The town of Green Bank, West Virginia, is the site of the largest radio telescope in the world, so Internet connections and anything else that can create electromagnetic(电磁的) waves, such as smart phones and microwave ovens, are banned.

    Green Bank is frozen in time, somewhere in the 1950s, because there's a 33,000-square-kilometer zone of silence due to the telescope. Cell phone towers are forbidden.

    The closer you get to the telescope, the greater the restrictions. There's a 16-kilometer radius(半径) around the observatory where radio-controlled items, even toys, cannot be used.

    Telescope employees even work in a special room that blocks electromagnetic waves from leaving it. “Here imagine a submarine(潜艇), water cannot get inside, and so this room is an electric submarine. No electromagnetic waves can get into this room, just as you can't go beyond it,” Michael Holstein, an observatory officer, said.

    The size of a football field, the telescope is so sensitive that it could pick up signals sent from an alien world. And scientists can't wait for that to happen.

    “All the signals that we now receive with the help of telescopes are signals that come from cosmic objects — stars, galaxies. We have not yet received anything from intelligent civilizations,” scientist Richard Lynch said.

    Local people respect the work of the scientists. “Yes, we are different. Many would say that we live the old-fashioned way, in the past. But for us, it's just the way of life that we have always lived,” Sherry said.

    “When we want to meet friends, we just call each other on a wire phone. And instead of sitting in front of your screen, we talk, we go fishing, to the mountains,” resident Sherry said.

    For the latest news, residents read the weekly local newspaper. When she's looking for a phone number, Sherry reaches for the phone book.

    And instead of Facebook, Sherry enjoys daily conversations with her customers. In this town, everyone knows each other and communication is face to face.

    Forcing waiters and waitresses to survive on tips from customers rather than normal wages is a pointless, crude, and unique American custom that, in the past several years, a handful of progressive restaurant owners have attempted to do away with. Danny Meyer, CEO of Union Square Hospitality Group, is about to join their ranks and has announced that he plans to gradually stop tipping at the company's 13 restaurants.

    What, exactly, is wrong with tipping? As Brian Palmer has explained, more or less it's everything. To start, leaving a waiter's pay in the hands of customers has a feeling of classism (阶级歧视). And in theory, handing restaurant customers the power to tip is at least supposed to motivate better service. This fails in practice because humans turn out to be pretty arbitrary (随意的) about their tipping behavior. Research has shown that the amount diners tip has very little to do with their level of satisfaction. All of this doesn't encourage waiters and waitresses to do anything but turn over as many tables as possible.

    Tipping is also very unfair to kitchen staff. The law allows restaurants to divide tips between front-of-the-house workers like waiters, hosts, hostesses, and bartenders (调酒师), but not cooks. This creates a system in which the people serving the food in a restaurant can earn more than the people preparing it.

    One of the most fascinating parts of Meyer's move is that, unlike some restaurant owners who have taken an anti-tipping stand, he won't simply add a standard extra charge to diners' bills. Rather, Union Square Hospitality Group means to raise menu prices enough to fully cover the cost of a meal. If Meyer manages to move away from tipping at all without hurting his profits, it would almost certainly set the stage for others to follow suit.

    When most of us look at our hands, we might notice that we need to clean, or stop biting our fingernails, and that's about it. But if you ask a doctor, he can see a whole lot more. Everything from poor diet and stress to serious kidney (肾) problems can be revealed by a glance at your fingernails.

    There are about 30 different nail signs that can be associated with medical issues, though may indicate more than one problem, according to Dr. Amy Derick, a clinical instructor of dermatology at Northwestern University.

    Here are five of the things a doctor can tell about your health based on your fingernails.

    ⒈People who aren't eating well and lack vitamin or dietary may have thinner than normal nails, which are more likely to break.

    ⒉Horizontal lines are associated with serious physical stress. They frequently occur in people who have gone through chemotherapy(化疗).They can also occur after some illnesses, injuries, or with severe malnourishment(营养不良).Interestingly, there may be an altitude connection too. They've also been found in people who dove 1,000 feet and others who participated in an Everest exploration.

    ⒊Vertical lines, however, are generally not such a big deal. Some people are more genetically prone to them than others, but they're commonly associated with aging.

    ⒋When people lack iron, their nails can turn spoon-like. Instead of curving down and covering the finger normally, they'll start to rise up on the sides and front, like the part of a spoon that holds liquid.

    ⒌Kidney and liver problems can create “half-and-half nails”, where one part of the nail is white and the other part dark or pink, according to Derick.

    Doctors note that because disease diagnosis is complex and some symptoms can be associated with different diseases, you should always see a medical professional if you are concerned about something you notice.

    Steven Spielberg's 2002 science-fiction thriller Minority Report produced a world where computers could read minds and predict the future. It seemed fanciful at the time, but fantasy is edging closer to fact.

    On Jan 31, a team of scientists at UC Berkeley, led by Robert Knight programmed computers to decode (破译) brain waves and replay them as words. Five months earlier, another group of Berkeley scientists showed their colleagues short movies and used computers to play back in color what people saw.

    These experiments are a big advance from 2006, when a French scientist first replayed images from a human mind, a black-and-white checkerboard pattern. The possibilities are great: a disabled person could" speak"; doctors could access the mind of a patient who fainted; you could rewatch your dreams on an iPad. There are, of course, equally dark side, such as the involuntary take out of information from the brain.

    In spite of these breakthroughs, Jack Gallant, the neuroscientist who led the first Berkeley team, says current technology for decoding brain activity is still "relatively primitive". The field is held back by its poor machinery, in particular the FMRI.

    "Eventually," says Gallant, "someone will invent a decoding machine you can wear as a hat." Such an advance into the human mind, he says, might take 30 years.

    Still, the recent advances at Berkeley offer small answers, which scientists can use to begin unlocking the secrets of memory and consciousness.

    There have always been a lot of commonly believed but false ideas about being fat and doing exercise. Some people believe that they can't help putting on weight as they get older, while others hold that if they stop exercising, their muscles will turn into fat. Here are some more myths:

I'll never lose weight — I come from a fat family.

Wrong! While we can't change the body type we are born with, we can't blame our genes for making us fat. There's plenty of evidence that fatness runs in families, and the main reason is that they share the same habits of eating too much and exercise too little.

    I am fat because I burn calories slowly.

Wrong! Fatness is not caused by a slow metabolism (新陈代谢). If fact, although fat people consume more energy that slim people, they also fail to realize how much they eat! Keeping a diary can help you work out your daily food intake more accurately.

    Exercise is boring.

    Wrong! Anything will become boring if you do it many times. The key is to develop a balanced and varied program that's fun as well as progressive. If you enjoy a Sunday walk, take a different route. If you do Yoga, try a tai chi class. If you like swimming, set yourself a distance or time challenge.

    No pain, no gain.

    Wrong! Exercise is not meant to hurt. Indeed, pain is your body telling you something's wrong, and continuing to exercise could lead to serious injury. You may experience mild discomfort as you begin to exercise regularly, but this your body adapting to the positive changes in your lifestyle and the aches should disappear relatively quickly. If you don't, rest and seek medical advice.

    Pangolins (穿山甲) are strange-looking creatures, covered with hard scales (鳞). They can roll up into a ball to protect themselves from enemies and have tongues that are longer than their bodies.

    Pangolins have recently become the focus of Chinese people. A screenshot (截屏) of a micro blog post showing some people eating pangolins at a feast spread. A few days later, people were angered again by pictures showing people eating protected animals, including pangolins.

    Yet this is only the tip of the iceberg. Many more pangolins have been hunted or killed. According to the International Union for Conservation of Nature (IUCN), more than 1 million of them have been killed or sold in the last 10 years. It also said that they are the most illegally traded mammals in the world. In September 2016, the IUCN added the pangolin to the world's "endangered animals list". They are now more endangered than pandas.

    A growing trade of their scales and meat is the main reason for their decline in numbers. Many people in Asia and Africa consider pangolin meat is delicious. Some people even think pangolin scales have medical qualities. However, their scales are made of keratin (角蛋白), the same material human fingernails are made of.

    Luckily, the situation is getting better. World Pangolin Day is on the third Saturday of February each year. It's a day to help people know more about pangolins. The government now stops anyone from buying and eating pangolins in China. Breaking this law is regarded as a crime. The trade of pangolins across the world is also not allowed, according to the Convention on Trade in Endangered Species of Wild Fauna and Flora.