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santecarloni

How Likely Is a Runaway Greenhouse Effect on Earth? - Technology Review - 1 views

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    Sometime in the last few billion years, disaster struck one of Earth's nearest neighbours. Planetary geologists think there is good evidence that Venus was the victim of a runaway greenhouse effect which turned the planet into the boiling hell we see today. A similar catastrophe is almost certain to strike Earth in about 2 billion years, as the Sun increases in luminosity.
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    the actual paper: http://arxiv.org/abs/1201.1593 just wondering if their conclusion that the long term solution is to change the orbit of Earth is really the ultimate wisdom ...
santecarloni

Computer Model Replays Europe's Cultural History  - Technology Review - 2 views

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    A simple mathematical model of the way cultures spread reproduces some aspects of European history, say complexity scientists
santecarloni

Artificial Braneworlds Made to Collide In Lab - Technology Review - 4 views

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    Physicists have simulated two universes colliding inside a metamaterial--  Now, this is cool (if it is true...)
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    we... the article is a bit overblown in my view ... except maybe the last paragraphs: "The collision between universe's is a variation on this theme. "The "colliding universe" scenario can be realized as a simple extension of our earlier experiments simulating the spacetime geometry in the vicinity of big bang," he says. He simulates an expanding universe using concetric rings of gold separated by a dielectric. "When the two concentric ring ("universe") patterns touch each other ("collide"), a Minkowski domain wall is created, in which the metallic stripes touch each other at a small angle," he says. Being able to recreate these exotic events in the lab is certainly interesting but it is beginning to lose its novelty. The problem is that this work is not telling us anything we didn't know--the universe behaves the same way inside a metamaterial as it does outside. What Smolyaninov needs is a way of using his exotic materials to do something interesting. In other words, he needs a killer app. Any ideas? "
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    Hm, they use more or less everything I don't especially like. They are nonmagnetic, so the relation materialGR is already rather weak. Usually, experimentalists prefer nonmagnetic media, since they are cheaper and broadband. At least the broadband is no argument here, since the frequency defines the "mass", which I find a rather strange point of view. And finally, they use strong anisotropy as a model of "time", which is rather problematic. Of course, the spatial direction with eps<0 appears in the wave equation with the same sign as time. But this does not mean that it behaves like time. But to teach material physicists that time is more than just a different sign in the wave equation seems to be as hopeless as to teach them that a black hole is more than something that absorbs all light... SIGHHH
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    Luzi I miss you ...
Luís F. Simões

The Secret of Ant Transportation Networks - Technology Review - 2 views

  • Just how ants create the highly efficient network of trails around their nests has never been fully understood. Now researchers think they've cracked it
  • They say the structure of ant trails can be entirely explained if the ants's response to a pheromone droplet concentration is linear. "One ant will turn to the left in proportion to the difference between the pheromone it has on its left side and the pheromone on its right," say Perna and co. They also point out that this is exactly what Weber's law predicts.
  • Ref:&nbsp;arxiv.org/abs/1201.5827&nbsp;:Individual Rules For Trail Pattern Formation In Argentine Ants (Linepithema Humile)
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    from the abstract: "Using a novel imaging and analysis technique on experimental data we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants." [...] "agent based simulations based on the Weber's Law response function determined experimentally produced results compatible with those reported in the literature and reproduced the formation of trails."
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    Nice article!
santecarloni

The Puzzling Problem Of Proportionate Growth - Technology Review - 3 views

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    Biologists have long wondered how our organs all grow at the same rate. Now theoretical physicists think they've found a clue in the special way sandpiles grow
Luís F. Simões

Stochastic Pattern Recognition Dramatically Outperforms Conventional Techniques - Techn... - 2 views

  • A stochastic computer, designed to help an autonomous vehicle navigate, outperforms a conventional computer by three orders of magnitude, say computer scientists
  • These guys have applied stochastic computing to the process of pattern recognition. The problem here is to compare an input signal with a reference signal to determine whether they match. &nbsp; In the real world, of course, input signals are always noisy so a system that can cope with noise has an obvious advantage.&nbsp; Canals and co use their technique to help an autonomous vehicle navigate its way through a simple environment for which it has an internal map. For this task, it has to measure the distance to the walls around it and work out where it is on the map. It then computes a trajectory taking it to its destination.
  • Although the idea of stochastic computing has been around for half a century, attempts to exploit have only just begun. Clearly there's much work to be done. And since one line of thought is that the brain might be a stochastic computer, at least in part, there could be exciting times ahead.
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  • Ref:&nbsp;arxiv.org/abs/1202.4495: Stochastic-Based Pattern Recognition Analysis
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    hey! This is essentially the Probabilistic Computing Ariadna
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    The link is there but my understanding of our purpose is different than what I understood from the abstract. In any case,the authors are from Palma de Mallorca, Balears, Spain "somebody" should somehow make them aware of the Ariadna study ... E.g somebody no longer in the team :-)
LeopoldS

The Cost of Knowledge - 1 views

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    interesting initiative with already some high profile names from space sector such as Martin Rees, Baumjohann, two guys from NASA ...
LeopoldS

Physical Review Letters - Extracting dynamical equations from experimental data is NP hard - 1 views

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    Something for Sante and Luis...
santecarloni

Computer Simulation Predicts New Allotrope Of Carbon  - Technology Review - 0 views

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    The new material matches the properties of a puzzling new form of carbon found in high pressure experiments
santecarloni

How To Build A Speech Jamming Gun - Technology Review - 1 views

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    he drone of speakers who won't stop is an inevitable experience at conferences, meetings, cinemas and public libraries.  Today, Kazutaka Kurihara at the National Institute of Advanced Industrial Science and Technology in Tskuba and Koji Tsukada at Ochanomizu University, both in Japan, present a radical solution: a speech jamming device that forces recalcitrant speakers into submission. 
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    ...must...not...make...the...obvious...ACT...meeting...joke...
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    Unfortunately it won't work when it is most needed .... Read this: "Their tests also identify some curious phenomena. They say the gun is more effective when the delay varies in time and more effective against speech that involves reading aloud than against spontaneous monologue. Sadly, they report that it has no effect on meaningless sound sequences such as "aaaaarghhh".
Luís F. Simões

Encouraging Behavioral Diversity in Evolutionary Robotics: An Empirical Study - MIT Pre... - 2 views

  • several papers recently proposed to explicitly encourage the diversity of the robot behaviors, rather than the diversity of the genotypes as in classic evolutionary optimization. Such an approach avoids the need to compute distances between structures and the pitfalls of the noninjectivity of the phenotype/behavior relation; however, it also introduces new questions: how to compare behavior?
  • In this paper, we review the main published approaches to behavioral diversity and benchmark them in a common framework.
  • The results show that fostering behavioral diversity substantially improves the evolutionary process in the investigated experiments, regardless of genotype or task.
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    paywall skipping: http://www.isir.upmc.fr/files/2011ACLI2061.pdf The most complete study I've seen so far on a new approach (Novelty Search) that has been gaining a lot of attention lately. And they even use parallel coordinates to visualize the results!! ;)
LeopoldS

The Space Review: The cislunar econosphere (part 1) - 1 views

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    visionary ..
santecarloni

Graphene Battery Turns Ambient Heat Into Electric Current - Technology Review - 0 views

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    "Physicists have built a graphene battery that harvests energy from the thermal movement of ions in solution." Can it actually work?
santecarloni

Quantum Biology and the Puzzle of Coherence - Technology Review - 4 views

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    Quantum processes shouldn't survive in hot, wet biological systems and yet a growing body of evidence suggests they do. Now physicists think they know how
  • ...2 more comments...
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    Tobias, José and myself considered an ACT project in quantum biomimetics, but it never led anywhere. Perhaps the field is sexy enough now...
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    Considered is the right word ... You unfortunately never passed the step after "considering" :-)
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    Yes, because our bosses forced us to write strategic reports on "system of systems" :-)
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    Oh these terrible ignorant slave masters .... Would love to see your "reports on system of systems" :-)
santecarloni

Intel Reveals Neuromorphic Chip Design  - Technology Review - 1 views

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    Intel's goal is to build chips that work more like the human brain. Now its engineers think they know how
johannessimon81

Big data, bigger expectations? - 1 views

Dario Izzo

Who's Afraid of Peer Review? - 0 views

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    A fake paper was accepted in 60% of tried open access journals, just because the author paid the fee :)
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    Love the comment that some papers which originally rejected it, in the end did accept it anyway after some correspondence
Daniel Hennes

Forget The Wisdom of Crowds; Neurobiologists Reveal The Wisdom Of The Confident | MIT T... - 5 views

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    The wisdom of crowds breaks down when people are biased. Now researchers have discovered a simple method of removing this bias-just listen to the most confident.
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    So, those who insist know better? I reckon that an ignorant can also insist on his opinion.
johannessimon81

Standing desks... - 6 views

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    I'm up for it.. literally :)
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    I will try it also ... quite convincing indeed ... could even free some more space for documents on my desk :-)
LeopoldS

Reconfigurable Electromagnetics Through Metamaterials-A Review - 5 views

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    Interesting overview paper by Massa from Trient on reconfigurable metamaterials … makes me wonder if it is time for us to look closer into it or already too late …
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