If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal(夜间活动的) species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun's light. This is a basic evolutionary fact, even though most of us don't think of ourselves as diurnal beings. Yet it's the only way to explain what we've done to the night: We've engineered it to  receive us by filling it with light.

    The benefits of this kind of engineering come with consequences 一 called light pollution 一 whose effects scientists are only now beginning to study. Light pollution is largely the result of bad  lighting design, which allows artificial light to shine outward and upward into the sky. III-designed lighting washes out the darkness of night and completely changes the light levels 一 and light  rhythms — to which many forms of life, including, ourselves, have adapted. Wherever human light spills into the natural world, some aspect or life is affected.

    In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze(霾) that mirrors our fear of the dark. We've grown so used to this orange haze that the original glory of an unlit nigh, - dark enough for the planet Venus to throw shadow on Earth, is wholly beyond our experience, beyond memory almost.

    We've lit up the night as if it were an unoccupied country, when nothing could be further form the truth. Among mammals alone, the number of nocturnal species is astonishing, Light is a powerful biological force, and on many species it acts as a magnet(磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

    Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times righter than normal, throwing nearly every aspect of their behavior out of joint including most other creatures ,we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

    Living in a glare of our making,we have cut ourselves off from our evolutionary and cultural heritage—the light of the stars and the rhythms of day and night .In a very real sense light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way—the edge of our galaxy arching overhead.

    I wasn't surprised when I read that actress Helen Hunt recently stated that she would never allow her young daughter to become a child star. Ms. Hunt is the daughter of a Hollywood technical director, and grew up in Hollywood. Now in her late 40s, she started acting and modeling when she was eight and has probably seen a lot over those years in show business.

    She has had a successful career. She earned four Golden Globes and four Emmys. She also attained the top honor of her profession when she won the Best Actress Academy Award for her role in the 1992 movie, As Good As It Gets. Given those accolades, Ms. Hunt is successful. There is no doubt that her early experiences as a child star prepared her for what has been an outstanding adult career. Given those achievements, why would this star declare she'll never allow her daughter, now at the age of six, to follow in her footsteps?

    Everyone familiar with the entertainment scene is aware of the reasons for her attitude. Recent tabloid (小报) news headlines featuring the troubles of former child stars, among them Lindsay Lohan, Britney Spears and the late Gary Coleman, may answer the question. Although Ms. Hunt managed to become a successful grown-up star, she apparently believes she's an exception.

    What Ms. Hunt may be suggesting is that many very young stars go through unnatural childhoods on movie and TV sets. While they're earning big incomes, they're so pampered (纵容) by directors and praised by fans; they may get false impressions that their lives will always be that way. Then, within a few years, when faced with reality, they're hurt and confused. After all the overwhelming affection, they find they can't deal with the problems. That's often when drugs and alcohol take over their lives.

    Helen Hunt has some other reasons why she doesn't want her daughter to be in the entertainment business. Many child stars can never make a successful transition to meaningful adulthood. However, as with many Hollywood movies, I believe there are both good and bad scenes about how it can be played out in real life.

    A little boy discovered what looked like a map to an unknown place. He soon realized it was the beginning of an exciting treasure hunt.

    He found two pieces of paper along with the mysterious map. One was written with the instructions, “FIND THE WORDS.” The other piece of paper had several strange symbols scattered all over it.

    Dad, fortunately, was there to help his son figure out the mystery. He folded up the paper with the symbols on it, and together they formed a message, which had another set of instructions, “UNDER STEPS.” The smart little boy knew exactly what to do so he went to look under the steps of his house. Without too much effort, he found a box below the staircase.

    It didn't take him long to figure out what to do next: open it up! Inside the box were some very interesting objects, including another piece of a treasure map and two broken pieces of paper. These were the most interesting finds because they contained what appeared to be a collection of letters on them. Finally, they knew where the treasure was from the letters: IN THE BUSH UNDER YOUR YARD.

    After searching all over the yard, following several clues and wondering where everything would lead, the pair finally found what they had been looking for. And it was exactly what you would want after such an adventure: a treasure box!

    The pair pulled it out of the ground and cleaned away all the dirt. The dad put the box in front of his son, and the little boy couldn't contain his excitement. So he opened it up and finally found out what was inside.

    Inside was more treasure than any little boy could ever want. There were hundreds of coins and all sorts of pirate treasure, including what looks like a pearl necklace and some silver dishes.

    Many of us have had this experience: we lie down in a bed other than our own, perhaps at a friend's house or in a hotel room, and find it difficult or impossible to fall asleep. Is it because the bed is uncomfortable? Maybe, but perhaps there can be other reasons.

    According to a new study published in Current Biology, a significant reason is what the scientists call "first night effect". They believe that one side of the brain acts as a "night watch" to warn us about potential dangers. It forces us to stay awake on the first night in a new environments.

    For the study, 35 young volunteers were asked to sleep in a sleep lab for several days. Meanwhile, researchers watched their brain activities.

    According to the researchers, on their first night, the left brain was more active than the right brain and people had a hard time sleeping. However, left-brain activities decreased as days went by, falling even to the point of complete calm. In this process, the participants got an increasingly better sleep experience.

    The findings suggest that the different rhythms of the sides of the brain affect our sleep. When the two sides work differently, the balance between them is broken. Thus, the brain can't relax and is sensitive to anything strange in the surroundings, just as it is in the daytime.

    "At some level, the brain is continuing to analyze things, even though you are not aware of the analysis, " US professor Jerome Siegel told Smithsonian

    "If something unusual happens - if a door opens or you hear a key in a lock --you can be alert, even though the intensity of the stimulus (刺激强度) is quite low." More surprisingly, this phenomenon is similar to the way some animals sleep.

    The researchers think that it is the result of evolution (进化), and works to protect us in potentially dangerous environments.

    If you have ever had what you think is "first night effect", researchers suggest that you bring your own pillow or sleep in a room similar to your bedroom next time you sleep away from home.

Walking has been considered as one kind of rewarding exercise. For many people, daily walking offers massive and long-term physical and mental benefits. {#blank#}1{#/blank#} A Stanford University study found that participants were more creative when walking as opposed to sitting. 

{#blank#}2{#/blank#} You've probably heard the phrase "exercise your creativity". Our creative mindset is stirred up by physical movement, which is exactly why walking with your dog, a friend, or alone feeds creative thinking. 

But the scenery is almost as important as the sweat. Just by going outside, you are stepping out of your habitual surroundings and your comfort zone, which is necessary if you want to open your mind to new possibilities. You can walk through a tree-filled neighborhood. {#blank#}3{#/blank#} Even when you walk down a busy street, you can't help but get distracted by the sweet smells from a food cart or the child pointing to a building you haven't even noticed before. 

Walking outside develops our ability to collect new ideas and take in new sights, sounds, smells, and flavors. Shinrin-yoku, a common form of relaxation in Japan, suggests that being in the forest and walking among the trees there can lower your stress levels. {#blank#}4{#/blank#} Research has shown that getting close to nature around your neighborhood or taking a break from multimedia increases performance on a creative problem-solving task. 

So instead of setting a fitness goal, why not set a creativity goal that starts with walking outdoors? {#blank#}5{#/blank#} For example, you can turn off your phone and give yourself the chance to be present in the world, to hear conversations and natural sounds, and to notice the way people move and the way the sun reflects in a lake. 

Walk not just for exercise. Walk for wonder.

A.Unfortunately, you often fail to do it.

B.Expose yourself more to your surroundings.

C.The movement during walking is obviously key.

D.Without enough energy, you cannot wonder or create.

E.But to receive the benefits, you do not have to live in a forest.

F.This habit, however, not only benefits well-being but also contributes to innovation.

G.Wandering around a park and observing people relaxing or birds singing is also a choice.

I was sitting at my desk when another graduate student in my lab approached me. "Can you help?" he asked. His experiment wasn't working and he desperately needed help. I was then a fifth year PhD student, and I took pride in being the senior member of the lab, whom everyone looked up to. But that also meant I was the one everyone turned to for help — which ate away bours, days, and sometimes weeks that I could have spent on my own research.

There were many reasons I had a hard time saying no to such pleas (恳求). I was new to the United States for graduate school. I found it difficult to make new friends and discover activities I enjoyed. So I spent a huge chank of my time in the lab, with my lab-mates serving as my primary source of social connection. I feared that if I turned down their requests, I'd lose their favor.

But the extra responsibilities came at a cost. I had to work extra hours to catch up with my own work, and I often made sacrifices to my personal life.

It wasn't until my wife gave birth to our first child that I realized how thin I had stretched myself and how misguided my priorities(优先次序) were. While she lay in a hospital bed in the early stages of labor, I sat nearby hunched(伏首前倾的) over my laptop finishing up a work report. Hours later, after hearing my daughter's first cry and watching her tiny fingers grab tightly onto mine, it dawned on me: I should have been fully present during my daughter's birth. I was clearly spending too much time working if my job had intruded(侵入) into one of the most precious moments of my life.

From then on ,I decided to spend more time with my family by declining extra assignments and carefully considering each request for help. I still enjoyed collaborating with others, but I prioritized mutually beneficial tasks or those my manager asked me to take on, rather than accepting everything that came my way.

I noticed many benefits: no longer working overtime and improved work performance. I was also pleased to discover that "Sorry , I'd love to help but I have a deadline coming up" is an acceptable response to a request for assistance.

It's hard to say "no " to those you work with. But I've learned that sometimes that's the best course of action to avoid an excessive workload and lead a freer and happier life.