Several times my daughter had telephoned to say, "Mum, you must come and see the daffodils (水仙花) before they are over."

    I wanted to go, but it was a two-hour drive from Lake Arrowhead. "I will go next Tuesday," I promised, a little unwillingly, on her third call.

    The next Tuesday dawned cold and rainy. Still, I had promised, and so I drove there. When I finally walked into Carolyn's house and hugged and greeted my grandchildren, I said, "Forget the daffodils, Carolyn! The road is invisible (看不见的) in the cloud and fog, and there is nothing in the world except you and these children that I want to see!"

    My daughter smiled calmly and said, "We drive in such weather all the time, Mum. You will never forgive yourself if you miss this experience."

    After about twenty minutes, we turned onto a small road and on the far side of a small church, I saw a hand-lettered sign that read "Daffodil Garden". We got out of the car and each took a child's hand, and I followed Carolyn down the path. Then, we turned a corner of the path, and I looked up amazed. Before me lay the most beautiful sight. Flows of flowers of different colors seemed poured down the peak and slopes. There were five acres of flowers! A sea of daffodil! It was like a fairyland all beyond description.

    "But who has done this?" I asked Carolyn. "It's just one woman," Carolyn answered. That's her home. "Carolyn pointed to a well-kept A-frame house that looked small and modest in the midst of all that glory. We walked up to the house. On the patio (露台), we saw a poster. “Answers to the Questions I Know You Are Asking" was the headline. The first answer was a simple one. "50,000 bulbs (鳞茎)" it read. The second answer was, "One at a time, by one woman." The third answer was, "Began in 1958."

    I thought of this woman whom I had never met, who, more than fifty years before, had begun--one bulb at a time--to bring beauty and joy to this remote mountain top. Just planting one bulb at a time, year after year, had changed the world where she lived and created something of magnificence, beauty, and inspiration.

    When we multiply tiny pieces of time with small amounts of daily effort, we too can accomplish great things. Everyone can do something to change the world.

    Scientists have found what they believe are pieces of a meteor(流星)that fell to the earth last year. The objects were discovered off the coast of the United States in the Pacific Ocean.

    The crew of the Nautilus, a private research ship, recovered the rock particles(颗粒).The Nautilus is operated by the Ocean Exploration Trust. The group says its aim at present is to examine areas of the ocean that have never been explored before.

    The search was launched after US government weather stations observed a large meteorite exploding some months ago. The explosion lit up the sky and sent the rock particles to the earth. The meteorite fall was the largest recorded over the United States in at least 20years. The team includes scientists from NASA, the Olympic Coast National Marine Sanctuary and the University of Washington. The scientists examined what they believe were two small meteorite fragments. Further testing is needed before they can confirm that the material came from the explosion.

    The Nautilus is equipped with two remotely operated vehicles(ROVs), called Hercules and Argus. These robotic submarines help researchers find and collect materials from the seafloor. The fact that the particles landed in the ocean, instead of on land, means larger pieces may have survived and can be studied. For this reason, scientists decided to launch the first intentional search for meteorites from the ocean. Until the latest research, scientists had only accidentally discovered a small number of meteorites from drilling operations.

    The objects recovered from the bottom of the sea likely came from the recent explosion for two main reasons. First, meteorite particles are basically made of glassy materials that do not tend to last long in seawater. Secondly, they came from what looked like a small hole on the seafloor. Some evidence shows that they came from something that fell.

    Have you ever fallen for a novel and been amazed not to find it on lists of great books? Or walked around a sculpture known as a classic, struggling to see why it is famous? If so, you've probably thought about the question a psychologist, James Cutting, asked himself: How does a work of art come to be considered great?

    The direct answer is that some works of art are just great: of inner superior quality. The paintings that win prime spots in galleries, get taught in classes are the ones that have proved their artistic value over time. If you can't see they're superior, that's your problem. But some social scientists have been asking questions of it, raising the possibility that artistic canons(名作目录)are little more than old historical accidents.

    Cutting, a professor at Cornell University, wondered if a psychological pattern known as the "mere­exposure effect" played a role in deciding which paintings rise to the top of the cultural league. Cutting designed an experiment to test his hunch(直觉). Over a lecture course he regularly showed undergraduates works of impressionism for two seconds at a time. Some of the paintings canonical, included in art­history books. Others were lesser known but of comparable quality were exposed four times as often. Afterwards, the students preferred them to the canonical works, while a control group liked the canonical ones best. Cuttings students had grown to like those paintings more simply because they had seen them more.

    Cutting believes his experiment casts light on how canons are formed. He reproduced works of impressionism today bought by five or six wealthy and influential collectors in the late 19th century. Their preferences given to certain works made them more likely to be hung in galleries and printed in collections. And the fame passed down the years. The more people were exposed to, the more they liked it, and the more they liked it, the more it appeared in books, on posters and in big exhibitions. Meanwhile, academics and critics added to their popularity. After all, it's not just the masses who tend to rate what they see more often more highly. Critics' praise is deeply mixed with publicity. "Scholars", Cutting argues, "are no different from the public in the effects of mere exposure."

    The process described by Cutting show a principle that the sociologist Duncan Watts calls "cumulative advantage": once a thing becomes popular, it will tend to become more popular still. A few years ago, Watts had a similar experience to Cutting's in another Paris museum. After queuing to see the "Mona Lisa" at the Louvre, he came away puzzled: why was it considered so superior to the three other Leonardos, to which nobody seemed to be paying the slightest attention?

    When Watts looked into the history of "the greatest painting of all time", he discovered that, for most of its life, the "Mona Lisa" remained in relative obscurity. In the 1850s, Leonardo da Vinci was considered no match for giants of Renaissance art like Titian and Raphael, whose works were worth almost ten times as much as the "Mona Lisa" It was only in the 20th century that "Mona Lisa rocketed to the number­one spot. What brought it there wasn't a scholarly re­evaluation, but a theft. In 1911 a worker at the Louvre walked out of the museum with the "Mona Lisa" hidden under his coat. Parisians were shocked at the theft of a painting to which, until then, they had paid little attention. When the museum reopened, people queued to see it. From then on, the "Mona Lisa "came to represent Western culture itself.

    The intrinsic (本质的) quality of a work of art is starting to seem like its least important attribute. But perhaps it's more significant than our social scientists admit. Firstly, a work needs a certain quality to reach the top of the pile. The "Mona Lisa" may not be a worthy world champion but it was in the Louvre in the first place, and not by accident. Secondly, some objects are simply better than others. Read "Hamlet" after reading even the greatest of Shakespeare's contemporaries, and the difference may strike you as unarguable.

    A study suggests that the exposure effect doesn't work the same way on everything, and points to a different conclusion about how canons are formed. Great art and mediocrity (平庸)can get confused, even by experts. But that's why we need to see, and read, as much as we can. The more were exposed to the good and the bad, the better we are at telling the difference.

    Scientists say they discovered an earth­like planet orbiting the star closest to our planet other than the sun. It is the closest planet ever found outside our solar system that could support life as we know it. This planet is just 4.2 light years away from us. It is so close that space scientists have compared it to a next door neighbor. They say it could be reached by an unmanned spacecraft before the end of the century. The newly­discovered planet is a little larger than the earth. Scientists have named it Proxima b. It orbits its sun, Proxima Centauri, once every 11days.

    Alan Boss is the Chairman of NASA's advisory group for planet exploration. He told VOA that Proxima b not only confirms the discovery of a planet, but also increases the number of other possible "earths" by a huge amount. Boss said it is possible that most stars may have at least one earth­like planet orbiting them.

    This makes the possibility of living organisms increasingly likely. Boss said he believes human beings will prove that there is life in places other than the earth in his lifetime. "I am 65," he told VOA, "But I expect to still be alive when it happens."

    Paul Butler works at the Carnegie Institution of Washington. He told VOA that finding Proxima b "makes the case concrete" that there are other planets where life could exist. Paul Butler said the researchers used two telescopes in different countries to look for possible planets like the earth. Discovering Proxima b, he believes, changes the world.

    "This work has resulted in the discovery of hundreds of planets around the nearest stars, and now a potentially habitable planet around the nearest star is in the sky," Butler said.

    Humans are social animals. They live in groups all over the world. As these groups of people live apart from other groups, over the years and centuries they develop their own habits and ideas, which are different from other cultures. One important particular side of every culture is how its people deal with time.

    Time is not very important in nonindustrial (非工业的) societies. The Nuer people of East Africa, for example, do not even have a word TIME that is in agreement with the abstract thing we call time. The daily lives of the people of such nonindustrial societies are likely to be patterned around their physical needs and natural events rather than around a time schedule (时间表) based on the clock. They cook and eat when they are hungry and sleep when the sun goes down. They plant crops during the growing seasons and harvest them when the crops are ripe. They measure time not by a clock or calendar, but by saying that an event takes place before or after some other event. Frequently such a society measures days in terms of "sleeps" or longer periods in terms of "moons". Some cultures, such as the Eskimos of Greenland measure seasons according to the migration of certain animals.

    Some cultures which do not have a written language or keep written records have developed interesting ways of "telling time". For example, when several Australian aborigines want to plan an event for a future time, one of them places a stone on a cliff or in a tree. Each day the angle of the sun changes slightly. In a few days, the rays of the sun strike the stone in a certain way. When this happens, the people see that the agreed-upon time has arrived and the event can take place.

    In contrast (成对比), exactly correct measurement of time is very important in modern, industrialized societies.

    This is because industrialized societies require the helpful efforts of many people in order to work. For a factory to work efficiently (well, quickly and without waste), for example, all of the workers must work at the same time. Therefore, they must know what time to start work in the morning and what time they may go home in the afternoon. Passengers must know the exact time that an airplane will arrive or depart. Students and teachers need to know when a class starts and ends. Stores must open on time in order to serve their customers. Complicated (复杂的) societies need clocks and calendars. Thus, we can see that if each person worked according to his or her own schedule, a complicated society could hardly work at all.

New research into a long-lived tree has shown some of the tricks that have helped it survive for thousands of years. The ginkgo(银杏树) is a huge, slow-growing tree with fan-shaped leaves, native to China, but planted in parks and gardens across the world. Some of the largest ginkgoes are said to be more than 3, 000 years old.

In order to discover how these and other trees can live for so long, scientists from the US and China studied 34 healthy ginkgoes of different ages. The team studied growth rings in each tree's trunk(树干), as well as cells(细胞) from the bark, leaves and seeds. They found that 600-year-old trees were just as healthy as 2-year-olds.

To learn more, the team then looked in detail at the DNA of nine trees aged between three and 667 years old. DNA is the chemical in the cells of plants and animals that holds instructions that tell any living thing how to grow and develop-including what to do at different times in its life At the beginning of a tree's life, DNA instructs the cells in a seedling to divide quickly so the tree grows rapidly. The cells also make special chemicals to help the young plant survive difficult situations, such as disease. As most trees grow older, their DNA tells their cells to divide more slowly (so growth slows down) and to make fewer chemical defenses(防御).

Ginkgoes, however, do things differently. The team found that although their growth finally slows, both young and old trees make protective chemicals." The secret is keeping a really healthy defense system," said researcher Richard Dixon." As ginkgoes age, they show no sign of weakening their ability to defend themselves from things like disease. "Other trees that live for a long time may have the same ability.

For all their defenses, though, ginkgoes cannot live forever--they finally meet with deadly accidents such as fire, disease and storms. While they last, however, these leafy trees are some of the most beautiful trees in the world.