KentuckyFC (1144503) writes The banjo is a stringed instrument that produces a distinctive metallic sound often associated with country, folk and bluegrass music. It is essentially a drum with a long neck. Strings are fixed at the end of the neck, stretched across the drum and fixed on the other side. They are supported by a bridge that sits on the drum membrane. While the instrument is straightforward in design and the metallic timbre easy to reproduce, acoustics experts have long puzzled over exactly how the instrument produces its characteristic tones. Now David Politzer, who won the Nobel prize for physics in 2004, has worked out the answer. He says the noise is the result of two different kinds of vibrations. First there is the vibration of the string, producing a certain note. However, the drum also vibrates and this pushes the bridge back and forth causing the string to stretch and relax. This modulates the frequency of the note. When frequency of this modulation is below about 20 hertz, it creates a warbling effect. Guitar players can do the same thing by pushing a string back and forth after it is plucked. But when the modulating frequency is higher, the ear experiences it as a kind of metallic crash. And it is this that gives the banjo its characteristic twang. If you're in any doubt, try replacing the drum membrane with a piece of wood and the twang goes away. That's because the wood is stiffer and so does not vibrate to the same extent. Interesting what Nobel prize-winning physicists do in their spare time.

meghan elizabeth writes: Temple physicist Rongjia Tao has a utopian proposal to build three massive, 1,000-foot-high, 165-foot-thick walls around the American Midwest, in order to keep the tornadoes out. Building three unfathomably massive anti-tornado walls would count as the infrastructure project of the decade, if not the century. It would be also be exceedingly expensive. "Building such walls is feasible," Tao says. "They are much easier than constructing a skyscraper. For example, in Philadelphia, the newly completed Comcast building has about 300-meter height. The wall with similar height as the Comcast building should be much easier to be constructed." Update: 06/28 04:14 GMT by T : Note: originally, this story said that Tao was at Drexel rather than Temple -- now corrected

Astronomers using the Chandra X-ray Observatory and the XMM-Newton have recorded an unusual emission of X-ray light from a remote cluster of galaxies which may turn out to be evidence of dark matter. Astronomers think dark matter constitutes 85% of the matter in the Universe, but does not emit or absorb light like “normal” matter such as protons, neutrons and electrons that make up the familiar elements observed in planets, stars, and galaxies. Because of this, scientists must use indirect methods to search for clues about dark matter. he latest results from Chandra and XMM-Newton consist of an unidentified X-ray emission line, that is, a spike of intensity at a very specific wavelength of X-ray light. Astronomers detected this emission line in the Perseus galaxy cluster using both Chandra and XMM-Newton. They also found the line in a combined study of 73 other galaxy clusters with XMM-Newton. ... The authors suggest this emission line could be a signature from the decay of a "sterile neutrino." (Abstract.) Sterile neutrinos are a hypothetical type of neutrino that is predicted to interact with normal matter only via gravity. Some scientists have proposed that sterile neutrinos may at least partially explain dark matter.

Lucas123 (935744) writes Starbucks today announced that after beta-testing wireless charging in several locations, it will roll it out to all of its cafes in the U.S. Unfortunately, the Powermat wireless chargers they chose to use doesn't support the overwhelming number of mobile devices that are enabled for wireless charging using the Qi standard. Of the 20 million consumer devices estimated to have shipped in 2013 with wireless charging capabilities, nearly all were built with the Qi specification, according to IHS. The majority of the Qi technology was built into devices such as the Google Nexus 4 and 5 smartphones, Google's Nexus 7 second-generation tablet and a number of models in Nokia's Lumia smart phone range. The battle between the three wireless charging consortiums is expected to continue to adversely impact adoption of the technology.

The Fuel 3-D website has a blurb that says, "The world’s first handheld point-and-shoot, full color 3D scanner. Our planned list price is $1500 but by placing your advanced order now you pay only $1,250. Fire up your creativity!" We've thought about getting a 3-D scanner ever since we first messed with a 3-D printer, but we've thought more about something in the sub-$300 price range than in $1000+ territory. But that's just us. There is no doubt a healthy market for 3-D scanners to use in commercial applications where $1250 (or even $1500) is hardly worth noticing. Ah, well. Maybe we need to look at the The DAVID website which describes their device as an "Incredibly Low-Cost 3D Scanner for Everyone!" Their 3-D starter kit is only $529 from a randomly-selected U.S. reseller, which isn't too bad compared to the alternatives. But waiting for prices in this market niche to come down is another possibility, and it's one a whole lot of individuals -- including us -- and smaller companies will probably choose. (Alternate Video Link)

EwanPalmer (2536690) writes "Alexander 'Sasha' Shulgin, the chemist, pharmacologist and author known for popularizing the drug MDMA as well as creating and synthesizing hundreds of psychoactive drugs, has died aged 88. Shulgin was known for discovering, creating and personally testing hundreds of psychoactive chemicals and documenting the results, along with his wife, in his books and papers. He is also known for introducing the positive aspects of MDMA to psychologists, which in term helped it become a popular recreational drug in the 1980s." With less irritation from auto-playing video sound, try the BBC.

miller60 (554835) writes "Citing strong demand from cryptocurrency miners, data center and colocation providers are beginning to accept Bitcoin as payment for large chunks of data center space. It's a sign that the data center industry sees an emerging opportunity in catering to the hosting needs of crypto miners, who typically seek high-density space with cheap power. While many web hosting companies accept Bitcoin, larger data center players have been slower to embrace cryptocurrency. Utah-based C7 Data Centers says it's accepting Bitcoin because of surging demand. The Utah-based company says it now hosts about 4.5 megawatts of mining gear, just down the road from the NSA data center." On-topic: Dish Networks has recently become the biggest company to accept Bitcoins.

An anonymous reader writes "Computer science professor Daniel Lemire explains why spreadsheets shouldn't be used for important work, especially where dedicated software could do a better job. His post comes in response to evaluations of a new economics tome by Thomas Piketty, a book that is likely to be influential for years to come. Lemire writes, 'Unfortunately, like too many people, Piketty used spreadsheets instead of writing sane software. On the plus side, he published his code ... on the negative side, it appears that Piketty's code contains mistakes, fudging and other problems. ... Simply put, spreadsheets are good for quick and dirty work, but they are not designed for serious and reliable work. ... Spreadsheets make code review difficult. The code is hidden away in dozens if not hundreds of little cells If you are not reviewing your code carefully and if you make it difficult for others to review it, how do expect it to be reliable?'"

This analysis of trading logs from the Mt. Gox Bitcoin exchange analyzes a subset of the transactions that took place there prior to the exchange's collapse, and makes the case that two bots (the writer calls them "Willy," and "Markus") were making suspicious transactions which may have been used to intentionally manipulate the trading price, and which can explain the loss of Bitcoin inventory on which the exchange's failure was blamed. The author of the analysis says "[T]here is more than plenty of evidence to suspect that what happened at Mt. Gox may have been an inside job. What I hope to achieve by releasing this analysis into the wild is for the public to learn the truth behind what happened at Mt. Gox, how it affected the Bitcoin price, and hopefully for the individuals responsible for the massive fraud that occurred at Mt. Gox to be put to justice. Although the evidence shown in this report is far from conclusive, it can hopefully spur a more rigorous investigation into Mt. Gox’s accounting data, both by the public (using the leaked data) and the authorities (forensic investigation on the actual data)."

An anonymous reader writes with this excerpt from the BBC about one very cool building material: "Real carbon fibre, mind, is still just as wondrous as it was in the last century, even if a bit more commonplace in road cars. But it's still very expensive to make in large pieces and quantities, it requires copious energy to manufacture, can be very brittle if made poorly, is not recyclable and can impose a detrimental impact of the environment when being produced. In other words, it is ripe for disruption. Technology stands still for no one. But could nature provide carbon fibre's replacement? So argues Gary Young, a renowned manufacturer of surfboards who has spent his life pioneering alternative materials use for that industry. 'With the right approach, bamboo can be used in many applications in the automotive world where its performance qualities can better carbon fibre's,' Young says. 'Plus, it does not have a negative effect on the environment.''"

New submitter Golem.de (3664475) writes with another security problem at eBay: "The German security expert Micheal E. discovered the persistent cross-site scripting vulnerability on eBay's website about two months ago and said he reported it to Ebay immediately. Ebay ceased to answer his emails, after writing that they considered it a mostly harmless error. Micheal E. sent Golem.de a PoC demonstrating that the error that has not yet been fixed. An attacker can manipulate an official auctioning web page and insert Javascript code. By visiting the malicious web page the code is executed by the victim and could potentially be used by the attacker to to execute arbitrary actions in the victim's Ebay account and gain full control over it. There is probably no connection to the huge database theft reported a few days ago. The XSS flaw can only be used to attack one victim at a time."

Nemo the Magnificent writes: " Everybody knows software development is a young man's game, right? Here's a guy who hires and manages programmers, and he says it's not about age at all — it's about skills, period. 'It's each individual's responsibility to stay fresh in the field and maintain a modern-day skillset that gives any 28-year-old a run for his or her money. ... Although the ability to learn those skills is usually unlimited, the available time to learn often is not. "Little" things like family dinners, Little League, and home improvement projects often get in the way. As a result, we do find that we face a shortage of older, more seasoned developers. And it's not because we don't want older candidates. It's often because the older candidates haven't successfully modernized their developer skills.' A company that actively works to offer all employees the chance to learn and to engage with modern technologies is a company that good people are going to work for, and to stay at."

MojoKid (1002251) writes "OCZ was recently acquired by Toshiba and has been going through its product stack, revamping its SSD portfolio with fresh re-designs based on Toshiba NAND Flash memory for not only increased performance but better cost structure as well. OCZ has now replaced their RevoDrive family of PCIe SSD cards with an almost complete re-designed of the product. The RevoDrive 350 is based on the same OCZ VCA 2.0 (Virtualized Controller Architecture) technology as the previous generation but is now enabled with a PCI Express X8 card interface and up to 4 LSI SandForce SD-2282 SSD processors, along with 19nm Toshiba NAND Flash. The good news is, not only is the new RevoDrive 350 faster at 1.8GB/sec claimed bandwidth for sequential reads and 1.7GB/sec for sequential writes, but it's also significantly more affordable, at literally half the price of the previous gen RevoDrive 3 when it first launched. In the benchmarks, the new PCIe card excels at read throughput, regularly hitting its 1.8GB/sec claimed bandwidth, especially with sequential workloads. Write performance is solid as well and the drive competes with the likes of some higher-end and more expensive SLC NAND-based PCIe cards like LSI's WarpDrive and Intel's SSD 910."

KentuckyFC (1144503) writes "There is growing evidence that the center of the Milky Way contains a mysterious object some 4 million times more massive than the Sun. Many astronomers believe that this object, called Sagittarius A*, is a supermassive black hole that was crucial in the galaxy's birth and formation. The thinking is that about 100 million years after the Big Bang, this supermassive object attracted the gas and dust that eventually became the Milky Way. But there is a problem with this theory--100 million years is not long enough for a black hole to grow so big. The alternative explanation is that Sagittarius A* is a wormhole that connects the Milky Way to another region of the universe or even a another multiverse. Cosmologists have long known that wormholes could have formed in the instants after the Big Bang and that these objects would have been preserved during inflation to appear today as supermassive objects hidden behind an event horizon, like black holes. It's easy to imagine that it would be impossible to tell these objects apart. But astronomers have now worked out that wormholes are smaller than black holes and so bend light from an object orbiting close to them, such as a plasma cloud, in a unique way that reveals their presence. They've even simulated what such a wormhole will look like. No telescope is yet capable of resolving images like these but that is set to change too. An infrared instrument called GRAVITY is currently being prepared for the Very Large Telescope Interferometer in Chile and should be in a position to spot the signature of a wormhole, if it is there, in the next few years."