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LeopoldS

Orbit Fab to launch first fuel tanker in 2021 with Spaceflight - SpaceNews - 1 views

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    interesting approach, quite a gamble in my view but moving in the right direction
pandomilla

Mission scheduled for tomorrow (if weather is fine) - 1 views

shared by pandomilla on 13 Oct 12 - Cached
LeopoldS liked it
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    The redbull mission will attempt to transcend human limits. Supported by a team of experts Felix Baumgartner plans to ascend to 120,000 feet in a stratospheric balloon and make a freefall jump rushing toward earth at supersonic speeds before parachuting to the ground.
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    since months austria is not speaking about anything else ... hope it is over soon :-) seriously: they even had last year Armstrong coming over to discuss with this guy on television (have posted it here) and the whole Red Bull advertisement machinery is working full speed on this ... quite impressive for just a jump ...
Annalisa Riccardi

New structures self-assemble in synchronized dance - 3 views

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    With self-assembly guiding the steps and synchronization providing the rhythm, a new class of materials forms dynamic, moving structures in an intricate dance. Researchers have demonstrated tiny spheres that synchronize their movements as they self-assemble into a spinning microtube.
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    This is quite similar to the following paper. Here they show how tiny variations of particle parameters can produce clearly distinct structures: Thermal and Athermal Swarms of Self-Propelled Particles --> http://arxiv.org/abs/1201.0180
johannessimon81

Nuclear isomer - 2 views

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    We had a short discussion yesterday about using nuclear isomers as batteries for spacecraft. The principle is that energy is stored as an excitation of the nucleus which can then release the energy as a gamma-photon. However angular momentum has to be conserved an this suppresses the decay strongly - making these states stable up to 10^35 longer than a typical decay.
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    The key is the triggering of the dacay wheras the triggering comsumes less energy than the decay provides. The x-ray based triggering of the gamma photon decay turned out to be quite controversial and needs significantly more scientific attention.
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    I think that there should be some references and traces of the discussions we had on this on the shared drive or wiki ... One other aspect: converting the omnidirectional gamma bursts into useful energy ....
Dario Izzo

Detexify LaTeX handwritten symbol recognition - 2 views

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    For hardcore latex users (btw ... implemented in haskell ... classical machine learning app, but useful)
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    Also available as Android app (not sure if called "texify" or "detexify".
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    works actually quite well!!
LeopoldS

Google Says the FBI Is Secretly Spying on Some of Its Customers | Threat Level | Wired.com - 3 views

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    not a surprise though still bad to read ....
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    On a side note, it's hilarious to read an article on something repeatedly referred to as being secret...
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    quite self-explanatory described though: "The terrorists apparently would win if Google told you the exact number of times the Federal Bureau of Investigation invoked a secret process to extract data about the media giant's customers. That's why it is unlawful for any record-keeper to disclose it has received a so-called National Security Letter. But under a deal brokered with the President Barack Obama administration, Google on Tuesday published a "range" of times it received National Security Letters demanding it divulge account information to the authorities without warrants. It was the first time a company has ever released data chronicling the volume of National Security Letter requests. National Security Letters allow the government to get detailed information on Americans' finances and communications without oversight from a judge. The FBI has issued hundreds of thousands of NSLs and has even been reprimanded for abusing them. The NSLs are written demands from the FBI that compel internet service providers, credit companies, financial institutions and businesses like Google to hand over confidential records about their customers, such as subscriber information, phone numbers and e-mail addresses, websites visited and more as long as the FBI says the information is "relevant" to an investigation." and ""You'll notice that we're reporting numerical ranges rather than exact numbers. This is to address concerns raised by the FBI, Justice Department and other agencies that releasing exact numbers might reveal information about investigations. We plan to update these figures annually," Richard Salgado, a Google legal director, wrote in a blog post. Salgado was not available for comment. What makes the government's position questionable is that it is required by Congress to disclose the number of times the bureau issues National Security Letters. In 2011, the year with the latest available figures, the FBI issued 16,511 National Sec
LeopoldS

[1305.3913] Indication of anomalous heat energy production in a reactor device - 5 views

shared by LeopoldS on 23 May 13 - No Cached
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    looks like some backwind for all the cold fusion believers ...
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    Actually Sante and me just reviewed their paper. Although (some of) the scientists in the paper seem to have good track records their experimental techniques are by far not the best to determine the excess amount of energy produced. Even though their methods may introduce fairly large errors they would not be able to negate the cited power output - so they either are super-sloppy (i.e. they lie) or there is TRULY new physics involved... A big problem is that they are basically verifying somebody else's experiment - however because this guy is paranoid he does not tell them exactly what he did. In fact they went to his lab and used a setup that HE put together. All they do is do a measurement on it and it seems like they try to be thorough. There is quite a chance that the guy behind it all (Rossi) is setting them up - personally I would think >95%. However, the implications of this being new physics are so big that I think further research should be conducted.
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    I just answered something very similar to Franco, except the conclusions: I don't think that there is a good reason for us or anybody else in ESA to get involved at this stage.
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    I agree - if this device would work it there would be other interest groups (like the energy sector) with a much more concrete stake in the technology.
johannessimon81

"Natural Light Cloaking for Aquatic and Terrestrial Creatures" - 3 views

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    Cheap and scalable invisibility cloaks being developed. The setup is so trivial that I would almost call it a "trick" (as in "Magicians trick"): 6 prisms of n=1.78 glass. Nontheless, it does the job of cloaking an object at visible wavelengths and from several directions.
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    can we build one?
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    Yes, I just did :-) It is on my desk
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    New video here (smaller file than previous): "https://dl.dropboxusercontent.com/u/58527156/20130613_101701.mp4" Note how close to the center of the field of view the hidden objects are. I am quite surprised that such poor lenses create such a sharp focus.
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    Well.. I would say that it is not "fully cloaking", as the image behind is mirrored as well
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    That just means that you have to double the setup, i.e., put 4 glasses in a row. Of course the obvious drawback is that you can only look at this cloak from one direction.
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    Is this really new? I don't know, but I know that the original idea of cloaking was pretty different. When cloaking as an application of transformation optics became popular people tried to make devices that work for any incidence angle, any polarization and in full wave optics (not just ray approximation). This is really hard to achieve and I guess that the people that tried to make such devices knew exactly that the task becomes almost trivial by dropping at least two of the three conditions above.
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    I think it is very easy to call something trivial when you're not the one who invested considerable time (5 min in my case) to design a cloaking device and fill the coffee mugs with water... Also, I did not really violate that many conditions: true I reduced the number of dimensions in which the device works to 1 (as opposed to the 2 dimensions of many metamaterial cloaks). However the polarization should not be affected in my setup as well as the wave phase and wave vector (so it works in full wave optics) - apart maybe from the imperfect lens distortion, but hey I was improvising.
Marcus Maertens

Everything You Wanted to Know about Space Tourism but Were Afraid to Ask | Space Safety... - 3 views

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    "chances are that if 700 passengers are flown annually, up to 10 of them might not survive the flight in the first years of the operations." most remarkable also the question who is to blame if a dead and burned space tourist corps comes crashing down from the sky into your car.
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    How sure is the information that a human body would not completely burn / ablate during atmospheric re-entry? I am not aware of any material ground tests in a plasma wind tunnel confirming that human tissue would survive re-entry from LEO.
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    Since a steak would not even be cooked by dropping it from very high altitudes (http://what-if.xkcd.com/28/) I would doubt that a space tourists body would desintegrate by atmospheric re-entry.
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    Funny link, however, some things are not clear enough: 1. Ablation rate is unknown 2. What are the entry conditions? The link suggests that the steak is just dropped (no initial velocity). 3. What about the ballistic coefficient? 4. How would the entry body orientation? It would be a quite non-steady state configuration I guess with heavy accelerations. 5. How would vacuum exposure impact on the water in the body/steak and what would be the consequence for ablation behaviour? 6. Does surface chemistry play a role (not ablation, but catalysis)? My conclusion: the example with the steak is a funny and not so bad exercise, not more.
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    This calls for some we serious simulations by the Petkow code it seems to me ...
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    I still would need some serious input data...
Marcus Maertens

MIT constructs synthetic analog computers inside living cells | ExtremeTech - 0 views

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    Just a small step till we can compute trajectories in our blood cells...
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    Really cool research. I think that the potential of analog computing has been neglected for quite a long time. Building the whole thing within a single cell makes it only more awesome.
johannessimon81

Bacteria grow electric wire in their natural environment - 1 views

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    Bacterial wires explain enigmatic electric currents in the seabed: Each one of these 'cable bacteria' contains a bundle of insulated wires that conduct an electric current from one end to the other. Cable bacteria explain electric currents in the seabed Electricity and seawater are usually a bad mix.
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    WOW!!!! don't want to even imagine what we do to these with the trailing fishing boats that sweep through sea beds with large masses .... "Our experiments showed that the electric connections in the seabed must be solid structures built by bacteria," says PhD student Christian Pfeffer, Aarhus University. He could interrupt the electric currents by pulling a thin wire horizontally through the seafloor. Just as when an excavator cuts our electric cables. In microscopes, scientists found a hitherto unknown type of long, multi-cellular bacteria that was always present when scientists measured the electric currents. "The incredible idea that these bacteria should be electric cables really fell into place when, inside the bacteria, we saw wire-like strings enclosed by a membrane," says Nils Risgaard-Petersen, Aarhus University. Kilometers of living cables The bacterium is one hundred times thinner than a hair and the whole bacterium functions as an electric cable with a number of insulated wires within it. Quite similar to the electric cables we know from our daily lives. "Such unique insulated biological wires seem simple but with incredible complexity at nanoscale," says PhD student Jie Song, Aarhus University, who used nanotools to map the electrical properties of the cable bacteria. In an undisturbed seabed more than tens of thousands kilometers cable bacteria live under a single square meter seabed. The ability to conduct an electric current gives cable bacteria such large benefits that it conquers much of the energy from decomposition processes in the seabed. Unlike all other known forms of life, cable bacteria maintain an efficient combustion down in the oxygen-free part of the seabed. It only requires that one end of the individual reaches the oxygen which the seawater provides to the top millimeters of the seabed. The combustion is a transfer of the electrons of the food to oxygen which the bacterial inner wires manage over centimeter-long distances. However, s
LeopoldS

The von Neumann Probe: A Nano Ship to the Stars | Dr. Kaku's Universe | Big Think - 0 views

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    Know his book but did not know his blog .... Tough I am sure Luis does :-)
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    No, actually I only know him from several documentaries. von Neumann probes, those I know quite well from sci-fi :). Alastair Reynolds' Revelation Space is a good example btw. Here's a relevant link: http://en.wikipedia.org/wiki/Self-replicating_machine#NIAC_studies_on_self-replicating_systems
Dario Izzo

Bold title ..... - 3 views

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    I got a fever. And the only prescription is more cat faces! ...../\_/\ ...(=^_^) ..\\(___) The article sounds quite interesting, though. I think the idea of a "fake" agent that tries to trick the classifier while both co-evolve is nice as it allows the classifier to first cope with the lower order complexity of the problem. As the fake agent mimics the real agent better and better the classifier has time to add complexity to itself instead of trying to do it all at once. It would be interesting if this is later reflected in the neural nets structure, i.e. having core regions that deal with lower order approximation / classification and peripheral regions (added at a later stage) that deal with nuances as they become apparent. Also this approach will develop not just a classifier for agent behavior but at the same time a model of the same. The later may be useful in itself and might in same cases be the actual goal of the "researcher". I suspect, however, that the problem of producing / evolving the "fake agent" model might in most case be at least as hard as producing a working classifier...
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    This paper from 2014 seems discribe something pretty similar (except for not using physical robots, etc...): https://papers.nips.cc/paper/5423-generative-adversarial-nets.pdf
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    Yes, this IS basically adversarial learning. Except the generator part instead of being a neural net is some kind of swarm parametrization. I just love how they rebranded it, though. :))
Joris _

video of the short hop test flight - 4 views

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    Have you seen this?!
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    no! quite impressive indeed! thanks for sharing it here
LeopoldS

[1205.2952] Synchronization and quorum sensing in a swarm of humanoid robots - 0 views

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    Nice topic for science coffee - see the first author :-)
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    Bonnie Bassler's TED talk on quorum sensing is quite interesting. Worth checking out, if you haven't done so already: http://www.ted.com/talks/bonnie_bassler_on_how_bacteria_communicate.html
LeopoldS

Demonstration of Blind Quantum Computing - 0 views

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    Another Zeilinger article in science
Dario Izzo

Check your country impact on science!!! - 8 views

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    Did you know that papers in space science are among the most quoted? Check how your country is doing .... you will be surprised :)
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    In terms of country based quotations ("Most scited countries") I cannot access space science, only Geosciences, Immunology, Material Science, and Psychiatry & Psychology. But when I first saw the list of countries at the left under "Impact in Science" I saw Argentinia was on top, and USA was on last position. Yes, I was surprised, until I realised that is was just an alphabetical order. Did you see the same list?
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    scotland's a separate country. must be preparing for independence already. and it's highest percentage is for space science. crazy
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    Dajan, you need to click on the country you are interested in ....
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    Nooo, can't be THAT simple.
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    data a bit old .... newer data (but less well presented) at http://sciencewatch.com/ there you can also read: "The 20th century was largely dominated by the US as a major powerhouse of scientific research and innovation, with 40% of the papers indexed in the Web of Science fielded by US scientists in the 1990s. By 2009, that figure was down to 29%. The US now struggles to keep pace with increased output from Europe and Asia."
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    hottest space science paper in January 2012: Field: Space Science Article Title: Herschel Space Observatory An ESA facility for far-infrared and submillimetre astronomy Authors: Pilbratt, GL;Riedinger, JR;Passvogel, T;Crone, G;Doyle, D;Gageur, U;Heras, AM;Jewell, C;Metcalfe, L;Ott, S;Schmidt, M Journal: ASTRON ASTROPHYS, 518: art. no.-L1 JUL-AUG 2010 * ESTEC SRE SA, ESA Res & Sci Support Dept, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands. * ESTEC SRE SA, ESA Res & Sci Support Dept, NL-2201 AZ Noordwijk, Netherlands. * ESTEC SRE OA, ESA Sci Operat Dept, NL-2201 AZ Noordwijk, Netherlands. * ESTEC SRE P, ESA Sci Operat Dept, NL-2201 AZ Noordwijk, Netherlands. * ESOC OPS OAH, ESA Mission Operat Dept, D-64293 Darmstadt, Germany. * ESAC SRE OA, ESA Sci Operat Dept, Madrid 28691, Spain.
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    Interestingly, Space Science is the only field in which my country has positive "Impact vs. world" value (even more interestingly as we don't even have a proper national space agency)...
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    this might also be an indication / point to an issue with their data concerning space science publications ... quite surprising indeed that all Europeans are doing so well in this field
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    Something should be wrong, for Spain I can read: Economics & Business 4.54 -28 Only minus 28!
LeopoldS

On creative machines and the physical origins of freedom : Scientific Reports : Nature ... - 4 views

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    For all the AI guys (Christos, Marek, Ed, Markus and co ...) and of course Luiz, Sante ... You will like this one :-)
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    Quite a lot of blabla, some usual misconceptions (like QT the source of randomness in nature), but a -- from my point of view -- very true (though in the text somehow hidden) conclusion: Free will, creativity etc. from the point of view of fundamental physics are just randomness! Many physicists won't like this conclusion, though, and in this respect also the title is rather misleading!
Tom Gheysens

Fur and feathers keep animals warm by scattering light - 1 views

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    In work that has major implications for improving the performance of building insulation, scientists at the University of Namur in Belgium and the University of Hassan I in Morocco have calculated that hairs that reflect infrared light may contribute significant insulating power to the exceptionally warm winter coats of polar bears and other animals.
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    That's quite interesting. Maybe the future of buildings and spacecraft is furry?
Thijs Versloot

Remote control camera buggy of lions @ChrisMcLennan (VIDEO) - 2 views

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    I think you should do something like this with your Botiful Johannes :)
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    Seems like drones are quite in this day when studying wildife: http://www.youtube.com/watch?v=-CoApUAZFf8
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