We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

    The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

    Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms(微生物)．If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

    With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth．Then he added the plastic powder and let the microbes work their magic for 3 months．Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control．Sure enough, the plastic exposed(暴露) to the live bacteria was 17% lighter than the control after six weeks.

    The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

    “Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me．One day, I got tired of it and I wanted to know what other people are doing with these plastic bags．The answer: not much．So I decided to do something myself.” Said Daniel Burd.

    The kids in this village wear dirty, ragged clothes. They sleep beside cows and sheep in huts made of sticks and mud. They have no school. Yet they all can chant the English alphabet, and some can make words.

    The key to their success: 20 tablet computers(平板电脑) dropped off in their Ethiopian village in February by a U.S. group called One Laptop Per Child.

    The goal is to find out whether kids using today's new technology can teach themselves to read in places where no schools or teachers exist. The Massachusetts Institute of Technology researchers analyzing the project data say they're already amazed. “What I think has already happened is that the kids have already learned more than they would have in one year of kindergarten,” said Matt Keller, who runs the Ethiopia program.

    The fastest learner—and the first to turn on one of the tablets—is 8-year-old Kelbesa Negusse. The device's camera was disabled to save memory, yet within weeks Kelbesa had figured out its workings and made the camera work. He called himself a lion, a marker of accomplishment in Ethiopia.

With his tablet, Kelbasa rearranged the letters HSROE into one of the many English animal names he knows. Then he spelled words on his own. “Seven months ago he didn't know any English. That's unbelievable,” said Keller.

The project aims to get kids to a stage called “deep reading,” where they can read to learn. It won't be in Amharic, Ethiopia's first language, but in English, which is widely seen as the ticket to higher paying jobs.

    Stephen Hawking has said he believes brains could exist independently of the body after people die, but that the idea of a conventional afterlife（传统意义上的死后重生）is a fairy tale. Speaking at the premiere（首映）of a documentary film about his life, Stephen Hawking said: “I think the brain is like a program in the mind, which is like a computer, so it's theoretically possible to copy the brain onto a computer and so provide a form of life after death.”

    “However, this is way beyond our present scientific and technological level. I think the conventional afterlife is a fairy tale for people afraid of the dark.” The author of “A Brief History of Time”, who earlier approved of the right for the deadly ill to end their lives as long as safeguards were in place, suffered from motor neurone(运动神经元) disease at the age of 21 and was given two to three years to live.

    “All my life I have lived with the menace of an early death, so I hate wasting time,” Hawking said on Thursday night, using the computer-created voice he controls with a facial muscle and a blink(贬眼) from one eye. The documentary explores a brilliant schoolboy with unclear handwriting who enjoyed the life of Oxford University before illness led to a lifelong desire of discovery about the origins of the universe, which began as a graduate at Cambridge University and has shocked the world.

    Hawking's sister Mary says in the film that her brother was highly competitive and curious about everything in a household which friends described as very academic, and explains how she received a toy house as a present when they were children, to which Stephen immediately added electricity.

    She said that life with her brother was attractive and exciting. “It's a waste of time arguing with Stephen because he always manages to turn the argument round,” she said. The film goes back to his childhood and his student days and shows the scientist, who uses a wheelchair, at home with break. It also explores his family life with his first wife, Jane, and their three children, the breakdown of their marriage and his marriage to one of his carers.

    Jane appears on camera to explain how the pressures of caring for the children and the increasingly disabled Hawking became even worse once full-time nurses were brought into the home, destroying any privacy（隐私）. His second wife and former nurse, Elaine Mason, does not appear in the film, and Hawking introduces their 1995-2007 marriage with a few pictures and a brief description.

    In 1869, the Smiley family purchased an area of land about 100 miles north of New York City. Over time, some of their property and much of the surrounding landscape became the Mohonk Preserve, which has since grown to 8,000 acres and attracts visitors and rock climbers.

    But the Mohonk Preserve also has a long scientific legacy. In the 1930s, Dan Smiley, a descendent of the original owners, began keeping track of the plants and animals that lived in the area.

    Megan Napoli is a research ecologist with the Mohonk Preserve in New York. She thinks Smiley's efforts produced a rare long-term data set of observations, which is useful for studying the impacts of climate change. For instance, other research has shown that songbirds are migrating north earlier and earlier in the spring.

    It's important for the birds to arrive at the proper time in the spring, because they need to time their arrival with the insect emergence. So they need to be here to establish their nesting sites, lay their eggs. Once the eggs hatch, they have their baby birds, so they need to time it when the insects are most abundant.

    Napoli has begun analyzing about 76,000 observations of songbird migration dates collected by Smiley and his team to see if they, too, show that climate change has altered the timing of migrations. Her results suggest that they do.

    Napoli found that short-distance migrants that spend their winters in the southern U. S. now arrive an average of eleven days earlier than they did in the 1930s. Long-distance migrants that overwinter in the tropics arrive roughly a week earlier. Napoli presented her results at a recent Ecological Society of America meeting in Portland, Oregon.

    Meanwhile, who knows how many other long-term, personal data collections like Smiley's are out there, waiting to be discovered and to help improve official attempts to track the planet's changes.

    Moving smoothly and silently through Alibaba Group Holding Ltd's futuristic "FlyZoo" hotel, black disc-shaped robots about a metre in height deliver food and drop off fresh towels.

    The robots are part of a set of high-tech tools that Alibaba says strongly cuts the hotel's cost of human labour and eliminates the need for guests to interact with other people.

    Formally opened to the public last month, the 290-room FlyZoo is an incubator for technology Alibaba wants to sell to the hotel industry in the future and an opportunity to showcase its prowess in artificial intelligence. It is also an experiment that tests consumer comfort levels with unmanned commerce in China.

    Inside the hotel, softly-lit white panelled walls bring to mind the interiors of Hollywood spaceships. Guests check in at podiums that scan their faces, as well as passports or other ID. Visitors with a Chinese national ID can scan their faces using their smartphones to check in ahead of time.

    Elevators scan guests' faces again to verify which floor they can access and hotel room doors are opened with another face scan.

    "It's very quick and safe. I haven't used it much yet, but basically, I can be in my room in one minute, "said guest Tracy Li. Li added that safety was one of her priorities and she was pleased her room could only be entered with a scan of her face.

    In the rooms, Alibaba's voice command technology is used to change the temperature, close the curtains, adjust the lighting and order room service.

    At the hotel's restaurant, taller capsule-shaped robots deliver food that guests have ordered via the FlyZoo app while at a separate bar, a large robotic arm can mix more than 20 different types of cocktails. Facial recognition cameras add charges to the room rate automatically.

    The hotel does employ humans, though Alibaba declined to detail how many. This includes chefs and cleaners as well as reception staff, who will assist with conventional check-in procedures for guests unwilling to have their faces scanned and want to use electronic key cards.

A Dream Chaser in a Wheelchair

    Since the age of three, Chelsie Hill had dreamed of becoming a dancer. That ambition nearly ended in 2010 when Hill was in a car accident, which put the 17- year-old high school senior in hospital for 51 days and left her paralyzed from the waist down. For most people, that would have destroyed any hope of a dancing career. But for Hill, it was the beginning. Far from being a barrier, her wheelchair encouraged her to fight. "I want to prove to everyone including myself that I'm still normal," she said, "whatever normal means."

    Normal for her meant dancing, so Hill did it in her wheelchair alongside her nondisabled high school dance team. Half of her body was taken away from her, so she had to move it with her hands. It took much learning and patience.

    After graduation from high school, Hill wanted to expand her dance network to include women like her. She met people online who were fighting for the dream of dancing against various spinal(脊椎的)injuries, and invited them to dance with her. To reach more people in a larger city, Hill moved to Los Angeles in 2014 and formed a team of dancers with disabilities she called the Rollettes.

    Every year Hill holds a dance camp called the Rollettes Experience for wheelchair users to help them bring out their acting talent. In 2019, 173 participants from ten countries attended. For many, it was the first time they'd felt they belonged. Edna Serrano said that being part of the Rollettes team gave her the courage to get behind the wheel of a car. "I didn't know I could do so many things that my fellow teammates had taught me." she said. "I didn't know I could be sexy. It's so powerful to have my teammates in my life, because they're my teachers. I have more confidence."

    Chelsie Hill attained what many of us never will: her childhood dream. She has been chasing her dream in the wheelchair. She's a dancer. The Rollettes have helped her find something else just as fulfilling.