Saturday, September 1, 2007

swarm theory


swarm theory


A single ant or bee isn't smart, but their colonies are. The study of swarm intelligence is providing insights that can help humans manage complex systems, from truck routing to military robots.



I used to think ants knew what they were doing. The ones marching across my kitchen counter looked so confident, I just figured they had a plan, knew where they were going and what needed to be done. How else could ants organize highways, build elaborate nests, stage epic raids, and do all the other things ants do?


Turns out I was wrong. Ants aren't clever little engineers, architects, or warriors after all-at least not as individuals. When it comes to deciding what to do next, most ants don't have a clue. "If you watch an ant try to accomplish something, you'll be impressed by how inept it is," says Deborah M. Gordon, a biologist at Stanford University.


How do we explain, then, the success of Earth's 12,000 or so known ant species? They must have learned something in 140 million years.


"Ants aren't smart," Gordon says. "Ant colonies are." A colony can solve problems unthinkable for individual ants, such as finding the shortest path to the best food source, allocating workers to different tasks, or defending a territory from neighbors. As individuals, ants might be tiny dummies, but as colonies they respond quickly and effectively to their environment. They do it with something called swarm intelligence.


Where this intelligence comes from raises a fundamental question in nature: How do the simple actions of individuals add up to the complex behavior of a group? How do hundreds of honeybees make a critical decision about their hive if many of them disagree? What enables a school of herring to coordinate its movements so precisely it can change direction in a flash, like a single, silvery organism? The collective abilities of such animals-none of which grasps the big picture, but each of which contributes to the group's success-seem miraculous even to the biologists who know them best. Yet during the past few decades, researchers have come up with intriguing insights.


One key to an ant colony, for example, is that no one's in charge. No generals command ant warriors. No managers boss ant workers. The queen plays no role except to lay eggs. Even with half a million ants, a colony functions just fine with no management at all-at least none that we would recognize. It relies instead upon countless interactions between individual ants, each of which is following simple rules of thumb. Scientists describe such a system as self-organizing.


Consider the problem of job allocation. In the Arizona desert where Deborah Gordon studies red harvester ants (Pogonomyrmex barbatus), a colony calculates each morning how many workers to send out foraging for food. The number can change, depending on conditions. Have foragers recently discovered a bonanza of tasty seeds? More ants may be needed to haul the bounty home. Was the nest damaged by a storm last night? Additional maintenance workers may be held back to make repairs. An ant might be a nest worker one day, a trash collector the next. But how does a colony make such adjustments if no one's in charge? Gordon has a theory.


Ants communicate by touch and smell. When one ant bumps into another, it sniffs with its antennae to find out if the other belongs to the same nest and where it has been working. (Ants that work outside the nest smell different from those that stay inside.) Before they leave the nest each day, foragers normally wait for early morning patrollers to return. As patrollers enter the nest, they touch antennae briefly with foragers.


"When a forager has contact with a patroller, it's a stimulus for the forager to go out," Gordon says. "But the forager needs several contacts no more than ten seconds apart before it will go out."


To see how this works, Gordon and her collaborator Michael Greene of the University of Colorado at Denver captured patroller ants as they left a nest one morning. After waiting half an hour, they simulated the ants' return by dropping glass beads into the nest entrance at regular intervals-some coated with patroller scent, some with maintenance worker scent, some with no scent. Only the beads coated with patroller scent stimulated foragers to leave the nest. Their conclusion: Foragers use the rate of their encounters with patrollers to tell if it's safe to go out. (If you bump into patrollers at the right rate, it's time to go foraging. If not, better wait. It might be too windy, or there might be a hungry lizard waiting out there.) Once the ants start foraging and bringing back food, other ants join the effort, depending on the rate at which they encounter returning foragers.


"A forager won't come back until it finds something," Gordon says. "The less food there is, the longer it takes the forager to find it and get back. The more food there is, the faster it comes back. So nobody's deciding whether it's a good day to forage. The collective is, but no particular ant is."


That's how swarm intelligence works: simple creatures following simple rules, each one acting on local information. No ant sees the big picture. No ant tells any other ant what to do. Some ant species may go about this with more sophistication than others. (Temnothorax albipennis, for example, can rate the quality of a potential nest site using multiple criteria.) But the bottom line, says Iain Couzin, a biologist at Oxford and Princeton Universities, is that no leadership is required. "Even complex behavior may be coordinated by relatively simple interactions," he says.


Inspired by the elegance of this idea, Marco Dorigo, a computer scientist at the Université Libre in Brussels, used his knowledge of ant behavior in 1991 to create mathematical procedures for solving particularly complex human problems, such as routing trucks, scheduling airlines, or guiding military robots.


In Houston, for example, a company named American Air Liquide has been using an ant-based strategy to manage a complex business problem. The company produces industrial and medical gases, mostly nitrogen, oxygen, and hydrogen, at about a hundred locations in the United States and delivers them to 6,000 sites, using pipelines, railcars, and 400 trucks. Deregulated power markets in some regions (the price of electricity changes every 15 minutes in parts of Texas) add yet another layer of complexity.


"Right now in Houston, the price is $44 a megawatt for an industrial customer," says Charles N. Harper, who oversees the supply system at Air Liquide. "Last night the price went up to $64, and Monday when the cold front came through, it went up to $210." The company needed a way to pull it all together.


Working with the Bios Group (now NuTech Solutions), a firm that specialized in artificial intelligence, Air Liquide developed a computer model based on algorithms inspired by the foraging behavior of Argentine ants (Linepithema humile), a species that deposits chemical substances called pheromones.


"When these ants bring food back to the nest, they lay a pheromone trail that tells other ants to go get more food," Harper explains. "The pheromone trail gets reinforced every time an ant goes out and comes back, kind of like when you wear a trail in the forest to collect wood. So we developed a program that sends out billions of software ants to find out where the pheromone trails are strongest for our truck routes."


Ants had evolved an efficient method to find the best routes in their neighborhoods. Why not follow their example? So Air Liquide combined the ant approach with other artificial intelligence techniques to consider every permutation of plant scheduling, weather, and truck routing-millions of possible decisions and outcomes a day. Every night, forecasts of customer demand and manufacturing costs are fed into the model.


"It takes four hours to run, even with the biggest computers we have," Harper says. "But at six o'clock every morning we get a solution that says how we're going to manage our day."


For truck drivers, the new system took some getting used to. Instead of delivering gas from the plant closest to a customer, as they used to do, drivers were now asked to pick up shipments from whichever plant was making gas at the lowest delivered price, even if it was farther away.


"You want me to drive a hundred miles? To the drivers, it wasn't intuitive," Harper says. But for the company, the savings have been impressive. "It's huge. It's actually huge."


Other companies also have profited by imitating ants. In Italy and Switzerland, fleets of trucks carrying milk and dairy products, heating oil, and groceries all use ant-foraging rules to find the best routes for deliveries. In England and France, telephone companies have made calls go through faster on their networks by programming messages to deposit virtual pheromones at switching stations, just as ants leave signals for other ants to show them the best trails.


In the U.S., Southwest Airlines has tested an ant-based model to improve service at Sky Harbor International Airport in Phoenix. With about 200 aircraft a day taking off and landing on two runways and using gates at three concourses, the company wanted to make sure that each plane got in and out as quickly as possible, even if it arrived early or late.


"People don't like being only 500 yards away from a gate and having to sit out there until another aircraft leaves," says Doug Lawson of Southwest. So Lawson created a computer model of the airport, giving each aircraft the ability to remember how long it took to get into and away from each gate. Then he set the model in motion to simulate a day's activity.


"The planes are like ants searching for the best gate," he says. But rather than leaving virtual pheromones along the way, each aircraft remembers the faster gates and forgets the slower ones. After many simulations, using real data to vary arrival and departure times, each plane learned how to avoid an intolerable wait on the tarmac. Southwest was so pleased with the outcome, it may use a similar model to study the ticket counter area.



WHEN IT COMES TO SWARM intelligence, ants aren't the only insects with something useful to teach us. On a small, breezy island off the southern coast of Maine, Thomas Seeley, a biologist at Cornell University, has been looking into the uncanny ability of honeybees to make good decisions. With as many as 50,000 workers in a single hive, honeybees have evolved ways to work through individual differences of opinion to do what's best for the colony. If only people could be as effective in boardrooms, church committees, and town meetings, Seeley says, we could avoid problems making decisions in our own lives.


During the past decade, Seeley, Kirk Visscher of the University of California, Riverside, and others have been studying colonies of honeybees (Apis mellifera) to see how they choose a new home. In late spring, when a hive gets too crowded, a colony normally splits, and the queen, some drones, and about half the workers fly a short distance to cluster on a tree branch. There the bees bivouac while a small percentage of them go searching for new real estate. Ideally, the site will be a cavity in a tree, well off the ground, with a small entrance hole facing south, and lots of room inside for brood and honey. Once a colony selects a site, it usually won't move again, so it has to make the right choice.


To find out how, Seeley's team applied paint dots and tiny plastic tags to identify all 4,000 bees in each of several small swarms that they ferried to Appledore Island, home of the Shoals Marine Laboratory. There, in a series of experiments, they released each swarm to locate nest boxes they'd placed on one side of the half-mile-long (one kilometer) island, which has plenty of shrubs but almost no trees or other places for nests.


In one test they put out five nest boxes, four that weren't quite big enough and one that was just about perfect. Scout bees soon appeared at all five. When they returned to the swarm, each performed a waggle dance urging other scouts to go have a look. (These dances include a code giving directions to a box's location.) The strength of each dance reflected the scout's enthusiasm for the site. After a while, dozens of scouts were dancing their little feet off, some for one site, some for another, and a small cloud of bees was buzzing around each box.



The decisive moment didn't take place in the main cluster of bees, but out at the boxes, where scouts were building up. As soon as the number of scouts visible near the entrance to a box reached about 15-a threshold confirmed by other experiments-the bees at that box sensed that a quorum had been reached, and they returned to the swarm with the news.


"It was a race," Seeley says. "Which site was going to build up 15 bees first?"


Scouts from the chosen box then spread through the swarm, signaling that it was time to move. Once all the bees had warmed up, they lifted off for their new home, which, to no one's surprise, turned out to be the best of the five boxes.


The bees' rules for decision-making-seek a diversity of options, encourage a free competition among ideas, and use an effective mechanism to narrow choices-so impressed Seeley that he now uses them at Cornell as chairman of his department.


"I've applied what I've learned from the bees to run faculty meetings," he says. To avoid going into a meeting with his mind made up, hearing only what he wants to hear, and pressuring people to conform, Seeley asks his group to identify all the possibilities, kick their ideas around for a while, then vote by secret ballot. "It's exactly what the swarm bees do, which gives a group time to let the best ideas emerge and win. People are usually quite amenable to that."


In fact, almost any group that follows the bees' rules will make itself smarter, says James Surowiecki, author of The Wisdom of Crowds. "The analogy is really quite powerful. The bees are predicting which nest site will be best, and humans can do the same thing, even in the face of exceptionally complex decisions." Investors in the stock market, scientists on a research project, even kids at a county fair guessing the number of beans in a jar can be smart groups, he says, if their members are diverse, independent minded, and use a mechanism such as voting, auctioning, or averaging to reach a collective decision.


Take bettors at a horse race. Why are they so accurate at predicting the outcome of a race? At the moment the horses leave the starting gate, the odds posted on the pari-mutuel board, which are calculated from all bets put down, almost always predict the race's outcome: Horses with the lowest odds normally finish first, those with second lowest odds finish second, and so on. The reason, Surowiecki says, is that pari-mutuel betting is a nearly perfect machine for tapping into the wisdom of the crowd.


"If you ever go to the track, you find a really diverse group, experts who spend all day perusing daily race forms, people who know something about some kinds of horses, and others who are betting at random, like the woman who only likes black horses," he says. Like bees trying to make a decision, bettors gather all kinds of information, disagree with one another, and distill their collective judgment when they place their bets.


That's why it's so rare to win on a long shot.



THERE'S A SMALL PARK near the White House in Washington, D.C., where I like to watch flocks of pigeons swirl over the traffic and trees. Sooner or later, the birds come to rest on ledges of buildings surrounding the park. Then something disrupts them, and they're off again in synchronized flight.


The birds don't have a leader. No pigeon is telling the others what to do. Instead, they're each paying close attention to the pigeons next to them, each bird following simple rules as they wheel across the sky. These rules add up to another kind of swarm intelligence-one that has less to do with making decisions than with precisely coordinating movement.


Craig Reynolds, a computer graphics researcher, was curious about what these rules might be. So in 1986 he created a deceptively simple steering program called boids. In this simulation, generic birdlike objects, or boids, were each given three instructions: 1) avoid crowding nearby boids, 2) fly in the average direction of nearby boids, and 3) stay close to nearby boids. The result, when set in motion on a computer screen, was a convincing simulation of flocking, including lifelike and unpredictable movements.


At the time, Reynolds was looking for ways to depict animals realistically in TV shows and films. (Batman Returns in 1992 was the first movie to use his approach, portraying a swarm of bats and an army of penguins.) Today he works at Sony doing research for games, such as an algorithm that simulates in real time as many as 15,000 interacting birds, fish, or people.


By demonstrating the power of self-organizing models to mimic swarm behavior, Reynolds was also blazing the trail for robotics engineers. A team of robots that could coordinate its actions like a flock of birds could offer significant advantages over a solitary robot. Spread out over a large area, a group could function as a powerful mobile sensor net, gathering information about what's out there. If the group encountered something unexpected, it could adjust and respond quickly, even if the robots in the group weren't very sophisticated, just as ants are able to come up with various options by trial and error. If one member of the group were to break down, others could take its place. And, most important, control of the group could be decentralized, not dependent on a leader.


"In biology, if you look at groups with large numbers, there are very few examples where you have a central agent," says Vijay Kumar, a professor of mechanical engineering at the University of Pennsylvania. "Everything is very distributed: They don't all talk to each other. They act on local information. And they're all anonymous. I don't care who moves the chair, as long as somebody moves the chair. To go from one robot to multiple robots, you need all three of those ideas."


Within five years Kumar hopes to put a networked team of robotic vehicles in the field. One purpose might be as first responders. "Let's say there's a 911 call," he says. "The fire alarm goes off. You don't want humans to respond. You want machines to respond, to tell you what's happening. Before you send firemen into a burning building, why not send in a group of robots?"

Taking this idea one step further, Marco Dorigo's group in Brussels is leading a European effort to create a "swarmanoid," a group of cooperating robots with complementary abilities: "foot-bots" to transport things on the ground, "hand-bots" to climb walls and manipulate objects, and "eye-bots" to fly around, providing information to the other units.

The military is eager to acquire similar capabilities. On January 20, 2004, researchers released a swarm of 66 pint-size robots into an empty office building at Fort A. P. Hill, a training center near Fredericksburg, Virginia. The mission: Find targets hidden in the building.

Zipping down the main hallway, the foot-long (0.3 meter) red robots pivoted this way and that on their three wheels, resembling nothing so much as large insects. Eight sonars on each unit helped them avoid collisions with walls and other robots. As they spread out, entering one room after another, each robot searched for objects of interest with a small, Web-style camera. When one robot encountered another, it used wireless network gear to exchange information. ("Hey, I've already explored that part of the building. Look somewhere else.")

In the back of one room, a robot spotted something suspicious: a pink ball in an open closet (the swarm had been trained to look for anything pink). The robot froze, sending an image to its human supervisor. Soon several more robots arrived to form a perimeter around the pink intruder. Within half an hour, all six of the hidden objects had been found. The research team conducting the experiment declared the run a success. Then they started a new test.

The demonstration was part of the Centibots project, an investigation to see if as many as a hundred robots could collaborate on a mission. If they could, teams of robots might someday be sent into a hostile village to flush out terrorists or locate prisoners; into an earthquake-damaged building to find victims; onto chemical-spill sites to examine hazardous waste; or along borders to watch for intruders. Military agencies such as DARPA (Defense Advanced Research Projects Agency) have funded a number of robotics programs using collaborative flocks of helicopters and fixed-wing aircraft, schools of torpedo-shaped underwater gliders, and herds of unmanned ground vehicles. But at the time, this was the largest swarm of robots ever tested.

"When we started Centibots, we were all thinking, this is a crazy idea, it's impossible to do," says Régis Vincent, a researcher at SRI International in Menlo Park, California. "Now we're looking to see if we can do it with a thousand robots."


IN NATURE, OF COURSE, animals travel in even larger numbers. That's because, as members of a big group, whether it's a flock, school, or herd, individuals increase their chances of detecting predators, finding food, locating a mate, or following a migration route. For these animals, coordinating their movements with one another can be a matter of life or death.

"It's much harder for a predator to avoid being spotted by a thousand fish than it is to avoid being spotted by one," says Daniel Grünbaum, a biologist at the University of Washington. "News that a predator is approaching spreads quickly through a school because fish sense from their neighbors that something's going on."

When a predator strikes a school of fish, the group is capable of scattering in patterns that make it almost impossible to track any individual. It might explode in a flash, create a kind of moving bubble around the predator, or fracture into multiple blobs, before coming back together and swimming away.

Animals on land do much the same, as Karsten Heuer, a wildlife biologist, observed in 2003, when he and his wife, Leanne Allison, followed the vast Porcupine caribou herd (Rangifer tarandus granti) for five months. Traveling more than a thousand miles (1,600 kilometers) with the animals, they documented the migration from winter range in Canada's northern Yukon Territory to calving grounds in Alaska's Arctic National Wildlife Refuge.

"It's difficult to describe in words, but when the herd was on the move it looked very much like a cloud shadow passing over the landscape, or a mass of dominoes toppling over at the same time and changing direction," Karsten says. "It was as though every animal knew what its neighbor was going to do, and the neighbor beside that and beside that. There was no anticipation or reaction. No cause and effect. It just was."

One day, as the herd funneled through a gully at the tree line, Karsten and Leanne spotted a wolf creeping up. The herd responded with a classic swarm defense.


"As soon as the wolf got within a certain distance of the caribou, the herd's alertness just skyrocketed," Karsten says. "Now there was no movement. Every animal just stopped, completely vigilant and watching." A hundred yards (90 meters) closer, and the wolf crossed another threshold. "The nearest caribou turned and ran, and that response moved like a wave through the entire herd until they were all running. Reaction times shifted into another realm. Animals closest to the wolf at the back end of the herd looked like a blanket unraveling and tattering, which, from the wolf's perspective, must have been extremely confusing." The wolf chased one caribou after another, losing ground with each change of target. In the end, the herd escaped over the ridge, and the wolf was left panting and gulping snow.

For each caribou, the stakes couldn't have been higher, yet the herd's evasive maneuvers displayed not panic but precision. (Imagine the chaos if a hungry wolf were released into a crowd of people.) Every caribou knew when it was time to run and in which direction to go, even if it didn't know exactly why. No leader was responsible for coordinating the rest of the herd. Instead each animal was following simple rules evolved over thousands of years of wolf attacks.

That's the wonderful appeal of swarm intelligence. Whether we're talking about ants, bees, pigeons, or caribou, the ingredients of smart group behavior-decentralized control, response to local cues, simple rules of thumb-add up to a shrewd strategy to cope with complexity.

"We don't even know yet what else we can do with this," says Eric Bonabeau, a complexity theorist and the chief scientist at Icosystem Corporation in Cambridge, Massachusetts. "We're not used to solving decentralized problems in a decentralized way. We can't control an emergent phenomenon like traffic by putting stop signs and lights everywhere. But the idea of shaping traffic as a self-organizing system, that's very exciting."

Social and political groups have already adopted crude swarm tactics. During mass protests eight years ago in Seattle, anti-globalization activists used mobile communications devices to spread news quickly about police movements, turning an otherwise unruly crowd into a "smart mob" that was able to disperse and re-form like a school of fish.

The biggest changes may be on the Internet. Consider the way Google uses group smarts to find what you're looking for. When you type in a search query, Google surveys billions of Web pages on its index servers to identify the most relevant ones. It then ranks them by the number of pages that link to them, counting links as votes (the most popular sites get weighted votes, since they're more likely to be reliable). The pages that receive the most votes are listed first in the search results. In this way, Google says, it "uses the collective intelligence of the Web to determine a page's importance."

Wikipedia, a free collaborative encyclopedia, has also proved to be a big success, with millions of articles in more than 200 languages about everything under the sun, each of which can be contributed by anyone or edited by anyone. "It's now possible for huge numbers of people to think together in ways we never imagined a few decades ago," says Thomas Malone of MIT's new Center for Collective Intelligence. "No single person knows everything that's needed to deal with problems we face as a society, such as health care or climate change, but collectively we know far more than we've been able to tap so far."

Such thoughts underline an important truth about collective intelligence: Crowds tend to be wise only if individual members act responsibly and make their own decisions. A group won't be smart if its members imitate one another, slavishly follow fads, or wait for someone to tell them what to do. When a group is being intelligent, whether it's made up of ants or attorneys, it relies on its members to do their own part. For those of us who sometimes wonder if it's really worth recycling that extra bottle to lighten our impact on the planet, the bottom line is that our actions matter, even if we don't see how.

Think about a honeybee as she walks around inside the hive. If a cold wind hits the hive, she'll shiver to generate heat and, in the process, help to warm the nearby brood. She has no idea that hundreds of workers in other parts of the hive are doing the same thing at the same time to the benefit of the next generation.

"A honeybee never sees the big picture any more than you or I do," says Thomas Seeley, the bee expert. "None of us knows what society as a whole needs, but we look around and say, oh, they need someone to volunteer at school, or mow the church lawn, or help in a political campaign."

If you're looking for a role model in a world of complexity, you could do worse than to imitate a bee.








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Friday, August 31, 2007

Climate Change to Bring Fewer but Stronger Storms


Md Moshiur Rahman 24hours news (space)/nasa



Climate scientists have developed a new model predicting the effect of global warming on storms, and for once, there's a little good news along with the bad.


Good news first: Under their new model, it appears that a slightly hotter, carbon dioxide-richer atmosphere would produce fewer big storms of the kind that trigger tornadoes and set off wildfires.


The bad: Those fewer storms will likely be more violent, intensifying the potential damage done instead. So, if you want to keep driving that SUV around, maybe you'd better get yourself a good lightning rod, and start clearing that brush away from your house. And don't even think about going near a trailer home.


Researchers from NASA's Goddard Institute For Space Studies were building on previous work that had shown that heavy rainstorms would likely be more common on a warming Earth, but which had rarely addressed the issues of updrafts, wind shear, and other elements that contribute to the violence of a storm.




They say the computer model they've developed is the first that successfully simulates measured differences between the strengths of storms over land and sea, as well as features of storm production over tropical areas in Africa and the Amazon Basin.


With those successes in mind, researchers modeled instead for an Earth with an average surface temperature five degrees warmer than today, and double the current carbon dioxide content. The result: Fewer overall storms over land masses, but more that rival the strongest thunderstorms and tornadoes that we experience today.


Comments


"These findings may seem to imply that fewer storms in the future will be good news for disastrous western U.S. wildfires," said Tony Del Genio, lead author of the study and a scientist at NASA's Goddard Institute for Space Studies, New York. "But drier conditions near the ground combined with higher lightning flash rates per storm may end up intensifying wildfire damage instead."





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Wednesday, August 29, 2007

Apple offers TV show downloads


presented by Md. Moshiur Rahman . sponsored by www.careerbd.net


Apple is offering customers the chance to download TV programs for the new iPhone, writes Claudine Beaumont













iPhone owners can now download TV shows


Apple this morning announced that UK customers of its iTunes music store will now be able to download episodes of hit TV shows including Lost, Desperate Housewives, Grey's Anatomy and Ugly Betty.


There are currently 28 programmes available for purchase via the iTunes store, at a cost of £1.89 per episode, with more to follow in the coming months, and Apple says that the programmes will be "near-DVD quality".


People will then be able to watch downloaded shows on their PC or Mac, iPod video, or on their television, via Apple TV and on the iPhone when it is released in the UK and Europe later this year.


iPhone owners can now download TV shows

from Another source


Apple offers TV show subscriptions


Itunesradiotuner_2 Apple's iTunes store has taken its first tentative steps towards a monthly subscription service with a new service called Multi-Pass that lets users purchase TV shows on a monthly basis.


iTunes is launching the service in the US (no news on a UK launch for this or even TV downloads) in partnership with Viacom's Comedy Central Network, which is initially offering up "The Daily Show with Jon Stewart" and "The Colbert Report" on the service. Fans will be able to buy the next month's series of 16 new episodes for $9.99, or to pay $1.99 per episode.


The addition of TV subscriptions could be followed by movie downloads on the iTunes service if current rumours prove to be founded.


More iTunes:
Apple to launch full-length movie downloads?
Who uses iTunes?


Click here to find out more!




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Chocoholics like drug addicts, say scientists


Brain changes in chocoholics that occur when they see or eat chocolate are similar to those in addicts when they take drugs, scientists say.



British researchers found certain regions of the brain were more active when people who confessed to cravings were fed or shown pictures of chocolate than in non-cravers.













Chocoates: Chocoholics like drug addicts, scientists say


The sight of chocolate can trigger cravings in 'addicts'


They also discovered the sight of chocolate contributed significantly to the activation of brain areas associated with reward - suggesting that dieters could cut their intake by avoiding the sight of foods they particularly desire.


Prof Edmund Rolls and Ciara McCabe at the University of Oxford's experimental psychology department carried out functional magnetic resonance (fMRI) imaging on the brains of eight chocoholics and eight non-cravers. All participants were women.


The volunteers were shown appetising pictures of chocolate and then fed liquid chocolate while having fMRI scans.


Among chocolate cravers, greater activity was seen in the medial orbitofrontal cortex, pregenual cingulated cortex and ventral striatum - regions of the brain known to be involved in pleasure sensation, habit-forming behaviours and drug addiction.



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Damage to the orbitofrontal cortex acquired through brain injury has previously been associated with compulsive gambling and excessive use of alcohol and drugs.


The fMRI scans also demonstrated the combination of the sight and taste of chocolate produced a stronger response in both cravers and non-cravers, than either separately.


Prof Rolls, whose findings were published in the European Journal of Neuroscience, said: "Understanding individual differences in brain responses to very pleasant foods helps in the understanding of the mechanisms that drive the liking for specific foods and thus intake of those foods.


"Sight and flavour combined give a much bigger response than seeing or tasting the food separately. The sight component is important and complements the flavour.


"If you want to limit [food] intake, you could limit the extent to which you are exposed to the combination of sight and taste. For example, you could eat in the dark."


Prof Rolls said eating a desired food without seeing it was a parallel experience to eating food when you cannot smell it because of having a blocked nose.


He added: "To our knowledge this is the first study to show that there are differences between cravers and non-cravers in their responses to the sensory components of a craved food in the orbitofrontal cortex, ventral striatum and pregenual cingulate cortex."


CHOCOHOLICS is more akin to an addiction.


presented by Md Moshiur Rahman sponsored by www.careerbd.net




British researchers have discovered that chocoholics' brains respond to chocolate as drug addicts' do to drugs.


The scientists also discovered that areas of the brain associated with reward were activated just by the sight of chocolate.


This led the researchers to suggest people may be able to lose weight by avoiding the sight of foods they desire.


Oxford University's Prof Edmund Rolls and Ciara McCabe performed functional magnetic resonance imaging on the brains of eight chocoholics and eight controls.


The volunteers were shown photos of chocolate and then sipped on liquid chocolate while having fMRI scans.


Among the chocoholics, greater activity was seen in the regions of the brain associated with pleasurable sensations, habit-forming behaviour and drug addiction.


The fMRI scans also showed that combining the sight and taste of chocolate generated a stronger response in both cravers and non-cravers than either sensation separately.


Prof Rolls, whose research was published in the European Journal of Neuroscience, said dieters could learn from his findings.


"If you want to limit (food) intake, you could limit the extent to which you are exposed to the combination of sight and taste," Prof Rolls said. "For example, you could eat in the dark."


Chocoholic Lindsey Wright, 28, said he craved chocolate every day.


Described by colleagues as the office "choc-head", the retail project manager said it wasn't unusual for him to devour chocolate mudcake for lunch.


"My afternoon cravings are second nature to me," he said.


"My girlfriend is just as bad or even worse than I am, so maybe chocoholics are attracted to each other."


A MAGAZINE survey says a quarter of Australians are addicted to coffee and say they cannot function without it.


Home Beautiful's poll of 552 people found 26 per cent of respondents said they were addicted to caffeine. About 12 per cent drank four or more cups a day and 14 per cent up to three cups.


According to the Australian Coffee Traders' Association, Australians consume 2.4kg of coffee each a year, compared with just over 500g 50 years ago.



Brain scans pinpoint how chocoholics are hooked


Chocoholics really do have chocolate on the brain. Their grey matter reacts differently when they see or taste chocolate than people who do not crave the food.


British researchers used brain scans to investigate subconscious reactions to the confection and found that the pleasure centres of chocolate lovers' brains lit up more strongly in response to the food than those who are less partial.


There may also be some truth in calling the love of chocolate an addiction in some people. When cravers viewed pictures of chocolate this activated regions of the brain known to be involved in habit-forming behaviours and drug addiction.Edmund Rolls and Ciara McCabe at the University of Oxford's experimental psychology department used functional magnetic resonance imaging to scan the brains of eight chocoholics and eight non-cravers. All the volunteers were women. The technique reveals where activity is happening in the brain.


The volunteers were presented first with appetising pictures of chocolate bars, before being allowed also to taste liquid chocolate fed to them through a tube in the confined space of the scanner.


As expected the cravers consistently rated the experience as more pleasant, but their brains also reacted differently. Three regions thought to be important in pleasure sensation and addictive behaviour - the orbitofrontal cortex, the ventral striatum and the cingulate cortex - were all more active in the chocolate fanciers. "We can tell what people will like from their brain response," said Prof Rolls. The findings are published this month in the European Journal of Neuroscience.


The study also found that combining the sight and taste of chocolate produced a stronger reaction in both cravers and non-cravers, than either separately. Prof Rolls said this suggests that seeing the food we eat plays a key role in enjoying its taste.


"Sight and flavour combined give a much bigger response than seeing or tasting the food separately. The sight component is important and complements the flavour," he said.


This finding might offer a way of making food less pleasurable for people on a diet. "The take-home message is that if you want to limit [food] intake, you could limit the extent to which you are exposed to the combination of sight and taste. For example, you could eat in the dark", he said. This is an "exact parallel" with the experience of eating food when you cannot smell anything - for example if you have a blocked nose, he said.




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TODAY The Night of Deliverance ,Shab-e-Baraat


THE belief of ISLAM by Md. Moshiur Rahman sponsored by www.careerbd.net


The fifteenth night of the month of Sha'baan, commencing with sunset, is a highly auspicious night. It is known as Shab-e-Baraat - tha Night of Deliverance from sins.


Authentic Traditions reveal that the account of a person's activities of the last year is closed this evening and simultaneously fresh account is opened for the new year. In this night Allah passes of His Knowledge of every individual's activities in the year ahead to the angels concerned.

It is revealed to us in Traditions that in this night Allah proclaims : Is there any seeker of deliverance from sins? Then I forgive him his sins. Is there any seeker of happiness ? Then I make him happy. Is there any seeker of provisions ? Then I provide him with provisions. Is there any seeker? Is there any seeker?

The giver is bent upon giving In this night. Where is the taker? If the taker is sleeping, he is the loser. Therefore, Allah's Messenger (Blessing of Allah and Peace be on him), the Mercy for the universe, has advised is to keep awake the whole night and occupy ourselves in the recitation of the Holy Qur'aan, voluntary namaaz (Nafl), visiting the graveyard and putting forth supplications before the Almighty Allah for the fulfillment of our material as well as spiritual desires. It is set out in Traditions that three hundred gates of Allah's Mercy are opened this night and all supplicants are granted their prayers except the polytheist, the sorcerer, the astrologer, the miser, the drinker of wine, malicious, the usurer and the adulterer. Therefore let everyone repent sincerely for his past misdeeds and wrong beliefs, make a vow to Allah that he shall never indulge in these and other vices and then stick to his vow in order fo derive the utmost benefit of the Divine Gifts showered in this night.

While visiting the graveyard, one must not indulge in idle talk, fireworks, and other absurdities. The time spent in this visit, including the time for coming and going, should not be wasted in trifles.

'LAA HAV-LAA WA- LAA QUV-VA-TA IL-LAA BIL-LAA HIL A-LIY-YIL A-ZEEM' at least forty times. Pray this after Asr and continue it till the Magrib Azaan. This will show credit entries at the end and beginning of your old and new accounts respectively. From sunset your life's new year begins. Begin it with prayers. After the Nagrib Namaaz, offer six raka'at Nafl. Two at a time. Offer the first two raka'at with the intention (niyyat) of seeking Allah's favour for granting you long and prosperous life.

The second two raka'at with the intention of warding off all calamities and the third two raka'at at with the intention that you may not be subjugated to the will of the creation for your needs.

After every two raka'at recite Suratul Yaaseen once or Suratul Iklas twenty-one times and then the Du'aa (Supplication) for the night. After the first recitation of the du'aa, seek Allah's favour for granting you long, prosperous life, after the second, pray for warding off all calamities and after the third pray that you may not be subjugated to the will of the creation for your needs.

Take permissible food and drink in the night till dawn. Then observe fast for the next day, the 15th Sha'baan (you may abserve fast on 14th as well). This will bring you happiness and Allah's favours in both the lives.




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Early Products in the Nanotech Revolution


Building complex products atom by atom with advanced nanotechnology: if and when this is accomplished, the resulting applications could radically transform many areas of human endeavor.

Products are manufactured in our modern industrial society for a variety of purposes, including transportation, recreation, communication, medical care, basic needs, military support, and environmental monitoring, among others. In this column I'll consider products in each category in order to convey a sense of the extent to which the early stages of the nanotech "revolution" could be limited by practical design problems, and to explore how those impacts, while limited, may still be quite profound.

Molecular manufacturing (MM) will be able to build a wide variety of products -- but only if their designs can be specified. If we know what kind of product we want and only need to enter the design into a CAD program, then certain nanofactory-built products may be relatively easy to design Extremely dense functionality, strong materials, integrated computers and sensors, and inexpensive full-product rapid prototyping will combine to make product design easier.

(See http://www.crnano.org/essays05.htm#8 ,August)

However, there are several reasons why the design of other products may be difficult. Requirements for backward compatibility, advanced requirements, complex or poorly understood environments, regulations, and lack of imagination are only a few of the reasons why a broad range of nanofactory products will be difficult to get right. Some applications will be a lot easier than others. So, let's look at what can -- and what can't -- be expected in the early stages of the "next industrial revlution."

Transportation is simple in concept: merely move objects or people from one place to another place. Efficient and effective transportation is quite a bit more difficult. Any new transportation system needs to be safe, efficient, rapid, and compatible with a wide range of existing systems. If it travels on roads, it will need to comply with a massive pile of regulations. If it uses installed pathways (future versions of train tracks), space will have to be set aside for right-of-ways. If it flies, it will have to be extremely safe to reassure those using it and avoid protest from those underneath.

Despite these problems, MM could produce fairly rapid improvements in transportation. There would be nothing necessarily difficult about designing a nanofactory-built automobile that exceeded all existing standards. It would be very cheap to build, and fairly efficient to operate -- although air resistance would still require a lot of fuel. Existing airplanes also could be replaced by nanofactory-built versions, once they were demonstrated to be safe. In both cases, a great deal of weight could be saved, because the motors would be many orders of magnitude smaller and lighter, and the materials would be perhaps 100 times as strong. Low-friction skins and other advances would follow shortly.

Molecular manufacturing could revolutionize access to space. Today's rockets can barely get there; they spend a lot of energy just getting through the atmosphere, and are not as efficient as they could be. The most efficient rocket nozzle varies as atmospheric pressure decreases, but no one has built a variable-nozzle rocket. Far more efficient, of course, would be to use an airplane to climb above most of the atmosphere, as Burt Rutan did to win the X Prize. But this has never been an option for large rockets. Another problem is that the cost of building rockets is astronomical: they are basically hand-built, and they must use advanced technology to minimize weight. This has caused rocketry to advance very slowly. A single test of a new propulsion concept may cost hundreds of millions of dollars.

When it becomes possible to build rockets with automated factories and materials ten times as strong and light as today's, rockets will become cheap enough to test by the dozen. Early advances could include disposable airplane components to reduce fuel requirements; far less weight required to keep a human alive in space; and far better instrumentation on test flights -- instrumentation built into the material itself -- making it easier and faster to determine the cause of failures. It seems likely that the cost of owning and operating a small orbital rocket might be no more than the cost of owning a light airplane today. Getting into space easily, cheaply, and efficiently will allow rapid development of new technologies like high-powered ion drives and solar sails. However, all this will rely on fairly advanced engineering -- not only for the advanced propulsion concepts, but also simply for the ability to move through the atmosphere quickly without burning up.

Recreation is typically an early beneficiary of inventiveness and new technology. Because many sports involve humans interacting directly with simple objects, advances in materials can lead to rapid improvements in products. Some of the earliest products of nanoscale technologies (non-MM nanotechnology) include tennis rackets and golf balls, and such things will quickly be replaced by nano-built versions. But there are other forms of recreation as well. Video games and television absorb a huge percentage of people's time. Better output devices and faster computers will quickly make it possible to provide users with a near-reality level of artificial visual and auditory stimulus. However, even this relatively simple application may be slowed by the need for interoperability: high-definition television has suffered substantial delays for this reason.

A third category of recreation is neurotechnology, usually in the form of drugs such as alcohol and cocaine. The ability to build devices smaller than cells implies the possibility of more direct forms of neurotechnology. However, safe and legal uses of this are likely to be quite slow to develop. Even illegal uses may be slowed by a lack of imagination and understanding of the brain and the mind. A more mundane problem is that early MM may be able to fabricate only a very limited set of molecules, which likely will not include neurotransmitters.

Medical care will be a key beneficiary of molecular manufacturing. Although the human body and brain are awesomely complex, MM will lead to rapid improvement in the treatment of many diseases, and before long will be able to treat almost every disease, including most or all causes of aging. The first aspect of medicine to benefit may be minimally invasive tests. These would carry little risk, especially if key results were verified by existing tests until the new technology were proved. Even with a conservative approach, inexpensive continuous screening for a thousand different biochemicals could give doctors early indications of disease. (Although early MM may not be able to build a wide range of chemicals, it will be able to build detectors for many of them.) Such monitoring also could reduce the consequences of diseases inadvertently caused by medical treatment by catching the problem earlier.

With full-spectrum continuous monitoring of the body's state of health, doctors would be able to be simultaneously more aggressive and safer in applying treatments. Individual, even experimental approaches could be applied to diseases. Being able to trace the chemical workings of a disease would also help in developing more efficient treatments for it. Of course, surgical tools could become far more delicate and precise; for example, a scalpel could be designed to monitor the type and state of tissue it was cutting through. Today, in advanced arthroscopic surgery, simple surgical tools are inserted through holes the size of a finger; a nano-built surgical robot with far more functionality could be built into a device the width of an acupuncture needle.

In the United States today, medical care is highly regulated, and useful treatments are often delayed by many years. Once the technology becomes available to perform continuous monitoring and safe experimental treatments, either this regulatory system will change, or the U.S. will fall hopelessly behind other countries. Medical technologies that will be hugely popular with individuals but may be opposed by some policy makers, including anti-aging, pro-pleasure, and reproductive technologies, will probably be developed and commercialized elsewhere.

Basic needs, in the sense of food, water, clothing, shelter, and so on, will be easy to provide with even minimal effort. All of these necessities, except food, can be supplied with simple equipment and structures that require little innovation to develop. Although directly manufacturing food will not be so simple, it will be easy to design and create greenhouses, tanks, and machinery for growing food with high efficiency and relatively little labor. The main limitation here is that without cleverness applied to background information, system development will be delayed by having to wait for many growing cycles. For this reason, systems that incubate separated cells (whether plant, animal, or algae) may be developed more quickly than systems that grow whole plants.

The environment already is being impacted as a byproduct of human activities, but molecular manufacturing will provide opportunities to affect it deliberately in positive ways. As with medicine, improving the environment will have to be done with careful respect for the complexity of its systems. However, also as with medicine, increased ability to monitor large areas or volumes of the environment in detail will allow the effects of interventions to be known far more quickly and reliably. This alone will help to reduce accidental damage. Existing damage that requires urgent remediation will in many cases be able to be corrected with far fewer side effects.

Perhaps the main benefit of molecular manufacturing for environmental cleanup is the sheer scale of manufacturing that will be possible when the supply of nanofactories is effectively unlimited. To deal with invasive species, for example, it may be sufficient to design a robot that physically collects and/or destroys the organisms. Once designed and tested, as many copies as required could be built, then deployed across the entire invaded range, allowed to work in parallel for a few days or weeks, and then collected. Such systems could be sized to their task, and contain monitoring apparatus to minimize unplanned impacts. Because robots would be lighter than humans and have better sensors, they could be designed to do significantly less damage and require far fewer resources than direct human intervention. However, robotic navigation software is not yet fully developed, and it will not be trivial even with million-times better computers. Furthermore, the mobility and power supply of small robots will be limited. Cleanup of chemical contamination in soil or groundwater also may be less amenable to this approach without significant disruption.

Advanced military technology may have an immense impact on our future. It seems clear that even a modest effort at developing nano-built weapon systems will create systems that will be able to totally overwhelm today's systems and soldiers. Even something as simple as multi-scale semi-automated aircraft could be utterly lethal to exposed soldiers and devastating to most equipment. With the ability to build as many weapons as desired, and with motors, sensors, and materials that far outclass biological equivalents, there would be no need to put soldiers on the battlefield at all. Any military operation that required humans to accompany its machines would quickly be overcome. Conventional aircraft could also be out-flown and destroyed with ease. In addition to offensive weapons, sensing and communications networks with millions if not billions of distributed components could be built and deployed. Software design for such things would be far from trivial, however.

It is less clear that a modest military development effort would be able to create an effective defense against today's high-tech attack systems. Nuclear explosives would have to be stopped before the explosion, and intercepting or destroying missiles in flight is not easy even with large quantities of excellent equipment. Hypersonic aircraft and battle lasers are only now being developed, and may be difficult to counter or to develop independently without expert physics knowledge and experience. However, even a near parity of technology level would give the side with molecular manufacturing a decisive edge in a non-nuclear exchange, because they could quickly build so many more weapons.

It is also uncertain what would happen in an arms race between opponents that both possessed molecular manufacturing. Weapons would be developed very rapidly up to a certain point. Beyond that, new classes of weapons would have to be invented. It is not yet known whether offensive weapons will in general be able to penetrate shields, especially if the weapons of both sides are unfamiliar to their opponents. If shields win, then development of defensive technologies may proceed rapidly until all sides feel secure. If offense wins, then a balance of terror may result. However, because sufficient information may allow any particular weapon system to be shielded against, there may be an incentive to continually develop new weapons.

This overview has focused on the earliest applications of molecular manufacturing. Later developments will benefit from previous experience, as well as from new software tools such as genetic algorithms and partially automated design. But even a cursory look at the things we can plan for today and the problems that will be most limiting early in the technology's history shows that molecular manufacturing will rapidly revolutionize many important areas of human endeavor.




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Monday, August 27, 2007

LHC ( large Hadron collider) facts


WHAT IS THE LHC?

CERN´s aerial view Where is it?
The LHC is being installed in a tunnel 27 km in circumference, buried 50-175 m below ground. Located between the Jura mountain range in France and Lake Geneva in Switzerland, the tunnel was built in the 1980s for the previous big accelerator, the Large Electron Positron collider (LEP). The tunnel slopes at a gradient of 1.4% towards Lake Geneva.


What will it do?
The LHC will produce head-on collisions between two beams of particles, either protons or lead ions. The beams will be created in CERN's existing chain of accelerators and then injected into the LHC. These beams will travel through a vacuum comparable to outer space. Superconducting magnets operating at extremely low temperatures will guide them around the ring. Each beam will consist of nearly 3000 bunches of particles and each bunch will contain as many as 100 billion particles. The particles are so tiny that the chance of any two colliding is very small. When the particle beams cross, there will be only about 20 collisions among 200 billion particles. However, the particle beams will cross about 40 million times per second, so the LHC will generate about 800 million collisions per second.


What is it for?
Due to switch on in 2007, the LHC will provide collisions at the highest energies ever observed in laboratory conditions and physicists are eager to see what they will reveal. Four huge detectors - ALICE, ATLAS, CMS and LHCb - will observe the collisions so that the physicists can explore new territory in matter, energy, space and time. A fifth experiment, TOTEM, installed with CMS, will study collisions where the protons experience only very small deflections.


How powerful?
The LHC is a machine for concentrating energy into a very small space. Particle energies in the LHC are measured in tera electronvolts (TeV). 1 TeV is roughly the energy of a flying mosquito, but a proton is about a trillion times smaller than a mosquito. Each proton flying round the LHC will have an energy of 7 TeV, so when two protons collide the collision energy will be 14 TeV. Lead ions have many protons, so they can be accelerated to even greater energy: the lead ion beams will have a collision energy of 1150 TeV. At full power, each beam will be about as energetic as a car travelling at 2100 kph. The energy stored in the magnetic fields will be even greater, equivalent to a car at 10 700 kph.


At near light-speed, a proton in a beam will make 11 245 turns per second. A beam might circulate for 10 hours, travelling more than 10 billion kilometres - far enough to get to the planet Neptune and back again.


How will it work?
To control beams at such high energies the LHC will use some 7000 superconducting magnets. These electromagnets are built from superconducting materials: at low temperatures they can conduct electricity without resistance, and so create much stronger magnetic fields than ordinary electromagnets. The LHC's niobium-titanium magnets will operate at a temperature of only 1.9 K (-271°C). The strength of a magnetic field is measured in units called tesla. The LHC will operate at about 8 tesla, whereas ordinary "warm" magnets can achieve a maximum field of about 2 tesla. If the LHC used ordinary "warm" magnets instead of superconductors, the ring would have to be at least 120 km in circumference to achieve the same collision energy.

LHC: the guide
A collection of facts and figures about the Large Hadron Collider (LHC) in the form of questions and answers.




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The LHC


presented by Md moshiur Rahman


The LHC is the next step in a voyage of discovery which began a century ago. Back then, scientists had just discovered all kinds of mysterious rays, X-rays, cathode rays, alpha and beta rays. Where did they come from? Were they all made of the same thing, and if so what?


These questions have now been answered, giving us a much greater understanding of the Universe. Along the way, the answers have changed our daily lives, giving us televisions, transistors, medical imaging devices and computers.


On the threshold of the 21st century, we face new questions which the LHC is designed to address. Who can tell what new developments the answers may bring?









Building 904, where the short straight sections are being assembled, is often called "Lego Land" by the workers because of the wide variety of these sets of magnets and cryostats.








The mirrors of the RICH2 detector, one of the two Ring Imaging Cherenkov detectors of the LHCb experiment, are meticulously assembled in a clean room.

Under a blood moon rising......!!!



A COSMIC ballet will bathe much of Australia's east coast in an ethereal red glow as the night sky becomes lit up by crimson moonshine.



But forget high-powered telescopes. A dark spot and roof tops will give some of the best views of tonight's Blood Moon eclipse.


At exactly 8.37pm (AEST) the Sun, Earth and Moon will be in total alignment, scattering light as it passes through the Earth's atmosphere and bounces off the moon in hues of bronze and red.


Tens of thousands of amateur astronomers are expected to turn outacross the city to catch a glimpse of the phenomenon.


NSW Astronomical Society astronomer Adrian Saw said that while a telescope or pair of binoculars would enhance the experience, it was not as important as finding a darkened location away from the city's lights.


"It's easily observable but the darker place you can find the better," Mr MOSi said. "There will be better views near the heads around Sydney Harbour or the Blue Mountains - anywhere away from street lamps."


The first stages of the eclipse will begin at 5.53pm but as the moon passes further into Earth's shadow at 6.51pm, it will gradually dim to an unusual golden colour.


When the total eclipse begins at 7.52pm it will become a bronze and reddish hue before turning blood red at its peak at 8.37pm.


"People will see things on the moon they've never seen before," Mr Saw, said.


The lunar kaleidoscope will reverse as the moon leaves Earth's shadow and becomes its bright white self again after 10.30pm.


It will be the first total lunar eclipse to be seen from start to finish in the city's skies since July 2000.


While they are not uncommon, it is rare to see one in its entirety, with the next blood moon not visible until 11.45pm on December 10, 2011.


Sydney, along with New Zealand, is in the perfect zone to view the eclipse - with people in Melbourne and Brisbane having to travel further north or south to find better views.



Stay up late - or get up early - for spectacular lunar eclipse


A lovely total lunar eclipse will be visible throughout the Bay Area and all of California before dawn Tuesday morning as the Earth's shadow darkens the bright full moon, and wherever skies are clear, it will be a time to look upward wide-eyed.


Astronomers say the eclipse should be a beauty, but only people willing to stay up very late or set their alarm clocks for long after midnight will see it.


It will last for a full hour and a half, and during that time, the moon's color could be anything from a dull and dusky red-brown to a reddish or even orange glow, depending on how much dust, pollution and mist is in the atmosphere, according to Andrew Fraknoi, chair of astronomy at Foothill College in Los Altos Hills, who has observed many in his time.


For the wide-awake, a partial eclipse will start at 1:51 a.m. Tuesday and become total starting at 2:52 a.m. By 4:22 a.m., the total phase will be over, but then as the moon begins to emerge from Earth's shadow, another partial phase will begin. The eclipse will end at 5:24 a.m., just as the sky lightens at dawn.


Lunar eclipses take place when the full moon and the sun are opposite each other in space, and the Earth in between them casts its shadow over the bright moon's face. But even when the eclipse is total, some indirect sunlight manages to reach the moon. The earth's atmosphere filters out most of the sun's blue light, leaving only the red frequencies to light the lunar surface.


"Since the moon is always safe to look at and the eclipse only makes the moon darker, there's no danger in watching this eclipse with your eyes or through a telescope," Fraknoi said.


Binoculars would be a neat way to watch the event, he said, because they could make some of the bigger craters stand out as the Earth's shadow begins to pass over the moon during the partial phase.


And watching the partial phase before totality should reveal something that the ancient Greeks discovered more than 2,000 years ago - that the Earth was round. So it wasn't Magellan whose voyage first showed that. It was Aristotle, who died in 322 B.C.


In eclipses of the moon, Aristotle wrote, the outline of the Earth's shadow is always curved, "and since it is the interposition of the earth that makes the eclipse, the form of this line will be caused by the form of the earth's surface, which is therefore spherical."


The lunar eclipse this year should be "really beautiful and like nothing you've ever seen before," said astronomer Ben Burress at the Chabot Space and Science Center high in the Oakland hills. "It's one of the longest lunar eclipses we've had."


The Chabot observatory is planning a big "Once in a Red Moon" all-night viewing party on its deck and in the planetarium with lunar-themed music. It will open at 10 o'clock tonight with hikes for the public and telescopes to see through. If the Bay Area's fog or clouds don't cooperate, the planetarium will show a simulation of the event.


Fred Espenak, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Md., has calculated the dates and times of past lunar eclipses from 2000 B.C. to the present, and on through to A.D. 3000. In that 5,000-year span, he said, there will have been 3,505 total eclipses of the moon, including 230 during the 21st century, and 4,213 partial eclipses, including 58 in this century.


Eclipses, of course, have long been harbingers of doom or evil in mythology, and lunar eclipses are no exception - mostly involving the moon swallowed up by gods or demons or other creatures.


According to some records, the Maya of Central America, for example, believed that a jaguar ate the moon and could devour people, too, while in ancient China it was a three-legged toad. To the Mongols it was a dragon named Alkha.


In Egypt in the time of the Pharaohs, lunar eclipses were bad omens indeed, because the moon was supposed to be the "ruler of the stars," and some ancient texts describe the entire sky as swallowing the moon during every eclipse.


While it wasn't Columbus who showed the Earth was round, the Great Navigator did use a lunar eclipse to save his crew during his last voyage to America in 1503, according to Bryan Brewer, author of the book "Eclipse."


After Columbus and his crew had been stranded on the island of Jamaica for months, the Indians finally refused to provide them with any food, Brewer said. But Columbus knew that a total eclipse of the moon would occur on Feb. 29, 1504. So on that night Columbus told his Indian neighbors that God was angry with them for not cooperating, and that God would make the moon disappear.


It did, and when the locals saw the eclipse ending, Columbus told them that God had forgiven them and the moon would return in full. It did, and Columbus and his crew ate heartily.






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Real time Yahoo Mail to cell phones in the U.S., Canada, India and the Philippines


August 27, 2007 www.24hoursnews.blogspot.com


Yahoo Inc. has closed the beta testing of its new e-mail service and will roll it out to its 254 million users over the next six weeks, the company said today. The beta testing of the new Yahoo Mail had been going on for two years.


Yahoo has added some new features to Yahoo Mail that were not included in its test of the service. For example, users can now send free text messages in real time from Yahoo Mail to cell phones in the U.S., Canada, India and the Philippines, according to a company statement. In addition, they can send instant messages from Yahoo Mail to Yahoo Messenger and Windows Live Messenger 2 users.


Yahoo said it will continue to offer its classic version of Yahoo Mail to users who might not want to switch to the new service. "We have always been focused on making it easy for people to connect to those who matter most to them, and during the beta-testing period of the new Yahoo Mail, we were able to incorporate a number of enhancements based on valuable feedback from our users," said John Kremer, vice president for Yahoo Mail.


Yahoo Mail will also add a feature called Shortcuts that lets the system automatically recognize things such as dates and addresses, giving users the option of adding the information to their Yahoo Calendar or Contacts lists, launching Web searches and displaying a map inside the Yahoo Mail interface. The new Yahoo Mail will be available to Yahoo Small Business Mail users this fall.


With competition heating up from Google Inc., Microsoft Corp. and others, Yahoo has to continually boost Yahoo Mail, which drives a lot of Web traffic for the company, Gartner analyst Mike McGuire said.


"Yahoo Mail is a keystone application for Yahoo, so continuing to enhance it is very important for the company, because there is a good chunk of ad inventory they get there," he said.


The challenge, McGuire said, is always to upgrade services in a way that provides tangible, concrete benefits to users, and to make people aware of the value of the improvements.


Because some users won't embrace the new version right away, giving them the option of using the "classic" version of Yahoo Mail is a smart move, he said. "That's important, because consumer inertia is a pretty powerful force," McGuire added.


Yahoo Mail is a free service, but it has a fee-based option called Plus that costs $19.95 annually and offers additional features, such as POP access, e-mail forwarding and no graphical ads.


The IDG News Service contributed to this report.






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