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Beniamino Abis

The Wisdom of (Little) Crowds - 1 views

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    What is the best (wisest) size for a group of individuals? Couzin and Kao put together a series of mathematical models that included correlation and several cues. In one model, for example, a group of animals had to choose between two options-think of two places to find food. But the cues for each choice were not equally reliable, nor were they equally correlated. The scientists found that in these models, a group was more likely to choose the superior option than an individual. Common experience will make us expect that the bigger the group got, the wiser it would become. But they found something very different. Small groups did better than individuals. But bigger groups did not do better than small groups. In fact, they did worse. A group of 5 to 20 individuals made better decisions than an infinitely large crowd. The problem with big groups is this: a faction of the group will follow correlated cues-in other words, the cues that look the same to many individuals. If a correlated cue is misleading, it may cause the whole faction to cast the wrong vote. Couzin and Kao found that this faction can drown out the diversity of information coming from the uncorrelated cue. And this problem only gets worse as the group gets bigger.
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    Couzin research was the starting point that co-inspired PaGMO from the very beginning. We invited him (and he came) at a formation flying conference for a plenary here in ESTEC. You can see PaGMO as a collective problem solving simulation. In that respect, we learned already that the size of the group and its internal structure (topology) counts and cannot be too large or too random. One of the project the ACT is running (and currently seeking for new ideas/actors) is briefly described here (http://esa.github.io/pygmo/examples/example2.html) and attempts answering the question :"How is collective decision making influenced by the information flow through the group?" by looking at complex simulations of large 'archipelagos'.
Thijs Versloot

Stimulated mutual annihilation: How to make a gamma-ray laser with positronium - 1 views

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    Theorists expect that positronium, a sort of 'atom' consisting of an electron and an anti-electron, can be used to make a powerful gamma-ray laser. Scientists now report detailed calculations of the dynamics of a positronium BEC. This work is the first to account for effects of collisions between different positronium species.
jessyjemy

What happens to your brain on the way to Mars - 1 views

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    This study from NASA shows that cosmic rays have a deleterious effect on the brain, more than expected, resulting in in symptoms similar to dementia (memory loss, decline in problem solving skills, general cognitive functions). A reason more to investigate into hibernation?
Thijs Versloot

Graphene coated silicon super-capacitors for energy storage - 1 views

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    Recharge in seconds and efficiently store power for weeks between charges. Added bonus is the cheap and abundant components needed. One of the applications they foresee is to attach such a super-capacitor to the back of solar panels to store the power and discharge this during the night
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    very nice indeed - is this already at a stage where we should have a closer look at it? what you think? With experience in growing carbon nanostructures, Pint's group decided to try to coat the porous silicon surface with carbon. "We had no idea what would happen," said Pint. "Typically, researchers grow graphene from silicon-carbide materials at temperatures in excess of 1400 degrees Celsius. But at lower temperatures - 600 to 700 degrees Celsius - we certainly didn't expect graphene-like material growth." When the researchers pulled the porous silicon out of the furnace, they found that it had turned from orange to purple or black. When they inspected it under a powerful scanning electron microscope they found that it looked nearly identical to the original material but it was coated by a layer of graphene a few nanometers thick. When the researchers tested the coated material they found that it had chemically stabilized the silicon surface. When they used it to make supercapacitors, they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors. Transmission electron microscope image of the surface of porous silicon coated with graphene. The coating consists of a thin layer of 5-10 layers of graphene which filled pores with diameters less than 2-3 nanometers and so did not alter the nanoscale architecture of the underlying silicon. (Cary Pint / Vanderbilt) The graphene layer acts as an atomically thin protective coating. Pint and his group argue that this approach isn't limited to graphene. "The ability to engineer surfaces with atomically thin layers of materials combined with the control achieved in designing porous materials opens opportunities for a number of different applications beyond energy storage," he said.
johannessimon81

IBM Speech Recognition, 1986 - 0 views

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    Interesting historical perspective. Progress since the late '80 really seems to be fairly slow. ?: Do we need to wait for the singularity until speech recognition works without flaws?
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    funny - tried just yesterday the one built in on mavericks: sending one email took three times as long at least as typing it And now my speech PowerPoint Funny, trade trust yesterday they're built in speech recognition in Mavericks sending one e-mail to at least three times a talk as long as typing it. Well this was actually quite okay and relatively fast cheers nice evening
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    "I thought I would give it a try on my android sexy seems to work pretty well and I'm speaking more less at normal speed" Actually I was speaking as fast as I could because it was for the google search input - if you make a pause it will think you finished your input and start the query. Also you might notice that Android thinks it is "android sexy" - this was meant to be "on my Android. THIS seems to work...". Still it is not too bad - maybe in a year or two they have it working. Of course it might also be that I just use the word "sexy" randomly... :-\
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    The problem is that we don't yet understand how speech in humans actually works. As long as we merely build either inference or statistical language models we'll never get perfect speech recognition. A lot of recognition in humans has a predictive/expectational basis to it that stems from our understanding of higher lvl concepts and context awareness. Sadly I suspect that as long as machines remain unembodied in their perceptual abilities their ability to either properly recognize sounds/speech or objects and other features will never reach perfection.
Ma Ru

I know at least *some* of you will like it... - 13 views

shared by Ma Ru on 29 Mar 10 - Cached
LeopoldS liked it
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    Shit!! I only got 79, should have lied better...
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    My score was obtained with *sincere* answers, don't cheat!
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    ouah, 80...! didn't think i was so nerd...!
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    Dario, Francesco, we're waiting for your scores... are you afraid of the truth??
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    hmm "Low Ranking Nerd. Definitely a nerd but low on the totem pole of nerds." , as of a score of 66
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    I am disappointed!!!!! Shame on me.......
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    Sigh
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    wow!
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    My girlfriend... She must be an archaeological nerd...
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    Great Scott, Leo! Honest answers?? I was kinda expecting Francesco's score, but this...
Thijs Versloot

Engineers identify how to keep surfaces dry underwater - 1 views

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    When submerged, water tends to cling to the top of the spikes, while air and water vapor accrue in the pores between them. The combination of trapped air and water vapor within these cavities forms a gaseous layer that deters moisture from seeping into the surface below. More materials with amazing properties. Might even be usefull for liquid fuel tanks?
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    I don't quite see how the trapped water vapor keeps the water out of the cavities... since the vapor is at the same low temperature as the water it should hardly exert any pressure at all. One would expect though that surface tension keeps water out of smaller cavities because it tries to minimize surface area. If the water would enter the cavities it would need increase its surface area dramatically which in turn is energetically unfavorable. Interesting application would also be in non-wetting electronics which might make cooling of circuitry a lot easier: you just sink your data center.
Nina Nadine Ridder

Sentinel-2 catches eye of algal storm - 0 views

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    The Sentinel-2A satellite has been in orbit for only a matter of weeks, but new images of an algal bloom in the Baltic Sea show that it is already exceeding expectations. Built essentially as a land monitoring mission, Sentinel-2 will also certainly find its way into marine applications.
jcunha

Explosion-Generated Collapsing Vacuum Bubbles Reach 20,000 Kelvin - 1 views

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    "In a recent paper published in Physical Review Letters (PRL) Jérôme Duplat and Emmanuel Villermaux developed a method to generate centimeter-sized vacuum bubbles in water with miniature laser-driven explosions, and observed the flash of light produced as the bubble collapsed a not-fully-understood phenomenon known as sonoluminescence." Amazingly they concluded that the temperatrue inside the bubble as it collapses is about 26000 K. At this temperatures some (not me) argue for nuclear fusion... Intriguing stuff!!! Check the videos! Yet another test for the 'Experimental Physics Stagiare' :-)?
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    For sure no fusion, that starts appr. from about 20keV, not 20kK. Between both there is still a factor of 11500. What I would rather expect is that the conditions are not appropriate to work with Maxwellian distribution functions. If certain fusion products should be measurable, than this would rather confirm (but not proof) the hypothesis that they do not have Maxwellians but something close to monoenergetic. But most probably they will not measure fusion products, hence no fusion, hence no confusion.
Juxi Leitner

SPACE.com -- Next Mars Rover's Landing Site Narrowed to 4 Choices - 0 views

  • is expected to determine whether Mars is or was ever habitable to microbial lif
  • whittled down to four. They are regions of Mars known as Mawrth Vallis, Gale crater, Holden crater and Eberswalde crater.
Joris _

American Institute of Aeronautics and Astronautics - Space and the Biological Economy - 0 views

  • the U.S. space program has a robust life science program that is diligently working to innovate new approaches, research and technologies in the fields of biotechnology and bio-nanotechnology science, which are providing new solutions for old problems – including food security, medical needs and energy needs
  • more money be allocated to develop environmentally sound and energy efficient engine programs for commercial and private aviation
  • waste water program
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  • we lack fundamental knowledge about the entire effect of the photosynthesis system on food growth, and that space-based research could provide vital clues to scientists on how to streamline the process to spur more efficient food growth
  • From the start of the space age until 2010 only around 500 people have journeyed into space, but with the advent of private space travel in the next 24 months another 500 people are expected to go into space
  • Wagner indentified prize systems that award monetary prizes to companies or individuals as an effective way to spur innovation and creativity, and urged the Congressional staffers present to consider creating more prize systems to stimulate needed innovation
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    a bunch of ideas, iinitiatives, and good points about upcoming changes in space ...
Luís F. Simões

This Will Change Everything: Ideas That Will Shape the Future (The Edge Annual Question - 2009) - 3 views

  • WHAT WILL CHANGE EVERYTHING? "What game-changing scientific ideas and developments do you expect to live to see?"
  • That's the question John Brockman, editor of the Web site edge.org, posed to about 160 cutting-edge minds in his 11th annual Edge Question. As in years past, they responded with bold, often thrilling, sometimes chilling, answers.
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    And here's the same thing, but in dead-trees format: http://www.amazon.com/This-Will-Change-Everything-Future/dp/0061899674 Anyone else thinks that the ACT should buy us all a copy as a Christmas present? :)
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    you are the ACT!!!
pacome delva

Accurate light-time correction due to a gravitating mass - 1 views

  • The Orbit Determination Program (ODP) of NASA's Jet Propulsion Laboratory, which was used in the data analysis, is based on an expression for the gravitational delay which differs from the standard formula; this difference is of second order in powers of $m$ -- the sun's gravitational radius -- but in Cassini's case it was much larger than the expected order of magnitude $m^2/b$, where $b$ is the ray's closest approach distance. Since the ODP does not account for any other second-order terms, it is necessary, also in view of future more accurate experiments, to systematically evaluate higher order corrections and to determine which terms are significant.
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    Some other crazy guys interested in high precision measurement of time of flight...
pacome delva

Higgs hunters face long haul - 2 views

  • to reduce the chances of the LHC being derailed again by a similar accident, physicists at the Geneva lab have decided to run the collider at just half its design energy for the next 18-24 months.
  • Once the 7 TeV run is over, CERN will shut the LHC down in 2012 for a year or more to prepare it to go straight to maximum-energy 14 TeV collisions in 2013. This will be a complex job that will involve replacing some 10,000 superconducting magnet connections with more robust ones.
  • choosing to stay at lower energies is a big price to pay in terms of the Higgs search. "We will need more than twice the data at 7 TeV compared to that needed at 10 TeV to reach the same discovery potential," she says. "At this energy we can at best expect to exclude a Higgs with a mass between 155 and 175 GeV."
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    no Higgs boson before 2013... and a replacement of 10,000 superconducting magnet connections ! Reminds me of the the gravitational detectors... no detection before an upgrade in 2013...! There are the big announcements to make the cash flow... and reality !
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    Higgs is almost 81, so he should better invest in his health if he wants the Nobel prize... But who cares, it's another 5 years window where high-energy theorists can produce nonsense with no experimental evidence. They should be happy!
pacome delva

Algae Show a Knack for Quantum Mechanics -- Berardelli 2010 (203): 3 -- ScienceNOW - 1 views

  • the discovery will open up a new field of research, and it could lead to a new generation of superefficient light-sensitive devices.
  • the experiments showed that the electron vibrations resulting from the photons striking the antennas persisted at full strength four times longer than expected. The reason, the researchers report this week in Nature, is that quantum mechanics controls the energy. "It was an utter surprise," says physical chemist and co-author Gregory Scholes of the University of Toronto in Canada. For the results to have occurred, he explains, a property called quantum coherence must have been operating.
  • the research "will open an entirely new area of biophysics." And that effort should have "huge implications," he says, "not only for how we think about biophysics, but also light harvesting and light-sensitive devices."
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    Very interesting work, showing that apparently algae mastered quantum coherence a few years before us... Inspiring for a new type of light-sensitive devices, and perhaps other applications...
Luzi Bergamin

Physics in a Crisis - 3 views

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    Luckily I'm far away from Geneva, but this has to be said today, when the LHC starts! No, not tiny black holes will eat us (what a nonsense!), but the supernovae energy will let LHC explode!!! Pacome, I expect you to debunk this with gratest care!
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    wtf is this! As I read this morning in the newspaper (not even a scientific one), 1 TeV is the kinetic energy of a flying mosquito... so be careful ! It seems they already sloved every thing on this website: "At the Institute for Space Quantum Physics ISQP, it was already proved in 1991-1992 that dark matter is in magnetic fields as magnetic space quantum flux." This website is the biggest source of crackpots i have seen in a long time...! (http://www.supernovae-energy.com/)
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    Come on guys, this website is hilarious! "The HAITI EARTHQUAKE (...) were impossible for the Institute for Space Quantum Physics (ISQP) to compute because on one single planet was on a common line or axis with the Sun: Venus."
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    Unfortunately, most information I have about the guy (Hans Lehner, a Swiss) is in German, his official homepage is http://www.rqm.ch/ According to EsoWatch he is the Swiss analogue to Dr. Mills and his Blacklight power. Lehner apparently founded a company, which should have produced a "Raum-Quanten-Motor" that -- of course -- produces energy out of nothing. The theory is based on spookey forces mediated by Lehneronen. 11 Million Swiss Franks (about 8 Million Euro) were lost when the company bankrupt. And the guy is selling new stocks on his homepage again... Lehner calls another crackpot named Oliver Crane Zweistein (from Einstein being "Onestone") and himself "Dreistein". Now he is looking for Mister or Misses Vierstein. Perhaps you should apply, good luck!!
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    i like the first line of their supernovae energy technology document "Dear potential investor:"...
Luís F. Simões

Shell energy scenarios to 2050 - 6 views

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    just in case you were feeling happy and optimistic
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    An energy scenario published by an oil company? Allow me to be sceptical...
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    Indeed, Shell is an energy company, not just oil, for some time now ... The two scenarii are, in their approach, dependant of economic and political situation, which is right now impossible to forecast. Reference to Kyoto is surprising, almost out-dated! But overall, I find it rather optimistic at some stages, and probably the timeline (p37-39) is unlikely with recent events.
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    the report was published in 2008, which explains the reference to Kyoto, as the follow-up to it was much more uncertain at that point. The Blueprint scenario is indeed optimistic, but also quite unlikely I'd say. I don't see humanity suddenly becoming so wise and coordinated. Sadly, I see something closer to the Scramble scenario as much more likely to occur.
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    not an oil company??? please have a look at the percentage of their revenues coming from oil and gas and then compare this with all their other energy activities together and you will see very quickly that it is only window dressing ... they are an oil and gas company ... and nothing more
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    not JUST oil. From a description: "Shell is a global group of energy and petrochemical companies." Of course revenues coming from oil are the biggest, the investment turnover on other energy sources is small for now. Knowing that most of their revenues is from an expendable source, to guarantee their future, they invest elsewhere. They have invested >1b$ in renewable energy, including biofuels. They had the largest wind power business among so-called "oil" companies. Oil only defines what they do "best". As a comparison, some time ago, Apple were selling only computers and now they sell phones. But I would not say Apple is just a phone company.
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    window dressing only ... e.g. Net cash from operating activities (pre-tax) in 2008: 70 Billion$ net income in 2008: 26 Billion revenues in 2008: 88 Billion Their investments and revenues in renewables don't even show up in their annual financial reports since probably they are under the heading of "marketing" which is already 1.7 Billion $ ... this is what they report on their investments: Capital investment, portfolio actions and business development Capital investment in 2009 was $24 billion. This represents a 26% decrease from 2008, which included over $8 billion in acquisitions, primarily relating to Duvernay Oil Corp. Capital investment included exploration expenditure of $4.5 billion (2008: $11.0 billion). In Abu Dhabi, Shell signed an agreement with Abu Dhabi National Oil Company to extend the GASCO joint venture for a further 20 years. In Australia, Shell and its partners took the final investment decision (FID) for the Gorgon LNG project (Shell share 25%). Gorgon will supply global gas markets to at least 2050, with a capacity of 15 million tonnes (100% basis) of LNG per year and a major carbon capture and storage scheme. Shell has announced a front-end engineering and design study for a floating LNG (FLNG) project, with the potential to deploy these facilities at the Prelude offshore gas discovery in Australia (Shell share 100%). In Australia, Shell confirmed that it has accepted Woodside Petroleum Ltd.'s entitlement offer of new shares at a total cost of $0.8 billion, maintaining its 34.27% share in the company; $0.4 billion was paid in 2009 with the remainder paid in 2010. In Bolivia and Brazil, Shell sold its share in a gas pipeline and in a thermoelectric power plant and its related assets for a total of around $100 million. In Canada, the Government of Alberta and the national government jointly announced their intent to contribute $0.8 billion of funding towards the Quest carbon capture and sequestration project. Quest, which is at the f
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    thanks for the info :) They still have their 50% share in the wind farm in Noordzee (you can see it from ESTEC on a clear day). Look for Shell International Renewables, other subsidiaries and joint-ventures. I guess, the report is about the oil branch. http://sustainabilityreport.shell.com/2009/servicepages/downloads/files/all_shell_sr09.pdf http://www.noordzeewind.nl/
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    no - its about Shell globally - all Shell .. these participations are just peanuts please read the intro of the CEO in the pdf you linked to: he does not even mention renewables! their entire sustainability strategy is about oil and gas - just making it (look) nicer and environmentally friendlier
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    Fair enough, for me even peanuts are worthy and I am not able to judge. Not all big-profit companies, like Shell, are evil :( Look in the pdf what is in the upstream and downstream you mentionned above. Non-shell sources for examples and more objectivity: http://www.nuon.com/company/Innovative-projects/noordzeewind.jsp http://www.e-energymarket.com/news/single-news/article/ferrari-tops-bahrain-gp-using-shell-biofuel.html thanks.
Luzi Bergamin

Prof. Markrams Hirnmaschine (Startseite, NZZ Online) - 2 views

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    A critical view on Prof. Markram's Blue Brain project (in German).
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    A critical view on Prof. Markram's Blue Brain project (in German).
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    so critical that the comment needed to be posted twice :-) ?
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    Yes, I know; I still don't know how to deal with this f.... Diigo Toolbar! Shame on me!!!
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    Would be nice to read something about the modelling, but it appears that there is nothing published in detail. Following the article, the main approach is to model each(!) neuron taking into account the spatial structure of the neurons positions. Once achieved they expect intelligent behaviour. And they need a (type of) supercomputer which does not exist yet.
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    As far as I know it's sort of like "Let's construct an enormous dynamical system and see what happens"... i.e. a waste of taxpayer's money... Able to heal Alzheimer... Yeah... Actually I was on the conference the author is mentioning (FET 2011) and I have seen the presentations of all 6 flagship proposals. Following that I had a discussion with one of my colleagues about the existence of limits of the amount of bullshit politicians are willing to buy from scientists. Will there be a point at which politicians, despite their total ignorance, will realise that scientists simply don't deliver anything they promise? How long will we (scientists) be stuck in the viscous circle of have-to-promise-more-than-predecessors in order to get money? Will we face a situation when we'll be forced to revert to promises which are realistic? To be honest none of the 6 presentations convinced me of their scientific merit (apart from the one on graphene where I have absolutely no expertise to tell). Apparently a huge amount of money is about to be wasted.
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    It's not just "Let's construct an enormous dynamical system and see what happens", it's worse! Also the simulation of the cosmological evolution is/was a little bit of this type, still the results are very interesting and useful. Why? Neither the whole cosmos nor the human brain at the level of single neurons can be modelled on a computer, that would last aeons on a "yet-to-be-invented-extra-super-computer". Thus one has to make assumptions and simplifications. In cosmology we have working theories of gravitation, thermodynamics, electrodynamics etc. at hand; starting from these theories we can make reasonable assumptions and (more or less) justified simplifications. The result is valuable since it provides insight into a complex system under given, explicit and understood assumptions. Nothing similar seems to exist in neuroscience. There is no theory of the human brain and apparently nobody has the slightest idea which simplifications can be made without harm. Of course, Mr. Markram remains completely unaffected of ''details'' like this. Finally, Marek, money is not wasted, we ''build networks of excellence'' and ''select the brightest of the brightest'' to make them study and work at our ''elite institutions'' :-). I lively remember the stage of one of these "bestofthebest" from Ivy League at the ACT...
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
Joris _

WISE Mission Assembled and Preparing for Launch - NASA Jet Propulsion Laboratory - 0 views

  • The mission will survey the entire sky at infrared wavelengths,
  • Among expected finds from WISE are hundreds of thousands of asteroids in our solar system's asteroid belt,
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