In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.

    Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating (挨打) and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.

    Until now, even the most advanced (先进的) robot was almost certain to break down when it was damaged. That is because its computer inside simply doesn't know how to make the machine work after its shape has changed.

    To deal with this problem, the scientists put eight motors (发动机) and two sensors (传感器) that read how the machine is working. They all give signals to the machine's software. Using this information, the computer can then figure out the machine's shape at any moment.

    The new technology is a big advance in robot-making, scientists say, and it's far from scary. It may someday help scientists create better artificial (假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.

    “It has been difficult to design robots that can work well when the environment changes or when it's damaged,” says Olaf Sporns of Indiana University in US. “With this work, we are nearer to solving this problem.”

    Clothes are traditionally made of natural materials, such as cotton, leather and wool. They are all from plants or animals, but that doesn't mean they're friendly to the earth. For example, farmers have to use a lot of chemicals to grow cotton plants.

    Scientists are now looking for new ways to make clothing materials. They hope the new materials are both comfortable and good for the earth. Scientists have worked out how to make materials out of corn husks(棉籽), chicken feathers and rice straws.

    "They used to be useless things. We always have a problem of how to deal with them," Yang, a scientist says, "Now, we can turn them into beautiful materials. Chicken feathers are better than other things. They have small air pockets like honeycombs. That means it will be very warm if you use them to make a jacket or sweater, and I think more and more people will like to buy these kinds of clothes."

Vision—phones(可视电话)

    Many inventions are very useful in our daily life. They have greatly changed our life. For example, radios, telephones and televisions are widely used in the world. When you turn on the radio, you can listen. But when you use the telephone, you can not only listen to others but also chat with them. However, you can't see anything at all. The television is much better than both of them. People can watch TV and listen to it, but they can't take part in what they see.

    Today, some people are using a type of telephone called the vision phone. With it two people can see each other when they are talking

    Vision-phones can be of great use when you have something to show the person when you are calling him or her. It may also have other uses in the future. Some day you may be able to call up a library and ask to read a book over your vision-phone. You may be able to do some shopping through it too. Perhaps in the future, the vision-phone will come into wide use in our everyday life.

    A black hole is a place in outer space with very strong gravity. Gravity is a great force(力量) that shapes the universe. On Earth, gravity makes apples fall from trees. It keeps your feet planted on the ground. The gravity in a black hole is much stronger. It is so strong that nothing around it can get away from it, not even light.

    Black holes are invisible. We can't actually see them because they don't throw back light. But scientists can find them with space telescopes(望远镜)and special tools. The strong gravity makes nearby stars move in a certain way. By studying how the stars move, scientists can find out if they are flying around a black hole. Strange things happen around black holes. This makes black holes a popular subject of science fiction(科幻)stories, although they are very real.

    A black hole forms when a star dies. The star falls in on itself and turns into a very small point. Because of its small size and huge mass(质量), the gravity will be so strong that it will pull light in and become a black hole. Black holes can grow huge as they continue to pull other things in and "eat" them. Many scientists believe that there are super-massive black holes at the center of galaxies, including the Milky Way.

    The idea of the black hole was first suggested by two different scientists in the 18th century: John Michelle and Pierre-Simon Laplace. In 1967, a physicist named John Archibald Wheeler came up with the name “black hole". Studying black holes can tell us many things about our galaxy and help scientists answer questions about the universe.