Adults understand what it feels like to be flooded with objects. Why do we often assume that more is more when it comes to kids and their belongings? The good news is that I can help my own kids learn earlier than I did how to live more with less.

    I found the pre-holidays a good time to encourage young children to donate less-used things, and it worked. Because of our efforts, our daughter Georgia did decide to donate a large bag of toys to a little girl whose mother was unable to pay for her holiday due to illness. She chose to sell a few larger objects that were less often used when we promised to put the money into her school fund(基金）(our kindergarten daughter is serious about becoming a doctor)

    For weeks, I've been thinking of bigger, deeper questions: How do we make it a habit for them? And how do we train ourselves to help them live with, need, and use less? Yesterday, I sat with my son, Shepherd, determined to test my own theory on this. I decided to play with him with only one toy for as long as it would keep his interest. I expected that one toy would keep his attention for about five minutes, ten minutes, max. I chose a red rubber ball-simple, universally available. We passed it, he tried to put it in his mouth, he tried bouncing it, rolling it, sitting on it, throwing it. It was totally, completely enough for him. Before I knew it an hour had passed and it was time to move on to lunch.

    We both became absorbed in the simplicity of playing together. He had my full attention and I had his. My little experiment to find joy in a single object worked for both of us.

    Once an Englishman named Jack Brown went to Russia for a holiday. He stayed there for several months and then came home again. Some of his friends visited him a few days after he got back. "I had a very dangerous trip while I was in Russia," Jack said to them. "I wanted to see a friend of mine in the country and the bad weather made me very late. So I was still traveling through a forest in a sleigh(雪橇) when the sun went down. It was a long way from my friend's house when about twenty wolves began to follow my sleigh. It was very dark in the forest. There was thick snow on the ground. It was cold, and there were no houses for miles and miles. First I heard the wolves. The noise was terrible! The horses heard them, too. They were frightened and began running faster. Then I saw long, gray forms among the trees, and soon the wolves were near us. They were running very fast, and they didn't seem to get tired like the horses."

    "What did you do?" one of Jack's friends asked.

    "When the wolves got very near," Jack answered, "I put up my gun and shot the first wolf. The sleigh was moving about, but I hit the animal and killed it. Then all the other wolves stopped and ate it, so our sleigh got away from them for a few minutes."

    "Then they finished their meal, and I heard them coming again. The moon was shining brightly on the snow now, and after a few minutes I saw them running among the trees once more. They came nearer again, and then I shot another of them, and the others stopped once more to eat it."

    "The same thing happened again and again, and my horses became more and more tired and ran slower and slower until, after about two hours, only one wolf was still alive and following us."

    "Wasn't it too fat to run?" one of his friends asked.

    More than a hundred years ago, two boys were fishing in a small river. They sat in a heavy-bottomed boat, each holding a long, bent pole in his hands and eagerly waiting for "a bite". When they wanted to move the boat from one place to another they had to push against a long pole into the bottom of the stream.

    "This is slow work, Robert," said the older of the boys. "Yes, Christopher, and it's hard work, too." answered Robert. "I think there's some better way of moving a boat."

    Christopher advised rowing it and Robert promised to make some paddles (桨). The next day Robert's aunt heard a great noise in her house. The two boys were there, busily working. "What are you making, Robert?" she asked. He told his plan. His aunt laughed and said, "Well done! I hope you'll succeed."

    After much work, they succeeded in making two paddle wheels. They were very rough, but strong and usable. They fixed each of these wheels to the end of an iron rod (长杆) which they passed through the boat from side to side. The rod was bent in the middle. When the work was finished, the old fishing boat looked rather strange, with a paddle wheel on each side. The boys lost no time in trying it. One of the boys could guide the boat while the other turned the paddle wheels.

    That night when Christopher went home, he told his father a wonderful story. "Robert Fulton planned the whole thing," he said, "and I helped him make the paddles and put them on the boat." When Robert Fulton became a man, he didn't forget his experiment with the old fishing boat. He kept on thinking and working, until at last he succeeded in making a boat with paddle wheels that could be run by steam. He's now honored as the inventor of the steamboat.

    Steven Spielberg's 2002 science-fiction thriller Minority Report produced a world where computers could read minds and predict the future. It seemed fanciful at the time, but fantasy is edging closer to fact.

    On Jan 31, a team of scientists at UC Berkeley, led by Robert Knight programmed computers to decode (破译) brain waves and replay them as words. Five months earlier, another group of Berkeley scientists showed their colleagues short movies and used computers to play back in color what people saw.

    These experiments are a big advance from 2006, when a French scientist first replayed images from a human mind, a black-and-white checkerboard pattern. The possibilities are great: a disabled person could" speak"; doctors could access the mind of a patient who fainted; you could rewatch your dreams on an iPad. There are, of course, equally dark side, such as the involuntary take out of information from the brain.

    In spite of these breakthroughs, Jack Gallant, the neuroscientist who led the first Berkeley team, says current technology for decoding brain activity is still "relatively primitive". The field is held back by its poor machinery, in particular the FMRI.

    "Eventually," says Gallant, "someone will invent a decoding machine you can wear as a hat." Such an advance into the human mind, he says, might take 30 years.

    Still, the recent advances at Berkeley offer small answers, which scientists can use to begin unlocking the secrets of memory and consciousness.

    Since 50 years ago, scientists have been searching for ways to link the brain with computers. Brain Computer Interface (BCI) technology could help people with disabilities send commands to machines.

    Recently, two researchers, Jose Millan and Michelle Tavella from the Federal Polytechnic School in Lausanne, Switzerland, demonstrated (展示) a small robotic wheelchair directed by a person's thoughts.

    In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.

    "Our brain has billions of nerve cells. These send signals through the spinal cord (脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles," Tavella says, "Our system allows disabled people to communicate with external world and also to control devices."

    The researchers designed a special cap for the user. This head cover picks up the signals from the scalp (头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.

    Prof. Millan, the team leader, says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. "The practical possibilities that BCI technology offers to disabled people can be grouped in two categories: communication, and controlling devices. One example is this wheelchair." He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.

    Throughout history scientists have risked their health and their lives in their search for the truth.

    Sir Isaac Newton, the seventeenth century scientist, was very smart, but that didn't stop him from doing some pretty stupid things. In his laboratory in Cambridge he often did the strangest experiments. Once, while testing how light passes through lenses (晶状体), he put a long needle into his eye, pushed it to the back, and then moved it around just to see what would happen. Luckily, nothing long-lasting did. On another occasion he stared at the sun for as long as he could bear, to discover what effect this would have on his sight. Again he escaped suffering permanent damage, though he had to spend some days in a darkened room before his eyes recovered.

    In the 1750s the Swedish chemist Karl Scheele was the first person to find a way to produce phosphorus (磷). He in fact discovered eight more chemical elements including chlorine (氯), though he didn't get any praise for them. He was a very clever scientist, but his one failing was a curious habit of tasting a little of every substance he worked with. This risky practice finally caught up with him, and in 1786 he was found dead in his laboratory surrounded by a large number of dangerous chemicals, any of which might have been responsible for his death.

    Eugene Shoemaker was a respected geologist. He spent a large part of his life studying craters (火山口) on the moon, and how they were formed, and later did research into the comets of the planet Jupiter. In 1997 he and his wife were in the Australian desert where they went every year to search for places where comets might have hit the earth. While driving in the Tanami desert, normally one of the emptiest places in the world, another vehicle crashed into them and Shoemaker was killed on the spot. Some of his ashes (骨灰) were sent to the moon aboard the Lunar Prospector spacecraft and left there — he is the only person who has had this honor.