Group items tagged

Great work from my former colleagues in Montreal. For more information (in french, sorry) please click on: http://www.nouvelles.umontreal.ca/recherche/sciences-technologies/20121114-perdue-dans-lespace-des-astronomes-lont-enfin-trouvee.html

Nice! How much dark matter still left to find?

They search numerically for initial conditions resulting in periodic orbits. Reminds to me the methods we employed for the "search for invariant relative motion" and which brought us to discover the magic inclinations (47.9 degrees). I wonder what are the implications. In any case nice plots :)

Haven't read in detail, but it's not clear to me what it means exactly. If they were discovered numerically (I assume it means via numerical integration), how can they be sure the orbits are truly periodic?

And thats why we do what we do :) Enjoy!!

and to poison the waters of an amazing performance, here's the relevant(?) copyright law: http://www.economist.com/blogs/economist-explains/2013/05/economist-explains-12?fsrc=scn/tw_ec/how_does_copyright_work_in_space_

And in case you wonder, this is *not* the most expensive music video ever made. Also, launching his guitar to the orbit was still far cheaper than the cost of some guitars sold on earth. Where else can this info come from if not http://what-if.xkcd.com/45/

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.

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.

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.

Recently, many competitions in the computer vision domain have been won by huge convolutional networks. In the image net competition, the convolutional network approach halves the error from ~30% to ~15%! Key changes that make this happen: weight-sharing to reduce the search space, and training with a massive GPU approach. (See also the work at IDSIA: http://www.idsia.ch/~juergen/vision.html) This should please Francisco :)

...mmmmm... they use 60 million parameters and 650,000 neurons on a task that one can somehow consider easier than (say) predicting a financial crisis ... still they get 15% of errors .... reminds me of a comic we saw once ... cat http://www.sarjis.info/stripit/abstruse-goose/496/the_singularity_is_way_over_there.png

I think the ultimate solution is still to put a human brain in a jar and use it for pattern recognition. Maybe we should get a stagiaire for this..?

Asimov's Foundation meets ACT's Tipping Point Prediction?

still, some interesting thoughts in there ... "Then you have the 50-year cycles of violence. Turchin describes these as the building up and then the release of pressure. Each time, social inequality creeps up over the decades, then reaches a breaking point. Reforms are made, but over time, those reforms are reversed, leading back to a state of increasing social inequality. The graph above shows how regular these spikes are - though there's one missing in the early 19th century, which Turchin attributes to the relative prosperity that characterized the time. He also notes that the severity of the spikes can vary depending on how governments respond to the problem. Turchin says that the United States was in a pre-revolutionary state in the 1910s, but there was a steep drop-off in violence after the 1920s because of the progressive era. The governing class made decisions to reign in corporations and allowed workers to air grievances. These policies reduced the pressure, he says, and prevented revolution. The United Kingdom was also able to avoid revolution through reforms in the 19th century, according to Turchin. But the most common way for these things to resolve themselves is through violence. Turchin takes pains to emphasize that the cycles are not the result of iron-clad rules of history, but of feedback loops - just like in ecology. "In a predator-prey cycle, such as mice and weasels or hares and lynx, the reason why populations go through periodic booms and busts has nothing to do with any external clocks," he writes. "As mice become abundant, weasels breed like crazy and multiply. Then they eat down most of the mice and starve to death themselves, at which point the few surviving mice begin breeding like crazy and the cycle repeats." There are competing theories as well. A group of researchers at the New England Complex Systems Institute - who practice a discipline called econophysics - have built their own model of political violence and

It's not the scientific activity described in the article that is uninteresting, on the contrary! But the way it is described is just a bad joke. Once again the results itself are seemingly not sexy enough and thus something is sold as the big revolution, though it's just the application of the oldest scientific principles in a slightly different way than used before.

Latest update: the European Space Agency says their experts "confirm there is no link between the meteor incidents in Russia and asteroid 2012DA14 flyby tonight". How did they find this? As they did not see this one coming, how could they come to that conclusion that early!

yes, now i get my 100% certainty with the reconstructed orbits nothing else (http://wiki.nasa.gov/cm/blog/Watch%20the%20Skies/posts/post_1361037562855.html) ... I still think that esa anouncemement was highly premature but with a high probability of being right...

Some more results on the topic (link to an arxiv article inside): http://www.bbc.co.uk/news/science-environment-21579422

this is a gold mine :D Portugal, a bankrupt country in crisis where the Most Searched How to... is "Como emagrecer" (how to lose weight?). Netherlands, where the Most Searched How to... is "Hoe overleef ik" (how do I survive?) UK where the most Trending What is... is "What is love?" and Italians... please explain how come the top Trending How to... are 1. Come fare Sesso 2. Come fare un Clistere !?!? Respect for Austria though, where the top trending What is... are: 1. Was ist ACTA 2. Was ist SOPA any other interesting finds?

From Ghana "What is...?": What is a Constitution What is Government [edit] Some top Science searches in the US: Hemorrhoid, Pregnancy Syndroms. Any potential for Ariadna? [edit] ... and finally, for the sake of my shield, top search from Poland in the Music category

Small scale laser induced electron accelerator followed by induced beta decay to produce positrons. Relatively simple, yet requires a high power fs laser and some precision engineering

Really? Is this what we were all waiting for?

to be honest, while the alien megastructure is a cookie idea, I highly doubt that those aliens woke up one day and thought: "hm, let's send laser pulses at this particular random spot in space sometime in the next 6 days".

The ALPHA collaboration reports the first ever measurement on the optical spectrum of an antimatter hydrogen atom. Optical transitions shown to be the same as for normal hydrogen. Paper at http://www.nature.com/nature/journal/vaap/ncurrent/full/nature21040.html#affil-auth

There has been much recent interest in accelerating materials discovery. High-throughput calculations and combinatorial experiments have been the approaches of choice to narrow the search space. The emphasis has largely been on feature or descriptor selection or the use of regression tools, such as least squares, to predict properties. The regression studies have been hampered by small data sets, large model or prediction uncertainties and extrapolation to a vast unexplored chemical space with little or no experimental feedback to validate the predictions. Thus, they are prone to be suboptimal. Here an adaptive design approach is used that provides a robust, guided basis for the selection of the next material for experimental measurements by using uncertainties and maximizing the 'expected improvement' from the best-so-far material in an iterative loop with feedback from experiments. It balances the goal of searching materials likely to have the best property (exploitation) with the need to explore parts of the search space with fewer sampling points and greater uncertainty.

Can AI create the next wonder material? http://www.nature.com/news/can-artificial-intelligence-create-the-next-wonder-material-1.19850?WT.ec_id=NATURE-20160505&spMailingID=51301208&spUserID=MTEzODM0NjYzMzgS1&spJobID=920498312&spReportId=OTIwNDk4MzEyS0

Nanometre-sized rods of carbon can expel water in puffs of vapour when the air is already humid. Materials such as carbon and silica gels typically pick up moisture as humidity increases. But Satish Nune and his colleagues at the Pacific Northwest National Laboratory in Richland, Washington, found that their carbon-based nanorods take up water at low humidity and then give off about half of it when the relative humidity exceeds 50-80%. The team thinks that water condenses between adjacent rods and then capillary forces draw the rods together until the water bursts from the ends of the rods and evaporates.

An incresingly popular scientific enome re-writting tool. Might prevent future generations from being born with some types of disorders or disabilities! Also, for fun, can be looked at one step closer to having a real wolverine..

"Chinese team uses CRISPR to genetically modify human embryo" http://medicalxpress.com/news/2016-04-chinese-team-crispr-genetically-human.html?utm_source=nwletter&utm_medium=email&utm_campaign=weekly-nwletter

Strong evidence for d-electron spin transport at room temperature

WOW! Great non-local signals, at room temperature!!! Spin transistor on the way finally!? (of course electric field gate controlled is fundamental) See more about the "quest" for the spin transistor here: http://spectrum.ieee.org/semiconductors/processors/the-quest-for-the-spin-transistor

Interesting. these guys are apparently gonna try developing pulsar navigation. They propose to solve the low apparent brightness problem using relatively complex signal processing and filtering to limit the antenna size etc. The say they've already had some promising results using ground based data. worth a science coffee perhaps?

Absolutely. Sante can you get in contact with them?

I like this one "The kind of idle pastime that might amuse physicists is to imagine drafting Einstein's grant applications in 1905. "I propose to investigate the idea that light travels in little bits," one might say. "I will explore the possibility that time slows down as things speed up," goes another. Imagine what comments these would have elicited from reviewers for the German Science Funding Agency, had such a thing existed. Instead, Einstein just did the work anyway while drawing his wages as a technical expert third-class at the Bern patent office. And that is how he invented quantum physics and relativity." There is an even more pointer example of the Prussian academy of sciences reviewing the Dr. application of Hertz ...

Shocking. What is federal research funding for? No, wrong question. Instead maybe: What is federally funded review for?

presentation: http://youtu.be/4efE_gO9lFo

random idea: how about using this thing as the "pheromone" to be by released by robots in a swarm... Recognizing an area as being of interest, for some reason, would lead to more "pheromones" being released there. This would in turn attract other robots to the area, by virtue of having also maximization of connectivity to the rest of the swarm as part of the navigation algorithm.

If this works as they claim this would be really interesting. Still no clue how they might be able to make this work though! Anybody?

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!! ;)