Getting rid of dirt, in the opinion of most people, is a good thing. However, there is nothing fixed about attitudes to dirt.

    In the early 16th century, people thought that dirt on the skin was a way to block out disease, as medical opinion had it that washing off dirt with hot water could open up the skin and let illnesses in. A particular danger was thought to lie in public baths. By 1538, the French king had closed the bath houses in his kingdom. So did the king of England in 1546. Thus it began a long time when the rich and the poor in Europe lived with dirt in a friendly way. Henry IV, King of France, was famously dirty. Upon learning that a nobleman had taken bath, the king ordered that, to avoid the attack of disease, the nobleman should not go out.

    Though the belief in the merit of dirt was long-lived, dirt has no longer been regarded as a nice neighbor ever since the 18th century. Scientifically speaking, cleaning away dirt is good to health. Clean water supply and hand washing are practical means of preventing disease. Yet, it seems that standards of cleanliness have moved beyond science since World War Ⅱ. Advertisements repeatedly sell the idea: clothes need to be whiter than white, cloths ever softer, surfaces to shine. Has the hate for dirt, however, gone too far?

    Attitudes to dirt still differ hugely nowadays. Many first-time parents nervously try to warn their children of touching dirt, which might be responsible for the spread of disease. On the contrary, Mary Ruebush, an American immunologist(免疫学家), encourages children to play in the dirt to build up a strong immune system. And the latter position is gaining some ground.

    As the days get shorter and the chilly weather rolls in, we all want to curl up in a blanket and hibernate until spring rolls around. But making time to get outside in the sun, even when it's cold out, could have bigger mood benefits than you might realize.

    While the link between sunshine and mental health is nothing new, new research from Brigham Young University (BYU) has shown that the association may be even stronger than previously realized. It finds that sunlight exposure is by far the greatest weather-related factor determining mental health outcomes. In other words: more sunshine, more happiness.

    For the study, a psychologist, a physicist and a statistician from BYU teamed up to compare daily environmental data from the university's Physics and Astronomy Weather Station with emotional health data archived by day for 16,452 adult therapy patients who were being treated at the BYU Counseling and Psychological Services Center.

    Exposure to sunlight is a significant factor in seasonal affective disorder. Research has shown that the brain produces more of the feel-good neurotransmitter serotonin on sunny days than it does on darker days. What's more, lack of sunlight is linked with lower vitamin D levels, which in turn has been correlated with depression and low energy.

    If you're getting enough sun, your emotions should remain relatively stable, the researchers found. But as the amount of sunlight in the day is reduced, levels of emotional pain can soar. Other weather variables including temperature, pollution and rain were not found to have an impact on mental health.

    “We were surprised that many of the weather and pollution variables we included in the study were not significantly correlated with clients' scores on the distress measure once we had accounted for suntime," Dr. Mark Beecher, a professor of psychology at the university and the study's lead author, told The Huffington Post. “People tend to associate rainy days, pollution, and other meteorological phenomena with sadness or depression, but we did not find that.”

    Have you ever made your life look a little more charming than it actually is by posting truths on social media? If so, you may be damaging your mental health.

    The posts we make on social media platforms allow us to look back and see what we did on a given day. But what happens when, in an effort to impress our online friends, photos and videos we post become beautified versions of the things we did?

    A young girl named Sophia went out to a romantic anniversary dinner with her boyfriend, had a near relationship-ending fight during dessert, then came home and posted, "Had the best time out with the love of my life!"—even with a photo of the meal. No surprise, but according to a new study, Sophia was by no means unique. Two-thirds of users admit lying about their lives on social media with 20 percent of young people between the ages of 18 and 24 stating that they edit their own stories by frequently lying about relationships and promotions.

    By beautifying our online stories, we are harming our memories. We start believing the stories we tell rather than remembering what really happened. Soon, the real experience is lost and all that remains is the beautified version of history.

    Scientists fear that these edited stories will end up changing our memories. It's well confirmed through research that our own memories are often unreliable and can be easily controlled. Writing down one's life in the form of a journal, or even on social media can help us keep our memories undamaged, but only if we tell the truth. So recording our experiences through whatever medium, to later recall lessons we learned, is not only acceptable but desirable. In fact, looking back at our own past—however embarrassing or uncomfortable - is not just healthy but can be enjoyable.

    HANGZHOU-Chinese internet giant Alibaba on Tuesday opened a hotel loaded with artificial intelligence (AI) and robots, automating a series of procedures like check-in, lights control and room service.

    FlyZoo Hotel, opened in Hangzhou, capital of East China's Zhejiang province, where Alibaba is headquartered, is known as the company's first "future hotel". Customers can check into the hotel by simply scanning their faces. The facial recognition system installed in the hotel also enables customers to use their faces as key cards to open doors and access another hotel service. Users can also control the lights, televisions and curtains in the room via Alibaba's voice-activated digital assistant, while robots are deployed to serve dishes, cocktails and coffee. Hotel bookings and check-out can also be done with a few clicks on mobile through an app. The Al-based solution can help customers save time and relieve hotel employees from repetitive work," said Wang Qun, CEO of FlyZoo Hotel. The hotel is the latest example of Chinese tech companies1 attempt into traditional industries such as the hotel industry.

    E-commerce giant JD.com announced in October its strategy to put smart home and electronic devices sold on its platform into hotels, in an effort to improve online sales.

    In July, Baidu teamed up with Intercontinental Hotels Group in Beijing to allow guests to use its voice-controlled assistant to adjust room temperature and order room service at ease.

    Before that, social media giant Tencent introduced QQ family, a similar tech solution for hotel operators, in the southern city of Zhuhai last year.

    "We want to install a 'smart brain' for hotels, " said Wang, "In the future, we will continue to make hotels smarter and more automated, as well as create more personalized experiences for consumers."

    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.

    who doesn't love sitting beside a cosy（舒适的）fire on a cold winter's night ? Who doesn't love to watch flames (火苗) curling up a chimney ? Fire is one of man's greatest friends, but also one of his greatest enemies. Many big fires are caused by carelessness. A lighted cigarette thrown out of a car or train window or a broken bottle lying on dry grass can start a fire. Sometimes, though, a fire can start on its own. Wet hay (草) can begin burning by itself. This is how it happens: the hay starts to rot (腐烂) and begins to give off heat which is trapped inside it. Finally, it bursts into flames. That's why farmers cut and store (贮存) their hay when it's dry .

    Fires have destroyed whole cities. In the 17th century, a small fire which began in a baker's shop burnt down nearly every building in London. Moscow was set on fire during the war against Napoleon. This fire continued burning for seven days . And, of course, in 64 A. D. a fire burnt Rome. Even today, in spite of modern fire - fighting methods, fire causes millions of pounds' worthy of damage each year both in our cities and in the countryside. It has been wisely said that fire is a good servant but a bad master.