For a long time, the traditional method of identifying liars was to watch their body language, including facial expressions.

    What if the person appears to be nervous? Is the person unable to look me in the eye? Is he or she look around the room? What about other nervous movements, such as fidgeting（坐立不安）or shifting from side to side? Many people—from parents to police officers and airport security personnel—depend on this method. But does a person's body and face reveal the truth? Not according to a new study.

    Talking, it seems, is the best way to smoke out a liar. That is what researchers in the United Kingdom found out recently. Their investigation took place at one place where lying can get you into big trouble—an airport.

    The researchers asked volunteers to pretend they were real passengers and then lie to airport security agents. Some of the agents used spoke conversation-based methods to question these make-believe passengers. Others depended instead on the person's body language, like lack of eye contact and showing signs of nervousness. The agents talking with the passengers were 20 times more likely to catch the liars. The study found that these conversation-based techniques can help you recognize when a person is lying to you. Like many methods, this conversation method has a name. It is called Controlled Cognitive Engagement or CCE, for short.

    The British government partly financed this study. The American Psychological (APA) published the findings. Body language cannot be trusted. Using body language and facial expressions to catch someone in a lie is really hard. And it only works, seemingly, by chance.

    Thomas Ormerod is the head of the School of Psychology at the University of Sussex in England. On the APA website, he reported that the “suspicious-signs method”—or using body language—“almost completely fails” in finding lies.

    Tulou, the special residential architecture of Fujian Province was included on the UNESCO's World Heritage List during the 32nd session of the World Heritage Committee in Quebec, Canada.

    In the fourth century, Han Chinese living in the Central Plains area began to migrate south, gradually gathering in Fujian and forming the Hakka communities. As a defence against enemies, the Hakkas chose to live in compact (紧凑的) communities, and the tulou was their preferred houses. Tens of thousands of such earthen structures were constructed in Fujian Province.

    Most tulous are to be found in the valleys, surrounded by high mountains, and some are in the depths of the great mountains. Most are three to four storeys high, and look like circular blockhouses (堡垒). Rooms on the first floor are used as kitchens, rooms on the second floor are used as barns (谷仓), and rooms on the third and fourth floors are for bedrooms and living rooms. For defensive purposes, the rooms on the first floor have no windows.

    Raw materials for the tulou were obtained locally. Their main building material was a mixture of clay, sand, lime and water, and egg whites, brown sugar and rice water were added as adhesive agents (粘合剂). It was then mixed to form the walls. Once they dried, the walls were so hard that driving a nail into them would have been difficult. Fir branches, which are extremely strong and do not rot, were used to strengthen them, and many centuries later they have remained their original look.

    Tulous are located in a region where earthquakes happen frequently, and their circular construction helps them resist the regular shocks.

    The proven design even inspired one famous Peruvian architect, who paid several visits to Yongding, to build a tulou back home. Not long after, an earthquake struck only 10 kilometers away, and while all the houses around the earthen building fell down, his tulou remained.

D

    We may think we're a culture that gets rid of our worn technology at the first sight of something shiny and new, but a new study shows that we keep using our old devices (装置) well after they go out of style. That's bad news for the environment – and our wallets – as these outdated devices consume much more energy than the newer ones that do the same things.

    To figure out how much power these devices are using, Callie Babbitt and her colleagues at the Rochester Institute of Technology in New York tracked the environmental costs for each product throughout its life – from when its minerals are mined to when we stop using the device. This method provided a readout for how home energy use evolved since the early 1990s. Devices were grouped by generation. Desktop computers, basic mobile phones, and box-set TVs defined 1992. Digital cameras arrived on the scene in 1997. And MP3 players, smart phones, and LCD TVs entered homes in 2002, before tablets and e-readers showed up in 2007.

    As we accumulated more devices, however, we didn't throw out our old ones."The Living-room television is replaced and gets planted in the kid's room, and suddenly one day, you have a TV in every room of the house," said one researcher. The average number of electronic devices rose from four per household in 1992 to 13 in 2007. We're not just keeping these old devices-we continue to use them. According to the analysis of Babbitt's team, old desktop monitors and box TV's with cathode ray tubes are the worst devices with their energy consumption and contribution to greenhouse gas emissions(排放) more than doubling during the 1992 to 2007 window.

    So what's the solution(解决方案)?The team's data only went up to 2007, but the researchers also explored what would happen if consumers replaced old products with new electronics that serve more than one function, such as a tablet for word processing and TV viewing. They found that more on-demand entertainment viewing on tables instead of TVs and desktop computers could cut energy consumption by 44%.

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components,” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing the components together. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, and then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Cameron is no ordinary dog, and not just because he was born on Valentine's Day. To Maggie, a first grader at Burgundy Farm Country Day School, the dog who spends most days on campus is more like a friend. When Cameron is near, Maggie feels "really, really, happy," she said, "I feel safe around him, she added." "He'll lie down and ask me to scratch his tummy," she explained, because Cameron likes Maggie.

    Cameron is one of a handful of dogs at Burgundy, a K-8 private day school in Alexandria, Virginia. Dogs started showing up there when the head of school, Jeff Sindler, brought his clumsy Labrador, Luke, to the main office building where Sindler works. After Luke died, Sindler adopted Cameron and brought him to campus, too, where the dog Maggie described as really cute" became a school favorite.

    "They don't care if you are good at basketball or a great reader, or popular," Sindler said. "They just want to be loved—equal opportunity," he added. "Cameron and the other dogs on campus—are always fastened with a rope and with their owner—go a long way toward improving students' social and emotional well-being," he said. They reduce tension and ease anxiety, and inspire happy feelings from students.

    "They bring out some important emotions/' he said, "and are especially helpful to children and adults who struggle in social communication, Children often came from challenging backgrounds: many lived in poverty, or had to travel through dangerous neighborhoods to get to school, or shared a too-crowded home. When these emotionally needy children met the dogs, they relaxed and were more prepared to learn.

    Just as important, dogs on school grounds set a positive, welcoming tone. They help preserve the school climate that is accepting, supportive and curious・"Dogs are one way to hold on to Sindler said, adding that "schools should be fun and exciting, and dogs can be a big part of that."

    For Sindler, including Cameron was all part of an effort to create a safe environment where learning could flourish.

Going out guide

    R&B: Melanie Fiona

    Known for such songs as "It Kills Me" and "This Time," R&B singer Melanie Fiona made her first musical album(唱片) in 2009 with "The Bridge" and followed it up with "The MF Life" in 2012. A new album, "Next Train," is planned to drop this year.

    8 pm, Feb. 13. Howard Theatre. 202-803-2899. $ 30—$ 59. 99.

    Ballet: John Cranko's "Romeo & Juliet"

    Celebrated South African choreographer (编舞者) John Cranko created the dance inspired by Shakespeare's lovers with a score by Sergei Prokofiev. The production was first performed in the United States in 1969 and returns to the Kennedy Center under the artistic direction of Julie Kent.

    Feb. 14 — 18. Kennedy Genter. 202-467-4600. $ 25— $ 160.

Exhibit(展览): "Brand New: Art and Commodity (商品) in the 1980s"

    This exhibit shows the commodification of art in the 1980s, when trade, art and entertainment became unclear. The exhibit shows works by 68 artists, including Jeff Koons, Barbara Kruger and Julia Wachtel.

    Feb. 14 through May 13. Hirshhorn Museum and Sculpture Garden. 202-633-1000. Free

    R&B: Valentine's Love Jam

    R&E artists are known for some of our most beloved(喜爱的) love songs, and the performers lined up for this show are no exception. Singer-songwriters Tyrese ("Sweet Lady") and Joe ("I Wanna Know") join forces with SWV ("Weak") ,Dru Hill ("Beauty") and Next ("Wifey") for this show.

    8 p. m., Feb. 17. EagleBank Arena. 703-493-4000. $ 59—$ 99.