Hugh Pickens writes "No two subway systems have the same design. New York City's haphazard rail system differs markedly from the highly organized Moscow Metro, or the tangled spaghetti of Tokyo's subway network. Now BBC reports that a study analyzing 14 subway networks around the world has discovered that the distribution of stations within each of the subway networks, as well as common proportions of the numbers of lines, stations, and total distances seem to converge over time to a similar structure regardless of where the networks were, when they were begun, or how quickly they reached their current layout. 'Although these (networks) might appear to be planned in some centralized manner, it is our contention here that subway systems like many other features of city systems evolve and self-organize themselves as the product of a stream of rational but usually uncoordinated decisions taking place through time,' write the study authors. The researchers uncovered three simple features that make subway system topologies similar all around the world. First, subway networks can be divided into a core and branches, like a spider with many legs. The 'core' typically sits beneath the city's center, and its stations usually form a ring shape. Second, the branches tend to be about twice as long as the width of the core. The wider the core, the longer the branches. Last, an average of 20 percent of the stations in the core link two or more subway lines, allowing people to make transfers. 'The apparent convergence towards a unique network shape in the temporal limit suggests the existence of dominant, universal mechanisms governing the evolution of these structures.'"

eldavojohn writes "The Logic of Chance: The Nature and Origin of Biological Evolution is a comprehensive snapshot of the latest research of biological evolution. The text is written by Eugene V. Koonin, an editor for a journal and researcher at NCBI. The book, although lacking in foundational knowledge and often foregoing explanation of research, presents a comprehensive and well-referenced view of modern evolutionary research. It is heavily laden with acronyms and jargon specific to biology and evolution. As a result, reading it requires either prior knowledge or a high tolerance for looking up these advanced topics with the reward of it being an extremely eye opening and enjoyable read worthy of your time." Keep reading for the rest of eldavojohn's review.

Hugh Pickens writes "The NY Times reports that Carson C. Chow, an MIT-trained mathematician and physicist, has taken a new look at America's obesity epidemic and found that a food glut is behind America's weight problem, with the national obesity rate jumping from 20 percent to over 30 percent since 1970. 'Beginning in the 1970s, there was a change in national agricultural policy. Instead of the government paying farmers not to engage in full production, as was the practice, they were encouraged to grow as much food as they could,' says Chow. 'With such a huge food supply, food marketing got better and restaurants got cheaper. The low cost of food fueled the growth of the fast-food industry. If food were expensive, you couldn't have fast food.' Chow and mathematical physiologist Kevin Hall created a mathematical model of a human with hundreds of equations, boiled it down to one simple equation, and then plugged in all the variables — height, weight, food intake, exercise. The slimmed-down equation proved to be a useful platform for answering a host of questions. For example, huge variations in your daily food intake will not cause variations in weight, as long as your average food intake over a year is about the same. Unfortunately, another finding is that weight change, up or down, takes a very, very long time. Chow has posted an interactive version of the model on the web where people can plug in their information and learn how much they'll need to reduce their intake and increase their activity to lose."

New submitter MathIsTasty writes "Recently, it was announced on the Octave-maintainers list that a Kickstarter campaign has been launched to bring Matlab style numerical computations and graphing to Android via a 'more than' port of Octave and gnuplot. While I doubt it will be as successful as some recent games on Kickstarter, is this a reasonable way to fund free software development? Now, we just have to worry about people working on simulating solar irradiation while driving. Here is a good blog post about the project."

mikejuk writes "The Goldbach conjecture is not the sort of thing that relates to practical applications, but they used to say the same thing about electricity. The Goldbach conjecture is reasonably well known: every integer can be expressed as the sum of two primes. Very easy to state, but it seems very difficult to prove. Terence Tao, a Fields medalist, has published a paper that proves that every odd number greater than 1 is the sum of at most five primes. This may not sound like much of an advance, but notice that there is no stipulation for the integer to be greater than some bound. This is a complete proof of a slightly lesser conjecture, and might point the way to getting the number of primes needed down from at most five to at most 2. Notice that no computers were involved in the proof — this is classical mathematical proof involving logical deductions rather than exhaustive search."

itwbennett writes "Peter Smith has done the math on Microsoft's $99 Xbox 360 — 4GB model (no hard drive) and a Kinect sensor. Here's why it's a bad deal: 'You'll be paying $99 + $359.76 in monthly fees, or $458.76 over the course of two years. Compare that with (I'm using prices from Amazon that were accurate as of May 7th, 2012) $287.70 for an Xbox 360 4GB + Kinect bundle, and two 12-month Xbox Live Gold cards at $48.41 each, a total of $384.52. So you're paying almost $75 for the privilege of laying out small cash now.' And then there's the not insignificant matter of early termination fees."

New submitter drom writes "Google released a key part of their Street View pipeline as open source on Tuesday: Ceres Solver. It's a large-scale nonlinear least squares minimizer. What does that mean? It's a way to fit a model (like expected position of a car) to data (like GPS positions or accelerometers). The library is completely general and works for many problems. It offers state of the art performance for bundle adjustment problems typical in 3D reconstruction, among others."

Hugh Pickens writes "Representing only 10 percent of the general human population, scientists have long wondered why left-handed people are a rarity. Now a new study suggests lefties are rare because of the balance between cooperation and competition in human evolution and a mathematical model was developed that predicts the percentage of left-handers by sport based on each sport's degree of cooperation versus competition. 'The more social the animal—where cooperation is highly valued—the more the general population will trend toward one side,' says study author Daniel M. Abrams. 'The most important factor for an efficient society is a high degree of cooperation. In humans, this has resulted in a right-handed majority.' If societies were entirely cooperative everyone would be same-handed, but if competition were more important, one could expect the population to be 50-50 because cooperation favors same-handedness—for sharing the same tools, for example while physical competition favors the unusual. In a fight, for example, a left-hander would have the advantage in a right-handed world. The mathematical model accurately predicted the number of elite left-handed athletes in baseball, boxing, hockey, fencing, and table tennis (PDF)—more than 50 percent among top baseball players and well above 10 percent (the general population rate) for the other sports. For other sports like football or hockey where team cooperation is paramount, it is ideal for all individuals to possess the same handedness. For example, in football, blocking schemes are often designed to protect a quarterback's blind side. As a result, it is beneficial for all quarterbacks on the roster to possess the same handedness to minimize variations of the offensive sets. 'The accuracy of our model's predictions when applied to sports data supports the idea that we are seeing the same effect in human society.'"

New submitter jools33 writes "The BBC has a fascinating story about how a mathematical formula revolutionized the world of finance — and ultimately could have been responsible for its downfall. The Black-Scholes mathematical model, introduced in the '70s, opened up the world of options, futures, and derivatives trading in a way that nothing before or since has accomplished. Its phenomenal success and widespread adoption lead to Myron Scholes winning a Nobel prize in economics. Yet the widespread adoption of the model may have been responsible for the financial crisis of the past few years. It's interesting to ponder how algorithms and formulas that we work on today could fundamentally influence humanity's future."

An anonymous reader writes "The Yupno people of New Guinea have provided clues to the origins of the number-line concept, and suggest that the familiar concept of time may be cultural as well. From the article: 'Tape measures. Rulers. Graphs. The gas gauge in your car, and the icon on your favorite digital device showing battery power. The number line and its cousins – notations that map numbers onto space and often represent magnitude – are everywhere. Most adults in industrialized societies are so fluent at using the concept, we hardly think about it. We don't stop to wonder: Is it 'natural'? Is it cultural? Now, challenging a mainstream scholarly position that the number-line concept is innate, a study suggests it is learned."

mikejuk writes with this excerpt from I Programmer: "A movie that features science and technology is always welcome, but is it not often we have one that focuses on computer science. Travelling Salesman is just such a rare movie. As you can guess from its name, it is about the Travelling Salesman problem, more precisely about the P=NP question. Written and directed by Timothy Lanzone, and produced by Fretboard Pictures, it should premiere on June 16. As the blurb to the movie trailer says: 'Travelling Salesman is an intellectual thriller about four of the world's smartest mathematicians hired by the U.S. government to solve the most elusive problem in computer science history — P vs. NP. The four have jointly created a "system" which could be the next major advancement for humanity or the downfall of society.'"

New submitter Durinia writes "Minnesota Public Radio is running a story about the University of Minnesota's Open Textbooks project. The goal of the project is to solicit reviews of college-level open source textbooks and collect those that pass muster onto their website. The project will focus first on high-volume introductory classes such as those for Math and Biology, because as David Ernst, director of the project, states in the interview: 'You know the world doesn't need another $150 Algebra One book. Algebra One hasn't changed for centuries, probably.'" Requirements for inclusion include: Open licensing (Creative Commons Attribution/Share Alike), complete content (no glorified collections of lecture notes), applicability outside of the author's institution, and print availability.

itwbennett writes "Computer Science Ph.D. candidate Federico Cirett says that he can predict with 80 percent accuracy when someone is about to make a mistake on a math question. Using an EEG machine, Cirett can identify the patterns in a volunteer's thinking that are likely to result in an error 20 seconds or so before it's made. 'If we can detect when they are going to fail, maybe we can change the text or switch the question to give them another one at a different level of difficulty, but also to keep them engaged,' Cirett said. 'Brain wave data is the nearest thing we have to really know when the students are having problems.' He will present a paper on his findings at the User Modeling, Adaptation and Personalization conference in July."

eldavojohn writes "The New York Review of Books has an article penned by Steven Weinberg lamenting the future of physics, cosmology and this era of 'big science' in which we find ourselves. A quote from Goldhaber sums up the problem nicely, 'The first to disintegrate a nucleus was Rutherford, and there is a picture of him holding the apparatus in his lap. I then always remember the later picture when one of the famous cyclotrons was built at Berkeley, and all of the people were sitting in the lap of the cyclotron.' The article is lengthy with a history of big physics projects (most painfully perhaps the SSC) but Weinberg's message ultimately comes across as pessimism laced with fatalism — easily understandable given his experiences with government funding. Unfortunately he notes, 'Big science has the special problem that it can't easily be scaled down. It does no good to build an accelerator tunnel that only goes halfway around the circle.' Apparently this article mirrors his talk given in January at the American Astronomical Society. If not our government, will anyone fund these immense projects or will physics slowly grind to a halt due to fiscal constraints?"

mikejuk writes "How does the Apple App Store actually work? What is the best strategy to employ if you want to get some users and make some money? There are some pointers on how it all works from an unusual source — artificial life. A pair of researchers Soo Ling Lim and Peter Bentley from University College London, set up an artificial life simulation of the app store's ecosystem. They created app developers with strategies such as — innovate, copy other apps, create useless variations on a basic app or try and optimize the app you have. What they found, among other things, was that the CopyCat strategy was on average the best. When they allow the strategies to compete and developer agents to swap then the use of the CopyCat fell to only 10%. The reason — more than 10% CopyCats resulted in nothing new to copy!"

miller60 writes "Apple says Greenpeace has wildly overestimated the amount of power it uses in its data center in North Carolina, and used that bad math to give the company a low grade on sustainability. Apple says it uses 20 megawatts of power at its iDataCenter, a fraction of Greenpeace's estimate of 100 megawatts in a new report on energy use by cloud computing providers. Apple says that its huge solar array and biogas-powered fuel cell will supply 60 percent of the facility's power, not the 10 percent claimed by Greenpeace."

concealment writes in with an interview with a creator of the (fairly) new language Julia designed for number crunching. Quoting Infoworld: "InfoWorld: When you say technical computing, to what type of applications are you specifically referring? Karpinski: It's a broad category, but it's pretty much anything that involves a lot of number-crunching. In my own background, I've done a lot of linear algebra but a fair amount of statistics as well. The tool of choice for linear algebra tends to be Matlab. The tool of choice for statistics tends to be R, and I've used both of those a great deal. But they're not really interchangeable. If you want to do statistics in Matlab, it's frustrating. If you want to do linear algebra in R, it's frustrating. InfoWorld: So you developed Julia with the intent to make it easier to build technical applications? Karpinski: Yes. The idea is that it should be extremely high productivity. To that end, it's a dynamic language, so it's relatively easy to program, and it's got a very simple programming model. But it has extremely high performance, which cuts out [the need for] a third language [C], which is often [used] to get performance in any of these other languages. I should also mention NumPy, which is a contender for these areas. For Matlab, R, and NumPy, for all of these options, you need to at some point drop down into C to get performance. One of our goals explicitly is to have sufficiently good performance in Julia that you'd never have to drop down into C." The language implementation is licensed under the GPL. Lambda the Ultimate has a bit of commentary on the language, and an R programmer gives his two cents on the language.

New submitter HeLLFiRe1151 sends this quote from Physics Central: "Here's a practical application for your physics education: using math to successfully beat a traffic ticket in court. Dmitri Krioukov, a physicist based at the University of California San Diego, did just that to avoid paying a fee for (purportedly) running a stop sign. Krioukov not only proved his innocence, but he also posted a paper detailing his argument online (PDF) on the arXiv server."

tqft writes "What the world needs is more truly random sources of numbers. Researchers from Australian National University have found a brilliant way to make one: 'We do this by splitting a beam of light into two beams and then measuring the power in each beam. Because light is quantised, the light intensity in each beam fluctuates about the mean. Those fluctuations, due ultimately to the quantum vacuum, can be converted into a source of random numbers. Every number is randomly generated in real time and cannot be predicted beforehand.' So if you need some really random numbers, just use their generator service."

TPIRman writes "In 1994, a physics doctoral student named Dave Ring assembled more than 100 math and puzzle enthusiasts on Usenet for what became one of the earliest online 'crowdsourcing' projects. Their goal: to determine if every hand in Windows' FreeCell solitaire game was in fact winnable, as the program's help file implied. Their efforts soon focused in on one incredibly stubborn hand: #11,982. They couldn't beat it, but in the process of trying, they proved the viability of an idea that would later be refined with crowdsourcing models like Amazon's Mechanical Turk."