In their study of Twitter’s “contagion process,” the team looked at data from 16,000 U.S. cities, focusing on the 408 with the highest number of Twitter users and seeking to update traditional models of how information spreads and technology is adopted. Just as marketing experts sometimes label consumers as early adopters, early majority adopters, late majority adopters or laggards, the researchers characterized cities in those terms, based on when Twitter accounts in a given city reached critical mass. Critical mass is generally defined as the point when something reaches 13.5 percent of the population, which for this study was 13.5 percent of the highest total number of Twitter users in a city through August 2009, the end of the study period.

As with most technologies, the growth in popularity initially spread via young, tech-savvy “innovators,” in this case from Twitter’s birthplace in San Francisco to greater Boston. But the site’s popularity then took a more traditional route of traveling only short distances, implying face-to-face interactions. This approach made early adopters of Somerville and Berkeley - cities close to Boston and San Francisco, respectively. Twitter use then spread through early majority cities such as Santa Fe and Los Angeles and late majority cities such as Baltimore and Las Vegas before reaching laggards such as Palm Beach and Newark. All these cities ultimately ranked among the 408 nationwide with the largest numbers of Twitter accounts.

“Even on the Internet where we may think the world is flat, it’s not,” says Marta González, assistant professor of civil and environmental engineering and engineering systems at MIT, who is co-author of a paper on this subject appearing this month in the journal PLoS ONE. “The big question for people in industry is ‘How do we find the right person or hub to adopt our new app so that it will go viral?’ But we found that the lone tech-savvy person can’t do it; this also requires word of mouth. The social network needs geographical proximity.”

For nearly 50 years, marketers have studied the “diffusion of innovations” (named by Everett Rogers in his 1962 book of the same title) to predict how the purchase of expensive, durable goods such as cars and refrigerators will spread. But the diffusion of high-tech websites and cheap smartphone apps is thought to occur in a very different way.

“Nobody has ever really looked at the diffusion among innovators of a no-risk, free or low-cost product that’s only useful if other people join you. It’s a new paradigm in economics: what to do with all these new things that are free and easy to share,” says MIT graduate student Jameson Toole, a co-author of the paper.

Meeyoung Cha of the Korea Advanced Institute of Science and Technology is the third co-author, and also the person who had the prescience to begin downloading Twitter-published user data (via Twitter API) in May 2006, when there were only a couple of hundred users. She downloaded data through August 2009, when user growth dropped off for a time. González and Toole said their model of Twitter contagion didn’t fit Cha’s data until they added media influence, based on the number of news stories appearing weekly in Google News searches, data they acquired using Google Insights for Search, which provides historical search-engine data.

“Other studies have included news media in their models, but usually as a constant,” González says. “We saw that news media is not a constant. Instead, it’s media responding to people’s interest and vice versa, so we included it as random spikes.”

The study data include the growth spike that began April 15, 2009, when actor Ashton Kutcher challenged CNN to see who could first attract 1 million Twitter followers. Kutcher ultimately won, reaching the million mark in the wee hours of April 17, about half an hour before CNN. Popular talk-show host Oprah Winfrey invited Kutcher to appear on her show that same day; when she ceremoniously sent her first tweet, the pace of new news stories picked up again, and so did new Twitter accounts.

The Twitter bird was suddenly on all the wires, and Twitter’s user accounts increased fourfold because of the media attention, indicating that as recently as 2009, location-based social networks and media attention still held sway over computer-based social networks. Photo: www.imagine-your-world.com

“To improve the experience of our customers, we now provide 24 x 7 phone support to small, medium, and large Google Apps for Business customers for all issues affecting the core services,” Google says on its blog. “Our customers may also receive support through our web-based support portal, online help forms, and online help center. All support cases are handled directly by trained Google Apps experts.”

Google Apps for Business was first introduced in 2007 to compete with traditional office suites, including Microsoft Office. A free version is limited to 10 users within the same domain and allows users to send a maximum of 500 emails per day per email account. Email attachments are limited to 25 megabytes or less. The business version (Google Apps for Business) features e-mail spam and malware filtering through Postini before it is delivered to a client's mail server, API’s for single sign-on, a 99.9 percent e-mail uptime guarantee, and now 24/7 telephone support, among other features.

U.S. based business and education customers can reach Google support at 877-355-5787, international customers can dial 1-404-978-9282. Photo: Public Domain

As the largest federal agency to adopt cloud technology to date, NOAA will migrate 25,000 mailboxes to the cloud rather than utilizing in-house servers. NOAA’s decision to pursue the cloud solution supports the Obama administration’s direction to pursue a “cloud first” approach.

“The cost to the taxpayer will be 50 percent less than an in-house solution,” said NOAA Chief Information Officer Joseph Klimavicz. “As the new standard, cloud computing has great value allowing us to ramp up quickly, avoid redundancy and provide new services and capabilities to large groups of customers.”

The award was made using small business vendors identified through NOAALink, the agency’s innovative acquisition model, which allows for the standardization of information technologies and solutions. Earth Resources Technologies, Inc., based in Laurel, Maryland, will deliver the “Google Apps for Government” in partnership with Google, Unisys and Tempus Nova. The new service will be operational by the end of the year.

“NOAA personnel are located coast to coast, on the oceans and in the air. This system will allow them to share information and strengthen collaborative productivity,” added Klimavicz. “As a cutting edge science agency, we are looking forward to bringing up-to-the-minute workplace technologies to our personnel.”

NOAA will migrate 25,000 mailboxes and it’s and calendar infrastructure to the cloud. The picture shows two highly modified Lockheed WP-3D aircraft collecting weather information in the clouds. Photo: Public Domain

Chances are some things will break but that most internet users won't notice. Some web sites might temporarily disappear because some networks may try, but be unable, to connect to the new-style addresses. The real purpose of the test day is to discover the impact of a large-scale shift to IPv6 on the millions of servers, routers, and switches that make up the internet.

The inertia that has resisted the deployment of IPv6 for years is finally being overcome by a simple reality: The 4 billion or so internet addresses available under the older IPv4 protocol have been exhausted. IPv6 offers an address pool that is, for all practical purposes, bottomless even if every person on earth has billions of devices that need network addresses.

IPv6 addresses are 128 bits long, compared to 32 bits for IPv4. A computer with an IPv4 address of 192.168.1.12 (a typical "private" address on a home network) might get an IPv6 address of 2001:0000:4137:9e76:100c:0bf4:3f57:fef7. That's a base-16, or hexadecimal, number; the letters a-f represents digits for 10 through 15.

But the new protocol offers additional advantages. It has built-in provisions for security, particularly data encryption, that are missing from IPv4. Devices assign themselves addresses automatically when they connect to a network, eliminating the need for a server to keep track of assignments. IPv6 is designed to let devices connect to multiple networks simultaneous, making home networking and mobile communications easier.

The trick remains getting from here to there. Most large enterprises should be largely or completely IPv6-enabled, since all computers and operating systems from the past few years are compatible with the new protocol, as are many commercial routers and other network gear. Homes and smaller businesses are more problematic. The computers are mostly ready, but home networking gear may not be. Residential internet service providers are also far from ready; and success is dependent upon IPv6 being available on their networks, so many home based users and small businesses may have to upgrade and test their equipment.

Until now, the great majority of servers on the internet have been running only IPv4. Test IPv6 servers typically have names like ipv6.server1.test-ipv6.com and are invisible to the IPv4 network. On June 8, participating companies including most of the biggest players in the tech industry will turn on IPv6 addressing on their regular servers, meaning that both addressing schemes will be active simultaneously on the same machines. In theory, devices using IPv4 addresses should reach these servers using the older protocols and the relatively few systems using IPv6 will connect with the new protocol. In practice, some systems will probably try to use IPv6 and will run into a roadblock somewhere along the way. It's those network problems that the test is supposed to detect.

Eventually, some servers and sites on the net will become IPv6 only. Fortunately, there are tools that will allow IPv6-enabled systems to connect with each other by tunneling through IPv4 networks. But that is not likely to become an issue for at least a year or two. In the end, the conversion to the new addressing system is likely to take place out of the sight of most internet users. But the result will be a better and more efficient network for everyone.

Many ISP’s and enterprises will switch their servers to the new Internet Protocol IPv6 on Wednesday, June 8, to discover bottlenecks and other issues that may arise. Photo: www.imagine-your-world.com

The PUE measures energy overhead. It is a ratio that compares the amount of energy used in a data center to power servers, switches and storage devices to the total amount of energy used, including what's needed to distribute power, air condition the facility and run the machines. The goal is to optimize data centers so that almost all the power is dedicated to powering servers, switches and disk drives, Cisco says in a press release. A perfectly efficient datacenter would have a PUE very close to 1, while the average for data centers today is about 2, Green Grid says.

The government approval was a result of work by the Global Metrics Harmonization Task Force on measurement protocols. The name sounds like a New Age association to study crystals and convergence, but it is actually comprised of engineers and policy wonks. They come from agencies like the U.S. Environmental Protection Agency and Energy Department, Japan's Economy, Trade and Industry ministry and its Green IT Promotion Council, and a European Community research center studying data centers.

Establishing standards for efficiency in data centers is becoming increasingly important. In 2007, the EPA estimated that data centers were using 1.5 percent of America's electric power and would be using 3 percent by 2011 if growth trends continued.

But the combination of new technology and higher electricity prices are helping reduce energy use by data centers. The biggest single change is the move to consolidate data centers and move applications and infrastructure to the cloud. Big, purpose-designed, stand-alone data centers can be much more efficient than smaller data centers located inside general-purpose office buildings.

And cloud architecture with virtualized servers dramatically increases the work run on each server, increasing efficiency. Before the age of virtualization, it was common to have one server handle each application, with each server running at 10 percent of its capacity. Some data centers had numerous "ghost servers" that kept humming away long after the project for which they were purchased had been cancelled.

Companies building new data centers are achieving dramatic results. Google, Facebook and Cisco have all achieved PUE numbers approaching the highest possible rating of 1. The need to reduce electric power use has made data center operators much more conscious of air-flow, and architects are careful to position racks of servers to avoid "hot spots" that require excessive cooling. Advice columns tell managers to take advantage of outside air for cooling when temperatures fall and to cover over holes in raised floors where cool air dissipates.

Facebook, for example, places batteries for backup power near servers, rather than in a separate battery room, to minimize power transmission losses. The company cools the plant by letting air from the outside flow over foam pads moistened by water sprays. Cisco's newest data center can use ambient fresh air up to 75 degrees before the air has to be chilled, which it calculates will be 65 percent of the time. If the power fails, instead of hundreds of batteries for backup power it uses rotary flywheels to run generators until the backup diesel engines can be started up.

Such gains and the promise of cloud computing led clean-tech analysts Pike Research to predict that data centers worldwide will use 38 percent less energy than estimated by 2020. That drop will contribute to a decline in total data center energy costs to $16 billion in 2020 from $23.3 billion in 2010.  Pike predicts the decline will also reduce greenhouse gas emissions by 28 percent.

Still, measuring the environmental impact of data centers requires more studies. Green Grid says it is working on metrics to relate the use of water by a facility to its useful work produced. It also is working on measures that reflect whether the center is powered by carbon-dioxide-emitting fossil fuels or by clean, renewable energy sources.

EPA has applied its EnergyStar rating system to evaluate the efficiency of data center servers. Now it is working on ratings for storage boxes and network switches.

New measurers called Power Usage Effectiveness (PUE) aim to make data centers greener by reducing the energy overhead. EPA estimates that data centers in the U.S. will be using 3 percent of America's available electric power by the end of 2011 if growth trends continue. Photo: www.imagine-your-world.com