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Luís F. Simões

New algorithm offers ability to influence systems such as living cells or social networks - 3 views

  • a new computational model that can analyze any type of complex network -- biological, social or electronic -- and reveal the critical points that can be used to control the entire system.
  • Slotine and his colleagues applied traditional control theory to these recent advances, devising a new model for controlling complex, self-assembling networks.
  • Yang-Yu Liu, Jean-Jacques Slotine, Albert-László Barabási. Controllability of complex networks. Nature, 2011; 473 (7346): 167 DOI: 10.1038/nature10011
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    Sounds too super to be true, no?
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    cover story in the May 12 issue of Nature
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    For each, they calculated the percentage of points that need to be controlled in order to gain control of the entire system.
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    > Sounds too super to be true, no? Yeah, how else may it sound, being a combination of hi-quality (I assume) research targeted at attracting funding, raised to the power of Science Daily's pop-pseudo-scientific journalists' bu****it? Original article starts with a cool sentence too: > The ultimate proof of our understanding of natural or technological systems is reflected in our ability to control them. ...a good starting point for a never-ending philosophers' debate... Now seriously, because of a big name behind the study, I'm very curious to read the original article. Although I expect the conclusion to be that in practical cases (i.e. the cases of "networks" you *would like to* "control"), you need to control all nodes or something equally impractical...
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    then I am looking forward to reading your conclusions here after you will have actually read the paper
pacome delva

[1107.5728] The network of global corporate control - 1 views

  • Abstract: The structure of the control network of transnational corporations affects global market competition and financial stability. So far, only small national samples were studied and there was no appropriate methodology to assess control globally. We present the first investigation of the architecture of the international ownership network, along with the computation of the control held by each global player. We find that transnational corporations form a giant bow-tie structure and that a large portion of control flows to a small tightly-knit core of financial institutions. This core can be seen as an economic "super-entity" that raises new important issues both for researchers and policy makers.
Luzi Bergamin

Gesture controlled Linux Desktop - 6 views

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    Demo of a Linux Desktop controlled by a PS3 move controller.
Thijs Versloot

Light brought to a complete stop - 3 views

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    "When a control laser is fired at the crystal, a complex quantum-level reaction turns it the opaque crystal transparent. A second light source is beamed into the crystal before the control laser is shut off, returning the crystal to its opaque state. This leaves the light trapped inside the crystal, and the opacity of the crystal keeps the light trapped inside from bouncing around, effectively bringing light to a full stop." is the simple explanation, but I am not sure how this is actually possible with the current laws of physics
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    There are two ways to make slow light: material slow light and structural slow light, where you either change the material or the structural properties of your system. Here they used EIT to make material slow light, by inducing transparency inside an otherwise opaque material. As you change the absorption properties of a material you also change its dispersion properties, the so-called Kramers-Kronig relations. A rapid positive change in the dispersion properties of a material will give rise to slow light. To effectively stop light they switched off the control beam, bringing back the opaque state. Another control beam is then used to retrieve the probe pulse that was 'frozen' inside the medium. Light will be halted according to the population lifetime on the energy level (~ 100s). They used an evolutionary algorithm to find an optimal pulse preparation sequence to reach close to the maximum possible storage duration of 100s. Interesting paper!
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    So it is not real storage then in a sense, as you are stimulating an excitation population which retains the phase information of your original pulse? Still it is amazing that they could store this up to 100s and retrieve it with a probe pulse, but light has never been halted.
jcunha

Interference of thermal waves - Can heat be controlled as waves? - 1 views

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    Imagine a material that only admits thermal conduction for certain temperatures. Martin Maldovan from Georgia Tech holds a tiny thermoelectric device that turns cold on one side when current is applied. Recent research has focused on the possibility of using interference effects in phonon waves to control heat transport in materials. These are exciting news (see Nature Materials paper here http://www.nature.com/nmat/journal/v14/n7/full/nmat4308.html). Heterostructure research lead to outstanding new possibilities when applied to electronic transport (e.g. in quantum well and quantum dots) and to photonics (e.g. Quantum Cascade Laser tunnable lasers). Apparently the time has come to see selective thermal control in this way! Truly exciting!!
Luís F. Simões

TED Talks: Gero Miesenboeck reengineers a brain - 1 views

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    "Using light and a little genetic engineering -- optogenetics -- Gero Miesenboeck has developed a way to control how living nerve cells work, and advanced understanding of how the brain controls behavior."
Dario Izzo

Robotics and optimal control - 6 views

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    Home page of teodorov.... He believes optimal control is the path to robot movement.... Not AI!!!
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    we were having a discussion about that here recently =) will look into that, grazie mille
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    Isn't it obvious! :)
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    I need to modify the first comment "He belives the path to AI goes through optimal control"... Big difference...
ESA ACT

European Control Conference 2007 (ECC'07) - 0 views

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    at least we can see how is important in (optimal) control using intervals
johannessimon81

Rat Neurons Grown On A Computer Chip Fly A Simulated Aircraft - 1 views

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    This could become quite relevant in future control systems if the setup can be made simple to keep alive and stable. I was doing some follow-up on a story about people controlling aircraft with their brainwaves (through EEG) when I ran into this really cool story. The idea of growing the neurons in patterns is incidentally very similar to the Physarium slime-mold stuff that Dario and me were curious about a little while ago.
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    I think we already had a discussion on this during a wednesday meeting :P
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    Oh, I thought that was on the little robot that was controlled by rat neurons and bumped into EVERYTHING. The interesting thing here is that they add a surface patterning (with some kind of nutrient) to control the growth of cells. (Maybe that is not new either, though.)
Guido de Croon

Robotic insects make first controlled flight - 3 views

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    The Robobee takes off without guide wires! It is still powered via a wire, and the control is done with the help of a VICON system and on an external computer, but this still is an amazing feat!
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    The way they make this thing is just as impressive. The manufacturing technique is "pop-up book" folding, a method that has been developed by the same group and that allows a two dimensional monolithic MEMS structures to be easily assembled into a 3D structure. I actually put this as an item of the "Technology List 2020" on the wiki this morning.
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    I agree, manufacturing is the amazing thing here ..... as soon as the power-consumption/density problem is solved these things will really take off :)
H H

The European Space Agency's Jupiter Mission Control Made of Lego - 3 views

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    The French Space Agency (CNES) commissioned Damien Labrousse to recreate the Jupiter Mission Control Room in Lego for display at the Kourou spaceport. The impressive build features 6,000 bricks, 80 minifigs, a working video screen that shows the rocket launch sequence and a sound system, displaying launch countdown.
Tom Gheysens

Biomimicr-E: Nature-Inspired Energy Systems | AAAS - 4 views

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    some biomimicry used in energy systems... maybe it sparks some ideas
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    not much new that has not been shared here before ... BUT: we have done relativley little on any of them. for good reasons?? don't know - maybe time to look into some of these again more closely Energy Efficiency( Termite mounds inspired regulated airflow for temperature control of large structures, preventing wasteful air conditioning and saving 10% energy.[1] Whale fins shapes informed the design of new-age wind turbine blades, with bumps/tubercles reducing drag by 30% and boosting power by 20%.[2][3][4] Stingray motion has motivated studies on this type of low-effort flapping glide, which takes advantage of the leading edge vortex, for new-age underwater robots and submarines.[5][6] Studies of microstructures found on shark skin that decrease drag and prevent accumulation of algae, barnacles, and mussels attached to their body have led to "anti-biofouling" technologies meant to address the 15% of marine vessel fuel use due to drag.[7][8][9][10] Energy Generation( Passive heliotropism exhibited by sunflowers has inspired research on a liquid crystalline elastomer and carbon nanotube system that improves the efficiency of solar panels by 10%, without using GPS and active repositioning panels to track the sun.[11][12][13] Mimicking the fluid dynamics principles utilized by schools of fish could help to optimize the arrangement of individual wind turbines in wind farms.[14] The nanoscale anti-reflection structures found on certain butterfly wings has led to a model to effectively harness solar energy.[15][16][17] Energy Storage( Inspired by the sunlight-to-energy conversion in plants, researchers are utilizing a protein in spinach to create a sort of photovoltaic cell that generates hydrogen from water (i.e. hydrogen fuel cell).[18][19] Utilizing a property of genetically-engineered viruses, specifically their ability to recognize and bind to certain materials (carbon nanotubes in this case), researchers have developed virus-based "scaffolds" that
johannessimon81

Norwegian army driving tank using Oculus Rift - 1 views

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    I guess it might also make sense to put a camera on an extension to look around corners without having to advance the vehicle to where it can be shot at... ?: Could the Oculus be used to let humans control humanoid robots? I guess so. Could humans perform experiments using such robots? Probably. Could Oculus be used to control these robots on the ISS? I guess so. --> Finally we eliminated the last need for humans in space!!! :-D (Maybe we could replace humans on Earth with robots that control one another through Oculus Rift...)
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    Even cooler would be to have like a swarm of drones around the tank to act as a sensor array and look around corners for you.
Dario Izzo

Optimal Control Probem in the CR3BP solved!!! - 7 views

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    This guy solved a problem many people are trying to solve!!! The optimal control problem for the three body problem (restricted, circular) can be solved using continuation of the secondary gravity parameter and some clever adaptation of the boundary conditions!! His presentation was an eye opener ... making the work of many pretty useless now :)
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    Riemann hypothesis should be next... Which paper on the linked website is this exactly?
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    hmmm, last year at the AIAA conference in Toronto I presented a continuation approach to design a DRO (three-body problem). Nothing new here unfortunately. I know the work of Caillau, although interesting what is presented was solved 10 years ago by others. The interest of his work is not in the applications (CR3BP), but in the research of particular regularity conditions that unfortunately make the problem limited practically. Look also at the work of Mingotti, Russel, Topputo and other for the (C)RTBP. Smart-One inspired a bunch of researchers :)
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    Topputo and some of the others 'inspired' researchers you mention are actually here at the conference and they are all quite depressed :) Caillau really solves the problem: as a one single phase transfer, no tricks, no misconvergence, in general and using none of the usual cheats. What was produced so far by other were only local solutions valid for the particular case considered. In any case I will give him your paper, so that he knows he is working on already solved stuff :)
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    Answer to Marek: the paper you may look at is: Discrete and differential homotopy in circular restricted three-body control
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    Ah! with one single phase and a first order method then it is amazing (but it is still just the very particular CRTBP case). The trick is however the homotopy map he selected! Why this one? Any conjugate point? Did I misunderstood the title ? I solved in one phase with second order methods for the less restrictive problem RTBP or simply 3-body... but as a strict answer to your title the problem has been solved before. Nota: In "Russell, R. P., "Primer Vector Theory Applied to Global Low-Thrust Trade Studies," JGCD, Vol. 30, No. 2", he does solve the RTBP with a first order method in one phase.
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    I think what is interesting is not what he solved, but how he solved the problem. But, are means more important than end ... I dunno
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    I also loved his method, and it looked to me that is far more general than the CRTBP. As for the title of this post, OK maybe it is an exageration as it suggests that no solution was ever given before, on the other end, as Marek would say "come on guys!!!!!"
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    The generality has to be checked. Don't you think his choice of mapping is too specific? he doesn't really demonstrate it works better than other. In addition, the minimum time choice make the problem very regular (i guess you've experienced that solving min time is much easier than mass max, optimality-wise). There is still a long way before maximum mass+RTBP, Topputo et al should be re-assured :p Did you give him my paper, he may find it interesting since I mention the homotopy on mu but for max mass:)
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    Joris, that is the point I was excited abut, at the conference HE DID present solutions to the maximum mass problem!! One phase, from LEO to an orbit around the moon .. amazing :) You will find his presentation on line.... (according to the organizers) I gave him the reference to you paper anyway, but no pdf though as you did not upload it on our web pages and I could not find it in the web. So I gave him some bibliography I had with be from the russians, and from Russell, Petropoulos and Howell, As far as I know these are the only ones that can hope to compete with this guy!!
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    for info only, my phd, in one phase: http://pdf.aiaa.org/preview/CDReadyMAST08_1856/PV2008_7363.pdf I prefered Mars than the dead rock Moon though!
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    If you send me the pdf I can give it to the guy .. the link you gave contains only the first page ... (I have no access till monday to the AIAA thingy)
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    this is why I like this Diigo thingy so much more than delicious ...
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    What do you mean by this comment, Leopold? ;-) Jokes apart: I am following the Diigo thingy with Google Reader (rss). Obviously, I am getting the new postings. But if someone later on adds a comment to a post, then I can miss it, because the rss doesn't get updated. Not that it's a big problem, but do you guys have a better solution for this? How are you following these comments? (I know that if you have commented an entry, then you get the later updates in email.) (For example, in google reader I can see only the first 5 comments in this entry.)
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    I like when there are discussions evolving around entries
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    and on your problem with the RSS Tamas: its the same for me, you get the comments only for entries that you have posted or that you have commented on ...
Juxi Leitner

SPACE.com -- Solar Sail Spacecraft Steers with Sunlight for First Time - 0 views

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    The Japan Aerospace Exploration Agency spacecraft Ikaros now represents the first solar sail to have harnessed sunlight for both attitude control and propulsion, after it first launched May 21 alongside the Venus-bound orbiter Akatsuki.
Giusi Schiavone

Selective attention processes - 2 views

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    they use invasive BCI for accessing to single neural cell on patiences with epilepsy.
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    scary ...
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    why? I think they used patients with epilepsy because they already had an implants with electrodes, for other reasons. Otherwise in normal subjects they could not obtain these results. I wonder who (among normal subject) would like to have electrodes implanted in the brain....thus they use subjects that already have an implant.
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    well if I got it correctly then the had to cut and fizzle around in these brains ... always scaring, and then they claim that we have in our brains in single neurons abstract images e.g. of marilyn monroe . they speak even of Marilyn Monroe neurons :-) similarily his question "who is in control? are we in control of our neurons or our neurons in control of us? " ....
Luís F. Simões

NASA Goddard to Auction off Patents for Automated Software Code Generation - 0 views

  • The technology was originally developed to handle coding of control code for spacecraft swarms, but it is broadly applicable to any commercial application where rule-based systems development is used.
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    This is related to the "Verified Software" item in NewScientist's list of ideas that will change science. At the link below you'll find the text of the patents being auctioned: http://icapoceantomo.com/item-for-sale/exclusive-license-related-improved-methodology-formally-developing-control-systems :) Patent #7,627,538 ("Swarm autonomic agents with self-destruct capability") makes for quite an interesting read: "This invention relates generally to artificial intelligence and, more particularly, to architecture for collective interactions between autonomous entities." "In some embodiments, an evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy." "In yet another aspect, an autonomous nanotechnology swarm may comprise a plurality of workers composed of self-similar autonomic components that are arranged to perform individual tasks in furtherance of a desired objective." "In still yet another aspect, a process to construct an environment to satisfy increasingly demanding external requirements may include instantiating an embryonic evolvable neural interface and evolving the embryonic evolvable neural interface towards complex complete connectivity." "In some embodiments, NBF 500 also includes genetic algorithms (GA) 504 at each interface between autonomic components. The GAs 504 may modify the intra-ENI 202 to satisfy requirements of the SALs 502 during learning, task execution or impairment of other subsystems."
LeopoldS

Access : Coherent terahertz control of antiferromagnetic spin waves : Nature Photonics - 1 views

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    terahertz lasers controling the spin of electrons ....
Luís F. Simões

Bitcoin P2P Currency: The Most Dangerous Project We've Ever Seen - 10 views

  • After month of research and discovery, we’ve learned the following:1. Bitcoin is a technologically sound project.2. Bitcoin is unstoppable without end-user prosecution.3. Bitcoin is the most dangerous open-source project ever created.4. Bitcoin may be the most dangerous technological project since the internet itself.5. Bitcoin is a political statement by technotarians (technological libertarians).*6. Bitcoins will change the world unless governments ban them with harsh penalties.
  • The benefits of a currency like this:a) Your coins can’t be frozen (like a Paypal account can be)b) Your coins can’t be trackedc) Your coins can’t be taxedd) Transaction costs are extremely low (sorry credit card companies)
  • An individual with the name -- or perhaps handle -- of Satoshi Nakamoto first wrote about bitcoins in a paper called Bitcoin: A Peer-to-Peer Electronic Cash System.
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  • * We made this term up to describe the “good people” of the internet who believe in the fundamental rights of individuals to be free, have free speech, fight hypocrisy and stand behind logic, technology and science over religion, political structure and tradition. These are the people who build and support things like Wikileaks, Anonymous, Linux and Wikipedia. They think that people can, and should, govern themselves. They are against external forms of control such as DRM, laws that are bought and sold by lobbyists, and religions like Scientology. They include splinter groups that enforce these ideals in the form of hacktivism, such as the takedown of the Sony Playstation Network after Sony tried to prosecute a hacker for unlocking its console.
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    Sounds good!
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    wow it's frigthening! it's the dream of every anarchist, every drug, arm, human dealer! the world made as a global fiscal paradise... the idea is clever however it will not replace real money because 1 - no one will build a fortune on bitcoin if a technological breakthrough can ruin them 2 - government never allowed parallel money to flourish on their territory, so it will be almost impossible to change bitcoin against euros or dollars
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    interesting stuff anyone read cryptonomicon by neal stephenson? similar theme.
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    :) yes. One of the comments on reddit was precisely drawing the parallels with Neal Stephenson's Snowcrash / Diamond Age / Cryptonomicon. Interesting stuff indeed. It has a lot of potential for misuse, but also opens up new possibilities. We've discussed recently how emerging technologies will drive social change. Whether it's the likes of NSA / CIA who will benefit the most from the Twitters, Facebooks and so on, by gaining greater power for control, or whether individuals are being empowered to at least an identical degree. We saw last year VISA / PayPal censoring WikiLeaks... Well, here's a way for any individual to support such an organization, in a fully anonymous and uncontrollable way...
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    One of my colleagues has made a nice, short write-up about BitCoin: http://www.pds.ewi.tudelft.nl/~victor/bitcoin.html
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    very nice analysis indeed - thanks Tamas for sharing it!
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    mmm I'm not an expert but it seemed to me that, even if these criticisms are true, there is one fundamental difference between the money you exchange on internet via your bank, and bitcoins. The first one is virtual money and the second one aims at being real, physical, money, even if digital, in the same way as banknotes, coins, or gold.
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    An algorithm wanna-be central bank issuing untraceable tax free money between internet users? not more likely than the end of the world supposed to take place tomorrow, in my opinion. Algorithms don't usually assault women though !:P
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    well, most money is anyway just virtual and only based on expectations and trust ... (see e.g. http://en.wikipedia.org/wiki/Money_supply) and thus if people trust that this "money" has some value in the sense that they can get something of value to them in exchange, then not much more is needed it seems to me ...
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    @Leopold: ok let's use the rigth words then. Bitcoin aim at being a currency ("physical objects generally accepted as a medium of exchange" from wikipedia), different than the "demand deposit". In the article proposed by Tamas he compares what cannot be compared (currencies, demand deposits and their mean of exchange). The interesting question is wether one can create a digital currency which is too difficult to counterfeit. As far as I know, there is no existing digital currency except this bitcoins (and maybe the currencies from games as second life and others, but which are of limited use in real world).
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    well of course money is trust, and even more loans and credit and even more stock and bond markets. It all represents trust and expectations. However since the first banks 500 years ago and the first loans etc. etc., and as well the fact that bonds and currencies bring down whole countries (Greece lately), and are mainly controlled by large financial centres and (central) banks, banks have always been on the winning side no matter what and that isn't going to change easily. So if you are talking about these new currencies it would be a new era, not just a new currency. So should Greece convert its debt to bitcoins ;P ?
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    well, from 1936 to 1993 the central bank of france was owned by the state and was supposed to serve the general interest...
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