Color is everywhere in lives. But what does color mean? Why are people more relaxed in green rooms? Why do people do their best in blue gyms? That's the magic of color!

    Scientists from the US did an experiment. They asked two people to go into two different rooms. One went into a room painted in pink, and the other went into a blue room. They had to stay in the rooms for one hour. But they had to guess the time, because they didn't have a watch or any other thing to see the time. In the end, the person in the pink room came out in about 40 to 50 minutes. The person in the blue room came out after 70 to 80 minutes.

    The results show that color can change people's feelings about time. Warm colors make people feel that time is going faster than cool colors.

    Teenagers are known for being creative and full of new ideas. Let's have a look at these teenage inventions that might change the world.

    Coloring is an activity that children worldwide have long enjoyed. With a picture already made for them, kids simply chose a crayon, pencil or marker of their favorite color and fill it in. Today, it also becomes more and more popular among teenagers and even adults, who are enjoying relaxing hours of coloring. In December, five of the top ten best-selling books in the United States were coloring books.

    They are fun, but are coloring books good for you?

    The good feedback(反馈)from customers is encouraging. Trina Lucida, a popular artist creating coloring books, says that many of her customers are buying the coloring books for others who are sick or going through a hard time. She adds that the "big idea" behind her latest book is to encourage people to do something creative.

    Lucida is right, according to Allan Rohan, a psychology(心理学)professor. "Many customers think of coloring books as a new creative stage," he said in an interview, "but what's more important is that people spend time coloring in order to reduce stress after a long day." Research shows that coloring can reduce stress by guiding people to focus on(专注)one simple task. When a person is filling in a flower with a light purple color, he focuses on the flower and forgets about all his troubles in life.

    Experts add that coloring may relieve a certain kind of pain. Doing the coloring helps people relax their mind and calm down. Also, coloring helps people's brain in a healthy way. The shape of the drawing makes one side of the brain active, while the color of the drawing improves the other. Coloring can bring out your imagination and take you back to your childhood. Interesting, isn't it?

    "It's very relaxing," said Susan Jackson, a big fan of Lucida's coloring books. "Coloring frees my mind. And it's not just to try to fill blank(空白的)pages. The pictures make me happy and there is just something about them. So I'm saving the pictures I like best to the very end."

    The idea of being able to walk on water has long interested humans greatly. Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid-we simply weigh too much, and all our mass pushes down through our relatively small feet, resulting in a lot of pressure that makes us sink.

    However, several types of animals can walk on water. One of the most interesting is the common basilisk Basilicus basilicus, a lizard(蜥蜴) native to Central and South America. It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water's surface with its feet. The lizard will take as many as 20 steps per second to keep moving forward. For humans to do this, we'd need huge feet that we could bring up to our ears in order to create adequate "hitting."

    But fortunately there is an alternative: cornflour. By adding enough of this common thickening agent to water (and it does take a tot), you can create a "non-Newtonian" liquid that doesn't behave like normal water. Now, if the surface of the water is hit hard enough, particles(粒子) in the water group together for a moment to make the surface hard. Move quickly enough and put enough force into each step, and you really can walk across the surface of an adequately thick liquid of cornflour.

    Fun though all this may sound, it's still rather messy and better read about in theory than carried out in practice. If you must do it, then keep the water wings handy in case you start to sink and take a shower afterward!

    Bamboo(竹子) is one of nature s most surprising plants. Many people call this plant a tree, but it is a kind of grass.

    Like other kinds of grass, a bamboo plant may be cut very low to the ground, but it will grow back very quickly. A Japanese scientist reported one bamboo plant which grew 1.5 metres in 24 hours! There are more than 1, 000 kinds of bamboo. Bamboo grows almost everywhere in the world, but in Europe, they can't grow.

    Not all bamboo looks the same. Some bamboo plants are very thin. They may only grow to be a few centimetres wide while others may grow to be more than 30 centimetres across. This plant also comes in different colours, from yellow to black to green.

    Bamboo has been used to make many things such as hats and kitchen tools. Because it is strong, bamboo is also used to build buildings.

    Many Asian countries have used bamboo for hundreds of years. They often use bamboo for buildings and supporting(支撑) new buildings and bridges while they are being built.

    In Africa, poor farmers are taught how to bring water using bamboo. These African countries need cheap ways to bring water because they have no money, and their crops often die from no rain and no water. Bamboo pipes(管子) help poor farmers bring water to their thirsty fields without spending much money.

    Is there intelligent (有智力的) life on other planets? For years, scientists said "no" or "we don't know". But today this is changing. Seth Shostak and Alexandra Barnett are astronomers (天文学家). They believe intelligent life exists (存在) somewhere in the universe. They also think we will soon contact these beings (人；生物).

    Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. "This is long enough for other planets to have intelligent life," say Shostak and Barnett. The second reason is size—the universe is huge. "Tools like the Hubble Telescope (哈勃望远镜) have shown that there are at least 100 billion galaxies," says Shostak. "And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth."

    In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes (高倍望远镜) allow scientists to discover smaller planets. These planets might have intelligent life.

    Have beings from space already visited Earth? "Probably not," says Shostak. However, intelligent beings may contact us in other way, such as radio signals (信号). In fact, they may be trying to communicate with us now, but we don't have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other.