Slashdot Mirror

StartsWithABang writes After successfully landing on a comet with all 10 instruments intact, but failing to deploy its thrusters and harpoons to anchor onto the surface, Philae bounced, coming to rest in an area with woefully insufficient sunlight to keep it alive. After exhausting its primary battery, it went into hibernation, most likely never to wake again. We'll always be left to wonder what might have been if it had functioned optimally, and given us years of data rather than just 60 hours worth. The thing is, it wouldn't have needed to function optimally to give us years of data, if only it were better designed in one particular aspect: powered by Plutonium-238 instead of by solar panels.

KentuckyFC writes: The halting problem is to determine whether an arbitrary computer program, once started, will ever finish running or whether it will continue forever. In 1936, Alan Turing famously showed that there is no general algorithm that can solve this problem. Now a group of computer scientists and ethicists have used the halting problem to tackle the question of how a weaponized robot could decide to kill a human. Their trick is to reformulate the problem in algorithmic terms by considering an evil computer programmer who writes a piece of software on which human lives depend.

The question is whether the software is entirely benign or whether it can ever operate in a way that ends up killing people. In general, a robot could never decide the answer to this question. As a result, autonomous robots should never be designed to kill or harm humans, say the authors, even though various lethal autonomous robots are already available. One curious corollary is that if the human brain is a Turing machine, then humans can never decide this issue either, a point that the authors deliberately steer well clear of.

An anonymous reader writes: Two researchers say time disparities identified through the network of satellites that make up our modern GPS infrastructure can help detect dark matter. In a paper in the online version of the scientific journal Nature Physics, they write that dark matter may be organized as a large gas-like collection of topological defects, or energy cracks. "We propose to detect the defects, the dark matter, as they sweep through us with a network of sensitive atomic clocks. The idea is, where the clocks go out of synchronization, we would know that dark matter, the topological defect, has passed by." Another reader adds this article about research into dark energy: The particles of the standard model, some type of dark matter and dark energy, and the four fundamental forces. That's all there is, right? But that might not be the case at all. Dark energy may not simply be the energy inherent to space itself, but rather a dynamical property that emerges from the Universe: a sort of fifth force. This is speculation that's been around for over a decade, but there hasn't been a way to test it until now. If this is the case, it may be accessible and testable by simply using presently existing vacuum chamber technology

gallifreyan99 writes When the shuttle program was ended, and manned space exploration was put on hold, the people of Titusville, Florida were left in big trouble. "Just 20 miles northwest of Kennedy Space Center in Florida, it used to have a proud nickname: Space City USA. The dizzying boom of the 1950s and '60s helped create myriad jobs by giving work to nearby aerospace companies. Unfortunately, the past 15 years have seen everything dry up By December 2010, Titusville had one of the America's highest unemployment rates, 13.8 percent." But even though there's been plenty of bad news recently, the city hopes that the private space industry can save it from destruction.

KentuckyFC writes During the Chinese New Year earlier this year, some 3.6 billion people traveled across China making it the largest seasonal migration on Earth. These kinds of mass movements have always been hard to study in detail. But the Chinese web services company Baidu has managed it using a mapping app that tracked the location of 200 million smartphone users during the New Year period. The latest analysis of this data shows just how vast this mass migration is. For example, over 2 million people left the Guandong province of China and returned just a few days later--that's equivalent to the entire population of Chicago upping sticks. The work shows how easy it is to track the movement of large numbers of people with current technology--assuming they are willing to allow their data to be used in this way.

superboj sends an article written after its author investigated the Mars One Project for over a year. Even though 200,000 people have (supposedly) signed up as potential volunteers on a one-way trip to Mars, there are still frightfully few details about how the mission will be accomplished. From the article: [Astronaut Chris Hadfield] says that Mars One fails at even the most basic starting point of any manned space mission: If there are no specifications for the craft that will carry the crew, if you don’t know the very dimensions of the capsule they will be traveling in, you can’t begin to select the people who will be living and working inside of it. "I really counsel every single one of the people who is interested in Mars One, whenever they ask me about it, to start asking the hard questions now. I want to see the technical specifications of the vehicle that is orbiting Earth. I want to know: How does a space suit on Mars work? Show me how it is pressurized, and how it is cooled. What’s the glove design? None of that stuff can be bought off the rack. It does not exist. You can’t just go to SpaceMart and buy those things." The author concludes that the Mars One Project is "...at best, an amazingly hubristic fantasy: an absolute faith in the free market, in technology, in the media, in money, to be able to somehow, magically, do what thousands of highly qualified people in government agencies have so far not yet been able to do over decades of diligently trying, making slow headway through individually hard-won breakthroughs, working in relative anonymity pursuing their life’s work."

theodp writes: TechCrunch reports that Codecademy has teamed up with online and offline coding schools to create ReskillUSA. "3 months," explains ReskillUSA's website, is "how long it takes a dedicated beginner to learn the skills to qualify for computing and web development jobs." TechCrunch's Anthony Ha explains,"By teaming up with other organizations, Codecademy is also hoping to convince employers that completing one of those programs is a meaningful qualification for a job, and that you don't necessarily need a bachelor's degree in computer science." In his Medium post, Codecademy CEO Zach Sims calls on "students learning for the jobs of the future or employers interested in hiring a diverse and skilled workforce – to join us. The future of our economy depends on it."

StartsWithABang writes: Out beyond Neptune, the last of our Solar System's gas giants, the icy graveyard of failed planetesimals lurks: the Kuiper Belt. Among these mixes of ice, snow, dust and rock are a number of worlds — possibly a few hundred — massive enough to pull themselves into hydrostatic equilibrium. The most famous among them are Pluto, the first one ever discovered, and Eris, of comparable size but undoubtedly more massive. But there's an even larger, more massive object from the Kuiper Belt than either of these, yet you never hear about it: it's Triton, the largest moon of Neptune, a true Kuiper Belt object!

TaleSlinger writes: One of the great theories of modern cosmology is that the universe began in a "Big Bang", but the mathematical mechanism by which this occurred has been lacking. Cosmologists at the Wuhan Institute have published a proof that the Big Bang could indeed have occurred spontaneously because of quantum fluctuations. "The new proof is based on a special set of solutions to a mathematical entity known as the Wheeler-DeWitt equation. In the first half of the 20th century, cosmologists struggled to combine the two pillars of modern physics— quantum mechanics and general relativity—in a way that reasonably described the universe. As far as they could tell, these theories were entirely at odds with each other.

At the heart of their thinking is Heisenberg's uncertainty principle. This allows a small empty space to come into existence probabilistically due to fluctuations in what physicists call the metastable false vacuum. When this happens, there are two possibilities. If this bubble of space does not expand rapidly, it disappears again almost instantly. But if the bubble can expand to a large enough size, then a universe is created in a way that is irreversible. The question is: does the Wheeler-DeWitt equation allow this? "We prove that once a small true vacuum bubble is created, it has the chance to expand exponentially," say the researchers.

KentuckyFC writes Back in 1947, a pair of physicists demonstrated that when a beam of light reflects off a surface, the point of reflection can shift forward when parts of the beam interfere with each other. 60 years later, another group of physicists discovered that this so-called Goos-Hanchen effect could sometimes be negative so the point of reflection would go back toward the source rather than away from it. They even suggested that if the negative effect could be made big enough, it could cancel out the forward movement of the light. In other words, the light would become trapped at a single location. Now, physicists have demonstrated this effect for the first time using light reflected off a sheet of silica. The trick they've employed is to place a silicon diffraction grating in contact with the silica to make the interference effect large enough to counteract the forward motion of the light. And by using several gratings with different spacings, they've trapped an entire rainbow. The light can be easily released by removing the grating. Until now, it has only been possible to trap light efficiently inside Bose Einstein Condensates at temperatures close to absolute zero. The new technique could be used as a cheap optical buffer or memory, making it an enabling technology for purely optical computing.

blastboy writes By pretty much any logic, Wikipedia shouldn't work: A vast website, built on the labor of volunteers, with very few tangible rewards and a fairly weird hierarchy. From the article: "The stewards would prefer to go unnoticed. Only one has ever had any real fame—Wikipedia co-founder Jimmy Wales served as a steward from 2006 to 2009. They operate above the fray, giving and taking user privileges and intervening in matters that lower-ranking editors can’t handle. You can summon them for emergencies in the Wikimedia Stewards IRC chat room by typing '!steward.' Their secrecy has a certain irony, given the very public product they manage, but perhaps it’s emblematic of Wikimedia as a whole. When your foundational value is that 'every single human being can freely share in the sum of all knowledge,' hierarchies become a necessary evil."

An anonymous reader writes: We frequently discuss diversity in the tech industry, and all the initiatives getting underway to encourage women and minorities to enter (and stay in) the field. The prevailing theme is that this will be good for companies, good for innovation, and good for the future of technology. While that's true, greater representation will also be good for the individuals themselves. Erica Joy has been in IT for a long time, and she's worked in many of the industry hotspots. She's written an insightful article on how the lack of diversity has affected her throughout her career. An excerpt: "Unfortunately, my workplace is homogenous and so are my surroundings. I feel different everywhere. I go to work and I stick out like a sore thumb. ... I feel like I've lost my entire cultural identity in effort to be part of the culture I've spent the majority of the last decade in."

HughPickens.com writes HyperCard, an application program and programming tool released for the Apple Macintosh in 1987, represented the 'computing for the people' philosophy that enabled users to go past the pre-built software that came on their machines, and to program and build software of their own. "Mac users could use Hypercard to build their own mini-programs to balance their taxes, manage sports statistics, make music – all kinds of individualized software that would be useful (or fun) for individual users." Now Jer Thorp writes that the end of HyperCard left a huge gap that desperately needs to be filled – a space for an easy to use, intuitive tool that will once again let average computer users make their own tools. According to Throp, this type of plain-language programming makes sense, particularly in an application that was designed specifically for non-programmers. "I find the largest concern for learners to be not with the conceptual hurdles involved in writing a program, but with obscure and confusing syntax requirements. I would love to be able to teach HyperTalk to my students, as a smooth on-road to more complex languages like JavaScript, Java or C++." By putting the tools of creation into the hands of the broader userbase, we would allow for the creation of ultra-specific personalized apps that, aside from a few exceptions, don't exist today."

HyperTalk wasn't just easy, it was also fairly powerful. Complex object structures could be built to handle complicated tasks, and the base language could be expanded by a variety of available external commands and functions (XCMDs and XFCNs, respectively), which were precursors to the modern plug-in. But ultimately, HyperCard would disappear from Mac computers by the mid-nineties, eclipsed by web browsers and other applications which it had itself inspired. The last copy of HyperCard was sold by Apple in 2004. "One thing that's changed in the intervening decades is that the hobbyist has largely gone by the wayside. Now you're either a user or a full-fledged developer, and the gulf is wider than ever," writes Peter Cohen. "There's really nothing like it today, and I think the Mac is lesser for it."

StartsWithABang writes: We like to think of our Solar System as typical: a central star with a number of planets — some gas giants and some rocky worlds — in orbit around it. Yes, there's some variety, with binary or trinary star systems and huge variance in the masses of the central star being common ones, but from a planetary point of view, our Solar System is a rarity. Even though there are hundreds of billions of stars in our galaxy for planets to orbit, there are most likely around a quadrillion planets in our galaxy, total, with only a few trillion of them orbiting stars at most. Now that we've finally detected the first of these, we have an excellent idea that this picture is the correct one: most planets in the Universe are homeless. Now, thank your lucky star!"

An anonymous reader writes John Oliver calls it "cable company f*ckery" and we've all suspected it happens. Now on Steven Levy's new Backchannel publication on Medium, Susan Crawford delivers decisive proof, expertly dissecting the Comcast-Netflix network congestion controversy. Her source material is a detailed traffic measurement report (.pdf) released this week by Google-backed M-Lab — the first of its kind — showing severe degradation of service at interconnection points between Comcast, Verizon and other monopoly "eyeball networks" and "transit networks" such as Cogent, which was contracted by Netflix to deliver its bits. The report shows that interconnection points give monopoly ISPs all the leverage they need to discriminate against companies like Netflix, which compete with them in video services, simply by refusing to relieve network congestion caused by external traffic requested by their very own ISP customers. And the effects victimize not only companies targeted but ALL incoming traffic from the affected transit network. The report proves the problem is not technical, but rather a result of business decisions. This is not technically a Net neutrality problem, but it creates the very same headaches for consumers, and unfair business advantages for ISPs. In an accompanying article, Crawford makes a compelling case for FCC intervention.

An anonymous reader writes John Oliver calls it "cable company f*ckery" and we've all suspected it happens. Now on Steven Levy's new Backchannel publication on Medium, Susan Crawford delivers decisive proof, expertly dissecting the Comcast-Netflix network congestion controversy. Her source material is a detailed traffic measurement report (.pdf) released this week by Google-backed M-Lab — the first of its kind — showing severe degradation of service at interconnection points between Comcast, Verizon and other monopoly "eyeball networks" and "transit networks" such as Cogent, which was contracted by Netflix to deliver its bits. The report shows that interconnection points give monopoly ISPs all the leverage they need to discriminate against companies like Netflix, which compete with them in video services, simply by refusing to relieve network congestion caused by external traffic requested by their very own ISP customers. And the effects victimize not only companies targeted but ALL incoming traffic from the affected transit network. The report proves the problem is not technical, but rather a result of business decisions. This is not technically a Net neutrality problem, but it creates the very same headaches for consumers, and unfair business advantages for ISPs. In an accompanying article, Crawford makes a compelling case for FCC intervention.

An anonymous reader writes John Oliver calls it "cable company f*ckery" and we've all suspected it happens. Now on Steven Levy's new Backchannel publication on Medium, Susan Crawford delivers decisive proof, expertly dissecting the Comcast-Netflix network congestion controversy. Her source material is a detailed traffic measurement report (.pdf) released this week by Google-backed M-Lab — the first of its kind — showing severe degradation of service at interconnection points between Comcast, Verizon and other monopoly "eyeball networks" and "transit networks" such as Cogent, which was contracted by Netflix to deliver its bits. The report shows that interconnection points give monopoly ISPs all the leverage they need to discriminate against companies like Netflix, which compete with them in video services, simply by refusing to relieve network congestion caused by external traffic requested by their very own ISP customers. And the effects victimize not only companies targeted but ALL incoming traffic from the affected transit network. The report proves the problem is not technical, but rather a result of business decisions. This is not technically a Net neutrality problem, but it creates the very same headaches for consumers, and unfair business advantages for ISPs. In an accompanying article, Crawford makes a compelling case for FCC intervention.

StartsWithABang writes: Wandering into the woods unprepared and without a plan sounds like a terrible idea. But if you're interested in scientific exploration at the frontiers, confronting the unknown with whatever you happen to have at your disposal, you have to take that risk. You have to be willing to take those steps. And you have to be okay with putting your best ideas out there — for all to see — knowing full well that you might get the entire thing wrong. Sometimes, that's indeed what happens. Some of the most revered and famous scientific minds in history confronted the great mysteries of nature, and came away having done nothing but set us back many years by leading the field down a blind alley. But other times, the greatest leaps forward in our understanding occur as a result. The article shares some notable examples, and explains why this is vital for scientific progress.

KentuckyFC writes It's 20 years since the FDA approved the Flavr Savr tomato for human consumption, the first genetically engineered food to gain this status. Today, roughly 85 per cent of corn and 90 per cent of soybeans produced in the US are genetically modified. So it's easy to imagine that the scientific debate over the safety of genetically modified organisms has been largely settled. Not for Nassim Nicholas Taleb, author of The Black Swan and several academic colleagues who say that the risks have been vastly underestimated. They say that genetically modified organisms threaten harm on a global scale, both to ecosystems and to human health. That's different from many conventional risks that threaten harm on a local scale, like nuclear energy for example. They argue that this global threat means that the precautionary principle ought to be applied to severely limit the way genetically modified organisms can be used.

KentuckyFC writes: Earth's closest white dwarf is called van Maanen 2 and sits 14 light-years from here. It was discovered by the Dutch astronomer Adriaan van Maanen in 1917, but it was initially hard to classify. That's because its spectra contains lots of heavy elements alongside hydrogen and helium, the usual components of a white dwarf photosphere. In recent years, astronomers have discovered many white dwarfs with similar spectra and shown that the heavy elements come from asteroids raining down onto the surface of the stars. It turns out that all these white dwarfs are orbited by a large planet and an asteroid belt. As the planet orbits, it perturbs the rocky belt, causing asteroids to collide and spiral in toward their parent star. This process is so common that astronomers now use the heavy element spectra as a marker for the presence of extrasolar planets. A re-analysis of van Maanen's work shows that, in hindsight, he was the first to discover the tell-tale signature of extrasolar planets almost a century ago.

StartsWithABang writes We like to think of the Mercury 7 — the very first group of NASA astronauts — as the "best of the best," having been chosen from a pool of over 500 of the top military test pilots after three rounds of intense physical and mental tests. Yet when women were allowed to take the same tests, one of them clearly distinguished herself, outperforming practically all of the men. If NASA had really believed in merit, Jerrie Cobb would have been the first female in space, even before Valentina Tereshkova, more than 50 years ago. She still deserves to go.

StartsWithABang writes If you can reach the fabled "breakeven point" of nuclear fusion, you'll have opened up an entire new source of clean, reliable, safe, renewable and abundant energy. You will change the world. At present, fusion is one of those things we can make happen through a variety of methods, but — unless you're the Sun — we don't have a way to ignite and sustain that reaction without needing to input more energy than we can extract in a usable fashion from the fusion that occurs. One alternative approach to the norm is, rather than try and up the energy released in a sustained, hot fusion reaction, to instead lower the energy inputted, and try to make fusion happen under "cold" conditions. If you listen in the right (wrong?) places, you'll hear periodic reports that cold fusion is happening, even though those reports have always crumbled under scrutiny. Here's why, most likely, they always will.

StartsWithABang writes If you can reach the fabled "breakeven point" of nuclear fusion, you'll have opened up an entire new source of clean, reliable, safe, renewable and abundant energy. You will change the world. At present, fusion is one of those things we can make happen through a variety of methods, but — unless you're the Sun — we don't have a way to ignite and sustain that reaction without needing to input more energy than we can extract in a usable fashion from the fusion that occurs. One alternative approach to the norm is, rather than try and up the energy released in a sustained, hot fusion reaction, to instead lower the energy inputted, and try to make fusion happen under "cold" conditions. If you listen in the right (wrong?) places, you'll hear periodic reports that cold fusion is happening, even though those reports have always crumbled under scrutiny. Here's why, most likely, they always will.

KentuckyFC writes: One way to explore the link between quantum mechanics and general relativity is to study the physics that occurs on a small scale in highly curved spacetimes. However, these conditions only occur in the most extreme environments such as at the edge of black holes or in the instants after the Big Bang. But now one physicist has described how it is possible to create curved spacetime in an ordinary quantum optics lab.

The idea is based on optical lattices, which form when a pair of lasers interfere to create an eggbox-like interference pattern. When ultracold atoms are dropped into the lattice, they become trapped like ping pong balls in an eggbox. This optical trapping technique is common in labs all over the world. However, the ultracold atoms do not stay at a fixed location in the lattice because they can tunnel from one location to another. This tunneling is a form of movement through the lattice and can be controlled by changing the laser parameters to make tunneling easier or more difficult.

Now, a physicist has shown that on a large scale, the tunneling motion of atoms through the lattice is mathematically equivalent to the motion of atoms in a quantum field in a flat spacetime. And that means it is possible to create a formal analogue of a curved spacetime by changing the laser parameters across the lattice. Varying the laser parameters over time even simulates the behavior of gravitational waves. Creating this kind of curved spacetime in the lab won't reveal any new physics but it will allow researchers to study the behavior of existing laws under these conditions for the first time. That's not been possible even in theory because the equations that describe these behaviors are so complex that they can only be solved in the simplest circumstances.

KentuckyFC writes: Machine learning algorithms use a training dataset to learn how to recognize features in images and use this 'knowledge' to spot the same features in new images. The computational complexity of this task is such that the time required to solve it increases in polynomial time with the number of images in the training set and the complexity of the "learned" feature. So it's no surprise that quantum computers ought to be able to rapidly speed up this process. Indeed, a group of theoretical physicists last year designed a quantum algorithm that solves this problem in logarithmic time rather than polynomial, a significant improvement.

Now, a Chinese team has successfully implemented this artificial intelligence algorithm on a working quantum computer, for the first time. The information processor is a standard nuclear magnetic resonance quantum computer capable of handling 4 qubits. The team trained it to recognize the difference between the characters '6' and '9' and then asked it to classify a set of handwritten 6s and 9s accordingly, which it did successfully. The team says this is the first time that this kind of artificial intelligence has ever been demonstrated on a quantum computer and opens the way to the more rapid processing of other big data sets — provided, of course, that physicists can build more powerful quantum computers.

An anonymous reader writes: To add some historical context to the currently controversy surrounding attitudes toward women in gaming, Jon Peterson provides an in-depth historical look at the unsurprisingly male origins of the "gamer" identity. It also examines how Dungeons & Dragons helped to open the door for women in gaming — overturning a sixty-year-old dogma that was born when Wells's Little Wars first assumed the "disdain" of women for gaming.

KentuckyFC writes Since 2001, crowdfunding sites have raised almost $3 billion and in 2012 alone, successfully funded more than 1 million projects. But while many projects succeed, far more fail. The reasons for failure are varied and many but one of the most commonly cited is the inability to match a project with suitable investors. Now a group of researchers from Yahoo Labs and the University of Cambridge have mined data from Kickstarter to discover how investors choose projects to back. They studied over 1000 projects in the US funded by over 80,000 investors. They conclude that there are two types of backers: occasional investors who tend to back arts-related projects, probably because of some kind of social connection to the proposers; and frequent investors who have a much more stringent set of criteria. Frequent investors tend to fund projects that are well-managed, have high pledging goals, are global, grow quickly, and match their interests. The team is now working on a website that will create a list of the Twitter handles of potential investors given the URL of a Kickstarter project.

KentuckyFC writes Photons have many properties, such as their frequency, momentum, spin and orbital angular momentum. But when it comes to quantum teleportation, physicists have only ever been able to to transmit one of these properties at a time. So the possibility of teleporting a complete quantum object has always seemed a distant dream. Now a team of Chinese physicists has worked out how to teleport more than one quantum property. The team has demonstrated it by teleporting both the spin and orbital angular momentum of single photons simultaneously. They point out that there is no reason in principle why the technique cannot be generalized to include other properties as well, such as a photon's frequency, momentum and so on. That's an important step towards teleporting complex quantum objects in their entirety, such as atoms, molecules and perhaps even small viruses.

KentuckyFC writes The human visual system has evolved to recognize people in almost any pose under a vast range of lighting conditions. But abstract art pushes this ability to its limits by distorting the human form. In particular, Cubism seeks to represent three-dimensional objects on a two-dimensional plane by juxtaposing snapshots from different angles. The result is that a Cubist picture contains many 'fragments of perception' of the same object. That's why it is often hard for people to recognize the human figures that these pictures contain. Now a group of computer scientists have tested how computer vision algorithms fare at the task of spotting human figures in Cubist art. They compared a variety of different algorithms against humans in trying to spot human figures in 218 Cubist paintings by Picasso. Humans easily outperform all the algorithms at this task. But some algorithms were much better than others. The most successful were based on so-called "deformable parts models" that recognize human figures by looking for body parts rather than the entire form. Interestingly, the team says this backs up various studies by neuroscientists suggesting that the human brain works in a similar way.

KentuckyFC writes One way of predicting the future is to study data about events in the past and build a statistical model that generates the same pattern of data. Statisticians can then use the model to generate data about the future. Now one statistician has taken this art to new heights by predicting the content of the soon-to-be published novels in the Song of Ice and Fire series by George R R Martin. The existing five novels are the basis of the hit TV series Game of Thrones. Each chapter in the existing books is told from the point of view of one of the characters. So far, 24 characters have starred in this way. The statistical approach uses the distribution of characters in chapters in the first five books to predict the distribution in the forthcoming novels. The results suggest that several characters will not appear at all and also throw light on whether one important character is dead or not, following an ambiguous story line in the existing novels. However, the model also serves to highlight the shortcomings of purely statistical approaches. For example, it does not "know" that characters who have already been killed off are unlikely to appear in future chapters. Neither does it allow for new characters that might appear. Nevertheless, this statistical approach to literature could introduce the process of mathematical modelling to more people than any textbook.

StartsWithABang writes: The next great leap in human spaceflight is a manned mission to a world within our Solar System: most likely Mars. But if something went wrong along the journey — at launch, close to Earth, or en route — whether biological or mechanical, would there be any way to return to Earth? This article is a fun (and sobering) look at what the limits of physics and technology allow at present. If you're interested in a hard sci-fi, near-future look at how a catastrophic Mars mission might go, you should read an excellent novel called The Martian by Andy Weir.

KentuckyFC writes: Back in the 1970s, the astronauts from Apollos 12, 14, 15, and 16 set up an array of seismometers on the lunar surface to listen for moonquakes. This array sent back data until 1977, when NASA switched it off. Now astrophysicists are using this lunar seismic data in the hunt for gravitational waves. The idea is that gravitational waves must squeeze and stretch the Moon as they pass by and that at certain resonant frequencies, this could trigger the kind of seismic groans that the array ought to have picked up. However, the data shows no evidence of activity at the relevant frequencies.

That's important because it has allowed astronomers to put the strongest limits yet on the strength of gravitational waves in this part of the universe. Earlier this year, the same team used a similar approach with terrestrial seismic data to strengthen the existing limits by 9 orders of magnitude. The lunar data betters this by yet another order of magnitude because there is no noise from sources such as oceans, the atmosphere and plate tectonics. The work shows that good science on gravitational waves can be done without spending the hundreds of millions of dollars for bespoke gravitational wave detectors, such as LIGO, which have yet to find any evidence of the waves either.

KentuckyFC writes: Underwater vehicles have never matched the extraordinary agility of marine creatures. While many types of fish can travel at speeds of up to 10 body lengths per second, a nuclear sub can manage a less than half a body length per second. Now a team of researchers has copied a trick used by octopuses to build an underwater robot capable of matching the agility of marine creatures. This trick is the way an octopus expands the size of its head as it fills with water and then squirts it out to generate propulsion. The team copied this by building a robot with a flexible membrane that also expands as it fills with water.

The fluid then squirts out through a rear-facing nozzle as the membrane contracts. To the team's surprise, the robot reached speeds of 10 body lengths per second with a peak acceleration of 14 body lengths per second squared. That's unprecedented in an underwater vehicle of this kind. What's more, the peak force experienced by the robot was 30 per cent greater than the thrust generated by the jet. The team think they know why and say the new technique could be used to design bigger subs capable of even more impressive octopus-like feats.

KentuckyFC writes It's not just star systems and galaxies that have habitable zones--regions where conditions are suitable for life to evolve. Astrophysicists have now identified the entire universe's habitable zones. Their approach starts by considering the radiation produced by gamma ray bursts in events such as the death of stars and the collisions between black holes and so on. Astrobiologists have long known that these events are capable of causing mass extinctions by stripping a planet of its ozone layer and exposing the surface to lethal levels of radiation. The likelihood of being hit depends on the density of stars, which is why the center of galaxies are thought to be inhospitable to life. The new work focuses on the threat galaxies pose to each other, which turns out to be considerable when they are densely packed together. Astronomers know that the distribution of galaxies is a kind of web-like structure with dense knots of them connected by filaments interspersed with voids where galaxies are rare. The team says that life-friendly galaxies are most likely to exist in the low density regions of the universe in the voids and filaments of the cosmic web. The Milky Way is in one of these low density regions with Andromeda too far away to pose any threat. But conditions might not be so life friendly in our nearest knot of galaxies called the Virgo supercluster."

HughPickens.com writes Medium reports that although many startups want to design something that mimics the fit and finish of an Apple product, it's a good way to go out of business. "What happened when Apple wanted to CNC machine a million MacBook bodies a year? They bought 10k CNC machines to do it. How about when they wanted to laser drill holes in MacBook Pros for the sleep light but only one company made a machine that could drill those 20 m holes in aluminum? It bought the company that made the machines and took all the inventory. And that time when they needed batteries to fit into a tiny machined housing but no manufacturer was willing to make batteries so thin? Apple made their own battery cells. From scratch." Other things that Apple often does that can cause problems for a startup include white plastic (which is the most difficult color to mold), CNC machining at scale (too expensive), Laser drilled holes (far more difficult than it may seem), molded plastic packaging (recycled cardboard is your friend), and 4-color, double-walled, matte boxes + HD foam inserts (It's not unusual for them to cost upwards of $12/unit at scale. And then they get thrown away.). "If you see a feature on an Apple device you want to copy, try to find it on another company's product. If you do, it's probably okay to design into your product. Otherwise, lower your expectations. I assure you it'll be better for your startup."

KentuckyFC (1144503) writes A growing number of police forces around the world are using data on past crimes to predict the likelihood of crimes in the future. These predictions can be made more accurate by combining crime data with local demographic data about the local population. However, this data is time consuming and expensive to collect and so only updated rarely. Now a team of data experts have shown how combing crime data with data collected from mobile phones can make the prediction of future crimes even more accurate. The team used an anonymised dataset of O2 mobile phone users in the London metropolitan area during December 2012 and January 2013. They then used a small portion of the data to train a machine learning algorithm to find correlations between this and local crime statistics in the same period. Finally, they used the trained algorithm to predict future crime rates in the same areas. Without the mobile phone data, the predictions have an accuracy of 62 per cent. But the phone data increases this accuracy significantly to almost 70 per cent. What's more, the data is cheap to collect and can be gathered in more or less real time. Whether the general population would want their data used in this way is less clear but either way Minority Report-style policing is looking less far-fetched than when the film appeared in 2002.

KentuckyFC writes: Pattern recognition is one of the few areas where humans regularly outperform even the most powerful computers. Our extraordinary ability is a result of the way our bodies process visual information. But surprisingly, our brains only do part of the work. The most basic pattern recognition—edge detection, line detection and the detection of certain shapes—is performed by the complex circuitry of neurons in the retina. Now particle physicists are copying this trick to hunt for new particles. A team at CERN has built and tested an artificial retina capable of identifying particle tracks in the debris from particle collisions. The retina can do this at the same rate the LHC smashes particles together: about 800 million collisions per second. In other words, it can sift through the data in real time. The team says the retina outperforms any other particle-detecting device by a factor of 400v.

StartsWithABang writes In 1992, scientists discovered the first planets orbiting a star other than our Sun. The pulsar PSR B1257+12 was discovered to have its own planetary system, and since then, exoplanet discoveries have exploded. But before that, in 1963, decades of research led to the much-anticipated publication and announcement of an exoplanet discovered around Barnard's star, the second-closest star system to Earth. Unfortunately, it turned out to be spurious, and it took years to uncover, an amazing story which is only now fully coming to light.

KentuckyFC writes: Most research into the origin of life focuses on the messy business of chemistry, on the nature of self-replicating molecules and on the behavior of autocatalytic reactions. Now one theorist says the properties of information also place important limits on how life must have evolved, without getting bogged down in the biochemical details. The new approach uses information theory to highlight a key property that distinguishes living from non-living systems: their ability to store information and replicate it almost indefinitely. A measure of this how much these systems differ from a state of maximum entropy or thermodynamic equilibrium. The new approach is to create a mathematical model of these informational differences and use it to make predictions about how likely it is to find self-replicating molecules in an artificial life system called Avida. And interestingly, the predictions closely match what researchers have found in practice. The bottom line is that according to information theory, environments favorable to life are unlikely to be unusual.

KentuckyFC writes One of the great mysteries in astrophysics surrounds the origin of ultra-high energy cosmic rays, which can have energies of 10^20 electron volts and beyond. To put that in context, that's a single proton with the same energy as a baseball flying at 100 kilometers per hour. Nobody knows where ultra-high energy cosmic rays come from or how they get their enormous energies. That's largely because they are so rare--physicists detect them on Earth at a rate of less than one particle per square kilometer per century. So astronomers have come up with a plan to see vastly more ultra high energy cosmic rays by using the Moon as a giant cosmic ray detector. When these particles hit the lunar surface, they generate brief bursts of radio waves that a highly sensitive radio telescope can pick up. No radio telescope on Earth is currently capable of this but astronomers are about to start work on a new one that will be able to pick up these signals for the first time. That should help them finally tease apart the origins of these most energetic particles in the Universe .

StartsWithABang writes Hydroelectric dams are one of the best and oldest sources of green, renewable energy, but — as the Three Gorges Dam in China exemplifies — they often cause a host of environmental and ecological problems and challenges. One of the more interesting ones is how to coax fish upstream in the face of these herculean walls that can often span more than 500 feet in height. While fish ladders might be a solution for some of the smaller dams, they're limited in application and success. Could Whooshh Innovations' Salmon Cannon, a pneumatic tube capable of launching fish up-and-over these dams, finally restore the Columbia River salmon to their original habitats?

IonOtter (629215) writes Matt Haughey, founder of MetaFilter, has challenged a Cease & Desist letter from Sundance Vacations, a seller of time-shares with a reputation for aggressive sales tactics and suppression of criticism. Only this time, it seems that the plaintiff may have forged court documents ordering Mr. Haughey, Facebook, Google, Yahoo, Bing and other search engines to remove any and all mentions of the links and posts in question. Legal blog Popehat has picked this up as well, prompting Ken White to wryly note, "...Sundance Vacations is about to learn about the Streisand Effect." The story is gaining traction, and being picked up by Boing-Boing, as well as hitting the first page of search results on Google.

KentuckyFC writes In 1980 and 1981, Voyager 1 and 2 flew past Saturn providing unprecedented images of its magnificent ring system. At that time, its most distant discrete ring, the F ring, was about 200 kilometres wide. But puzzlingly, images sent back by Cassini show that the ring is now 580 kilometres wide and twice as bright as it was thirty years ago. Now astronomers think they have finally solved the mystery of the expanding F ring. The ring is shepherded by a number of small moons, the most famous of which is Prometheus. These moons interact gravitationally with the ring creating structures such as braids and spokes. The new thinking is that the moons' orbits resonate with the F ring, pushing clouds of dust and ice further away from Saturn. This makes the ring wider. But beyond a certain radius the orbit of the dust becomes unstable and it begins to spiral back towards Saturn and collides with the rest of the ring. This causes a chain reaction of collisions that dramatically increases the number of particles in the ring and hence its brightness. This theory also leads to a prediction--the resonant process is currently at a maximum but should reduce sharply in the coming years, if the theory is correct. So by 2018, the F ring should be back to the same configuration the Voyagers saw in 80/81.

KentuckyFC writes The Great Pyramid of Giza in Egypt is constructed from 2.4 million limestone blocks, most about 2.5 tonnes but some weighing in at up to 80 tonnes, mostly sourced from local limestone quarries. That raises a famous question. How did the ancient Egyptians move these huge blocks into place? There is no shortage of theories but now a team of physicists has come up with another that is remarkably simple--convert the square cross section of the blocks into dodecadrons making them easy to roll. The team has tested the idea on a 30 kg scaled block the shape of a square prism. They modified the square cross-section by strapping three wooden rods to each long face, creating a dodecahedral profile. Finally, they attached a rope to the top of the block and measured the force necessary to set it rolling. The team say a full-sized block could be modified with poles the size of ships masts and that a work crew of around 50 men could move a block with a mass of 2.5 tonnes at the speed of 0.5 metres per second. The result suggests that this kind of block modification is a serious contender for the method the Egyptians actually used to construct the pyramids, say the researchers.

KentuckyFC writes: Superconductors allow current to flow with zero resistance when cooled below some critical temperature. They are the crucial ingredients in everything from high-power magnets and MRI machines to highly sensitive magnetometers and magnetic levitation devices. But one big problem is that superconductors work only at very low temperatures — the highest is around 150 kelvin (-120 degrees centigrade). So scientists would dearly love to find ways of raising this critical temperature. Now a group of physicists say they've found a promising approach: to build metamaterial superconductors that steer electrons in the same way as other metamaterials steer light to create invisibility cloaks. The inspiration for the work comes from the observation that some high temperature superconductors consist of repeated layers of conducting and dielectric structures. So the team mixed tin — a superconductor at 3.7 kelvin — with the dielectric barium titanate and found that it raised the critical temperature by 0.15 kelvin. That's the first demonstration that superconductors can be thought of as metamaterials. With this proof of principle under their belts, the next step is to look for bigger gains at higher temperatures.

StartsWithABang writes It's the holy grail of modern particle physics: discovering the first smoking-gun, direct evidence for physics beyond the Standard Model. Sure, there are unanswered questions and unsolved puzzles, ranging from dark matter to the hierarchy problem to the strong-CP problem, but there's no experimental result clubbing us over the head that can't be explained with standard particle physics. That is, the physics of the Standard Model in the framework of quantum field theory. Or is there? Take a look at the evidence from the muon's magnetic moment, and see what might be the future of physics.

KentuckyFC writes Art experts look for influences between great masters by studying the artist's use of space, texture, form, shape, colour and so on. They may also consider the subject matter, brushstrokes, meaning, historical context and myriad other factors. So it's easy to imagine that today's primitive machine vision techniques have little to add. Not so. Using a new technique for classifying objects in images, a team of computer scientists and art experts have compared more than 1700 paintings from over 60 artists dating from the early 15th century to the late 20 the century. They've developed an algorithm that has used these classifications to find many well known influences between artists, such as the well known influence of Pablo Picasso and George Braque on the Austrian symbolist painter Gustav Klimt, the influence of the French romantic Delacroix on the French impressionist Bazille, the Norwegian painter Munch's influence on the German painter Beckmann and Degas' influence on Caillebotte. But the algorithm also discovered connections that art historians have never noticed (judge the comparisons for yourself). In particular, the algorithm points out that Norman Rockwell's Shuffleton's Barber Shop painted in 1950 is remarkably similar to Frederic Bazille's Studio 9 Rue de la Condamine painted 80 years before.

StartsWithABang writes: With some 10^90 particles in the observable Universe, even stretched across 92 billion light-years today, the Universe is precariously close to recollapsing. How, then, is it possible that back in the early stages after the Big Bang, when all this matter-and-energy was concentrated within a region of space no bigger than our current Solar System, the Universe didn't collapse down to a black hole? Not only do we have the explanation, but we learn that even if the Universe did recollapse, we wouldn't get a black hole at all!

KentuckyFC writes In 1931, after a 3- month visit to the U.S., Einstein penned a little known paper that attempted to show how his theory of general relativity could account for some of the latest scientific evidence. In particular, Einstein had met Edwin Hubble during his trip and so was aware of the latter's data indicating that the universe must be expanding. The resulting model is of a universe that expands and then contracts with a singularity at each end. In other words, Einstein was studying a universe that starts with a big bang and ends in a big crunch. What's extraordinary about the paper is that Einstein misspells Hubble's name throughout and makes a number of numerical errors in his calculations. That's probably because he wrote the paper in only 4 days, say the historians who have translated it into English for the time. This model was ultimately superseded by the Einstein-de Sitter model published the following year which improves on this in various ways and has since become the workhorse of modern cosmology.

KentuckyFC (1144503) writes One of the most interesting emerging treatments for certain types of cancer aims to starve the tumor to death. The strategy involves destroying or blocking the blood vessels that supply a tumor with oxygen and nutrients. Without its lifeblood, the unwanted growth shrivels up and dies. This can be done by physically blocking the vessels with blood clots, gels, balloons, glue, nanoparticles and so on. However, these techniques have never been entirely successful because the blockages can be washed away by the blood flow and the materials do not always fill blood vessels entirely, allowing blood to flow round them. Now Chinese researchers say they've solved the problem by filling blood vessels with an indium-gallium alloy that is liquid at body temperature. They've tested the idea in the lab on mice and rabbits. Their experiments show that the alloy is relatively benign but really does fill the vessels, blocks the blood flow entirely and starves the surrounding tissue of oxygen and nutrients. The team has also identified some problems such as the possibility of blobs of metal being washed into the heart and lungs. Nevertheless, they say their approach is a promising injectable tumor treatment.