Houses fall down. Trees fall over. Large holes form in the ground. Could Alaska be sinking? That's what some villagers in Alaska have been asking themselves recently and scientists think they know why. Warmer temperatures may be causing Alaska's frozen ground to thaw (解冻).

    About 85 percent of Alaska's land surface has permafrost (永久冻结带). Permafrost supports the ground above it—including trees, houses, and roads. But why is the permafrost thawing?

    Some scientists say that human-caused pollution is leading to global warming. And most scientists agree that Alaska has been getting warmer. They say that the warmer temperature is causing permafrost to thaw in some areas. The thawing permafrost can cause problems for people, plants, and animals.

    The collapsing (倒塌) is a problem in the villages in Alaska which are built on permafrost, and some of them may have to move to safer ground, where there is no permafrost.

    The Alaskan town of Glennallen saw its old post office collapse. And, according to James Walters, a permafrost expert at the University of Northern Iowa, house-moving companies have been very busy.

    “Melting permafrost can also destroy trees and forests,” Walters said. “When holes in the ground form, trees fall into them and die. This could turn a forest into a swamp (沼泽), and animals which need the forests will have to move elsewhere.”

    “The melting could cause severe problems.” Walters says, “This could take hundreds of years, but in the end Alaska will look quite different from what it looks like now.”

    What Does the Length of Your Fingers Say About You? Are you the peace-loving type or the ambitious go-getter?

    Your finger length might be a clue. Take a look at your fingers. Would you believe me if I told you that the length of your fingers in relation to one another can predict your personality? I know that it sounds like one of those silly tests you see on Facebook, but I have to admit that it is exactly correct for me. Here's how it works.

    Look at your three middle fingers of your hand. Is your index finger longer than your ring finger? Is your ring finger longer than your index finger? Or are the two of the same length? Find the situation that best matches your hand and see if what follows is an accurate description of your personality.

Longer ring finger: The Sweet Talker

    If your ring finger is longer than your index finger, research shows that you're likely a charming type, and you can probably talk yourself out of any situation. Others often find this personality type irresistible and will go to great lengths to help you. You're more likely to take risks, and you're good at problem-solving. People in this category make great engineers, soldiers and crossword-puzzle solvers.

Longer index finger: The (Over) Confident One

    If your index finger is longer than your ring finger, chances are you are full of confidence—possibly even to the point of being over-confident and proud. You are not necessarily introverted (内向的), but you do enjoy time to yourself, especially when you're trying to complete a project. You are a dream pursuer who can make things happen, but you may be shy when it comes to taking the first step in a relationship. You are also probably happy with what you have, but you're always wishing for more.

Index and ring finger are of the same length: The Peacemaker

    If your index finger and ring finger are roughly of the same length, you are likely to avoid conflict at all costs and seek to keep the peace in your relationships. You are well-organized, faithful and sympathetic. But deep down under all of that caring and peace-loving, you also have a hot-tempered side that can appear unexpectedly when you're pushed too far. You will try your hardest to avoid a fight.

    How well do these descriptions match your personality? I was surprised at the accuracy in my case, but I'm not going to tell you which one it was!

    As the world's population grows, farmers will need to produce more and more food. And large farms are increasingly using precision farming to increase yields (产量), reduce waste, and reduce the economic and security risks that inevitably accompany agricultural uncertainty.

    Traditional farming relies on managing entire fields—making decisions related to planting, harvesting, irrigating, and applying pesticides and fertilizer (农药和化肥)—based on regional conditions and historical data. Precision farming, by contrast, combines sensors, robots, GPS, mapping tools and data-analytics software to customize（量身定制）the care that plants receive without increasing labor. Robot-mounted sensors and camera-equipped drones (无人机) wirelessly send images and data on individual plants to a computer, which looks for signs of health and stress. Farmers receive the feedback in real time and then deliver water, pesticide or fertilizer in adjusted doses（剂量）to only the areas that need it. The technology can also help farmers decide when to plant and harvest crops.

    As a result, precision farming can improve time management, reduce water and chemical use, and produce healthier crops and higher yields—all of which benefit farmers' bottom lines and conserve resources while reducing chemical runoff.

    Many small businesses are developing new software, sensors, and other tools for precision farming, as are large companies such as Monsanto, John Deere, Bayer, Dow and DuPont. The U.S. Department of Agriculture, NASA and the National Oceanic and Atmospheric Administration all support precision farming, and many colleges now offer course work on the topic.

    In a related development, seed producers are applying technology to improve plant characteristics. By following individual plants over time and analyzing which ones flourish in different conditions, companies can relate the plants' response to their environments with their genomics (基因组学). That information, in turn, allows the companies to produce seed varieties that will grow well in specific soil and weather conditions. This advanced technology may also help to improve crop nutrition.

    Farmers do not universally welcome precision agriculture for various reasons, such as high equipment costs and lack of access to the Internet. The technology may bring great challenges to experienced farmers who are not good at computers. And large systems will also be beyond the reach of many small farming operations in developing nations. But less expensive, simpler systems could potentially be applied. For others, though, cost savings in the long run may reduce the financial concerns. And however reticent some farmers may be to adopt new technology, the next generation of farmers are likely to warm to the approach.

    I travel a lot, and I find out different "styles" of directions every time I ask "How can I get to the post office?"

    Foreign tourists are often confused in Japan because most streets there don't have names; in Japan, people use landmarks in their directions instead of street names. For example, the Japanese will say to travelers, "Go straight down to the corner. Turn left at the big hotel and go past a fruit market. The post office is across from the bus stop."

    In the countryside of the American Midwest, there are not usually many landmarks. There are no mountains, so the land is very flat; in many places there are no towns or buildings within miles. Instead of landmarks, people will tell you directions and distances. In Kansas or Iowa, for example, people will say, "Go north two miles. Turn east, and then go another mile."

    People in Los Angeles, California, have no idea of distance on the map; they measure distance in time, not miles. "How far away is the post office?" you ask. "Oh," they answer, "it's about five minutes from here." You say, "Yes, but how many miles away is it?" They don't know.

    It's true that a person doesn't know the answer to your question sometimes. What happens in such a situation? A New Yorker might say, 'Sorry, I have no idea." But in Yucatan, Mexico, no one answers "I don't know." People in Yucatan believe that "I don't know" is impolite, they usually give an answer, often a wrong one. A tourist can get very, very lost in Yucatan!

    My friend, Jack, was a taxi driver. We became friends quite by accident. Five years ago, I made a trip to Chicago. The moment I stepped into a cab, I realized it was different. The floor was covered with a rug (小地毯). There were small reproductions of paintings by Van Gogh inside the cab. And the windows were spotless. I told the driver I had never ridden in a more attractive taxi.

    "I like to hear my passengers say that," he replied. "How long have you been decorating your cab?" I asked. "It's not mine," he said. "It's a company cab. I hit upon the idea years ago when I worked as a clean-up man for the taxi company. Each car that came in at the end of the day was like a garbage pit. Cigarette butts and matches covered the floor. Sticky stuff like peanut butter was on the seats or door handles. I thought that if the company and the drivers would give people a car worth keeping clean, they might be more considerate."

    "As soon as I got my taxi license, I tried out my ideas. I put a lot of extra decorations into the cab they gave me to drive. I got a nice rug and some flowers. When each passenger got out, I checked to make sure that everything was in order for the next fare. After about a month of my bringing in a spotless cab, the boss reserved the same car for me each day. That was when I put up the reproductions of great paintings."

    "I've never been disappointed by people in the past ten years—no garbage. Like I say, people appreciate beautiful things. If we planted more flowers and trees in the city and made the buildings more attractive, more people would tend to keep the city clean."

    Later, we became good friends. I was impressed by the taxi-driver, who had hit on a great truth—a sense of beauty comes with the gift of life. Most people don't have to be instructed about the rarity of beauty. They respond when they find it. And, if they are made to feel a part of it, they will try to add to it.

Our Museums, Galleries, and Zoo

19 world-class museums, galleries, and a zoo

The Smithsonian offers eleven museums and galleries on the National Mall and six other museums and the National Zoo in the greater National Capital Area. In New York City, we invite you to tour two museums in historic settings.

Not near a Smithsonian museum? Look for exhibitions and museums in your community. Here we have listed some places to visit:

Tips & Guidelines:

    Stop at any Smithsonian museum information desk where friendly and knowledgeable staff and volunteers can assist you in planning your visit.

    Service animals are welcome at the museums and the National Zoo. Pets are not permitted.

    Lunches should be properly closed or stored in lockers during your visit.