When we can see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we come to see how important our eyes are.

    People who are nearsighted can only see things that are very close to their eyes. Many people who do a lot of close work, such as writing, reading and sewing（缝纫）, become nearsighted. Then they have to wear glasses in order to see distant things clearly.

    People who are farsighted（远视的）suffer from just the opposite problem. They can see things that are far away, but they have difficulty reading a book unless they hold it at arm's length. If they want to do much reading, they must get glasses too.

    Other people do not see clearly because their eyes are not exactly the right shape. This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts（白内障）. Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.

    When night falls, colors become fainter to the eye and finally disappear. After your eyes have grown used to the dark, you can see better if you use the sides of your eyes rather than the centers. Sometimes, after dark, you see a small thing to one side of you, which seems to disappear if you turn you head in its direction. This is because when you turn your head, you are looking at the thing too directly. Men on guard duty sometimes think they see something moving to one side of them. When they turn to look straight at it, they cannot see it any more, and they believe they were mistaken. However, this mistake happens because the center of the eye, which is very sensitive(敏感的) in daylight, is not as sensitive as the sides of the eyes after dark.

    It isn't often that zookeepers call on craftsman for help. But cold weather at the Wildlife SOS Elephant Conservation and Care Center in northern India was putting elephants at risk. So the center's staff joined forces with locals to find a creative way to keep the animals warm. Now the elephants are stepping out in style, thanks to volunteers who made use of their crafting talents to knit (编织) enormous sweaters to protect the animals.

    Wildlife SOS is a conservation group that has been taking action against animal cruelty and saving wildlife in danger since 1995. Their Elephant Conservation and Care Center is devoted to rescuing the large animals from abuse in circuses, illegal dealing, and other circumstances where they have been ignored or treated with extreme cruelty. There are currently 20 elephants living at the center, and the staff hope to take in 50 more of the creatures this year.

    Because most of the elephants housed at the center are recovering from injuries or are elderly and weak, they are particularly vulnerable to cold temperatures. When the staff reported near-freezing nighttime temperatures in the winter, volunteers from surrounding villages began knitting enormous sweaters to keep the elephants warm. The monumental sweaters are large enough to cover the elephants' backs, bellies, and legs.

    Making the sweaters is a big undertaking—each one takes approximately four weeks to create, with volunteers working together on the enormous clothes. Local villagers have already made sweaters for three of the 23 elephants on their own, each with a unique pattern and color.

    If you're also looking for something happy and heartwarming, this is it. The elephants usually wear blankets to keep warm during colder months and you can purchase a blanket for an elephant on the Wildlife SOS website.

    The TED speaker series features “ideas worth spreading.” With over 1,400 to choose from, we've selected a few that are perfect for students.

    Larry Smith: Why You Will Fail to Have a Great Career

    We humans have an excellent ability to make excuses for ourselves. Larry Smith, a professor of economics at the University of Waterloo in Canada, tells us why most of us will fail to have a great career. But there is a way out— if you try to pursue your passion.  

    Andy Puddicombe: All It takes Is 10 Mindful Minutes

    Between dance team, volunteering and—oh, right—lectures, your life's crazy factor is about to go way up. In this entertaining and informative talk, mindfulness expert Andy Puddicombe teaches us how to be “healthier, more mindful and less distracted” by taking just 10 minutes out of the day to be more present.

    Shane Koyczan: To This DAY for the Bullied and Beautiful

    This talk is sure to stay with you. Shane Koyczan's “To this DAY” is an affecting spoken-word poem about bullying and being different that gained over 10 million views on YouTube. In this talk, Koyczan gives a live reading of the poem, along with some stories about his background.

    Susan Cain: The power of Introverts (性格内向者)

    Does a cup of tea and a good book sound like a perfect Friday night? In this personal talk, Susan Cain argues that introverts have important talents and abilities. Our culture may value being social and outgoing, but the world needs all kinds.

Dark Sky Parks around the World

    Warrumbungle National Park

    Situated in the central west slopes of New South Wales is Australia's only dark sky park, Warrumbungle. The park has served as a dark sky park since July 2016. Its crystal-clear night skies and high altitude make it a natural, educational, and astronomical heritage site in the southern half of the earth. Tourists can use Australia's largest optical telescope within the park boundaries to view the auroras (极光), the Milky Way, and faint shooting stars.

    Sark

    Sark is a Channel Island near the coast of Normandy under the protection of the UK. It was the World's First Dark Sky Island set up in January 2011. Its historical and cultural blend attracts over 40,000 tourists annually. With no motor vehicles and public lighting on the island, there is an exceptional view of the dark skies. A rich Milky Way is visible in the dark night skies from the shores of the island.

    Pic du Midi de Bigorre

    Pic du Midi de Bigorre in France was designated as a dark sky park in December 2013 making it the second largest dark sky park in the world. The park covers 3. 112 square kilometers spread across the Pyrenees National Park and UNESCO's World Heritage site, Pyrenees-Mont Perdu. The park attracts over one hundred star watchers every year. The Observatory Midi-Pyrenees, which was built in 1870, is one of the world's highest museums at a height of 2,877 meters above sea level.

    Ramon Crater/Makhtesh Ramon

    Ramon Crater is a unique 1,100-square-kilometer nature reserve located in the Negev Desert in Israel. In 2017, the Ramon Crater became the first designated dark sky park in the Middle East. Its location, rough climate, and forbidding landscape that are characteristic of the Negev have largely defeated historical attempts for human settlement, making it a great place to view the night skies. Stargazers usually camp in the desert to have an uninterrupted view of the stars, planets, and the Milky Way.

Smart Cameras to Help You Take Better Photos

    Google Clips

    One of the latest to launch is Google Clips. It is designed to be put somewhere in a room to take pictures by itself. It can also be attached to an object or a person's clothing.

    Google says machine learning helps the camera choose the best times and situations for taking pictures and videos. Interested buyers can join a waiting list to be informed when it is on the market.

    GoPro Hero

    GoPro also uses machine learning to power its QuikStories characteristic. This tool takes existing photos and videos and automatically creates a finished video piece, complete with music and effects.

    Snap Spectacles

    Messaging app Snapchat sells a pair of sunglasses with a built-in camera that can record short videos with the push of a button. Snap Inc. says the product, called Spectacles, is designed to "catch the moment, without taking you out of it."

    The glasses can record short video clips that can be shared with Snapchat users. Snap Inc. has started selling its Spectacles sunglasses online in the United States.

    Apple iPhone X

    Apple's new iPhone X is being launched with its new Face ID system that it says will unlock the phone just by having the user look at it. This replaces the Touch ID on previous ones that used a fingerprint to unlock the phone.

    Apple says the system works by projecting more than 30,000 dots on the face to create a kind of map. Apple says its facial recognition is even secure enough to allow payments through its Apple Pay service.

    Like many other people who speak more than one language, I often have the sense that I'm a slightly different person in each of my languages­more confident in English, more relaxed in French, more emotional in Czech. Is it possible that, along with these differences, my moral compass (指南针) also points in somewhat different directions depending on the language I'm using at the time?

    Psychologists who study moral judgments have become very interested in this question. The findings of several recent studies suggest that when people are faced with moral dilemmas (困境), they do indeed respond differently when considering them in a foreign language than when using their native tongue.

    In a 2014 paper led by Albert Costa  volunteers were presented with a moral dilemma known as the "trolley problem": imagine that a runaway trolley is moving quickly toward a group of five people standing on the tracks, unable to move. You are next to a switch that can move the trolley to a different set of tracks, therefore sparing the five people, but resulting in the death of one who is standing on the side tracks. Do you pull the switch?

    Most people agree that they would. But what if the only way to stop the trolley is by pushing a large stranger off a footbridge into its path? People tend to be very hesitant to say they would do this, even though in both situations, one person is sacrificed to save five. But Costa and his colleagues found that presenting the dilemma in a language that volunteers had learned as a foreign tongue dramatically increased their stated willingness to push the sacrificial person off the footbridge, from fewer than 20% of respondents working in their native language to about 50% of those using the foreign one.

    Why does it matter whether we judge morality in our native language or a foreign one? According to one explanation, such judgments involve two separate and competing ways of thinking­one of these, a quick, natural "feeling," and the other, careful deliberation about the greatest good for the greatest number. When we use a foreign language, we unconsciously sink into the more careful way simply because the effort of operating in our non-native language signals our cognitive (认知的) system to prepare for difficult activity.

    An alternative explanation is that differences arise between native and foreign tongues because our childhood languages are filled with greater emotions than are those learned in more academic settings. As a result, moral judgments made in a foreign language are less filled with the emotional reactions that surface when we use a language learned in childhood.

    There's strong evidence that memory connects a language with the experiences and interactions through which that language was learned. For example, people who are bilingual (双语的) are more likely to recall an experience if reminded in the language in which that event occurred. Our childhood languages, learned in the middle of passionate emotion, become filled with deep feeling. By comparison, languages acquired late in life, especially if they are learned through limited interactions in the classroom or dully delivered over computer screens and headphones, enter our minds lacking the emotionality that is present for their native speakers.