Light Repels Light

Optical highway: Yale researchers generated repulsive optical forces by splitting a single beam of light so that each half traveled through a different length of waveguide. Because one half of the beam traveled farther than the other, they arrived in the center region out of phase, causing the two waveguides to repel each other. When the light beams were in phase, they attracted each other. The two triangular shapes at the bottom are the optical input and output ports.   Credit: Mo Li

The repulsive side of an optical force could lead to ultra-fast telecommunications.

Demonstrating a fundamentally new optical phenomenon, researchers at Yale University have shown the second half of an optical force that could make silicon photonics devices–such as those used in high-speed communications, network cards, even video and TV cables–faster and more capable.

Results like these showing novel ways to control light “don’t come along very often,” says Oskar Painter, a microphotonics researcher at Caltech who was not involved in the work. “There’s a push to do more with optical components,” Painter adds, and the Yale group’s results are “totally new.”

Scientists theorized in 2005 that tiny beams of light confined on a silicon chip could attract or repel each other when placed in close proximity, similar to the electromagnetic forces between positive and negative charges. Last year a group led by Yale University professor Hong Tang first demonstrated the “attractive” side of this optical force. Now the group has demonstrated the second side of the force, repulsion, which makes its effects reversible.

Previously, says Mo Li, the lead author of the paper published in Nature Photonics, they could “pull” with the force, but they couldn’t “push.” Now the researchers can do both. The accomplishment opens the possibility of using light to manipulate light in microphotonic devices, rather than using mechanical elements like microheaters or power-hungry optical crystals.

Though the force is too weak to use on larger scales–two laser pointers couldn’t attract or repel each other, for example–the optical force operates strongly on the microscale, making it ideal for ultrahigh-speed, all-optical control of nanomechanical devices, according to MIT applied-mathematics professor Steven Johnson. In particular, Johnson points to the importance of being able to switch between attractive and repulsive optical forces, something that has not been experimentally demonstrated before.

http://www.technologyreview.com/communications/23024/

Semiconductor Industry Splits On 450mm Wafers

(Geek Translation: wafers are the disc that microchips are etched on, bigger wafers means they make more chips at once, thus cheaper processors and in turn cheaper more powerful computers)

Global Foundaries Fab 1 - Dresden, Germany

Back in May, Intel partnered with TSMC and Samsung to announce their intention of developing and deploying 450mm wafer starts by 2012. The shift from 300mm (12″ diameter wafers) to 450mm was touted as necessary for all the usual reasons—think cheaper, faster chips—and we’ve not heard much in the way of pushback until now. At the Semicon West conference this week, a number of companies voiced their belief that a shift to 450mm wafers was premature, unproven, and would impose a tremendous financial burden.

“The rush to 450-mm suggests a lack of ideas for improving fab productivity,” said GlobalFoundries VP of manufacturing systems and technology Thomas Sonderman. “At GlobalFoundries, we see a tremendous amount of headroom left in the 300-mm process.” With all due respect to Mr. Sonderman, that’s precisely the response we’d expect from any company that can’t reasonably expect to shoulder the cost of a 450mm conversion in the near future. Both the Fab 38 conversion GF completed earlier this year and the New York State fab it intends to build are based around 300mm wafers. The current state of the global economy combined with a distinct lack of interest from a number of semiconductor firms could combine to push 450mm wafer adoption out well past the current 2012 goal. Intel may be willing to shoulder the burden for various reasons that we’ll touch on in another update, but companies like UMC, Chartered, and Globalfoundries could wait another six-to-eight years before deciding to take the plunge themselves.

http://hothardware.com/News/Semiconductor-industry-splits-on-450nm-wafers/

Delivering Security on Demand

Companies are increasingly offering security products as services, but is it the best approach?

Businesses looking to make their IT departments more efficient and cost-effective have seized hold of the idea of “software as a service”–using software that is delivered remotely instead of hosted on in-house servers. Recognizing this trend, several computer-security companies have begun offering their products as services. Today, McAfee released a new version of a suite of security products called Total Protection Service, as part of its own push toward “security as a service.”

Yet the security industry’s shift toward delivering software from “the cloud” highlights some of the difficulties involved in transitioning to this approach. While experts agree that the newer approach can certainly increase efficiency and bring technical benefits, some also warn that not all security products work well when delivered this way. Since companies often disagree over what it means to provide software as a service, the shift can also create confusion for potential business customers looking to evaluate their options.

McAfee’s Total Protection Service suite operates remotely, with the exception of a few small pieces of software installed on individual employees’ computers. The product protects computers against Web and e-mail threats, monitors inbound and outbound network traffic, and analyzes devices connected to a corporate network. It also assesses a company’s website for potential vulnerabilities that attackers could exploit.

http://www.technologyreview.com/business/23022/

(HFCs) – The CFC replacement – Hydrofluorocarbons, Once a Solution, Now a Problem?

Scientists say the chemicals that helped solve the last global environmental crisis — the hole in the ozone layer — are making the current one worse.

They worked: The earth’s protective shield seems to be recovering.

But researchers say what’s good for ozone is bad for climate change . In the atmosphere, these replacement chemicals act like “super” greenhouse gases, with a heat-trapping power that can be 4,470 times that of carbon dioxide.

Now, scientists say, the world must find replacements for the replacements — or these super-emissions could cancel out other efforts to stop global warming. Last month, a group of scientists published a paper projecting that, if unchecked, the emissions would rise rapidly over the next 40 years. By 2050, they found, the amount of super greenhouse gases in the atmosphere might be equal to six or more years’ worth of carbon dioxide emissions.

And last week, diplomats met in Geneva to discuss ideas for a worldwide reduction in HFCs.

http://www.enn.com/pollution/article/40232

http://www.washingtonpost.com/wp-dyn/content/article/2009/07/19/AR2009071901817.html

Integrated circuits with no standby power could be in use by year’s end

There’s certainly no shortage of company’s working to make electronics of all sorts more energy efficient, but NEC and Rohm Co now say that they’re on the verge of a breakthrough that could change things in a big way, and we could possibly see it in “practical use” by the end of this year. As Tech-On! reports, both companies are hard at work on integrated circuits that consume no power at all when they’re in standby mode, and turn themselves on only when power is needed. That’s apparently possible by making the entire chip nonvolatile, as opposed to many current chips that only use nonvolatile merged memory. According to NEC, that’ll let them “cut dissipation for digital consumer electronics in the standby mode to just a few percent of what it is now,” and at no expense of convenience. While NEC isn’t making any promises for the near future just yet, Rohm says that it’ll begin shipping its first custom ICs in the second half of this year, and that the first products using them could start showing up by the end of 2009.

http://www.engadget.com/2009/07/19/integrated-circuits-with-no-standby-power-could-be-in-use-by-yea/

Laser Technology Creates New Forms Of Metal And Enhances Aircraft Performance

Dr. Chunlei Guo of the University of Rochester stands in front of his femtosecond laser. (Credit: Walter Colley Studio)

AFOSR-funded researchers at the University of Rochester are using laser light technology that will help the military create new forms of metal that may guide, attract and repel liquids and cool small electronic devices.

Dr. Chunlei Guo and his team of researchers for the project discovered a way to transform a shiny piece of metal into one that is pitch black, not by paint, but by using incredibly intense bursts of laser light. The black metal created, absorbs all radiation that shines upon it.

“With the creation of the black metal, an entirely new class of material becomes available to us, which may open up a whole new horizon for various applications,” said Guo.

“To do this, we looked at the reverse process of light absorption or light radiation and transformed the incandescent lamp into a bulb that glows twice as brightly as a regular light source, while consuming the same amount of energy,” he said.

The key to creating this super-filament is an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse. The laser burst lasts only a few quadrillionths of a second. That intense blast forces the surface of the metal to form nano-structures and micro-structures that dramatically alter how efficiently light can radiate from the filament.

In addition to increasing the brightness of a bulb, Guo’s process can be used to tune the color of the light as well. Last year, his team used a similar process to change the color of nearly any metal to blue, gold, gray, in addition to the black. They controlled the size and shape of the nano-structures — and thus what colors of light those structures absorb and radiate — to change the amount of each wavelength of light the filament radiates.

http://www.sciencedaily.com/releases/2009/07/090715174936.htm

New Geothermal Heat Extraction Process To Deliver Clean Power Generation

PNNL’s introduction of a metal-organic heat carrier, or MOHC, in the biphasic fluid may help improve thermodynamic efficiency of the heat recovery process. This image represents the molecular makeup of one of several MOHCs. (Credit: Image courtesy of DOE/Pacific Northwest National Laboratory)

A new method for capturing significantly more heat from low-temperature geothermal resources holds promise for generating virtually pollution-free electrical energy. Scientists at the Department of Energy’s Pacific Northwest National Laboratory will determine if their innovative approach can safely and economically extract and convert heat from vast untapped geothermal resources.

The goal is to enable power generation from low-temperature geothermal resources at an economical cost. In addition to being a clean energy source without any greenhouse gas emissions, geothermal is also a steady and dependable source of power.

“By the end of the calendar year, we plan to have a functioning bench-top prototype generating electricity,” predicts PNNL Laboratory Fellow Pete McGrail. “If successful, enhanced geothermal systems like this could become an important energy source.” A technical and economic analysis conducted by the Massachusetts Institute of Technology estimates that enhanced geothermal systems could provide 10 percent of the nation’s overall electrical generating capacity by 2050.

PNNL’s conversion system will take advantage of the rapid expansion and contraction capabilities of a new liquid developed by PNNL researchers called biphasic fluid. When exposed to heat brought to the surface from water circulating in moderately hot, underground rock, the thermal-cycling of the biphasic fluid will power a turbine to generate electricity.

http://www.sciencedaily.com/releases/2009/07/090716113356.htm

Learning Is Both Social And Computational, Supported By Neural Systems Linking People

Using magnetoencephalography, a non-invasive technique, neuroscientists have studied baby brain activity and have found a link between the listening and speaking areas of the brain in newborns, 6-month and one-year old infants. (Credit: UW Institute for Learning and Brain Sciences)

Education is on the cusp of a transformation because of recent scientific findings in neuroscience, psychology, and machine learning that are converging to create foundations for a new science of learning.

Writing in the July 17 edition of the journal Science, researchers report that this shift is being driven by three principles that are emerging from cross-disciplinary work: learning is computational, learning is social, and learning is supported by brain circuits linking perception and action that connect people to one another. This new science of learning, the researchers believe, may shed light into the origins of human intelligence.

“We are not left alone to understand the world like Robinson Crusoe was on his island,” said Andrew Meltzoff, lead author of the paper and co-director of the University of Washington’s Institute for Learning and Brain Sciences. “These principles support learning across the life span and are particularly important in explaining children’s rapid learning in two unique domains of human intelligence, language and social understanding.

“Social interaction is more important than we previously thought and underpins early learning. Research has shown that humans learn best from other humans, and a large part of this is timing, sensitive timing between a parent or a tutor and the child,” said Meltzoff, who is a developmental psychologist.

“We are trying to understand how the child’s brain works – how computational abilities are changed in the presence of another person, and trying to use these three principles as leverage for learning and improving education,” added co-author Patricia Kuhl, a neuroscientist and co-director of the UW’s Institute for Learning and Brain Sciences.

 

….”A person can get more information by looking at another person face to face,” she said. “We are digging to understand the social element and what does it mean about us and our evolution.”

Apparently babies need other people to learn. They take in more information by looking at another person face to face than by looking at that person on a big plasma TV screen,” she said. “We are now trying to understand why the brain works this way, and what it means about us and our evolution.”

Meltzoff said an important component of human intelligence is that humans are built so they don’t have to figure out everything by themselves.

“A major role we play as parents is teaching children where the important things are for them to learn,” he said. “One way we do this is through joint visual attention or eye-gaze. This is a social mechanism and children can find what’s important – we call them informational ‘hot spots’ – by following the gaze of another person. By being connected to others we also learn by example and imitation.”….

http://www.sciencedaily.com/releases/2009/07/090716141134.htm

Is There Undiscovered “Weird Life” on Earth?

Is There Undiscovered “Weird Life” on Earth? Leading Expert Says It Could Be Biggest Discovery Since Darwin

“The concept of a shadow biosphere is still just a theory. If someone discovers shadow life or weird life it will be the biggest sensation in biology since Darwin. We are simply saying, ‘Why not let’s take a look for it?’ It doesn’t cost much (compared to looking for weird life on Mars, say), and, it might be right under our noses.”

Paul Davies, director -Arizona State University -BEYOND Center for Fundamental Concepts in Science

A famous theoretical physicist is says we should search for Shadow Life, unknown or undetected lifeforms that may have been hidden on Earth all along.  We expect his team to consist of one military expert (male, stubbled), one technical expert (female, Asian), and three non-determinate other characters (at least one “funny”) and a season cliffhanger after twelve episodes.

Except it’s real, and it’s not unreasonable.  Whenever we talk about the origins of life we assume that there was only one – the one which led to us.  This isn’t pure egocentricity, though, as there is a complete lack of evidence of any other kind of life.  Paul Davies says that may be because we don’t recognize what we’re seeing.

 

“Life as we know it appears to have had a single common ancestor, yet, could life on Earth have started many times? Might it exist on Earth today in extreme environments and remain undetected because our techniques are customized to the biochemistry of known life?” asks Davies, who also is the director of the BEYOND Center for Fundamental Concepts in Science at Arizona State University.

An “alien” biochemistry could have completely different effects from our own.  They won’t suddenly turn out to have been stalking us for years, horror-movie style – it doesn’t matter if you’re based on silicon or soap suds, enough life will leave some kind of visible mark.  But they may exist in extreme environments where anything carbon based would choke or catch fire, and so be squirreled away in the remoter parts of the planet we haven’t examined in any detail.

The idea of unconventional life isn’t new – Stephen Baxter has made great use of alternatives to organics in his works – but serious rational discussion of “We might be wrong about everything, and what can we do if we are?” is why we’ve come so far as a species.

http://www.dailygalaxy.com/my_weblog/2009/07/is-there-undiscovered-weird-life-on-earth-worldleading-expert-says-it-could-be-biggest-discovery-sin.html

Beyond BMI: Why doctors won’t stop using an outdated measure for obesity.

A few extra pounds can extend your life. Or so chirped the press, reporting on a recent study from the journal Obesity. The new research, which supports earlier findings that being slightly overweight is associated with living longer, has added to an ongoing controversy over how we measure obesity. At the center of this debate is the body mass index, a simple equation (your weight in kilograms divided by the square of your height in meters) that has in the last decade claimed a near-monopoly on obesity statistics. Some researchers now argue that this flawed and overly reductive measure is skewing the results of research in public health.

For years, critics of the body mass index have griped that it fails to distinguish between lean and fatty mass. (Muscular people are often misclassifed as overweight or obese.) The measure is mum, too, about the distribution of body fat, which makes a big difference when it comes to health risks. And the BMI cutoffs for “underweight,” “normal,” “overweight,” and “obese” have an undeserved air of mathematical authority. So how did we end up with such a lousy statistic?

Belgian polymath Adolphe Quetelet devised the equation in 1832 in his quest to define the “normal man” in terms of everything from his average arm strength to the age at which he marries. This project had nothing to do with obesity-related diseases, nor even with obesity itself. Rather, Quetelet used the equation to describe the standard proportions of the human build—the ratio of weight to height in the average adult. Using data collected from several hundred countrymen, he found that weight varied not in direct proportion to height (such that, say, people 10 percent taller than average were 10 percent heavier, too) but in proportion to the square of height. (People 10 percent taller than average tended to be about 21 percent heavier.)

…..Gradually, though, the popularity of BMI spread from epidemiologists who used it for studies of population health to doctors who wanted a quick way to measure body fat in individual patients. By 1985, the NIH started defining obesity according to body mass index, on the theory that official cutoffs could be used by doctors to warn patients who were at especially high risk for obesity-related illness. At first, the thresholds were established at the 85^th percentile of BMI for each sex: 27.8 for men and 27.3 for women. (Those numbers now represent something more like the 50^th percentile for Americans.) Then, in 1998, the NIH changed the rules: They consolidated the threshold for men and women, even though the relationship between BMI and body fat is different for each sex, and added another category, “overweight.” The new cutoffs—25 for overweight, 30 for obesity—were nice, round numbers that could be easily remembered by doctors and patients……

http://www.slate.com/id/2223095/pagenum/all