Yet the truth is, in more than 20 games I witnessed between Watson and former Jeopardy! players, humans frequently beat Watson to the buzzer. Their advantage lay in the way the game is set up. On Jeopardy! when a new clue is given, it pops up on screen visible to all. (Watson gets the text electronically at the same moment.) But contestants are not allowed to hit the buzzer until the host is finished reading the question aloud; on average, it takes the host about six or seven seconds to read the clue.

Players use this precious interval to figure out whether or not they have enough confidence in their answers to hazard hitting the buzzer. After all, buzzing carries a risk: someone who wins the buzz on a $1,000 question but answers it incorrectly loses $1,000.

Often those six or seven seconds weren't enough time for Watson. The humans reacted more quickly. For example, in one game an $800 clue was "In Poland, pick up some kalafjor if you crave this broccoli relative." A human contestant jumped on the buzzer as soon as he could. Watson, meanwhile, was still processing. Its top five answers hadn't appeared on the screen yet. When these finally came up, I could see why it took so long. Something about the question had confused the computer, and its answers came with mere slivers of confidence. The top two were "vegetable" and "cabbage"; the correct answer "cauliflower" was the third guess.

He explained that each vehicle contains "layers of computer code that may be added from one model year to next" that control nearly every system, from acceleration to braking to stability. Rizzoni said this software is rigorously tested, but he added: "It is well-known in our community that there is no scientific, firm way of actually completely verifying and validating software."

Here's an example everyone is familiar with: You're working at your computer in Windows software and an error message pops up. It asks whether you want to report the error to Microsoft. Microsoft has exhaustively tested this version of Windows before its release, but it cannot completely predict how it will operate out in the world, subject to user demands. That's why it gathers error reports and uses them to fix the software on a rolling basis.

If you put a lot of parts together to form a complex electromechanical machine and make it talk to itself via software, it can behave, sometimes, in ways you cannot anticipate. It can fail for reasons you cannot anticipate.

Ahrens ends the piece with a quote from a 2009 LA Times interview with a psychologist:

"Richard Schmidt, a former UCLA psychology professor and now an auto industry consultant specializing in human motor skills, said the problem almost always lies with drivers who step on the wrong pedal.

'When the driver says they have their foot on the brake, they are just plain wrong,' Schmidt said. 'The human motor system is not perfect, and it doesn't always do what it is told.' "

Assisted by instruments that can track in fine detail how parcels of fluid move, and by low-cost computers that can crunch vast amounts of data quickly, researchers have found hidden structures beyond Monterey Bay, structures that explain why aircraft meet unexpected turbulence, why the air flow around a car causes drag and how blood pumps from the heartâ(TM)s ventricles. In December, the journal Chaos will highlight the research under way to track the moving skeletons embedded in complex flows, known as Lagrangian coherent structures.

[..the ] particle contains only two quarks, making it simpler to simulate than the three-quark proton. To tackle protons and neutrons, Dürr's team used more than a year of time on the parallel computer network at Jülich, which can handle 200 teraflops — or 200 trillion arithmetical calculations per second.

Even so, they had to tailor their code to use the network efficiently. "We spent an enormous effort to make sure our code would make optimum use of the machine," says Dürr.

Without the quarks, earlier simulations got the proton mass wrong by about 10%. With them, Dürr gets a figure within 2% of the value measured by experiments.

The sudsy water, direct from the sewage-treatment plant, was the color of Guinness. "This is the most exciting thing you'll see here, and I didn't want you to miss it," he said.

Wildermuth went on to explain what we were looking at: inside each of 16 concrete bays hangs a rack of vertical tubes stuffed with 15,000 polypropylene fibers the thickness of dental floss. The fibers are stippled with holes 1/300th the size of a human hair. Pumps pull water into the fibers, leaving behind anything larger than 0.2 microns, stuff like bacteria, protozoa and the dread "suspended solids."

While reporting this article, I did everything I could to verify the trolls' stories and identities, but I could never be certain. After all, I was examining a subculture that is built on deception and delights in playing with the media. If I had doubts about whether Fortuny was who he said he was, he had the same doubts about me. I first contacted Fortuny by e-mail, and he called me a few days later. "I checked you out," he said warily. "You seem legitimate." We met in person on a bright spring day at his apartment, on a forested slope in Kirkland, Wash., near Seattle. He wore a T-shirt and sweat pants, looking like an amiable freelancer on a Friday afternoon. He is thin, with birdlike features and the etiolated complexion of one who works in front of a screen. He'd been chatting with an online associate about driving me blindfolded from the airport, he said. "We decided it would be too much work."

In Pittsylvania County, just north of the North Carolina border, the largest undeveloped uranium deposit in the United States — and the seventh largest in the world, according to industry monitor UX Consulting — sits on land owned by neighbors Henry Bowen and Walter Coles. Large uranium deposits close to the surface are virtually unknown in the U.S. east of the Mississippi River. And that may be the problem.

Now, however, with the US importing most of its uranium from Australia and Canada, mining firms and the landowners are interested in developing portions of the land holding, "Coles' Hill". Environmentalists in Virginia don't want the land developed for uranium extraction, despite the facts:

James Kelly, who directed the nuclear engineering program at the University of Virginia for many years, says that fears about uranium mining are wildly overblown. "It's an aesthetic nightmare, but otherwise safe in terms of releasing any significant radioactivity or pollution," he told me. "It would be ugly to look at, but from the perspective of any hazard I wouldn't mind if they mined across the street from me."

Views like these not only make biology teachers nervous, they also alarm those who have a stake in the state's reputation for scientific exploration. "Serious students will not come to study in our universities if Texas is labeled scientifically backward," said Dr. Dan Foster, former chairman of the department of medicine at the University of Texas Southwestern Medical Center at Dallas.

"I'm an orthodox Christian," Dr. Foster said, "and I don't want to say that Christianity is crazy." But science, not scripture, belongs in a classroom, he said. To allow views that undermine evolution, he said, "puts belief on the same level as scientific evidence."

Scientists believe the Earth's field comes from molten metal churning deep inside its core. If you could dig a deep hole, about 2,000 miles down, you would hit the outer core, which is probably made of liquid iron. That iron can conduct electricity. And if it flows in the right way, it can turn the Earth into what scientists call a dynamo, generating a self-sustaining magnetic field — in Earth's case, producing one pole up in Canada and another down in Antarctica.

Iron only melts at high temperatures, though, so Lathrop's team will fill his sphere with a different metal — sodium. Sodium becomes liquid at stovetop temperatures and conducts electricity well, but it's flammable. A sodium fire can't just be put out with water. Water can actually make things worse — Lathrop's team has disabled the sprinkler system.

Most companies are trying to figure out how to move jobs gracefully from one server to another, but Google is a few orders of magnitude above that challenge. It wants to be able to move jobs from one data center to another — automatically, at that.

The pixie dust powder itself doesn't regrow the missing tissue, it tricks the patient's body into doing that itself. All bodies have stem cells. As we are developing in our mothers' wombs, those stem cells grow our fingers, toes, organs — essentially our whole body. The stem cells stop doing that around birth, but they don't go away. The researchers believe the "pixie dust" can put those stem cells back to work growing new body parts.

But the biggest change was not Silicon Valley itself. Rather, the new technology created a range of mental playgrounds where the new geeks could display their cultural capital. The jock can shine on the football field, but the geeks can display their supple sensibilities and well-modulated emotions on their Facebook pages, blogs, text messages and Twitter feeds. Now there are armies of designers, researchers, media mavens and other cultural producers with a talent for whimsical self-mockery, arcane social references and late-night analysis.