While the U.S. is still debating about getting rid of the penny, Sweden is rapidly moving towards abolishing currency altogether. Though this may sound radical(过激的), it is a natural evolution in this digital society.

    Sweden, which was the first European country to introduce banknotes in 1661, has just been working harder to convince its residents that digital payments are a safer alternative to carrying cash.

Over the years, the idea has gained popularity with residents, especially the younger generation that is much more comfortable with technology. Today many banks don't even have ATMs and some have stopped handling cash altogether!

    Tickets to ride public buses in most Swedish cities can only be purchased via cell phones. Numerous businesses are also moving towards accepting only digital payments. Even the homeless that sell street paper to make ends meet have to start accepting this mode of payment!

But despite its growing popularity, some people don't like this radical idea. They include the homeless, elderly people as well as those living in rural areas who are still uncomfortable with mobile phones and computers. But the officials are confident that in the very near future, they will be able to convince everyone to move this safe and more cost-effective payment system.

    Sweden is not the only country trying to abolish paper currency and coins. The movement is rapidly gaining ground in Denmark and Finland as well. In 2014, Israel announced a three-step plan to go cashless and just last week the vendors(小贩)of a popular street in Sydney declared they would stop accepting currency from customers. Whether this phenomenon spreads remains to be seen. But one thing is for sure—With increasingly advanced payment systems being introduced every day, pulling out cash is rapidly becoming “uncool”.

You can't always predict a heavy rain or remember your umbrella. But designer Mikhail Belyaev doesn't think that forgetting to check the weather forecast before heading out should result in you getting wet. That's why he created lampbrella, a lamp post with its own rain- sensing umbrella.

    The designer says he come up with the idea after watching people get wet on streets in Russia. “once, I was driving on a central Saint Petersburg street and saw the street lamps lighting up people trying to hide from the rain. I thought it would be appropriate to have a canopy (伞蓬) built into a street lamp.” he said.

    The lampbrella is a standard-looking street lamp fitted with an umbrella canopy. It has a built-in electric motor which can open or close the umbrella on demand. Sensors (传感器) then ensure that the umbrella offers pedestrians shelter whenever it starts raining.

In addition to the rain sensor, there's also a 360° motion sensor on the fiberglass street lamp which detects whether anyone is using the lampbrella. After three minutes of not being used the canopy is closed.

     According to the designer, the lampbrella would move at a relatively low speed, so as not to cause harm to the pedestrians. Besides, it would be grounded to protect from possible lighting strike. Each lampbrella would offer enough shelter for several people. Being installed (安装) at 2 meters off the ground, it would only be a danger for the tallest of pedestrians.

      While there are no plans to take lampbrella into production, Belyaev says he recently introduced his creation to one Moscow Department, and insists his creation could be installed on any street where a lot of people walk but there are no canopies to provide shelter.

    Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.

    Some scientists believe that birds do sing some of the time just because they are happy. However, they sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay out of their territory.

    Do you know what a “territory” is? A territory is an area that an animal, usually the male, claims（声称）as its own. Only he and his family are welcome there. No other families of the same species are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away.

    If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time, especially at nesting（筑巢）season. So he is screaming all the time, whether he can see an outsider or not. This screaming is what we call a bird's song, and it is usually enough to keep an outsider away.

    Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs.

    You can see that birds have a language of their own. Most of it has to do with attracting mates and setting up territories.

    Cultural rules determine every aspect of food consumption. Who eats together defines social units. For example, in some societies, the nuclear family is the unit that regularly eats together. The anthropologist Mary Douglas has pointed out that, for the English, the kind of meal and the kind of food that is served relate to the kinds of social links between people who are eating together. She distinguishes between regular meals, Sunday meals when relatives may come, and cocktail parties for relatives and friends. The food served symbolizes the occasion and reflects who is present. For example, only snacks are served at a cocktail party. It would be inappropriate to serve a steak or hamburgers. The distinctions among cocktails, regular meals, and special dinners mark the social boundaries between those guests who are invited for drinks, those who are invited to dinner, and those who come to a family meal. In this example, the type of food symbolizes the category of guest and with whom it is eaten.

    In some New Guinea societies, the nuclear family is not the unit that eats together. The men take their meals in a men's house, separately from their wives and children. Women prepare and eat their food in their own houses and take the husband's portion to the men's house. The women eat with their children in their own houses. This pattern is also widespread among Near Eastern societies.

    Eating is a metaphor that is sometimes used to signify marriage. In many New Guinea societies, like that of the Lesu on the island of New Ireland in the Pacific and that of the Trobriand Islanders, marriage is symbolized by the couple's eating together for the first time. Eating symbolizes their new status as a married couple. In U.S. society, it is just the reverse. A couple may go out to dinner on a first date.

    Other cultural rules have to do with taboos against eating certain things. In some societies, members of a family group, are not allowed to eat the animal or bird that is their totemic ancestor. Since they believe themselves to be descended from that ancestor, it would be like eating that ancestor or eating themselves.

    There is also an association between food prohibitions and rank, which is found in its most extreme form in the caste system of India. A caste system consists of ranked groups, each with a different economic specialization. In India, there is an association between caste and the idea of pollution. Members of highly ranked groups can be polluted by coming into contact with the bodily secretions, particularly saliva(唾液),of individuals of lower-ranked castes. Because of the fear of pollution, Brahmans and other high-ranked individuals will not share food with, not eat from the same plate as, not even accept food from an individual or from a low-ranking class.

    Teachers'Day is, interestingly, not celebrated on the same day all over the world. In some countries it is marked by a holiday, in others it is a working day.

    International Teachers' Day is celebrated on October 5. Being held ever since 1994, it is in honor of teachers' organizations worldwide. Its aim is to encourage supports for teachers and to meet the needs of students.

    China   In 1939, Teachers' Day was set for August 27, Confucius' birthday. In1951, the celebration was stopped. However, it was founded again in 1985, and the day was changed to September 10.

    India   Teachers' Day is celebrated on September 5 in honour of Dr. Sarvepalli Radhakrishnan, the second president of India, whose birthday falls on that day.

    Russia   In Russia, Teachers' Day was celebrated on the first Sunday of October between 1965 and 1994. Since 1994, the day is observed on the October 5, just the same day as World Teachers' Day.

    The US   In the US, Teachers' Day is non-official holiday. It is celebrated on the Tuesday of the first full week of May. A number of activities are organized in schools to honor teachers. The celebrations can continue for the whole week of May.

    Thailand   In Thailand, National Teachers' Day is celebrated every year on January 16. The first Teachers' Day was held in 1957. The day is a holiday in schools.

    Shark attacks not only disturb beach activities, but can affect associated tourist industries. Shark nets are a common solution to preventing shark attacks on beaches, but they cause dangers to sea ecosystems.

    Seeking a cost-effective way to monitor beach safety over large areas, we have developed a system called Shark Spotter. It combines artificial intelligence (AI), computing power, and drone (无人机) technology to identify and warn lifesavers to sharks near swimmers. The project is a cooperation between the University of Technology Sydney and The Ripper Group, which is pioneering the use of drones—called "Westpac Little Ripper Lifesavers"—in the search and rescue movement in Australia.

    SharkSpotter can detect sharks and other potential threats using real-time aerial imagery. The system analyses video from a camera attached to a drone to monitor beaches for sharks, send warnings, and conduct rescues. Developed with techniques known as "deep learning", the Shark Spotter system receives imagery from the drone camera and attempts to identify all objects in the scene. Once certain objects are detected, they are put into one of 16 categories: shark, whale, dolphin, rays, different types of boats, surfers, and swimmers.

    If a shark is detected, Shark Spotter provides both a visual sign on the computer screen and an audible warning to the operator. The operator confirms the warning and sends text messages from the Shark Spotter system to the Surf Life Savers for further action. In an emergency, the drone is equipped with a lifesaving flotation pod (漂浮仓) together with an electronic shark repellent (驱逐装置) that can be dropped into the water in cases where swimmers are in severe trouble, trapped in a rip, or if there are sharks close by.

    In January 2018, the Westpac Little Ripper Lifesavers was used to rescue two young swimmers caught in a rip at Lennox Head, NSW. The drone flew down the beach some 800 meters from the lifeguard station, and a lifesaving flotation pod was dropped from the drone. The complete rescue operation took 70 seconds.

    We believe Shark Spotter is a win-win for both marine life and beachgoers. This unique technology combines dynamic video image processing AI and advanced drone technology to creatively deal with the global challenge of ensuring safe beaches, protecting environments, and promoting tourism.