The Physics arXiv Blog produces daily coverage of the best new ideas from an online forum called the Physics arXiv on which scientists post early versions of their latest ideas. Contact me atKentuckyFC @ arxivblog.comIt's a question that many dog owners will have spent sleepless nights pondering.

How rapidly should a wet dog oscillate its body to dry its fur?Today we have an answer thanks to the pioneering work of Andrew Dickerson at the Georgia Institute of Technology in Atlanta and a few buddies. But more than that, their work generates an interesting new conundrum about the nature of shaken fur dynamics.Dickerson and co filmed a number of dogs shaking their fur and used the images to measure the period of oscillation of the dogs' skin. For a labrador retriever, this turns out to be 4.3 Hz.They then created a simple mathematical model of what's going on. They reasoned that the water is bound to the dog by surface tension between the liquid and the hair. [Read the full article]

Determining the most influential users of Twitter is probably not what the creators of the Cray XMT supercomputer had in mind when they designed their machine. But when you're packing this much computational heat, you go where the hard problems are. Twitter, Facebook and the rest of the social Web have become the modern-day equivalent of the water cooler, albeit with an automatic transcriptionist present. And processing all the data that conversation generates turns out to be a very hard problem.For example, as of February 2010, Facebook included 400 million active users with an average of 120 "friend" connections each, all of whom collectively shared 5 billion pieces of information in a single month.Figuring out who the "influencers" are in such a massive social networks requires creating a gigantic social graph, where each user is a vertex and the connections between them are lines. Ranking users within such a graph requires a determination of their "centrality". [Read the full article]

Much has been made of the 'unprecedented' scale of the IT infrastructure required to store all the data coming from the world's largest physics experiment - the Large Hadron Collider (LHC) near Geneva, Switzerland. But another gigantic science experiment, one you've probably never heard of, will some day pump out data on a similar scale. And, unlike the LHC, the data it produces will be comprehensible by non-scientists, and made freely available.Once it's complete, The Large Synoptic Survey Telescope on top of Cerro Pachn ridge in Chile will sport the world's largest digital camera. It will peer deep into space yet have a field of view unprecedented in modern telescopes -- ten square degrees of the heavens encompassed by a collecting area of forty square meters. The telescope will take 800 panoramic pictures a night, covering the entire night sky twice each week.The result will be an unfathomably huge photo collection: 20 terabytes of data stored every 24 hours. [Read the full article]

At this year's Hot Chips conference at Stanford University, Weiwu Hu, the lead architect of the "national processor" of China, revealed three new chip designs. One of them could enable China to build a homegrown supercomputer to rank in a prestigious list of the world's fastest machines.The Loongson processor family (known in China by the name Godson), is now in its sixth generation. The latest designs consist of the one-gigahertz, eight-core Godson 3B, the more powerful 16-core, Godson 3C (with a speed that is currently unknown), and the smaller, lower-power one-gigahertz Godson 2H, intended for netbooks and other mobile devices. The Godson 3B will be commercially available in 2011, as will the Godson 2H, but the Godson 3C won't debut until 2012.According to Tom Halfhill, industry analyst and editor of Microprocessor Report, the eight-core Godson 3B will still be significantly less powerful than Intel's best chip, the six-core Xeon processor. [Read the full article]