A Big Test for New Internet Addresses

A Big Test for New Internet Addresses

Why Google, Facebook, and others are taking part in World IPv6 Day this week.

What is World IPv6 Day?

At 8 p.m. EST on Tuesday, more than 300 organizations, including Google, Facebook, and Yahoo, will test a new way of routing information around the Internet: Internet Protocol version 6 (IPv6). Though the test run will only last 24 hours, participants may learn valuable lessons about how transitioning to IPv6 could affect their sites and their users. Spearheaded by the Internet Society (ISOC), World IPv6 Day is an international, coordinated effort to test this transition. ISOC hopes the effort will also encourage other organizations to adopt IPv6.

What is IPv6?

Each URL has its own Internet Protocol (IP) address. When you type a URL into a browser, a domain name server provides the corresponding IP address. (The IP address forwww.technologyreview.com is 69.147.160.210.) IP addresses are assigned to devices such as Web servers, PCs, cell phones, and printers so that these devices can be located and contacted. IPv6 enables many more devices to connect over the Internet.

Safari, Internet Explorer, Chrome, and Firefox browsers support IPv6 and have done so for several years, but some devices, including many popular home routers, aren't yet IPv6-enabled. Devices released as recently as February lack IPv6 support, and some devices need firmware updates to access IPv6-enabled sites.

Why is IPv6 needed?

The Internet has simply outgrown IPv4—the last few addresses were allotted this past February. IPv4 uses 32-bit addresses, which allow about 4.3 billion unique addresses. IPv6 uses 128-bit addresses, which make possible around 340 trillion trillion trillion unique addresses.

Some unused IPv4 addresses still exist, but they have been claimed by large companies and organizations. Other IPv4 addresses have been pooled by five regional Internet registries (RIRs) worldwide. While these can be reassigned, the process is expensive and akin to treading water as the IPv6 transition approaches.

How will participants enable IPv6?

Participants will run IPv4 and IPv6 simultaneously, by "stacking" two types of address records—"A" records and "AAAA" (or Quad-A) records. The A records pair an IPv4 address with a domain name so that, for instance, a user who types Facebook.com into a browser is taken to the correct IP address. Quad-A records do the same, but with IPv6 addresses.

Google has been running IPv6 for several years, but on different URLs (http://ipv6.google.com/ and http://google.com). By stacking A and Quad-A records, the URL http://google.com will access both IPv6 and IPv4 versions of the home page. Users who can't connect to the IPv6 site will be redirected to the IPv4 site.

One potential technical challenge is "IPv6 brokenness": problems in IPv6 connectivity that prevent users from accessing websites using the newer protocol. When a website such as Google runs two versions of its site for IPv4 and IPv6, it can't properly monitor for brokenness, because users must specifically type in the IPv6 URL to access it. On World IPv6 Day, traffic will be automatically directed to the IPv6 version, which will highlight brokenness and help organizations fix problems.

Global network: A map of the 2005 Internet shows IPv4 addresses connected by colored lines. The different colors represent domain types such as .com, .net, .gov, and .jp.
Credit: Wikipedia, The Opte Project

How will this affect you?

You probably won't notice any difference. ISOC estimates that only 0.05 percent of users will have difficulty accessing websites such as Facebook, Google, or Yahoo on World IPv6 Day. For those unlucky few, the problem may lie with incompatible browsers, routers, or operating systems. Home networks, says ISOC, are likely to cause most connectivity problems. Internet service providers (ISPs) generally have not provided IPv6-capable routers, partly because demand simply hasn't surfaced.

ISOC recommends that users prepare for World IPv6 Day by testing their connectivity viathis link. The test tells users whether their browsers are capable of accessing the IPv6 Internet and whether they should anticipate trouble during World IPv6 Day. To further minimize problems, ISOC also urges users to keep current with browser, operating system, and firmware updates, especially for routers and other network equipment.

Startup Thinks It Can Make Flow Batteries Cheaper

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Power play: Primus Power provides this glimpse of part of its new flow battery cells. It’s keeping quiet about many of the details of the system as it develops its first full-scale battery.
Credit: Primus Power

ENERGY

Startup Thinks It Can Make Flow Batteries Cheaper

The key is a modular design, which could make the technology practical as a way to keep the grid stable and reduce electricity costs.

A startup called Primus Power has received $11 million in venture capital to help it build the first full-scale version of a new, low-cost flow battery. The company earlier received $18 million via multiple government grants. Its battery is designed to help stabilize the power grid, making electricity cheaper, and making it easier for utilities to integrate intermittent renewable power sources like wind and solar.

Primus Power is trying to overcome one of the fundamental problems that have plagued flow batteries. The technology, in theory, at least, could be one of the cheapest forms of grid storage, since it requires inexpensive and abundant materials. But in practice, flow batteries have been very expensive, in part because they're large and have to be custom-built on site. Primus is hoping get around this with a new design that can be mass-produced in factories.

The need for such batteries has been growing as utilities anticipate increases in demand that could overload the power grid. Also, many states, most notably California, require the use of large amounts of renewable energy, but because such forms of energy are intermittent, it's difficult for utilities to maintain the match between supply and demand needed to prevent blackouts.

Batteries could even out the spikes in supply and demand by rapidly charging or delivering power to the grid, preventing blackouts and reducing the need for new power lines. But they've been too expensive for widespread use. In almost all cases, it's cheaper to build new power lines or to use natural gas power plants to make up for changes in power output from solar and wind plants. While Primus Power's technology is still too expensive to solve all of the energy storage problems on the grid, it will have many uses.

With flow batteries, a mixture of electrolyte and energy storage materials are stored in massive tanks—some as large as 10 meters high and 20 meters wide—and then pumped into a device where current is generated. Because flow batteries use cheap materials such as water-based electrolytes and energy storage materials made of abundant materials such as iron and zinc, the initial high costs could come down once enough of them are built, says Haresh Kamath, a senior project manager for energy storage at the Electric Power Research Institute, a nonprofit research organization supported by the electricity industry. But so far, the high cost of initial demonstration projects has stifled investment. Primus Power is replacing large storage tanks with cells the size of hot water tanks. This approach sacrifices some of the potential cost savings of large storage tanks, but it more than makes up for this with the savings possible from mass production in a factory, says Primus CEO Tom Stepien.

The company is also using novel zinc-based energy storage materials and a better design to increase the power output of the battery by about four to five times. These changes would allow for smaller, cheaper batteries that use less material, and that can be easily installed on existing utility property, such as at substations. The system, which is stored inside shipping containers, is portable. This can be a boon for utilities that need battery systems temporarily while waiting for new power lines to be installed. Some other companies are also working on modular systems, but these still use relatively large components capable of delivering one megawatt each or more. Primus Power is taking this approach further—its cells are smaller, delivering only 20 kilowatts each.

Primus Power joins about 20 other companies that are attempting to make cheaper flow batteries. It's aiming to reach costs near $500 per kilowatt hour of storage capacity. (It will be at least a year before the company can quote solid cost figures, Stepien says.) This would be much cheaper than ones that have been made so far, according to Kamath.  Companies often don't disclose their costs, but he estimates that many are upwards of $2,000 per kilowatt hour.

At $500 per kilowatt hour, the batteries would be cheap enough for widespread use on the grid for applications such as deferring power line construction, Kamath says. It would also be substantially cheaper than the technology's key competitor now—lithium-ion batteries—which cost about $1,000 per kilowatt hour, he says. But it would still be too expensive to meet the U.S. Department of Energy's goal of  energy storage systems that cost less than $100 per kilowatt hour.

If flow batteries could supply power for as little as $100 per kilowatt hour, they'd be a cheaper option for utilities than the installation of a new fossil-fuel-based power plant to offset the daily variations in wind or solar power, Kamath says. Primus Power recently won a grant from the DOE's Advanced Research Projects Agency for Energy to develop such a low-cost battery, but that will be a different design than the one it is currently scaling up, and the company isn't saying much about it yet.

Many other experimental storage technologies are being developed to reach these low costs. A "semi-solid" flow battery technology being developed by a startup called 24M uses much higher concentrations of energy storage materials in the electrolytes, which means they can stores 10 times as much energy as conventional flow batteries. A startup called Liquid Metal Battery is commercializing a battery that uses electrodes and electrolytes that are made of molten metals and salts.

Why Didn't Apple Launch a Music Streaming Service?

WEB

Why Didn't Apple Launch a Music Streaming Service?

Data-hungry apps are colliding with limited data plans.

Many expected Apple to announce a streaming music service today that would allow users to stream songs from iTunes to multiple devices, much as they do with Internet radio services such as Pandora. Apple did launch "iTunes in the Cloud" at its annual developers' conference, but the emphasis was not on streaming music. Instead, as part of Apple's iCloud offering, iTunes will let users buy music once and have it automatically downloaded to multiple devices, as well as backed up on Apple's servers. Apple CEO Steve Jobs made no mention of a Web interface through which users could access this music.

Apple certainly has the technology to launch a streaming music service. In December 2009, it bought the music startup Lala, which sold "Web songs" that users had the right to stream through their browser but not download. In March, Amazon began offering a Cloud Drive that let users access music from multiple devices or stream it through a Web interface. Google followed suit, announcing a music service to allow users to access songs through the Web.

It is possible that the record labels from which Apple has to license the music it sells were unwilling to allow music streaming. But another important factor that could have deterred Apple is mobile carriers' movement away from unlimited data plans. A streaming version of iTunes could have hugely increased the amount of data that carriers would be expected to carry. The largest carriers in the U.S., AT&T and Verizon, both cancelled their unlimited plan in June 2010. T-Mobile and Sprint both still offer unlimited plans. Today, T-Mobile says, the average 4G smart-phone user consumes about a gigabyte of data per month. That number could change significantly if a popular service like iTunes truly moved to the cloud.

"When the iPhone launched, it had no Netflix client, no Rdio, no Pandora, no streaming baseball—and AT&T was still almost brought to its knees," says Stephen O'Grady, an industry analyst at RedMonk. "Carriers witnessed what happened to AT&T. The days of unlimited numbers appear to be numbered no matter what." Though capped data plans come in different flavors, AT&T now offers a fairly standard set of choices: monthly plans of 200 megabytes, two gigabytes, and four gigabytes. The carrier notes that four gigabytes of data translates to streaming standard-quality YouTube video for just over six and a half hours. According to a data calculator offered by AT&T, streaming an hour of music a day comes to just under a gigabyte of usage each month. These numbers, however, refer to services used in isolation. A user who sends e-mail and surfs the Web in addition to watching the occasional YouTube video will use up the data more quickly. (Because Wi-Fi usage doesn't count toward the cap, a user could set up a mobile device to run on Wi-Fi in home or office, only depleting the data allowance when on the road.)

The disappearance of unlimited data plans means many consumers will need to monitor their data habits. But plenty of factors make monitoring data use extremely confusing. Not only do different kinds of content burn data at different rates, but carriers also give different figures. T-Mobile's data calculator, for example, says that streaming an hour of music a day will use up about 1.5 gigabytes of data per month--quite different from AT&T's figures.

Streaming media--very popular with Netflix customers--burns data the fastest, says Dan Hays, a partner and consultant at PRTM, a global management consulting firm. "The densest, largest content [such as music and video] will provide the greatest strain on mobile networks for the same reason that they're attractive to the cloud."

"The collision is here," Hays says. "In many ways, there's a fundamental disconnect between communications-hungry applications and limited mobile broadband resources." Part of the problem, he says, is that carriers and consumers are the ones who have to worry about the costs of streaming data--application manufacturers don't suffer financially if they produce software that is more data-hungry. As apps move to the cloud, he says, "there needs to be some sharing of the cost of that access."

The Shocking Truth About Running Shoes

by Gisela Telis 

To shoe or not to shoe? Whereas the shod runner (left) strikes with the heel of his foot, barefoot runners land on the front and middle of their feet, blunting the impact on their bodies.

Credit: Daniel Lieberman/Harvard University

Haile Gebrselassie, the world's fastest marathoner, once said of his early career, "When I wore shoes, it was difficult." A new study reveals why: Humans run differently in bare feet. Researchers have discovered that sneakers and other sports shoes alter our natural gait, which normally protects us from the impact of running. The finding offers new insight on how early humans ran and raises concerns that sports shoes may promote more injuries than they prevent.

About 2 million years ago, the ancestors of modern humans evolved the physiological "equipment" for running--long legs, large buttocks, and springy structures in the feet, among other features. Athletic shoes weren't invented until the early 1900s, and it wasn't until the 1970s that they found widespread popularity. So how did humans manage to run comfortably before the invention of purpose-built footwear?

Daniel Lieberman, a human evolutionary biologist at Harvard University--and an avid runner--decided to find out. He and colleagues looked at more than 200 shod and unshod runners in the United States and the Rift Valley Province of Kenya, which is known for its great endurance runners. The volunteers represented a spectrum of shoe experience, including adults who had grown up wearing shoes, those who had grown up running shoeless but who now wore shoes, and those who had never worn shoes at all. Lieberman's team arranged a trial in which each group ran shod (either in ASICS GEL-Cumulus 10s or in their own shoes) and bare and measured their running gait and the impact on their bodies.

The researchers noticed a difference right away. Whereas shod runners tended to land on the heel of the foot, barefoot runners landed on the ball of the foot or with a flat foot. The unshod runners' style causes more flex in the foot's springlike arch, ankle, and knee and engages more foot and calf muscles, blunting the impact on the body and making for a more comfortable "ride." As their feet collide with the ground--in this case, a running track--barefoot runners experience a shock of only 0.5 to 0.7 times their body weight, whereas shod heel strikers experience 1.5 to two times their body weight--a threefold to fourfold difference.

"I always assumed it was painful and crazy to run barefoot," says a surprised Lieberman. Instead, the findings--published tomorrow in Nature--suggest that going barefoot can reduce the likelihood of pain and damage, because many running injuries, like shin splints and plantar fasciitis, are stress- and impact-induced.

"This is an excellent study," says Dennis Bramble, an evolutionary morphologist at the University of Utah in Salt Lake City. "Heel strikes don't allow you to use these really nifty springs that are unique to human beings, so we're being less efficient than we could be," he says. "It confirms what we should have known all along: We're built to run barefoot."

That confirmation will stoke an ongoing debate. As a glance at this month's Runner's World magazine and a recent book on shoeless running called Born to Run attest, barefoot running has gained a small but devoted following in the past decade, prompting controversy in the running community over whether it is best to run shod or unshod.

So should sporty types shed their shoes and jump on the barefooted bandwagon? "Not at all," says Lieberman. "Shoes are comfortable, and they protect the foot" from glass, asphalt, and other harsh realities of urban running, he notes. Instead, Lieberman (who has since taken up occasional barefoot running himself) recommends a gradual transition for the bare-curious, one that allows the feet and calves to strengthen slowly and avoid injury.

Is Your Dog Pessimistic?

by Helen Fields 

Come back! Dogs that experience separation anxiety when their owners leave may also be pessimistic.

Credit: Mike Mendl

Yip yip yip yip whiiiine aarrooooooooOOOOoooo! About a third of dogs display some kind of behavior problem when their owners leave home, like howling, peeing on the floor, or chewing up remote controls. A new study finds that anxious dogs may be miserable for a reason: They're pessimistic about life.

The study was part of a project funded by the U.K.-based Royal Society for the Prevention of Cruelty to Animals, which wanted to devise a test to predict whether shelter dogs are likely to have problems with separation after they're adopted. The researchers decided to look at the dogs' emotional state, says Emily Blackwell, an animal behaviorist at the University of Bristol in the United Kingdom. Blackwell says she got interested in separation anxiety in high school: She lived so close to the school that between classes she could hear her dog howling from home.

Blackwell and her colleagues studied the moods of 24 dogs at two shelters in southwest England. One of the researchers held a dog behind a plywood screen while a colleague put out a metal food bowl on the other side of the screen. If the bowl was all the way to one side of the room, it had a delicious treat in it. If it was all the way to the other side, it was empty. When the bowl was in place, the dog was let loose. The dogs learn quickly "if it's on one side, to race over and nearly knock over the screen to get it," says Blackwell. "If it's on the other side, they look around and quite often give us a big sigh." Some dogs amble over to check out the empty bowl; others just lie down.

Once a dog learned the pattern, the researchers started mixing it up by sometimes putting the bowl somewhere between the far-right and far-left positions. Dogs that ran to check those ambiguously positioned bowls were judged to be more optimistic. Dogs that were less interested in the ambiguous bowls were judged to be more pessimistic. Similar trials are used to judge optimism and pessimism in other species, including humans.

The researchers also tested how the dogs behaved when they were left alone in a room. Dogs that howled, scratched, relieved themselves, or showed other separation-related behaviors were also those shown to be more pessimistic, a sign that they're unhappy animals. "So many people think [separation-related behavior] is just something dogs do," says Blackwell. They think the dog is angry the owner is leaving, say, and exacting its revenge on the owner's slippers. "We want to get that message out there that this could represent a welfare problem for the dogs." Owners should focus on treating Fido's separation anxiety rather than dismissing it as normal behavior, says Blackwell, whose team reports its findings online today in Current Biology.

Samuel Gosling, a psychologist at the University of Texas, Austin, likes the study. But he would go even further—canines have personalities, he says, that go beyond optimism and pessimism. He suspects that the experiments are actually revealing that the dogs rank high on the personality trait usually called neuroticism, which can include having a pessimistic outlook and being worried. "Dogs high on this anxiety-and-neuroticism dimension are more likely to get upset when the owner leaves," he suggests, and would be less likely to show interest in the food bowls, too.

Tiny 'Flying Saucers' Could Save Earth From Global Warming

by Eli Kintisch 

Using a trick of sunlight itself, tiny metallic disks could be levitated to the stratosphere where they would shade Earth's surface and counteract the effects of global warming, a new paper proposes. But even the scientist who dreamed up the idea says the little saucers should be used only as a last resort, if efforts to stem global warming by limiting the build-up of heat-trapping greenhouse gases fails.

The idea is a novel type of geoengineering—the concept of tinkering with the atmosphere to reduce the effects of global warming. Spelled out online today in the Proceedings of the National Academy of Sciences, it takes advantage of a natural phenomenon called photophoresis, in which the movement of a particle in a gas is affected by light shining on the particle and warming it. For example, suppose a disk-shaped particle is warmer than the surrounding air and its top consists of a different material than its bottom. Differences in how the two materials react with light cause gas molecules to push the object upward. In nature, photophoresis makes particles like silicate dust migrate up and down in the atmosphere, and it explains how "solar mills" like the one in the illustration spin.

Now, physicist David Keith of the University of Calgary in Canada proposes using the effect to control the climate. He envisions cranking out scads of 20-nanometer-wide nanodisks whose tops are made of aluminum and whose bottoms are made of barium titanate. Because the barium titanate more readily transmits heat and energy to impinging air molecules than the aluminum, the push on the bottom of the disk would be greater than on the top when it is warmed by sunlight. So that pressure would push it upward to a height of 40 to 50 kilometers, just out of the stratosphere. In addition, because barium titanate can be electrically polarized, electric fields in the atmosphere would stabilize the disks and keep them from flipping over. The particles would sink slowly during the night but rise during the day. And the aluminum tops, protected with a thin coating, would reflect sunlight back into space, cooling the planet. “I've invented a flying saucer,” Keith jokes.

Previously, scientists have proposed various other ways of cooling the planet using various sun blocking techniques. The most widely discussed is to mimic the cooling effect of volcanic eruptions of sulfur dioxide. This gas in the atmosphere is converted into droplets of sulfuric acid, which scatter sunlight away from the Earth's surface. However Keith says that the nanodisks technique might have fewer risks. For example, the sulfur dioxide particles can contribute to the destruction of the ozone layer. In contrast, the disks would block the sun above the stratosphere and avoid that danger.

Keith emphasises that the scheme should be used only in an emergency, as its possible side effects—sun-blocking can alter rain patterns, for example—could be worse than the effects of warming. In the meantime, he says, some laboratory testing—and with proper oversight, possible outdoor tests—could help spell out the dangers and costs.

But volcano expert Alan Robock of Rutgers University in New Brunswick, New Jersey, says that even such testing is going too far. "It's irresponsible to advocate in situ atmospheric testing" before issues such as international governance or environmental risks are spelled out, he says. Ken Caldeira, a geochemist at the Carnegie Institution of Washington in Stanford, California, also urges caution. "I have no idea whether such particles could really be cost-effectively manufactured and deployed," he says. "This study illustrates how we are at the infancy of thinking about how we might seek to diminish the impacts of excess greenhouse gases in the atmosphere."

Keith himself says that it's crucial to cut emissions of greenhouse gases, such as carbon dioxide, which cause global warming in the first place. The little disks should be the last line of protection, he says. "Seat belts reduce the risk of being injured in accidents," he says "But having a seat belt doesn't mean you should drive drunk at 100 miles an hour."