Parents who help their children with homework may actually be bringing down their school grades. Other forms of parental involvement, including volunteering at school and observing a child's class, also fail to help, according to the most recent study on the topic.

    The findings challenge a key principle of modern parenting where schools expect them to act as partners in their children's education. Previous generations concentrated on getting children to school on time, fed, dressed and ready to learn.

    Keith Robinson, the author of the study, said, "I really don't know if the public is ready for this but there are some ways parents can be involved in their kids' education that leads to declines in their academic performance. One of the things that was consistently negative was their parents' help with homework." Robinson suggested that may be because parents themselves struggle to understand the tasks."They may either not remember the material their kids are studying now, or in some cases never learnt it themselves, but they're still offering advice."

    Robinson assessed parental involvement performance and found one of the most damaging things a parent could do was to punish their children for poor marks. In general, about 20% of parental involvement was positive,  about 45% negative and the rest statistically insignificant.

    Common sense suggests it was a good thing for parents to get involved because "children with good academic success do have involved parents", admitted Robinson. But he argued that this did not prove parental involvement was the root cause of that success. "A big surprise was that Asian-American parents whose kids are doing so well in school hardly involved. They took a more reasonable approach, conveying to their children how success at school could improve their lives."

    The more interested you are in a topic, the more likely you may be to form “false memories” about the events related to that topic.

    “Most people are pretty confident about their own memory for some events, but new research shows that false memory is a lot more frequent than many people realize. In terms of daily life, the key point here may be to understand that someone who remembers an event differently from yours isn't necessarily lying—someone's memory may be faulty, or it might be you,” said study co-author Ciara Greene, a psychologist at the university College Dublin.

    In the study, the researchers asked 489 people to read four news stories about events that were related to the topics they ranked as the most interesting, and four stories about events related to the topics they rated as the least interesting. In each case, three of these events really did occur, but the fourth one was made up.

    It turned out that people tended to remember the stories of the topics they said they were more interested in compared with the topics they were not interested in. However, the participants also tended to store more false memories related to the topics they were interested in compared with the topics they were not interested in, the researchers found.

    The more people know about a topic, the more memories related to this topic they have stored in their brains, the researchers said. Therefore, when a person meets new information on this topic, that information may find traces of similar memories that have already stored in the brain, Greene said.

    “This can result in a sense of familiarity or recognition of the new material, leading to the conviction (确信) that the information has been met before and is in fact an existing memory,” Greene said. In other words, this new material or information may “feel” familiar and therefore the person may believe it must be true, he said.

    Learning more about how false memories work may help protect against the harmful results of them, such as when eyewitness accounts(证言) of crimes are faulty.

    A Spanish company Siesta&Go has opened the first public napping (小睡) space in Madrid. It promises people a quiet rest in the middle of the city's business center.

    Napping spaces are nothing new; places to rest are already set up in other big cities in the world. But the idea would appear to work well with the culture of Spain, where people traditionally take an afternoon nap, called siesta.

    The Madrid nap space recently opened with 19 beds. People can use them by the minute or by the hour, and they can also choose either a private or shared room. An hour of napping inside a private room costs about $15.

    Siesta &Go provides all bedding, clean nightshirts and other materials. Nippers can request to be woken up when their time is up. It also offers areas to work, with armchairs, newspapers and coffee for those not wishing to sleep.

    Philip &Go is one happy customer. Marco says he gets tired during the day because of hard work. He says a siesta is the perfect way to build up energy. "I come for about 30 minutes or something like that. That is usually enough for me to be full of energy."

    While many Spanish people love their naps, others like Carlos Villarroja say they are just too busy to keep the tradition. "It's a Spanish tradition, but I think it's more of a legend (传说) than a tradition. Because of the lifestyle and the working hours, we have very little free time for a siesta at least during the week."

    But many health experts believe there is evidence that taking a short nap can be very good for the body and mind. Scientific studies show that taking a siesta can also prevent illness and lower blood pressure.

    "Don't answer it," I said to Sam. Our door in the inner city is constantly knocked on; our previous door in the suburbs rarely so. Sam has a full-time job and cannot spend his days answering requests to fix leaking baths or carry cash to the bank.

    Sam opened the door and it was Mervin.

    "There's a bird on the second floor," he said. "It's in trouble."

    Sam followed Mervin upstairs. Mervin pointed and turned to let Sam look. It was a pigeon, the most common of all birds, the bird most likely to foul (弄脏) your newly washed car. And it wasn't flying away. It was stamping in circles. As Sam bent to look, Mervin coughed, "Number two."

    Sam asked him to repeat that. "Number two," Mervin said. "The pigeon has been sitting in his own number two, and now it's stuck to his foot."

It had rained for five days, and the bird was young. It could have been sheltering in a     wet nest of its own waste, which had then dried on its foot, preventing it from flying away. The pigeon moved in a few more circles. Sam bent to take another look. Mervin said, "All right, then." and walked away.

    "Why does everyone think you must solve the problems around here?" I said to Sam when he returned with his story. "It's a bird. Just leave it on the stairs, and let nature take its course." Sam didn't agree. Then he went to the garage and emptied the cardboard box containing our imported camping mats. He returned with the gray pigeon in the box. He showed the bird to our children and they decided to keep it.

    They put its foot in the warm water bath and got rid of its waste. Immediately the pigeon erupted in a bomb of feathers and began flying.

    Throughout much of human history, man has been the measure of many, if not all, things. Lengths were divided up into feet and smaller units from the human hand. Other measures were equally characteristic. Mediterranean traders for centuries used the weight of grains of wheat to define (定义) their units of mass. The Romans used libra, forerunner of the pound, by referring to the weight of a carob (角豆树) seed.

    The sizes of similarly named units could also differ. The king's foot, used in France for nearly

    1,000 years after its introduction by Charlemagne in around 790 AD, was, at 32.5cm,around a centimeter shorter than the Belgic foot, used in England until 1300.Greek,Egyptian and Babylonian versions of water in a fixed container varied from one another by a few kilos, Nor was there agreement on such things within countries. In France, where there was no unified (统一的) measurement system at the national level, the situation was particularly terrible. The lieue (former measure of distance), for example, varied from just over 3 km in the north to nearly 6 km in the south.

    Although John Wilkins, an Englishman, first put forward a decimal system (十进制) of measurement in 1668,it was the French who in 1799 made it law. The Système International d'Unités (SI, or the metric system, as it is better known) developed from it and became the official measurement in all countries except Myanmar, Liberia and the United States. Now the International Bureau of Weights and Measures in Paris is set to give the metric system its biggest shake-up yet.

    At a meeting in Versailles, France, on November 16th,2018,the world's measurement bodies are almost certain to approve a decision that will mean four out of the seven base SI units, including the kilogram, will follow the other three, including the metre, in being redefined in terms of the values of physical constants (物理常数).Each of the chosen constants has been measured incredibly precisely, which would mean that from May 20^th 2019 the constants will themselves be fixed at their current values for ever. Any laboratory in the world will then be able to measure, for example, the mass of an object as precisely as the accuracy of their equipment will allow.

    Thirteen vehicles lined up last March to race across the Mojave Desert, seeking a million in prize money. To win, they had to finish the 142-mile race in less than 10 hours. Teams and watchers knew there might be no winner at all, because these vehicles were missing a key part－drivers.

    DARPA, the Defense Advanced Research Projects Agency, organized the race as part of a push to develop robotic vehicles for future battlefields. But the Grand Challenge, as it was called, just proved how difficult it is to get a car to speed across an unfamiliar desert without human guidance. One had its brake lock up in the starting area. Another began by throwing itself onto a wall. Another got tied up by bushes near the road after 1.9 miles.

    One turned upside down. One took off in entirely the wrong direction and had to be disabled by remote control. One went a little more than a mile and rushed into a fence; another managed to go for six miles but stuck on a rock. The "winner," if there was any, reached 7.8 miles before it ran into a long, narrow hole, and the front wheels caught on fire.

    "You get a lot of respect for natural abilities of the living things," says Reinhold Behringer, who helped design two of the car-size vehicles for a company called Sci-Autonics. "Even ants (蚂蚁) can do all these tasks effortlessly. It's very hard for us to put these abilities into our machines."

    The robotic vehicles, though with necessary modern equipment such as advanced computers and GPS guidance, had trouble figuring out fast enough the blocks ahead that a two-year-old human recognizes immediately. Sure, that very young child, who has just only learned to walk, may not think to wipe apple juice off her face, but she already knows that when there's a cookie in the kitchen she has to climb up the table, and that when she gets to the cookie it will taste good. She is more advanced, even months old, than any machine humans have designed.