After ruling the tennis world for almost five years,Roger Federer is adjusting to life at NO.2.But,like any king whose throne has been taken away,the Swiss star is already planning secretly bis return to power,beginning at this week's US Open.

    The problem is, many experts think he will never do it.They blame everything from age and tough competition to his racket and psychology.

    For years Federer, had enjoyed the view from the top.Competitors saw him as undefeated,and for the most part he was.However,before the 2008 season began,Federer had an illness that stole his strength and clearly affected his play on the court.Ever since,he has struggled to return to form,winning just two of his last 14 tournaments.

    "Twenty-seven is an age when your body starts talking back to you."tennis great John McEnroe told the New York Times.

    Pancho Sefura, another tennis great, noted that Federer is also facing a maturing crop of young talents."There are too many great players now,"he said,naming Britain's Andy  Murray,21,and Latvia's Ernests Gulbis,20.

    US magazine Sports Illustrated tennis columnist Jon Wertheim suggested that part of Federer's problem could be his insistence on using a small racket.He says that the smaller head demands ball control.But we see time and again that racket makers try to get players to use a certain stick-one they would like to market to consumers and it has a negative effect on the professional game.

    Sports psychologist Jim Loehr told the Times that Federer is probably feeling "a sense of doubt"after being considered as undefeated for so long.If Federer is to recover his state of being undefeated,Loehr said he must overcome his doubt."Federer doesn't need fame and money.But he has to get better.He has to go t.o a whole new level.That's the only way he stays in the game," he said.

    As for beginning his first Grand Slam in ages as the NO.2 seed, Federer said it might be for the best."Five years almost,I was expected to win every tournament I entered,"he said,"so maybe Rafael Nadal now feels what I had to feel for a very long time.It will be interesting to see how he handles it."

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    Science textbooks around the world have become suddenly out of date. Four new chemical elements(元素)have been added to the periodic table. A big decision now lies ahead-elements 113,115,117 and 118 need to be given their official names and symbols.

    New elements can be named after a mythical(神话的) concept, a mineral, a place or country, a property(性质) or a scientist. The names have to be unique and maintain “historical and chemical consistency”. This means a lot of “-iums”.

    “They're Latinising the name,” explains chemist Andrea Sella. “The most recent tradition is to name them after places or people.” The places chosen tend to be where the element was discovered or first produced.

    No one has yet named an element after themselves but many elements are named in honour of important scientists. Albert Einstein was given einsteinium. This can also be a way of righting the wrongs of the past. “Lise Meitner was really the chemist who spotted nuclear fission(核裂变)but she was never really recognised for it because she was Jewish and a woman, ” says Sella. “Giving an element a name that reminds us of her is greatly important. ”

    The naming process isn't quick. The scientists who discovered them will start things off by suggesting a name. But it will be down to the International Union of Pure and Applied Chemistry (IUPAC) to approve it. A special division of the US-based group has to accept the suggestion. Then there is a public review period of five months before the IUPAC gets the final approval. Once it's ready, the name is announced in the scientific journal Pure and Applied Chemistry.

    Naming an element is not just about functionality. Names are always important.

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    Everybody sleeps, but what people stay up late to catch or wake up early in order not to miss varies by culture？

    From data collected, it seems the things that cause us to lose the most sleep, on average, are sporting events, time changes, and holidays.

    Around the world, people changed sleep patterns thanks to the start or end of daylight savings time. Russians, for example, began to wake up about a half-hour later each day after President Vladimir Putin shifted the country permanently to "winter time" starting on October 26.

    Russia's other late nights and early mornings generally correspond to public holidays. On New Year's Eve, Russians have the world's latest bedtime, hitting the hay at around 3:30 a. m.

    Russians also get up an hour later on International Women's Day, the day for treating and celebrating female relatives.

    Similarly, Americans' late nights, late mornings, and longest sleeps fall on three-day weekends.

    Canada got the least sleep of the year the night it beat Sweden in the Olympic hockey (冰球) final.

    The World Cup is also chiefly responsible for sleep deprivation. The worst night for sleep in the U. K. was the night of the England-Italy match on June 14. Brits stayed up a half-hour later to watch it, and then they woke up earlier than usual the next morning. Thanks to summer nights, the phenomenon in which the sun barely sets in northern countries in the summertime. That was nothing, though, compared to Germans, Italians, and the French, who stayed up around an hour and a half later on various days throughout the summer to watch the Cup.

    It should be made clear that not everyone has a device to record their sleep patterns; in some of these nations, it's likely that only the richest people do. And people who elect to track their sleep may try to get more sleep than the average person. Even if that's the case, though, the above findings are still striking. If the most health-conscious among us have such deep swings in our shut-eye levels throughout the year, how much sleep are the rest of us losing?

    It was Sunday, so Dad and I were at the second-hand goods market, looking for tools, appliances(家用电器), and other things that needed cleaning. Some were broken; others, like silver cups, just needed to be cleaned and polished. It was 1974, and the Depression(经济大萧条) was very serious. Dad worked full-time at a factory, but the money wasn't enough. Dad had tried a second job for a while, but he found it was too hard on the family. One day, he had an excellent idea that set me on a lifelong course of making money to support myself. Standing beside a crowded table at the second-hand goods market, I looked over an ancient manual sewing machine. Someone had changed it to run on electric power. It was much older than Mom's machine, but it looked like it had quality and a long life built into it. "Dad!" I called. "This is a beauty!"

    Dad walked over, pulling a cart full of audio equipment, tools, worn-out appliances, and what appeared to be a block of dull kitchen knife." What have you got, Son?" I described what I saw and what I figured I could do to x the beauty up. Dad paid for my discovery, and we headed home.

    Every day after school I worked on the ancient machine, and every night Dad and I sharpened tools and knives, sanded off rust, polished metal, and replaced missing parts from various items. The next Saturday we headed off, as we did every weekend, to that same market, where we sold the treasures we'd purchased the week before—at a tidy profit. My antique beauty brought in more money than anything else, and Dad let me keep every penny.

    Dad's gone now, but I can never thank him enough. Even if we hadn't needed the extra money Dad and I brought in, I wouldn't have traded those weekends for all the picnics or Little League games in St. Louis—not in a million years.

    Google's new camera, called Clips, is a small, smart device. It comes with a case that has a clip (夹子)，but it's not designed to be worn on your clothing. Most interestingly, it uses artificial intelligence to take photography out of your hands so it can capture moments on its own.

    This roughly 2-inch by 2-inch camera, with a three-hour battery life and Gorilla Glass for toughness, is intended for candid moments, like when a child does something cute that may happen too quickly for you to pull out your smartphone.

On board the Clips device, it uses machine learning algorithms (计算程序) to help capture scenes. Those algorithms include face recognition. “Once it learns that there's a face you see frequently, it'll try to get nice photos of those faces,” said Juston Payne, the device's product manager. And they also want it to recognize facial expressions, which involved “training it to know what happiness looks like”. The Google team also trained it to recognize what not to shoot — like when a child's hand is over the lens, or if it is tossed in a dark purse.

    The only way to see the images is by connecting the camera with your phone, as it has no screen for viewing or editing.

    Were people concerned it could seem strange? Yes, Payne admitted. But they said they addressed that by making it obvious what it is. A green light on the front signals that it is on. Besides, unlike a camera meant to monitor your home, it is not connected to the Internet.

    “This product is only possible because of the way that silicon has advanced” Payne said, noting that it was only in the past year or so that they could squeeze the technology down into a device this size. Going forward, we're likely to get more assistance from the artificial intelligence packed into our apps and gadgets.

    It sounds almost too good to be true, but a new study on sleeping brains suggests that listening to languages while you sleep can actually help you to learn them.

    For the study, researchers played recordings of foreign words and their translations to subjects enjoying slow-wave sleep, a stage when a person has little consciousness of their environment. To ensure that the results were not compromised by foreign language words that subjects may have had some contact with at some point in their waking lives, researchers made up totally nonexistent foreign words.

    When the subjects woke up, they were presented with the made-up words again without their translations. The subjects were then asked to imagine whether this made-up word indicated an object that was either smaller or larger. This vague(模糊的)way of testing their understanding of the words is an approach that is supposed to tap into the unconscious memory.

    Unbelievably, the subjects were able to correctly classify the words in this way at an accuracy rate that was 10 percent higher than random chance. That's not a rate high enough to have them suddenly communicating in a foreign tongue, but it is enough to suggest that the brain is still absorbing information on some level, even during sleep.

    Researchers have long known that sleep is important for memory, but previously its role in memory was thought to relate only to the preservation and organization of memories acquired during wakefulness. This is the first time that memory formation has been shown to be active during sleep.

    In other words, our brains are listening to the world, and learning about it, even when our conscious selves are not present.

    The next step for researchers will be to see if new information can be 1earned quicker during wakefulness if it was already presented during sleep. If so, it could forever change how we train our brains to learn new things. Sleep learning might become a widespread practice.