This could be the perfect gift for the partner, who embarrasses you on the dance floor. Smart socks, which can teach to dance, may be the answer for anyone with two left feet.

    The socks have been developed as a running tool to help runners improve their skills. Thanks to the socks, users can accurately record not only how far and fast they run but also how well. It means the user maximizes their performance, and reduces damage to body and prevents hurt. The hi-tech socks are made of special fibers that watch the movements of your feet. They look, feel and can be washed like normal clothes.

    Sensors (传感器) record each movement and send it by an ankle transmitter (脚踝发射器) to a smart phone. Then a “virtual coach” application shows the information and can tell the user what they are doing wrong, and help to improve skill in any task with feet.

    The socks should be useful to athletes and weekend joggers. “People think running is so easy and of course everybody can do it but not necessarily safely and well,” Dr Davide Vigano said. A recent study showed that between 60 and 80 percent of runners got hurt per year. This is pretty much more than any other human activity. Researchers say the technology can also be developed to teach people how to dance, play sports such golf, or even to help to teach women to walk better in high heels.

    Mr. Vigano said, “People could all benefit from the idea. We have had interest from all sorts of sports, like skiing, football, cycling and golf. Anything where you have to use your feet can use it. It could even be put in high heels to help women walk in them safely.”

    Socks are just the start, and the technology could be used in gloves, hats and boots. The socks, anklet and software package, are expected to be sold for around £120, which will go on sale in March.

    Obama, Lady Gaga and Steve Jobs—what do they have in common? They are, of course, all Americans. And according to a survey by social networking site baidu. com, they all best illustrate(举例说明) the word “cool”.

    But just what does it mean to say someone is “cool”? Most would answer that it is something to do with being independent-minded and not following the crowd.

    Yale University art professor Robert Farris Thompson says that the term “cool” goes back to 15th century West African philosophy. “Cool” relates to ideas of grace under pressure.

    “In Africa, ” he writes, “coolness is a positive quality which combines calmness, silence, and life.”

    The modern idea of “cool” developed largely in the US in the period after World War II. “Post-war ‘cool' was in part an expression of war-weariness (厌战情绪), ... it went against the strict social rules of the time,” write sociologists Dick Pountain and David Robins in Cool Rules: Anatomy of an Attitude.

    But it was the American actor James Dean who became the symbol for “cool” in the hugely successful 1955 movie Rebel without a Cause. Dean plays a tough guy who disobeys his parents and the authorities. He always gets the girl, smokes cigarettes, wears a leather jacket and beats up bullies. In the movie, Dean showed what “cool” would mean to American young people for the next 60 years.

    Today the focus of “cool” has changed to athletics (体育运动) stars. Often in movies about schools, students gain popularity on the athletics field more than in the classroom. This can be seen quite clearly in movies like Varsity Blues and John Tucker Must Die.

    But many teenagers also think being smart is cool. Chess and other thinking games have been becoming more popular in schools.

    “Call it the Harry Potterization of America—a time when being smart is the new cool,” writes journalist Joe Sunnen.

    Women are friendly. They often share with others. But men are more competitive. They are trying to improve their social status. Why? Researchers have found it's all due to the hormone oxytocin (荷尔蒙催生素). Although known as the love hormone, it affects the sexes differently.

    Generally, people believe that the hormone oxytocin is let out in our body in various social situations and our body creates a large amount of it when falling in love or giving birth.

    But in a former experiment Professor Ryan found that the hormone is also let out in our body during a negative situation such as envy (嫉妒).

    Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relations, but in women it raises the ability to recognize friendship.

    Professor Ryan's recent experiment used 62 men and women aged 20 to 37.

    Half of the participants (参与者) received oxytocin. The other half received placebo (安慰剂).

    After a week, the two groups switched with participants. They went through the same steps with the other material.

    Following each treatment, they were shown some video pictures with different social behavior. Then they were asked to analyze the relations by answering some questions. The questions were about telling friendship from competition. And their answers should be based on gestures, body language and facial expressions.

    The results showed that, after treatment with oxytocin, men's ability to correctly recognize competitive relations improved, but in women it was the ability to correctly recognize friendship that got better.

    Professor Ryan thus concluded, “Our experiment proves that the hormone oxytocin can raise people's abilities to better tell apart different social behaviors.”

    The day will come when renewable energy such as wind, solar, geothermal and others replace fossil fuels as the major source of world energy. However, most analysts insist that this day will not arrive for many decades to come—certainly well past the middle of the century. Systems of fossil fuels have already been firmly set up, and it is too costly or impractical to replace the existing systems with renewables. But there are good reasons to believe that the transition (转变) to renewables will come much faster than previously thought.

    It is hardly surprising that many experts say we will see a relatively slow transition from fossil fuels to renewables, given what is known about previous energy changes of this sort. "Energy transitions take a long time," observed Vaclav Smil of the University of Manitoba in Scientific American. It took more than 50 years for coal to replace wood as the world's leading source of energy and another 50 years for oil to replace coal; the change from fossil fuels to renewables, he argued, is not likely to come any faster.

    Under ordinary circumstances, Smil's forecast would no doubt prove accurate. But these are not ordinary times. Growing concern over climate change is leading to increasingly strict controls on CO₂ and other greenhouse gas (GHG) emissions (排放), while the development in renewables technology is lowering their price and speeding their installation.

    There are, of course, many difficulties in the effective control of carbon emissions, as demonstrated by coal companies to block the introduction of new rules by the US Environmental Protection Agency. Nevertheless, it is impossible to dismiss the progress being made at the local and international levels to promote the use of renewables. The European Union (E. U), for example, is well on the way to achieving a 20% reduction in GHG emissions from 1990 levels by 2020, along with a 20% increase in the use of renewable energy.

    The transition to renewables will be faster due to dramatic improvements in the pricing and performance of such systems. As a result of the steady increases in the efficiency of wind and solar systems, together with the savings achieved through large-scale manufacture, the price of renewables is falling globally. With prices dropping this fast, solar energy is now proving competitive with fossil fuels for generating electricity in many areas.

    The change from fossil fuels to renewable energy will not come overnight, and it will not escape many setbacks. Nevertheless, renewables are likely to replace fossil fuels as the main source of electrical power well before mid-century.

 "A moth (飞蛾) to a flame" is often used to indicate an inescapable attraction, yet it is a strange example of animal behavior that continues to confuse people today. Scientists have raised a number of theories over the years to explain why. One holds that insects flying at night are following their nature to fly toward the brightest spot in their field of vision, which they mistake for the sky. Another suggests that insects are trying to warm themselves with the heat produced by the light. The most popular theory, though, is that insects are confusing lights with the moon or other celestial bodies (天体) that they normally use to navigate (导航).

To find out the real reason, the team carried out a first set of experiments in an insect flight area. The researchers used eight high-speed infrared (红外线) cameras equipped with motion-capture technologies to track 30 insects from three moth and two dragonfly species. They also flew lab-raised insects from six different insect orders that were too small for motion-capture technology, including fruit flies and honeybees, to make sure different insects all showed similar responses to light. Working with co-author Pablo Allen of the Council on International Educational Exchange in Monteverde, Costa Rica, the researchers put heavy cameras, lights and tripods in two field sites to gather behavioral data from insects in the wild.

The team was able to confirm that insects were not beelining to the light but rather circling it as they tilted (倾斜) in an attempt to turn their backs toward it. This behavior, known as a "dorsal light response", normally helps insects to remain in an unchanging path of flight that is properly lined to the horizon (地平线). Artificial light that arrives from a point source causes them to fly in unpredictable patterns as they try to turn their backs to what they are mistaking for the sky.

Now research might have finally solved the mystery mentioned first: artificial light confuses insects' ability to turn themselves to the horizon, confusing their sense of what is up and down and causing them to fly in circles.

A recent study has found that using wood for construction instead of concrete (混凝土) and steel can reduce emissions (排放). But Tim Searchinger at Princeton University says many of these studies are based on the false foundation that harvesting wood is carbon neutral (碳中和). "Only a small percentage of the wood gets into a timber (木料) product, and a part of that gets into a timber product that can replace concrete and steel in a building," he says. Efficiencies vary in different countries, but large amounts of a harvested tree are left to be divided into parts, used in short-lived products like paper or burned for energy, all of which generate emissions.

In a report for the World Resources Institute, Searchinger and his colleagues have modelled (塑造) how using more wood for construction would affect emissions between 2010 and 2050, accounting for the emissions from harvesting the wood. They considered various types of forests and parts of wood going towards construction. They also factored in the emissions savings from replacing concrete and steel.

Under some circumstances, the researchers found significant emissions reductions. But each case required what they considered an unrealistically high portion (份额) of the wood going towards construction, as well as rapid growth only seen in warmer places, like Brazil. In general, they found a large increase in global demand for wood would probably lead to rising emissions for decades. Accounting for emissions in this way, the researchers reported in a related paper that increasing forest harvests between 2010 and 2050 would add emissions equal to roughly 10 percent of total annual emissions.

Ali Amiri at Aalto University in Finland says the report's conclusions about emissions from rising demand are probably correct, but the story is different for wood we already harvest. "Boosting the efficiency of current harvests and using more wood for longer lived purposes than paper would cut emissions," he says. "We cannot just say we should stop using wood."