AT the Zhuhai air show in southeastern China last November, Chinese companies startled some Americans by unveiling 25 different models of remotely controlled aircraft and showing video animation of a missile-armed drone taking out an armored vehicle and attacking a United States aircraft carrier.

The presentation appeared to be more marketing hype than military threat; the event is China’s biggest aviation market, drawing both Chinese and foreign military buyers. But it was stark evidence that the United States’ near monopoly on armed drones was coming to an end, with far-reaching consequences for American security, international law and the future of warfare.

In 2006, the artist and computer scientist Jaron Lanier published an incisive, groundbreaking and highly controversial essay about “digital Maoism” — about the downside of online collectivism, and the enshrinement by Web 2.0 enthusiasts of the “wisdom of the crowd.” In that manifesto Mr. Lanier argued that design (or ratification) by committee often does not result in the best product, and that the new collectivist ethos — embodied by everything from Wikipedia to “American Idol” to Google searches — diminishes the importance and uniqueness of the individual voice, and that the “hive mind” can easily lead to mob rule.

Once again, The Times Magazine looks back on the past year from our favored perch: ideas. Like a magpie building its nest, we have hunted eclectically, though not without discrimination, for noteworthy notions of 2009 — the twigs and sticks and shiny paper scraps of human ingenuity, which, when collected and woven together, form a sort of cognitive shelter, in which the curious mind can incubate, hatch and feather. Unlike birds, we can also alphabetize. And so we hereby present, from A to Z, the most clever, important, silly and just plain weird innovations we carried back from all corners of the thinking world. To offer a nonalphabetical option for navigating the entries, this year we have attached tags to each item indicating subject matter. We hope you enjoy.

The first alarms about the sudden widespread disappearance of honeybees came in late 2006, and the phenomenon soon had a name: colony collapse disorder. In the two years that followed, about one-third of bee colonies vanished, while researchers toiled to figure out what was causing the collapse. A study published last week in the Proceedings of the National Academy of Sciences surmises that there may not be a single pathogen involved but a collection of culprits. What have entomologists and beekeepers learned in the last few years of dealing with the crisis? We asked May R. Berenbaum, an author of the study, and other experts for an update.

The American Time Use Survey asks thousands of American residents to recall every minute of a day. Here is how people over age 15 spent their time in 2008.

One of the most influential economic papers of the postwar era was Kenneth Arrow’s Uncertainty and the welfare economics of health care, which demonstrated — decisively, I and many others believe — that health care can’t be marketed like bread or TVs. Let me offer my own version of Arrow’s argument.

research also seems to support Ms. Boyd’s contention that social media “mirrors and magnifies” our social divisions, rather than removes them. “We can use technology as a tool to connect with people, but we can’t assume that it will eliminate all of the serious issues we have to face in this country,” Ms. Boyd said at PDF. “Pervasive social stratification is being reified in a new era.

The Euphrates is drying up. Strangled by the water policies of Iraq’s neighbors, Turkey and Syria; a two-year drought; and years of misuse by Iraq and its farmers, the river is significantly smaller than it was just a few years ago. Some officials worry that it could soon be half of what it is now. The shrinking of the Euphrates, a river so crucial to the birth of civilization that the Book of Revelation prophesied its drying up as a sign of the end times, has decimated farms along its banks, has left fishermen impoverished and has depleted riverside towns as farmers flee to the cities looking for work.

While attitudes toward privacy can appear paradoxical, the seeming contradiction is really about something else: control. When people bare their bodies on Facebook or their souls in the digital confessional of Google’s search engine, they feel as if they are in charge. Not so, when the private embarrassments come to light unexpectedly. The subtle relationship between privacy and control has complicated things for marketers, too. Advertisers talk about having to move away from analog-era “push” tactics and embracing digital-age “pull” strategies, in which consumers are enticed into seeking information about a product or brand, rather than having ads foisted on them.

Today, at the Semantic Technology Conference, Rob Larson and Evan Sandhaus of the New York Times announced together that the Times will soon be publishing its copious index as Linked Data.

That’s why we need a climate bailout along with our economic bailout. Hal Harvey is the C.E.O. of a new $1 billion foundation, ClimateWorks, set up to accelerate the policy changes that can avoid climate catastrophe by taking climate policies from where they are working the best to the places where they are needed the most. “There are five policies that can help us win the energy-climate battle, and each has been proven somewhere,” Harvey explained. First...

Have a file up on the Mac’s screen and want to know where it’s stored on the hard drive? Hold down the Command key (the one with the Apple logo next to the space bar) and click on the file name in the title bar to see the full path.

After a year of watching adults engage in devastating recklessness in the financial markets and depressing fecklessness in the global climate talks, it’s refreshing to know that the world keeps minting idealistic young people who are not waiting for governments to act, but are starting their own projects and driving innovation.

Kamal Meattle reported the results of his efforts to fill an office building with plants, in an effort to reduce headache, asthma, and other productivity-sapping aliments in thickly polluted India. After researching NASA documents, he concluded that a set of three particular common, waist-high houseplants—areca palm, Mother-in-Law’s Tongue, and Money Plant—could be combined to scrub the air of carbon dioxide, formaldehyde and other pollutants. At about four plants per occupant (1200 plants in all), the building’s air freshened considerably, and the health and productivity results were staggering. Eye irritation dropped by 52 percent, lower respiratory symptoms by 34 percent, headaches by 24 percent and asthma by 9 percent. There were fewer sick days, employee productivity increased, and energy costs dropped by 15 percent.

Collective intelligence could make it possible for insurance companies, for example, to use behavioral data to covertly identify people suffering from a particular disease and deny them insurance coverage. Similarly, the government or law enforcement agencies could identify members of a protest group by tracking social networks revealed by the new technology. “There are so many uses for this technology — from marketing to war fighting — that I can’t imagine it not pervading our lives in just the next few years,” says Steve Steinberg, a computer scientist who works for an investment firm in New York.

A group of Canadian human-rights activists and computer security researchers has discovered a huge surveillance system in China that monitors and archives certain Internet text conversations that include politically charged words.

"Q. Is it possible to install Ubuntu Linux on my Windows XP computer so I can have both systems on one machine — without having to reinstall Windows?" - WTF, the NY Times is answering questions abotu Ubuntu?

Photoshopping can alter our media reality. However: "change the caption and you change the meaning of the photographs. You don’t need Photoshop. That’s the disturbing part. Captions do the heavy lifting as far as deception is concerned. The pictures merely provide the window-dressing. The unending series of errors engendered by falsely captioned photographs are rarely remarked on."

Europe's demographic developments will strongly influence the future of the continent.

Why do Americans spend so much time and money performing menial tasks when they don't have to? What's with all the knitting, gardening, and — as the Census Bureau dubs it — "cooking for fun"? Why do we fill our hours with leisure activities that look

Isn’t it puzzling that so many middle-aged Americans are spending so much of their time and money performing menial labors when they don’t have to? Just as the radio and phonograph proved to be powerful substitutes for the piano, the forces of technol