Radio, telephone and TV are widely used in the world. When you turn on the radio, you can listen. But when you use telephone, not only can you listen to others but also you can chat with them, however, you can't see anything at all. TV 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 vision-phone（可视电话）. With it, two people who are talking can see each other. It is better than radio, telephone or TV.

    Vision-phones can be of great use when you have something to show the person whom you are calling. It will be helpful in people's life. Some day you may be able to call up a library and ask to read a book on your vision-phone. You may be able to do some shopping too. Perhaps in the future, people will use vision-phone.

    The word, "photography", was first used in 1839. It comes from the Greek words that mean "to write with light". But photography could only give people static pictures. So scientists were trying hard to find ways to make pictures that can move. They made lots of experiments, but failed again and again. It was Eadweard Muybridge who finally succeeded. He was the first photographer to try this successfully. But how did he make it? It was an interesting story.

    Back in 1872, people didn't know exactly(确切地) whether all four of a horse's hooves(蹄) left the ground at the same time when it was running. A gentleman called Leland Stanford made a bet with his friend about it. Most people believed that a horse always had one hoof on the ground, or it would fall over. But Stanford didn't think so.

    At that time, it was hard to know who could win the bet, because a horse's legs move so fast that it is impossible to tell just by looking. So they needed a way to record the movement of a running horse. Then Stanford offered $ 25,000 to the famous photographer, Muybridge, to help find the answer. In the beginning, Muybridge failed to get clear images, but he didn't give up. He continued to improve his cameras. In 1878, after many experiments, he managed to get a sequence(连续) of 12 photos. One of them clearly showed that all four of the horse's hooves were off the ground at the same time. And when the photos moved fast, people could see a horse running.

    Though Edison is usually considered as the person who created the first movie in 1889, it was the work of Eadweard Muybridge and the bet that led to Edison's invention.

    Our eyes may be playing tricks on us.  New research shows that sometimes people physically see what they want to see. Cornell University social psychologist(心理学家) David

    Dunning carried out experiments to test whether wishful thinking can actually affect what we see.

    “It's well proved from what is experienced in everyday life, and from the laboratory as well, that people think what they want to think," he says. "We're taking this a step further.

    We're asking if strong wishes and fears can actually affect what people physically see."

    Dunning and his assistants told volunteers that a computer game would show them either a letter or number to decide whether they would drink orange juice or fruit syrup(果子露).

    As they wrote in the Journal of Personality and Social Psychology, the computer would flash an ambiguous picture, which could be seen as the letter "B" or the number "13". Volunteers who were told that a letter would get them orange juice most often reported seeing "B". Those who were told that a number would get them orange juice most often saw "13".

    The researchers also used a hidden camera to track volunteers' eye movements, particularly the first eye movement. "We don't control them," Dunning says, "and they don't even know that we are watching them, so it honestly shows what a person is seeing."

    "This research suggests that the brain is doing a lot of work between the eye and the conscious awareness to affect what we think," Dunning concludes (得出结论). "Before we even see the world, our brain has decided to keep what we want to see and avoid what we don't want to see."

Why salmon will newer get lost

    When you're packing for an adventure, what's the most important thing you'll need? If you don't want to get lost, you' need a map. Or better yet, a GPS. What about other animals? How do they know where they're going?

    While humans depend on technology to travel, some animals have something far more advanced. Researchers, mainly from Oregon State University, US, found that Chinook salmon have a "built in GPS" of the Earth's magnetic field(磁场). This means as soon as they are born they are able to direct themselves in the ocean. It acts like a big map inside their brain.

    Scientists placed some baby salmon into a big swimming pool. To simulate the Earth's magnetic field, they put magnetic coils(线圈) all around the pool. Then, by changing the direction of the coils, the salmon began to change their own direction. They started to face in the direction of their ocean feeding area. This is a safe place in the ocean where salmon can find food to eat. When the scientists changed the coils to the opposite side, the salmon also turned in the opposite direction. Just by using their "built-in GPS", the salmon were able to figure out the direction of their feeding area.

    How did Chinook salmon get their "built in GPS"? The scientists believe that their navigation(导航) skills came through evolution(进化). The fish that were able to reach the feeding area lived longer. Then they could pass on their navigation skills to their babies. So if you're ever lost and in need of some help, maybe you should ask a salmon to point you in the right direction!