Look to many of history's cultural symbols, and there you'll find an ancestor of Frosty, the snowman in the movie Frozen. It appeared on some of the first postcards, starred in some of the earliest silent movies, and was the subject of a couple of the earliest photos, dating all the way back to the 1800s. I discovered even more about one of humanity's earliest forms of life art during several years of research around the world.

For example, snowmen were a phenomenon in the Middle Ages, built with great skill and thought. At a time of limited means of expression, snow was like free art supplies dropped from the sky. It was a popular activity for couples to leisurely walk through town to view the temporary works of chilly art. Some were created by famous artists, including a 19-year-old Michelangelo, who in 1494 was appointed by the ruler of Florence, Italy, to build a snowman in his mansion's courtyard.

The Miracle of 1511 took place during six freezing works called the Winter of Death. The city of Brussels was covered in snowmen—an impressive scene that told stories on every street corner. Some were political in nature, criticizing the church and government. Some were a reflection of people's imagination. For the people of Brussels, this was a defining moment of defining freedom. At least until spring arrived, by which time they were dealing with damaging floods.

           If you fear the heyday of the snowman has passed, don't worry:  I've learned that some explosive snowman history is still being made today. Every year since 1818, the people of Zurich, Switzerland, celebrate the beginning of spring by blowing up a snowman. On the third Monday of April, the holiday Sechselauten is kicked off when a cotton snowman called the Boogg is stuffed with explosive and paraded through town by bakers and other tradesmen who throw bread to the crowds. The parade ends with the Boogg being placed on a 40-foot pile of firewood. After the bells of the Church of St. Peter have rung six times, representing the passing of winter, the pile is lit. When the snowman explodes, winter is considered officially over—the quicker it is burnt down, the longer summer is said to be.

    A ground-based system that uses much stronger signals than GPS can find your location in cities and indoors. It is a new positioning system that could compete with GPS to make sure you never lose your directions again.

    Instead of satellites, Locata uses ground-based equipment to send a radio signal over a localized area that is a million times stronger on arrival than GPS. It can work indoors as well as outdoors, and the makers claim that the receivers can be shrunk(缩小) to fit inside a regular cell phone. Even the US armies, which invented GPS technology, signed a file last month agreeing to a test of Locata at the White Sands Missile Range in New Mexico.

    “This is one of the most important technology developments for the future of the positioning industry,” says Nunzio Gambale, CEO and co-founder of the firm Locata, based in Griffith, Australia.

    As for the Locata's correctness, Christopher Morin of the US Air Force tested it recently at White Sands, and it worked to within 18cm along any axis(轴). Morin said it should be possible to get the exactitude down to 5cm.

    The tests were performed in an open desert where GPS also worked beautifully, but its signal was weak—like a car headlight from 20,000 kilometers away—and easily cut off by solid objects(实心的物体). Locata's signal was far stronger, though not guaranteed to work in a complex urban environment, said David, speaker of the UK' s General Lighthouse Authorities.

    Locata's technology will face competition in the race to transform indoor navigation. But it could shine in specific areas, Gambale said. Robots with Locata could easily navigate inside buildings without the complex optical(视觉的) systems they need at the moment. And the process that handles correct location data could not only guide you around a mall, railway station or airport, but also take you to the exact shelf in a shop for the product you want. It would be small and cheap enough for smart phones and it should be available within five years—a similar path to the one GPS took on its way towards the world, he said.

    The world itself is becoming much smaller by using modern traffic and modern communication means. Life today is much easier than it was hundreds of years ago, but it has brought new problems. One of the biggest problems is pollution. To pollute means to make things dirty. Pollution comes in many ways. We see it, smell it, drink it and even hear it.

    Man has been polluting the earth. The more people, the more pollution. Many years ago, the problem was not so serious because there were not so many people. When the land was used up or the river was dirty in one place, man moved to another place. But this is no longer true.

    Man is now slowly polluting the whole world.

    Air pollution is still the most serious. It's bad for all living things in the world, but it is not the only one kind of pollution. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us angry more easily.

    Many countries are making rules to fight pollution. They stop people from burning coal in houses and factories in the city, and from putting dirty smoke into the air. Pollution by SO2 is now the most dangerous kind of air pollution. It is caused by heavy traffic. We are sure that if there are fewer people driving, there will be less air pollution.

    The earth is our home. We must take care of it. That means keeping the land, water and air clean. And we must take care of the rise in pollution at the same time.

    From self-driving cars to carebots for elderly people, rapid development in technology has long represented a possible threat to many jobs normally performed by people. But experts now believe that almost 50 percent of occupations existing today will be completely unnecessary by 2025 as artificial intelligence continues to change businesses.

    "The next fifteen years will see a revolution in how we work, and a revolution will necessarily take place in how we plan and think about workplaces," said Peter Andrew, Director of Workplace Strategy for CBRE Asia Pacific.

    A growing number of jobs in the future will require creative intelligence, social skills and the ability to use artificial intelligence.

    The report is based on interviews with 200 experts, business leaders and young people from Asia Pacific, Europe and North America. It shows that in the US technology already destroys more jobs than it creates.

    But the report states: "Losing occupations does not necessarily mean losing jobs — just changing what people do." Growth in new jobs could occur as much, according to the research.

    "The growth of 20 to 40 person companies that have the speed and technological know-how will directly challenge big companies," it states.

    A 2014 report by Pew Research found 52 percent of experts in artificial intelligence and robotics were optimistic about the future and believed there would still be enough jobs in the next few years. The optimists pictured "a future in which robots do not take the place of more jobs than they create," according to Aaron Smith, the report's co-author.

    "Technology will continue to affect jobs, but more jobs seem likely to be created. Although there have always been unemployed people, when we reached a few billion people there were billions of jobs. There is no shortage of things that need to be done and that will not change," Microsoft's Jonathan Grudin told researchers.

    Robots make me nervous—especially the ones which seem to think for themselves. I was embarrassed to admit this till I heard that Bill Gates, the founder of Microsoft, felt the same way.

    Gates said in an interview with the social networking and news website Reddit: "I am in the camp that is concerned about super intelligence. First the machines will do a lot of jobs for us and not be super intelligent．That should be positive if we manage well. A few decades after that, though, the intelligence is strong enough to be a concern."

    Well, maybe I don't have to worry about my computer and kitchen equipment yet. After I use them I can always pull the plug. But in the future, machines might find a way to prevent us from switching them off. There's a terrible thought!

    Maybe the problem with computers too clever for us is not that they are evil like some we've seen in sci-fi movies. What could put us in danger is that they might be too efficient. That's what philosopher Nick Bostrom from Oxford University believes. He says that machines are indifferent to humans and in pursuit of their own goals，the destruction of people might be just additional damage. Bostrom gives us an example: A machine which might have its only goal to produce as many paperclips as possible might look at human bodies as extra material for paperclips and go after you. Because it is, well, a machine, it would not take pity on you.

    It's a good thing that American writer Isaac Asimov thought about how far robots can go and left us his three rules of robotics. They state that a robot may not hurt a human being or allow the human being to come to harm.

    I'm glad my machines at home are "dumb". All my cleaner wants to take over is the carpet in my living room. Let's hope they don't create an appliance which wants to take over the world!

    Hip-hop culture covers many fields; it includes spoken words, break-dancing, beat-making, painting, fashion, lively design, technology, and more. Hip-hop is becoming the unofficial music in the education world, as more artists launch school programs, summer camps, and other activities connected city youth in the classroom through the beliefs of hip-hop culture. Even more and more university teachers — who once would have been strongly against hip-hop — have joined the crew. In the past two decades, hip-hop culture, including hip-hop education, has become a legitimate(合法的) field of study in universities and the subject of numerous books.

    Hip-hop culture has influenced every piece of American and global culture because the culture is so prevalent. Teachers must be willing to engage in it if it's part of the unique reality of their students' lives. That way, teachers can truly be effective, reaching students in a meaningful, culturally connected way.

    Teachers might at first feel frightened by hip-hop culture, an area in which they might not have previous knowledge or experience. But a lack of knowledge is actually a blessing; the best trained hip-hop educators have been those that are at the beginning disconnected(分离的) from the culture. One of the biggest sayings in hip-hop is “keep it real”. If a teacher comes to the classroom and says, “I don't know hip-hop, but I recognize that it's your culture and I want to learn,” the kids will teach the teacher, and then the students will be more willing to learn from that educator. Hip-hop is about a respect for youth culture.