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.

    Thanksgiving Day is a special holiday in the United States and Canada. Families and friends gather to eat and give thanks for their blessing.

    Thanksgiving Day is really a harvest festival. This is why it is celebrated in late fall, after the crops are in. But one of the first thanksgivings in America had nothing to do with a good harvest. On December 4,1619, the Pilgrims from England landed near what is now Charles City, Virginia. They knelt down and thanked God for their safe journey across the Atlantic.

    The first New England Thanksgiving did celebrate a rich harvest. The Pilgrims landed at what is now Plymouth, Massachusetts, in 1620.They had a difficult time and the first winter was cruel. Many of the Pilgrims died. But the next year, they had a good harvest. So Governor Bradford declared a three­day feast (盛宴).The Pilgrims invited Indian friends to join them for their special feast. Everyone brought food.

    In time, other colonies (殖民地) began to celebrate a day of thanksgiving. But it took years before there was a national Thanksgiving Day. During the Civil War, Sarah Josepha Hale persuaded Abraham Lincoln to do something about it. He proclaimed (宣布) the last Thursday of November 1863 as a day of thanksgiving.

    Today, Americans celebrate this happy harvest festival on the fourth Thursday in November. Canadians celebrate Thanksgiving Day in much the same way as their American neighbours. But the Canadian Thanks­giving Day falls on the second Monday in October.

    As we age, our ability to think and remember starts to deteriorate. But not everyone. Some of us have brains that age more slowly. Enter the super-ager!

    Super-agers are people over the age of 80 who have the brain structures and abilities of much younger people. Eighty-seven-year-old Bill Gurolnick is a super-ager. “What do I feel like? If I was to give a number, I probably feel like I'm about my early 70s…”

    Scientists know that parts of the brain decrease in size with age. But in super-agers that process is much slower. Emily Rogalski is a neuroscientist at Northwestern University's Feinberg School of Medicine, in Chicago, Illinois. In a recent study, she showed that super-agers have young brains. The area of the brain responsible for attention and memory—the cortex—was shown to be thicker in super-agers. “When we look at the cortex of their brain, we see that, on average, that it looks more like a 50-year-old brain that it looks like an average 80-year-old bran…”

    Not only do super-ages have thicker cortexes, they have more spindle neurons. These large brain cells appear to be involved with social-emotional communication. But their exact purpose is still a mystery. Scientists writing for Smithsonian magazine say they are “brain cells for socializing.”

    Several factors affect how our brains age. Scientists say super-agers have several things in common, including an active lifestyle. Many travel and play sports. They are often big readers. And they usually have healthy relationships and spend time with friends. Super-agers also seem to have certain common personality traits. Rogalski says they are, for the most part, known for their optimism, resilience and perseverance. Growing old, she adds, does not have to be depressing and sad. “Perhaps, if we expected a bit better from ourselves, then we would understand that not all aging is stressful!”

    Can we all be super-agers? The science behind super-aging is a relatively new, but growing field. Scientists involved in the research offer this advice as we age: Stay active. Learn new things. Challenge yourself. Surround yourself with healthy relationships.

    Thomas Edison was one of ten said to be the greatest genius of his age. There are only a few men in all of the history, who have changed the lives of other men as much as the inventor of the first useful electric light. But Edison could never be happy only because someone said he was a genius. “There is no such thing as genius,” Edison said. He said that what people called genius was mostly hard work.

    But Edison was a dreamer as well as a worker. From his earliest days as a child he wondered about the secrets of nature. Nature, he often said, is full of secrets. He tried to understand them; then, he tried to learn what could usefully be done with them.

    Edison enjoyed thinking. He knew that most people will do almost anything instead of the difficult work of thinking, especially if they do not think very often. But he knew, too, that thinking can give men enjoyment and pleasure.

    Edison could not understand how anyone could be uninterested in life. As he loved to think, he also loved to work. On the day he became 75 years old, someone asked him what ideas he had about life. “Work,” he answered. “Discovering the secrets of nature and using them to make men happier.” He said he had enough inventions in his mind to give him another 100 years of work.

    My elephant adventures began in 1984 when, with our one-year-old daughter, my husband and I crossed the jungle in a jeep, slicking behind a lorry for comfort and company. The elephants standing like watchers on either side of the forest highway had us praying for our safety. One elephant made loud noise and angrily pawed (抓) the ground, warning us off. We raced away before they could attack.

    It was wise to keep elephants at a distance. We heard stories of tourists whose jeeps were overturned, and a couple of photographers were killed because they moved too close. Elephants are misleading animals. They give people an impression of being quiet and kind, so tourists think it's safe to picnic in the jungle (丛林). Yet angry elephants have knocked them down in seconds before they could take off.

    Elephants might make life unpredictable and dangerous. It's difficult for inexperienced environmentalists to even, begin to grasp this reality. I've heard city people say " We humans are encroaching (侵害) on their forests." But what's the solution?

    When a poor farmer borrows heavily to plant a crop, he'll do anything to protect it His life depends on it Elephants ruining an about-to-be-harvested corn field cannot expect to be welcomed like special guests. The battle between beast and farmer is violent.

    Experts are working on solutions to human-elephant conflicts (冲突). Some are sure to fail to like the plans to build electric fences around human settlements. Elephants rapidly figure them out and come in, around and over them.

    There are more questions than answers, for sure. But as my husband said, "More people die in car accidents every single day, in every city on the earth. But they won't take cars off the roads, will they?" So we need to seek practical ways of preventing elephant accidents.

    Roughly the size of a soda can, sitting on a bookshelf, a relatively harmless device(设备) may be turning friends away from your home. The elephant in your living room is your Internet-connected camera, a device people are increasingly using for peace of mind in their homes. But few stop to think about the effect these devices may have on house guests. Should you tell your friends, for instance, that they're being recorded while you all watch the big game together?

    "It's certainly new territory, especially as home security cameras become easier to fix," says Lizzie Post, president of the Emily Post Institute, America's distinguished manners advisors." I think it will be very interesting to see what manners appear in terms of whether you tell people you have a camera or not, and whether guests have a right to ask that it be turned off, if it's not a security issue. "Post wants to make clear that she's not talking about legal rights, but rather personal preference.

When it comes to security cameras, Post says it's a host's responsibility to make sure guests feel comfortable within their home. If the host casually acknowledges that there is a camera in the room by telling a story about it, that may be enough to provide an opening for a guest to say if they are uncomfortable.

    However, if a contractor(合约工)is working in your home, you don't need to tell them that there are cameras watching. Then again, the camera can also work in contractors' favor. "If anything does go wrong while they're in the house, they don't want to be blamed for it," she says. "In fact, the camera could be the thing that proves that they didn't steal the $20, or knock the vase off the table.