For centuries, people wondered how big the Earth was. Unfortunately, although the Earth was flat, no one was able to figure out its size. Gradually, however, people began to realize that the Earth was really round.

    Then, in the third century BC(2,300 years ago), a Greek man named Eratosthenes had an idea. Eratosthenes was sure that the Earth was a sphere. He used the sun and geometry(几何学) to figure out the size of the Earth. He calculated that the circumference(圆周) of the Earth was 28,600 miles(46,000 kilometers). The true size of the Earth is 25,000 miles(40,000 kilometers).

    Eratosthenes' measurement was wrong, but it was very close to the truth.

    For many centuries after Eratoshenes lived, people made maps of the Earth. However, they did not know very much about the world outside of Europe, Asia, and North Africa. Mapmakers could not draw accurate maps of the Earth until people began traveling around the world in the fifteenth century, mapping small areas each time. In the eighteenth and nineteenth centuries, people began making correct maps of countries, but the first accurate maps of the world were not made until the 1890s.

    Maps today are reliable(可依靠的), inexpensive, and easy to understand. People depend on maps every day. What would our lives be like without them?

    Flat Holm, a small island in Britain's Bristol Channel, has no permanent residents and minimal infrastructure（设施）. The pretty land mass is now, however, becoming increasingly popular with tourists wishing to explore the rural landscape and view the island's seabird colonies.

    Though this is welcome news, meeting the island's growing energy needs without ruining its environment poses a challenge. Flat Holm team leader Natalie Taylor says, “As we promote the island more and we get more visitors here, there's going to be a lot more demand for electricity so it's really important that we've got a really high functioning system that can provide for those people. From an environmental point of view, we want to reduce the use of diesel（柴油）generators so that we can have as small ecological footprints as possible.”

    While the Cardiff Council, which oversees the island, considered traditional solar and hydroelectricity, it was reluctant to carry out either, due to their high cost and permanent nature. According to energy and sustainability manager Gareth Harcombe, the officials were seeking a portable option that could be moved if the site was needed for another purpose.

    Fortunately, the UK-based company Renovagen had the perfect solution. A small panel can provide 11kW of power within two minutes. A more extensive version, unrolled from a shipping container, can yield 300kW of electricity in less than an hour.

    The solar panel “carpets”, laid on the island in early October, are being used to provide electricity to its sole pub and lighthouse. The Cardiff Council also plans to use them to charge two Nissan e-NV200 electric vehicles in the future.

    In addition to providing power to remote islands like Flat Holm, Hingley hopes the Rapid Roll technology will be useful in areas affected by natural disasters. A good example is Puerto Rico, where most residents have been without electricity since Hurricane Maria destroyed the power lines in late September.

    People from East Asia tend to have more difficulty than those from Europe in distinguishing facial expressions — and a new report published online in Current Biology explains why.

    Rachael Jack from University of Glasgow, said that rather than scanning evenly across a face as Westerners do, Easterners fix their attention on the eyes.

    "We show that Easterners and Westerners look at different face features to read facial expressions," Jack said. "Westerners look at the eyes and the mouth in equal measure, while Easterners favor the eyes and ignore the mouth."

    According to Jack and his colleagues, the discovery shows that communication of human emotions is more complex than previously believed. As a result, facial expressions that had been considered universally recognizable cannot be used reliably to convey emotions in cross­cultural situations.

    The researchers studied cultural differences in the recognition of facial expressions by recording the facial movements of 13 Western people and 13 Eastern people while they observed pictures of expressive faces and put them into categories: happy, sad, surprised, fearful, disgusted, or angry. They compared how accurately participants read those facial expressions using their particular eye movement strategies.

    It turned out that Easterners focused much greater attention on the eyes and made significantly more errors than Westerners did. "The cultural difference in eye movements that they show is probably a reflection of cultural difference in facial expressions," Jack said. "Our data suggests that while Westerners use the whole face to convey emotions, Easterners use the eyes more and the mouth less."

    In short, the data shows that facial expressions are not universal signals of human emotions. From here on, examining how cultural factors have diversified these basic social skills will help our understanding of human emotions. Otherwise, when it comes to communicating emotions across cultures, Easterners and Westerners will find themselves lost in translation.

    We were silently waiting on the platform in the late afternoon. There he was, my 80-year-old grandfather with his silvery hair. And there I was, a teenage girl in my jeans and T-shirt. His aged but still clear blue eyes were taking in the scene as I wondered how I was going to get through the next two days. Why did I ever agree to accompany my cranky grandpa on a train ride from New York to Georgia?

    No one else wanted to be the fellow traveler since my grandfather refused to fly. In contrast, I loved to fly since I wanted to get to the destination as quickly as possible. No matter what anyone told my grandfather about the comfort and safety of flying, he refused to book a flight, saying, "It's not just the trip; it's the adventure of getting there."

    With my first step onto the train, the journey was already different from what I expected. The train was modem and filled with friendly travelers. We settled into the club car, where we could enjoy food and drinks while watching the scenery pass. Instead of listening to my music, I became a willing audience and learned family history that I had never had the time or patience to learn. With teary eyes, he told me that going to family events was hard for him since my grandmother died. It always made him think about those who were no longer with us. For the first time I felt I understood him. I gained a new appreciation for our time together.

    In this fast-paced world, we often miss important moments. There is great significance in listening to elders who offer a piece of their history and experience. I may be more open to opportunities to stay with my grandpa. Life isn't just about the destination; it's about the journey.

    Misael is three times the size of other children at his age due to a symdrome(综合症 状) which means he is unable to stop eating.

    He is so heavy that he often stops breathing while sleeping — leaving his parents fearing that one day he may not wake up. His dad Manoel Abreu, 38, said, "Everything is hard for him — he is a baby carrying an adult's weight. His heart must be working under a lot of pressure. If he doesn't get the treatment he requires, there is a very good chance that he will pass away."

    Miseal, from Sanot, Brazil, was born a healthy 6lb 6oz, but immediately he started piling on the pounds. Doctors believe he may be suffering from Prader-Willi symdrome, a rare genetic condition that leaves him with greed. He now weighs a heavy 178lb and is still gaining despite following a low-fat diet and walking for 40 minutes each day.

    Mum Josiane, 37, said, "He has been putting on a lot of weight since he was a baby—even when I was breastfeeding him. But it was only when he was one and a half years old that we began to worry. He was gaining 3kg a month and was starting to get very heavy. We know we could lose him at any time. Sometimes when he is sleeping, I watch him to see if he is breathing. I cry a lot because we want to help him. But I am also very proud of him because he doesn't surrender(投降)."

    Misael visits a doctor every three months to try to control his condition, but currently there is no cure for Prader-Willi symdrome. Paediatric neurologist(儿科神经科专家)

    Lucio said, "Every time we meet, he has put on a lot of weight — sometimes up to 5 kg. I think Misael could get help from someone outside Brazil — both medically and financially — so that he can get the laboratory and genetic testing he needs."

    Britain's first zero-carbon homes are being built—and they look like something from a science-fiction movie.

    There are 25 eco-friendly homes currently being built in Southmoor, near Abingdon, Oxon. Buyers are able to have the final say on floor layouts，kitchens and bathrooms. One three-bedroom home is on the market for￡801 ,000,with a custom build available to suit your own specification. These eco-friendly houses are powered entirely by electricity from solar panels around the houses. They also have advanced ventilation (通风) systems, making sure that temperatures inside the building don't go beyond 25℃ for more than 10% of hours annually, as well as mini heat pumps to generate (产生) the heating and hot water on-site. Part of the cooling design includes avoiding east-or west-facing windows, and window shading.

    And they're in high demand. Ian Pritchett, of Ssassy Property, thinks the Government should do more to promote the construction of this type of housing. "Unfortunately, the Government relaxed the proposed 2016 zero-carbon targets after being lobbied(游说)by house builders," Ian explained. "At present, the main house-building corporations control the land and only build at the rate they are sure will sell, keeping the UK's housing shortage so that the normal rules of 'supply and demand' don't apply. When there is a shortage of housing, buyers have to purchase what is available rather than what they might want."

    In any sensible society, we would expect the planning system to actively encourage zero-carbon houses, and he tough on anyone failing to deliver the necessary standard. Instead, we have a planning system that focuses on other aspects such as numbers of bedrooms, garden sizes, and parking places. These are important aspects, but they pale into insignificance compared to the catastrophic consequences of climate change.