Why do human beings still risk their lives under ground and doing one of the dirtiest and most dangerous jobs in the world? It is an increasingly urgent question, given the recent mining accidents in Sago, W. Va and Huntington, Utah. A small group of engineers and robotics experts look forward to a day in the not-too-distant future when robots and other technology do most of the dangerous mining work.

    Robotic technology, in particular, holds much promise, McAteer says, especially when it comes to mapping mines and rescuing trapped miners — the special operations of the mining industry.

    One of the first mining robots was developed five years ago at Carnegie Mellon University's Robotics Institute. It was called Groundhog. It used lasers(激光器) to “see” in dark tunnels and map abandoned mines—some of the most dangerous work in the business.

    The latest design is called Cave Crawler. It's a bit smaller than Groundhog, and even more advanced. It can take photos and videos and has more sensors that can detect the presence of dangerous gases. Incredibly, the robot has a real sense of logic. If it comes across an obstacle it gets momentarily confused. It has to think about what to do and where to go next. Sometimes it throws a fit just like a real person.

    The greatest problem, though, is cost. The money of the earliest research project was provided by the government, but that money had dried up, and it's not clear where future money will come from. Partly for that reason, and partly because of advances in safety, mining is not nearly as dangerous as it was in the past. Since 1990, fatalities(致命性) have declined by 67% and injuries by 51% , according to the National Mining Association.

    Some experts predict that robots in mines will serve much of the same function that they do in the automotive industry. The robots do the most boring and dangerous jobs，but won't get rid of the need for human workers.

    Believe it nor not, ancient Chinese people had their own methods of heat preservation in winter.

    “Wen Ding”, ancient rice cooker

    The “Wen Ding”, an ancient cooking container, preserved heat by burning fuels like charcoal. The one unearthed in Nanjing in 1989 is thought to be the oldest of its kind discovered in China, dating back to the Stone Age.

    Ran Lu”, ancient small hot pot

    The “Ran Lu” is a small-sized cooking vessel (器皿) made of bronze. A charcoal stove forms the main structure, with a bottom tray to hold charcoal ashes, and a movable cup at the top. Some experts have concluded that the vessel's structure suggests that these vessels became popular in the Warring States Period (475—221 BC).

    Bronze You, ancient kettle

    The Bronze You, one of the most common wine containers during the Shang and Zhou, dynasties, could also be used to warm wine. For example, the Bronze You with beast mask design, unearthed in Jiangxi province, had an opening where charcoals could be placed, allowing people to enjoy a hot drink.

    Bronze Yan, ancient steamer

    Although the “Wen Ding” was effective at keeping food warm, ancient Chinese people later found that its burning produced pollution. As a result, the Bronze Van was made with a two-tier (双层的) structure and used to steam rice and other grains. After the Eastern Han Dynasty (AD 25-AD 220), further improvements to the Bronze Yan led to the modern day steamer.

    Every pet owner loves his pet. There is no argument here.

    But when we asked our readers whether they would clone their beloved animals, the responses were split almost down the middle. Of the 228 readers who answered it, 108 would lone, 111 would not and nine weighed each side without offering an opinion.

    Clearly, from readers' response, this is an issue that reaches deeply into both the joy and eventual sadness of owning a pet. It speaks, as well, to people's widely differing expectations over the developing scientific procedure.

    Most of the respondents who favored the idea strongly believed it would produce at least a close copy of the original; many felt the process would actually return an exact copy. Those on the other side, however, held little hope a clone could never truly recreate a pet, many simply didn't wish to go against the natural law of life and death.

    Both sides expressed equal love for their animals. More than a few respondents owned “the t dog/cat in the World”. They thought of their pets as their “best friend”, ''a member of the family,” “the light of my life.” They told moving stories of pets' heroism, intelligence and selfless devotion.

Little wonders the loss is so disturbing—and the cloning so attractive. “People become very lose to their animals, and the loss can be just as hard to bear as when a friend or family member dies,” says Gary Kowalski, author of Goodbye, Friend: Healing Wisdom for Anyone Who Has Ever Lost a Pet. “For me, cloning feels like an attempt to turn death away... It's understandable. Death is always painful. It's difficult to deal with. It's hard to accept.”

    But would cloning reduce the blow? This question seemed to be at the heart of this problem.

    Why we cry with happiness show: Responding with a negative reaction helps us deal with extreme joy. If you cry with happiness at weddings, you are responding to a happy experience with a negative reaction. The researchers believe the unusual reaction may help renew emotional balance in us and keep extreme emotions under control. The findings make it clear how people express and control their emotions, which could help improve their understanding of people's mental(精神的) health.

    Dr Oriana Aragon set out to explore the phrase “tears of joy”, which she said never made sense to her. But after studying a series of incongruous(不和谐的) expressions, she now understands better why people cry when they are happy. “People may be renewing emotional balance with these expressions,” she explained. “They seem to take place when people are struck by strong positive emotions. People, who do this, seem to recover better from those strong emotions.”

    The report show various examples of responding to a positive experience with a negative emotion, such as, a crying wife seeing the husband returning from war again, and teenage girls screaming at a Justin Bieber concert. Examples also include a baseball player who hits a home run, only to be slapped(拍) on the back by teammates, as well as when people cannot help kissing babies' faces who they consider lovely.

    Dr Aragon and her team discovered that people, who expressed negative reactions to positive news, were able to moderate(缓和) strong emotions more quickly. There is also some evidence that strong negative feelings may provoke positive expressions. For example, nervous laughter often happens when people are faced with a hard situation. We've seen people smiling during times of extreme sadness.

    “The findings affect our knowledge of how people express and control their emotions, which is importantly related to mental and physical health, the quality of relationships with others, and even how well people work together,” Dr Aragon said.

    It was New Year's Night. An aged man was standing at a window. He raised his mournful (悲哀的) eyes towards the deep blue sky, where the stars were floating like white lilies (百合花) on the surface of a clear calm lake. He had already passed sixty and brought from his journey nothing but errors (错误) and regrets. Now his health was poor, his mind vacant and his heart sorrowful (悲伤的).

    The days of his youth appeared like dreams before him, and he recalled the serious moment when his father placed him at the entrance of the two roads—one leading to a peaceful, sunny place, covered with flowers, fruits and filled with soft, sweet songs; the other leading to a deep, dark cave, which was endless, where poison flowed instead of water and devils and poisonous snake hissed (发撕嘶声) and crawled (爬行).

    He saw the lights flowing away in the darkness. These were the days of his wasted life; he saw a star fall from the sky and disappeared, and this was the symbol (象征) of himself. His regret like a sharp arrow (箭) struck deeply into his heart. Then he remembered his friends in his childhood. But they had made their way to success and were now honoured and happy on this night.

    The high church clock struck and the sound made him remember his parents' early love for him. They had taught him and prayed for his good. But he chose the wrong way. With shame and grief he dared no longer look towards that heaven. His darkened eyes were full of tears, and with a despairing (绝望的) effort, he burst out a cry: "Come back, my early days!"

    His youth did return, for all this was only a dream which he had on New Year Night. He was still young though his faults were real; he had not yet entered the deep, dark cave, and he was still free to walk on the road which leads to the peaceful and sunny land.

    Those who still wander (徘徊) on the entrance of life, hesitating (犹豫) to choose the bright road, remember that when years are passed and your feet stumble (绊脚) on the dark mountains, you will cry bitterly, but in vain (徒劳): "Oh youth, return! Oh give me back my early days!"

When driving, Clara - Marina Martinez makes a note of any unusual behaviour she sees on the road. She then feeds these into machine- learning algorithms(算法), a form of AI, which she is helping develop for Porsche Engineering.

Those algorithms are intended to produce a system reliable enough for a car to drive itself. Such a fully autonomous car, known in the industry as Level 5, should be able to complete an ____ entire journey without any intervention (介入) from the driver, and deal with all situations on the road. But this is proving hard to achieve, and many attempts to do so are being abundoned. Last year, for instance, Uber sold off its unit developing self- driving cars.

Autonomous vehicles are said to be not just convenient but potentially safer. However, just as people take time to learn how to drive safely, so do machines. And machines are not quick learners. The RAND Corporation calculates that to develop a system 20% safer than a human driver, 100 self- driving cars would have to operate 24 hours a day, 365 days a year.

 Carmakers such as Porsche therefore speed up the development process using simulators(模拟器). These teach software about dangers rarely encountered in reality. Dr Martinez and her colleagues employ "game engines" to do this. These are used to create virtual worlds through which the software can drive. Objects in these virtual worlds are assigned their physical characteristics ( ie, buildings are hard, people are soft) so that the sensors in vehicles respond in the appropriate way. Once the software has been trained, it is tested in real autonomous vehicles by re- creating those situations on a test track.

 How quickly all this will translate into reality remains to be seen. Both regulators and customers will need to overcome the doubt that a software driver really can be safer than a human being.

 From Porsche's point of view, though, there is another question. Given that much of the reason owning a sports car is for owners to show off their driving skills, just how big a market will there be for a version where software takes those bragging(炫耀的) rights away?