Last night's meteor (流星) shower left many people in the community dissatisfied and demanding answers. According to Gabe Rothschild, Emerald Valley's mayor, people gathered in the suburbs of the city, carrying heavy telescopes, expecting to watch the brightly burning meteors passing through the sky. What they found instead was a sky so brightened by the city's lights that it darkened the light of the meteors passing overhead.

     “My family was so frustrated,” admitted town resident Duane Cosby, “We wanted to make this an unforgettable family outing, but it turned out to be a huge disappointment.”

    Astronomers—scientists who study stars and planets—have been complaining about this problem for decades. They say that light pollution prevents them from seeing objects in the sky that they could see quite easily in the past. They call on people and the government to take measures to fight against it.

    There is yet a population besides professional and amateur star observers that suffers even more from light pollution. This population consists of birds, bats, frogs, snakes, etc. For example, outdoor lighting severely affects migrating (迁徙的) birds. According to the International Dark-Sky Association, “100 million birds a year throughout North America die in crashes with lighted buildings and towers.”

    Countless more animal casualties (伤亡) result from the use of artificial lighting. Clearly, people enjoy the benefits of lighting their evenings. But some scientists think it can be harmful for humans, too. They worry that exposure to light while sleeping can increase a person's chances of getting cancer.

    Emerald Valley is only one community that is becoming aware of the negative effects of light pollution. For years, Flagstaff, Arizona, has enforced lighting regulations in its city in order to assist astronomers at the Lowell Observatory. Similar efforts have been made worldwide, and a movement is underway to remind us to turn off lights when we are not using them, so that other creatures can share the night.

    The "Boomerang Kids" — young adults who leave to go to college, get married or just show off their independence — are moving back in with mom and dad. Boomerang Kids can be a mixed blessing for parents, both emotionally and financially.

    Especially during hard economic times, adult children head for home. According to a survey, about 40 percent of 2017 graduates still live with their parents. Moreover, 42 percent of the 2015 graduates surveyed said they are still living at home.

    The reasons are many, the first being economics. While the recession(衰退) has touched Americans of all ages, it has been very hard for young adults. This has sent many kids back home. Plus, there is the matter of debt, especially college loans. For many recent graduates, it makes smart economic sense to move back in with their parents where life is comfortable and rent is either low or nonexistent. Then, of course, some return for personal reasons, such as recovering from a divorce or an illness.

    Parents are often glad to help out, both emotionally and financially. As a result, the arrangement often works to everyone's satisfaction. However, there are risks, especially for the parents. These include not only family tension and misunderstandings, but also money. The return to the family can become a financial burden that can affect the parents' plans and their financial future, especially their retirement, as they try to do too much for their children.

A Teenage Inventor

    The world could be one step closer to quick and inexpensive Ebola detection thanks to a teenager from Connecticut.

    Olivia Hallisey, a junior at Greenwich High School, was awarded $50,000 in the Google Science Fair for her new method that detects Ebola, a virus that causes bleeding from different parts of the body and usually causes death. Olivia's method is to ask patients to put their saliva (唾液) onto a testing card. The card changes color if the person is catching Ebloa. Present Ebloa tests take up to 12 hours and cost $1,000. Olivia's method, however, can be done just in 30 minutes for about $25. Besides, the sample (样本) doesn't have to be put in a refrigerator thanks to the silk material Olivia uses to produce the testing cards.

    Olivia was inspired to deal with this global problem after watching the news that more than 10,000 people died from Ebola in West Africa. She was particularly worried about the fact that, while the acts of involvement can improve survival rates, present detection methods are costly, time-consuming and require complex tools. Olivia got help from her science research teacher. She drew out directions from past research, and figured out detection systems that have proven to work with other diseases, including Lyme disease and yellow fever.

    "What affects one country affects everyone," Olivia told CNBC. "We have to work together to find answers to the huge challenges which cause harm to the global health." The Connecticut's teen, who hopes to become a doctor one day, was named the Google Science Fair winner in the competition of 20 competitors from across the globe. The fair is open to young people between the ages of 13 and 18 in most countries.

    Olivia hopes her success will inspire other girls interested in science and computers. "I would just encourage girls to try it in the beginning, and remind them that they don't have to feel naturally drawn or feel like they have a special talent for maths or science," she told CNBC, "but just really look at something they are interested in and then think how to improve something or make it more enjoyable or relate it to their interests."

    If humans pump enough carbon dioxide (CO₂) into the atmosphere, the stratocumulus clouds(层积云) could disappear, and the earth's temperature could climb sharply to heights not predicted in current climate models. It would burn the planet. That's the conclusion of a paper published in the journal Nature Geoscience and described in detail by Natalie Wolchover for Quanta Magazine.

    As Wolchover explained, clouds have long been one of the great uncertainties of climate models. Computer models that easily capture the complexity and detail of most climate systems just aren't powerful enough to predict worldwide changes in cloud behavior. But clouds are important. They reflect sunlight away from the earth's surface. And stratocumulus clouds are those white blankets you might have seen as you looked out the window of arm airplane, rolling out below you and hiding the ground Researchers suspect that certain sudden, past jumps in temperature may have been caused by changes to clouds like these.

    For the new research, scientists modeled just a small patch of sky using a supercomputer. They found that if carbon dioxide levels reach about 1, 200 parts per million(ppm) in the atmosphere, stratocumulus clouds break up. That's a very high carbon dioxide concentration.  Right now, levels have climbed past 410 ppm--a dangerous change from 280 ppm before the Industrial Revolution.

    But humans put more and more CO₂ into the atmosphere every year. If current trends continue, the earth could reach 1, 200 ppm within 100 to 150 years. This could happen if our society doesn't follow through on any of its commitments to reduce emissions(排放), Wolchover reported. And even if it does, the result would be another 8 degrees Celsius of heat added to the global average, on top of the dangerous changes already underway due to greenhouse gases.

    That's an enormous change, and it goes beyond predictions of worldwide ice melt and catastrophic sea level rise. And, once the stratocumulus clouds are gone, Wolchover reported, they likely wouldn't reappear until atmospheric carbon dioxide levels dropped below where they are currently.

    There's still some uncertainty in the data. The 1, 200 ppm figure could change as scientists look into the issue further.

    Scientists are studying different foods, and they will see which foods protect us from cancer (癌症), and which cause it. It is known that a healthy diet (饮食) will help keep a healthy body weight, which can also decrease the risk (风险) of many types of cancer.

    Fruit and vegetables

    Fruit and vegetables are an important part of a healthy diet. They can decrease the risk of some cancer types like mouth and throat cancer. They are a good source of many important nutrients such as vitamin A, vitamin C, vitamin E, and are an excellent source of fiber.

    Our advice

    Try to get plenty of fruit and vegetables in your diet. Eating fruit and vegetables with a variety of colors will help you get many kinds of vitamins and minerals as the chemicals that give these foods their colors are good for you.

    Meat

    Eating lots of red and processed meat can increase (增加) your risk of stomach cancer. Red meat includes all fresh and frozen beef, pork and lamb. Processed meat includes ham, bacon and sausage. White meat, such as chicken, is unlikely to increase your risk of cancer.

    Our advice

    Eat smaller and fewer parts of red and processed meat. Try using beans or peas instead of meat in your diet. When you cook meat, use low-temperature methods.

    Fat

    Fat is a necessary part of our diet but high-fat diet can increase our risk of cancer, heart disease and other diseases. Meat is higher in saturated fat (饱和脂肪) and eating too much saturated fat may increase your risk of breast cancer.

    Our advice

    Try not to eat too much fatty foods. In particular, try to cut down on saturated fat contained in fatty meat, biscuits, and butter. Try to avoid frying foods in lots of oil.

    When a terrible earthquake hit, many people were killed and many houses fell down. After the earthquake, all the newspapers reported many stories about some of the families who were in trouble.

    One Sunday, when I was reading a newspaper, a special picture touched me. It gave the clothing sizes of each family member. I thought that this would be a good chance to teach my children to help those who were less lucky than ourselves. I said to my seven-year-old twins, Brad and Brett, and three-year-old Meghan. "We have so much, and these poor people now have nothing. We'll share what we have with them."

    I filled a box with foods and clothes. While I was doing this, I encouraged the boys to choose their toys and donate some of their less favorite things. Meghan watched quietly as the boys took out their old toys and games and put them together. Then she walked away. A few minutes later she came back with Lucy, her much-loved doll. She put the doll on top of the other toys. "Oh, dear," I said. "You don't have to give Lucy. You love her so much." Meghan said, "Lucy makes me happy, Mommy. Maybe she'll make another little girl happy, too."

    I looked at Meghan for a long moment. She taught me a lesson. It's easy to give something that we don't want any more, but harder to give what we cherish (珍爱), isn't it?