matter you are correct that about ten minutes is typical and longer than a half hour is almost unheard of. I have seen two blocks generated less than ten seconds apart, and some that take much longer to be processed.
If you don't bother including any transaction fee in a transaction, it may get passed over until somebody who is generous decides to incorporate your transaction into the block. Most block processors are greedy little capitalists though that will process even the most minor and insignificant transaction with the least bit of a transaction fee, so including some sort of transaction fee is almost always guaranteed to get that transaction included into the next block. Most client software won't even let you inject a transaction without a fee, but it is still possible to send them into the network.
It is hard for the government of any country to know how many Bitcions you may have, as they can be stored in a "private" hash key that can only be known to you and recorded somewhere that a government can't discover. If there are laws of this nature that you must live under, it is up to you as if you want to comply with those laws voluntarily or not.
As for how to verify how many Bitcoins you may have or not have without the government discovering that quantity, that may be a bit harder. Not impossible as you could in theory even perform the verification "by hand" without a computer, or with a computer you are 100% certain has no spyware and no government agent would be able to view the calculations, but presumably a determined government might eventually figure a way out in terms of discovering the hash code necessary to find your current Bitcoin balance. It couldn't happen through a "brute force attack" (at least not until the heat death of the universe or the development of large scale quantum computers with thousands of qubits linked together) but a "TEMPEST" type attack on your computer system might be able to find the hash key necessary to investigate the current balance.
I could say the same thing about gold, but you need to take the gold and hide it in your basement or trade it in the "black market" where records aren't kept.
Don't worry. Until about the mid 1970's it was illegal for most Americans to even own gold bullion in large quantities without explicit government licenses and extensive record keeping. Your country isn't alone in idiotic laws of that nature. It wouldn't surprise me to see legislators and parliament members coming up with insane laws that prohibit transactions in Bitcoins and arresting people simply for having the software on their computer... even if from a virus or malware.
Anonymity is not guaranteed with Bitcoin, and it is wrong to suggest that it is. There is some partial anonymity built into the system, but built into the protocol is a way to track where each coin has been spent, so far as what hash addresses it has gone to and where those "Bitcoins" eventually were spent. It is possible to trace each and every bitcoin to the block where the "coin" was generated.
Public hash codes such as something published on a website (including a Slashdot signature) or posted in a public place and has other information associated with that hash code certainly does not preserve any sort of anonymity.
This said, you can move stuff around from a public hash code to a private one rather easily, or do something like move your bitcoins in and out of one of the various exchanges to hide your tracks if that is what you want to do. The real headaches with Bitcoins happen when you try to convert them from one currency to another, and seems to be where most of the actual fraud happens as well.
Not quite. There still is the "Cartel attack" that doesn't require 50% of the computing power of the network in order to become an actor. It is the one kind of attack that could succeed.
The attack goes something like this:
You have a "cartel" that represents a significant fraction of the network (but not 50%). Among themselves they calculate and publish among themselves successful hashes and develop chains of blocks that attempt to out compete the network as a whole. Only when a "competing" chain might overtake the cartel's internal chain would that internal chain need to be published.
The main advantage of the "Cartel attack" is that the cartel is able to capture a large number or even most of the newly minted Bitcoins and transaction fees. On the other hand, there is a risk that the cartel could lose out on a number of those opportunities as well.
As for a single computing facility or "actor" being able to capture 50% of the computing power of the whole network.... I find that highly unlikely. There have been huge server farms that have tried including significant malware bot nets that have tried. The U.S. government as a whole, if it really tried, might be able to get that to happen. It would also require the cooperation of so many bureaucrats that it wouldn't be worth the effort. You would be surprised at how many computers are calculating the hash blocks now.
Hash codes can still be sent around on "sneaker net" and other ways to ensure that Bitcoins can be transmitted to each other.
You don't need a 24/7 internet connection, all you really need is the ability to get your transactions processed eventually on the global network. Eventually means just that... it just has to be incorporated into the larger chain when it becomes convenient. As long as everybody acting locally agrees upon the values being exchanged there isn't even a loss of value among the bitcoins being exchanged. About the only thing "lost" is the ability to "coin" new Bitcoins and to receive payments for processing transactions as that sub-net will not be participating with the global network until it reconnected.
It is also possible to set up a "local network" that would be processing the payments between users using the regular Bitcoin system. It would need to be noted that such a local network would be in effect a different "bitcoin" currency though in terms of coining new bitcoins and payments received. That is something to keep in mind too.... there can be more than one Bitcoin network. In fact, there is a "test network" that has a different "root block" which is being used only for testing the Bitcoin network ideas and isn't really taken seriously by the rest of the developers as having value. You can set up your own "root block" if you care to only transmit values between close friends. Good luck on getting your own private Bitcoin accepted by anybody else though. In an extreme situation such private Bitcoin currencies certainly could be created (such as an independent Bitcoin network on Mars). There would obviously be an exchange rate between the alternate Bitcoin and the main "Earth" or "global" Bitcoin, but such alternate currencies certainly could be created.
Double spending can't happen because the subsequent attempts at making a purchase (or rather transferring the Bitcions) would be invalidated and wouldn't actually happen. The person "receiving" the Bitcoins might be pissed, but that is between you and the person who thought they were getting paid and didn't. Verification that the 2nd person didn't receive the Bitcoins is public knowledge, as it is in the Bitcoin chain itself and can be verified.
As for how to transmit information about transactions for eventual incorporation into the global transaction chains, you could use a system similar to RFC 1149. This system has been implemented in the past, and certainly could be used for transmitting transaction information instead of just Internet Protocol packets instead.
All of this of course would take somebody who knows the Bitcoin protocol very well, but it isn't impossible.
It is also possible to "print" Bitcoins as paper currency, but that is a whole other subject.