If humans were truly at home under the light of the moon and stars，we would go in darkness happily，the midnight world as visible to us as it is to the vast number of nocturnal(夜间活动的) species on this planet. Instead，we are diurnal creatures, with eyes adapted to living in the sun's light. This is a basic evolutionary fact, even though most of us don't think of ourselves as diurnal beings. Yet it's the only way to explain what we've done to the night: We've engineered it to  receive us by filling it with light.

    The benefits of this kind of engineering come with consequences 一 called light pollution 一 whose effects scientists are only now beginning to study. Light pollution is largely the result of bad  lighting design，which allows artificial light to shine outward and upward into the sky. III-designed lighting washes out the darkness of night and completely changes the light levels 一 and light  rhythms — to which many forms of life, including, ourselves, have adapted. Wherever human light spills into the natural world, some aspect or life is affected .

    In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze(霾) that mirrors our fear of the dark. We've grown so used to this orange haze that the original glory of an unlit nigh, - dark enough for the planet Venus to throw shadow on Earth, is wholly beyond our experience, beyond memory almost.

    We^'ve lit up the night as if it were an unoccupied country, when nothing could be further form the truth. Among mammals alone, the number of nocturnal species is astonishing, Light is a powerful biological force, and on many species it acts as a magnet(磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

    Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times righter than normal, throwing nearly every aspect of their behavior out of joint including most other creatures ,we do need darkness .Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

    Living in a glare of our making,we have cut ourselves off from our evolutionary and cultural heritage—the light of the stars and the rhythms of day and night .In a very real sense light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way—the edge of our galaxy arching overhead.

    The Coolest Inventions

    An Oceans Vacuum(吸尘器)

    There's a collection of plastic trash in the middle of the Pacific Ocean. It's bigger than Texas and growing. The way to clean it up now is to catch it with nets. That is both costly and slow. Instead, the Ocean Cleanup Project proposes a 62-mile-long floating barrier that would use natural currents to trap trash. If next year's trials succeed, a full cleanup operation would aim to start in 2020. It could reduce the trash by 42% over 10 years.

    Easy-On Shoes

    In 2012, Matthew Walzer, a high school student with a disability, sent a note to Nike. “My dream is to go to college,” he wrote, “without having to worry about someone coming to tie my shoes every day.” Nike assigned a design team to the challenge. This year, they came out with their solution: the FlyEase. The basketball shoe can be fastened with one hand. A pair of Nike FlyEase shoes sells for $130.

    An Airport for Drones (无人机)

    As Amazon, Google, and others get ready for drone delivery service, there is one big question: What kinds of home bases will their drones have? Rwanda, in Africa, may have the answer. There, workers will soon start work on three “drone ports”. The goals is to make it easier to transport food, medical supplies, electronics, and other goods through the hilly countryside. Construction is set to be completed in 2020.

    Native to America, the cane toad (癞蛤蟆) was introduced to Northern Queensland 70 years ago to control sugarcane beetles (甘蔗害虫). The toads failed in that duty but spread across Queensland and into neighboring northern areas.

    Now it calmly invades(侵略) the stats of Western Australia and New South Wales ( NSW). NSW wildlife experts fear the amphibians － which have poisonous backs that kill hungry predators (食肉动物) 一will have a terrible effect on native animals.

    Those fears may be about to be realized. Australia's leading government research body, the Commonwealth Science and Industry Research Organization (CSIRO), forecasts that a rise in average temperatures will make NSW an ideal living place for the cane toads.

    Tony Robinson, head of CSIRO's Wildlife, Pests, and Diseases Program, said climate change is increasing the amount of suitable living place for the cane toads.

    “With climate change, the cane toads might go down as far as Sydney and some areas of Western Australia,” Robinson said.

Recent estimates put the pace of the toads' westward march at nearly 17 miles (27 kilometers) a year and slightly slower from north to south.

    “More southerly (南部的) cities, such as Melbourne and Adelaide, would likely remain too cold and dry to ever suit the toads,” Robinson noted, “but Perth could expect cane toads in five years' time.”

    Sydney could see their arrival in the next 20 years.

    Robinson said there is no method that will keep the toads under control.

    The cane toads already cover at least half of Queensland and most of the northern country. The toads are believed to number in the billions.

    A Venezuelan virus was tried in the 1990s but had to be given up after it was found to also kill native frog species. Scientists and governmental bodies believe a national approach is needed.

    The main threat the toads cause to species such as dingoes, and crocodiles is the poison contained in glands (腺) on each of their shoulders. The poison sprays out when the toads are threatened or handled roughly. The poison is made up of 14 different chemicals.

    Cane toads also compete, and usually win, the hunt for food and living space.

    "”If the government and other states combine resources, I believe we can achieve a very practical biological-control research program,” Bums said.

    People typically wash their hands seven times a day in the United States, but they do it at a far higher temperature than is necessary to kill germs, a new study says. The energy waste is equivalent to the fuel use of a small country. Amanda R. Carrico, a research assistant professor at the Vanderbilt Institute for Energy and Environment in Tennessee, told National Geographic that hand washing is often “a case where people act in ways that they think are in their best interest, but they in fact have inaccurate beliefs or outdated perceptions.”

    Carrico said, “It's certainly true that heat kills bacteria, but if you were going to use hot water to kill them it would have to be a way too hot for you to tolerate.”

Carrico said that after a review of the scientific literature, her team found “no evidence that using hot water that a person could stand would have any benefit in killing bacteria.” Even water as cold as 40°F (4.4℃) appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed(冲洗)and dried properly.

    Using hot water to wash hands is therefore unnecessary, as well as wasteful, Carrico said, particularly when it comes to the environment. According to her research, people use warm or hot water 64 percent of the time when they wash their hands. Using that number, Carrico's team calculated a significant impact on the planet.

    “Although the choice of water temperature during a single hand wash may appear unimportant, when multiplied by the nearly 800 billion hand washes performed by Americans each year, this practice results in more than 6 million metric tons of CO2 equivalent emissions annually,” she said.

    The researchers published their results in the July 2013 issue of International Journal of Consumer Studies. They recommended washing with water that is at a “comfortable” temperature, which they noted may be warmer in cold months and cooler in hot ones.

There has been tremendous concern recently over misinformation on social media. This concern is quite justifiable, as the consequences of believing false information are greatly affecting the individual and collective health.

Many people tend to fall for misinformation they encounter online. There is one influential explanation for this phenomenon. As the thinking goes, someone, who possesses very limited skills in finding and consuming digital content, creating digital content, and communicating it, is likely to have difficulty recognizing false information and thus is more vulnerable to believing false information. As a result, these less digitally literate people may play a significant part in the spread of misinformation.

This argument sounds perfectly plausible. Yet very little research has actually investigated the link between digital literacy and the vulnerability to believing false information. There's even less understanding of the potential link between digital literacy and what people share on social media. A group of MIT researchers explored these potential associations by surveying 1,341 Americans.

In the experiment, the researchers first showed the participants two dozen news headlines about politics, half of which were accurate, and half of which were false. In the second phase, they included a series of tests: having the participants report their familiarity with various Internet-related terms and answer questions about how social media platforms decide what to show in their newsfeeds. At last, the participants were required to assess the accuracy of a set of headlines and point out their likelihood of sharing each headline on social media.

The researchers found "clear evidence" that digital literacy was a strong predictor of accuracy discernment (识别能力). However, the results were "strikingly different" regarding sharing discernment. Digitally literate subjects were just as likely to share inaccurate information. Most surprisingly, even people with high digital literacy were not immune from clicking "share" for false news.

This sounds odd. Although most people don't want to spread misinformation, social media is distracting: people are scrolling quickly, and their attention is drawn to social validation (社会认知度), such as how many likes their posts will get. So make sure a certain post is accurate before you click the "share" button.