While other H.P. staff members checked on the company’s workers in Japan — none of whom were injured in the disaster — Mr. Prophet and his team scrambled to define the impact on the company’s suppliers in Japan and, if necessary, to draft backup plans. “It’s too early to tell, and we’re not going to pretend to predict the outcome,” Mr. Prophet said in an interview on Thursday. “It’s like being in an emergency room, doing triage.”

The emergency-room image speaks volumes. Modern global supply chains, experts say, mirror complex biological systems like the human body in many ways. They can be remarkably resilient and self-healing, yet at times quite vulnerable to some specific, seemingly small weakness — as if a tiny tear in a crucial artery were to cause someone to suffer heart failure.

Day in and day out, the global flow of goods routinely adapts to all kinds of glitches and setbacks. A supply breakdown in one factory in one country, for example, is quickly replaced by added shipments from suppliers elsewhere in the network. Sometimes, the problems span whole regions and require emergency action for days or weeks. When a volcano erupted in Iceland last spring, spewing ash across northern Europe and grounding air travel, supply-chain wizards were put to a test, juggling production and shipments worldwide to keep supplies flowing.

But the disaster in Japan, experts say, presents a first-of-its-kind challenge, even if much remains uncertain.

…

The field of buying and shipping supplies has been transformed in the last decade or two. Globalization and technology have been the driving forces. Manufacturing is outsourced around the world, with each component made in locations chosen for expertise and low costs. So today’s computer or smartphone is, figuratively, a United Nations assembly of parts. That means supply lines are longer and far more complex than in the past.

The ability to manage these complex networks, experts say, has become possible because of technology — Internet communications, RFID tags and sensors attached to valued parts, and sophisticated software for tracking and orchestrating the flow of goods worldwide.

That geographic and technological evolution, in theory, should make adapting to the disaster in Japan easier for corporate supply chains. “In the past, when you had a disruption, the response was regional,” says Timothy Carroll, vice president for global operations at I.B.M. “Now, it’s globalized.”

Most anything can be tracked, but it takes smart technology, investment and effort to do so. And as procurement networks become more complex and supply lines grow longer — “thin strands,” as the experts call the phenomenon — the difficulty and expense of seeing deeper into the supply chain increases.

“Major companies have constant communications and deep knowledge of primary suppliers,” says David B. Yoffie, a professor at the Harvard Business School. “It’s in the secondary layers of suppliers — things that are smaller, barely noticed — where the greater risk is.”

…

Further down the supply chain lie raw materials. Trouble for a supplier to a company’s parts supplier can cascade across an industry. For example, reports that a Mitsubishi Gas Chemical factory in Fukushima was damaged by the tsunami have fanned fears of a coming shortage of a resin — bismaleimide triazine, BT — used in the packaging for small computer chips in cellphones and other products.

Two Japanese companies are the leading producers of silicon wafers, the raw material used to make computer chips, accounting for more than 60 percent of the world’s supply. The largest is the Shin-Etsu Chemical Corporation. Its main wafer plant in Shirakawa was damaged by the earthquake, and the factory is down. “The continuing violent aftershocks are complicating the inspection work,” said Hideki Aihara, a Shin-Etsu spokesman in Japan, on Friday. “Right now we can’t say how badly it was damaged or how long it might take to get started.”

…

THE Japan quake, some experts say, will prompt companies to re-evaluate risk in their supply chains. Perhaps, they say, there will be a shift from focusing on reducing inventories and costs, the just-in-time model, pioneered in Japan, to one that places greater emphasis on buffering risk — a just-in-case mentality.

Adding inventories and backup suppliers reduces risk by increasing the redundancy in a supply system. It is one way to enhance resilience, experts say, but there are others.

They point to an example that is well known to supply-chain mavens. In 1997, there was a fire at a plant of one of Toyota’s main suppliers, Aisin Seiki, which made a brake valve used in all Toyota vehicles. Because of the carmaker’s just-in-time system, the company had just two or three days of stock on hand. So the fire threatened to halt Toyota’s production for weeks.

But Toyota and teams of suppliers in the company’s supply-chain network worked round the clock for days to design and set up alternative production sites. Toyota’s assembly plants reopened after being shut down for just two days.

“That kind of resilient capability, I think, is what we’ll see in Japan over the weeks and months ahead to put these supply chains back on their feet,” says Charles H. Fine, a professor at the Sloan School of Management at the Massachusetts Institute of Technology.

Yukio Edano, the chief cabinet secretary, said that spinach and milk were the only two products that were found with abnormally high levels of radioactive materials. The newly discovered radioactivity contained in the average amount of spinach and milk consumed during an entire year would be equal to the amount received in a single CAT scan.

..Food safety inspectors said that the amount of iodine-131 found in the tested milk was five times higher than levels deemed safe. They said that the iodine found in the spinach was more than seven times higher. The spinach also contained slightly higher amounts of cesium-137.

Iodine-131 and cesium-137 are two of the more dangerous elements that are feared to have been released from the plants in Fukushima. Iodine-131 can be dangerous to human health, especially if absorbed through milk and milk products, because it can accumulate in the thyroid and cause cancer. Cesium-137 can damage cells and lead to an increased risk of cancer.

..Leafy spinach is especially susceptible to absorbing radioactive material, Mr. Ohara said.

Asparagus, cucumbers, radish, tomatoes and other vegetables are also grown in Fukushima, but have not been found to be contaminated. However, only a small number of farms have been tested because officials have been overwhelmed in the wake of the earthquake, tsunami and the nuclear crisis that followed, Mr. Ohara said.

The government has not banned shipments of milk or spinach from the affected areas, but it would further study the issue, Mr. Edano said. The milk that contained higher levels of radioactive material was tested at farms about 19 miles from the hobbled nuclear plants in Fukushima Prefecture. The spinach was found in Ibaraki Prefecture farther south.

Apple is one of the company’s iSuppli has identified as being vulnerable to shortages in components for its latest iPad. Such components as the tablet’s touch screen-overlay glass, electronic compass, and battery are unique to the device and can’t be easily replaced if the Japanese suppliers are unable to resume full production.

Japanese components are used in smartphones and other high-end mobile devices because of the quality of the parts. If factories in Japan are unable to resume normal operations over the next few weeks, then mobile phone makers may find it difficult to find replacement parts of similar quality. “There’s a lot of hand wringing going on right now with some of the leaders in the handset market,” Pierson says.

7 hours and 118 aftershocks later, the store was still open. Why? Because with the phone and train lines down, taxis stopped, and millions of people stuck in the Tokyo shopping district scared, with no access to television, hundreds of people were swarming into Apple stores to watch the news on USTREAM and contact their families via Twitter, Facebook, and email. The young did it on their mobile devices, while the old clustered around the macs. There were even some Android users there. (There are almost no free wifi spots in Japan besides Apple stores, so even Android users often come to the stores.)

You know how in disaster movies, people on the street gather around electronic shops that have TVs in the display windows so they can stay informed with what is going on? In this digital age, that’s what the Tokyo Apple stores became. Staff brought out surge protectors and extension cords with 10s of iOS device adapters so people could charge their phones & pads and contact their loved ones. Even after we finally had to close 10pm, crowds of people huddled in front of our stores to use the wifi into the night, as it was still the only way to get access to the outside world.

“My life”, says Rice, “is a testament to the idea that you can achieve whatever the hell you want if you possess a modicum of creativity, and a certain amount of naïveté concerning what is and isn’t possible in this world. I’ve had one-man shows of my paintings in New York, but I’m not a painter. I’ve authored several books, but I’m not a writer. I’ve made a living as a recording artist for the last 30 years, but I can’t read a note of music or play any instrument. I’ve somehow managed to make a career out of doing a great number of things I’m in no way qualified to do”.

FOMO is a great motivator of human behavior, and I think a crucial key to understanding social software, and why it works the way it does. Many people have studied the game mechanics that keep people collecting things (points, trophies, check-ins, mayorships, kudos). Others have studied how the neurochemistry that keeps us checking Facebook every five minutes is similar to the neurochemistry fueling addiction. Social media has made us even more aware of the things we are missing out on. You’re home alone, but watching your friends status updates tell of a great party happening somewhere. You are aware of more parties than ever before. And, like gym memberships, adding Bergman movies to your Netflix queue and piling up unread copies of the New Yorker, watching these feeds gives you a sense that you’re participating, not missing out, even when you are.

There is a company that sells radar equipment to the police as well as radar detectors to the public. Clorox is one of the world’s worst polluters of water, and also sells Brita filters to get the bad stuff out of the water again. Lawyers create mazes that you have to hire a lawyer to escape. Similarly social software both creates and cures FOMO. If you didn’t know that party was going on, you’d be home contentedly reading your latest New Yorker. But since you do, you hungrily watch each new tweet.

I think one of the enduring tragedies of the 22nd century will be that during the 20th and 21st centuries we persistently treat nuclear reactors as if they’re nuclear weapons, and nuclear weapons as if they’re nuclear reactors.

In Tunisia, the post-revolution government is using the popular PiratePad collaborative, open-source text editor to help construct their constitution. The idea appears to have originated with Slim Amamou, a blogger with deep roots in the hacker community who’s ascended into the upper echelons of Tunisian politics to become a Tunisian cabinet member.