It is said that if you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of our brains are not getting enough exercise — and as a result, we are growing old unnecessarily soon.

    Professor Taiju Matsuzawa wanted to find out why otherwise healthy farmers in northern Japan appeared to be losing their ability to think and reason at a relatively early age, and how the process of aging could be slowed down. With a team of colleagues at Tokyo National University, he set about measuring brain volumes of a thousand people of different ages and varying occupations. Computer technology enabled the researchers to obtain precise measurements of the volume of the front and side parts of the brain, which controls functions like eating and breathing, does not contract with age, and one can continue living without intellectual on economical faculties. Contraction of front and side parts — as cells die off — was observed in some subjects in their thirties, but it was still not evident in some sixty-and seventy-year-olds. Matsuzawa concluded from his tests that there is a simple way to the contraction normally connected with age — using the head.

    The findings show in general terms that contraction of the brain begins sooner in people in the country than in the town. Those least at risk, says Matsuzawa, are lawyers, followed by university professors and doctors. White collar workers doing routine work in government offices are, however, as likely to have shrinking (萎缩) brains as the farm worker, bus driver and shop assistant.

    Matsuzawa's findings show that thinking can prevent the brain from shrinking. Blood must circulate properly in the head to supply the fresh oxygen the brain cells need. “The best way to maintain, good blood circulation is through using the brain.” he says. “Think hard and engage in conversation. Don't rely on pocket calculators.”

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    Physics is a different world now. Will there ever be another Einstein?

    Scientists say a new Einstein will appear, but it may take a long time. After all, more than 200 years separated Einstein from his nearest rival (对手) , Isaac Newton. Many physicists say the next Einstein hasn't been born yet, or is only a baby now. That's because the searching for a unified(统一的) theory that would explain all the forces of nature has pushed current mathematics to its limits. New math must be created before the problem can be solved.

    But researchers say there are many other factors working against another Einstein appearing anytime soon. For one thing, physics is quite a different field today. In Einstein's day, there were a few thousand physicists worldwide, and fewer theoreticians. Education is different, too. One extremely important aspect of Einstein's training that failed to be considered is the philosophy he read as a teenager. It taught him how to think theoretically about space and time.

    And he was a skilled musician. The interplay between music and math is well known. Einstein would fiercely play his violin as a way to think through a knotty physics problem.

    Today, universities have produced millions of physicists. There aren't many jobs in science for them, so they go to Wall Street and Silicon Valley to apply their analytical skills to more practical and rewarding efforts.

    Besides, those who stay in science don't work alone. It's very difficult to imagine an independent person like Einstein ever tolerating this.

    Once there was an 11-year-old boy who went fishing with his father in the middle of the Finger lake. On the day before salmon(鲑鱼) season opened, they were fishing early in the evening, catching other fish with worms. Then the boy tied on a small silver lure (鱼饵) and put it into the lake. Suddenly he felt that something very big pulling on the lure. His father watched with admiration as the boy skillfully brought the fish beside the bank. Finally he lifted the tired fish from the water. It was the largest one he had ever seen, but it was a salmon.

    The boy and his father looked at the big fish. The father lit a match and looked at his watch. It was 10 pm – two hours before the season opened. He looked at the fish, then at the boy. “You'll have to put it back, son,” he said.

    “Dad!” cried the boy, “There will be other fish,” said his father. “Not as big as this one,” cried the boy. He looked around the lake. No other fishermen or boats were in sight in the moonlight. He looked again at his father.

    Even though no one had seen them, nor could anyone ever know what time he had caught the fish, the boy could tell from his father's voice that the decision couldn't be changed. He threw the huge salmon into the dark water. The big fish disappeared. The boy thought that he would never again see such a big fish.

    That was 34 years ago. Today the boy is an successful architect in New York City. He often takes his own son and daughters to fish at the same place.

    And he was right. He has never again caught such a large fish as the one he got that night long ago. But he does see that same fish … again and again … every time he has an ethical (伦理的，道德的) decision to make. For, as his father had taught him, ethics are simple matters of right and wrong. It is only the practice of ethics that is difficult.

    Against the supposition that forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.

    This finding suggests that taking steps to prevent northern forest to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over next several centuries as a result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.

    This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.

    Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone (臭氧) levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.

    "We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere." Scientists tracked the change in amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicated, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.

    On a recent spring morning. Susan Alexander, a retired government intelligence analyst, left her Maryland home, climbed into her Volkswagen Passat and drove about three miles to pick up two strangers. She battled rush-hour traffic on the Capital Beltway and George Washington Memorial Parkway before dropping them off at Reagan National Airport. She didn't earn a cent for her trouble, and that was the point.

    Alexander is a member of the Silver Spring Time Bank-one of more than 100 such exchanges around the world trying to build community by exchanging time credits for services instead of dollars and cents. "I have time," she said. "I like giving the gift of time to other people."

    In Alexander's case, passengers Mary and Al Liepold were grateful for the ride, but it wasn't charity. Mary, a retired writer and editor for nonprofit organizations, used time credits she banked for editing work and baking. Senior citizens who don't drive, the Liepolds cashed in their credits to catch a flight to Montreal for a five-day vacation.

    Without money changing hands or shifting between virtual accounts, the airport drop-off was more like a coffee party than a taxi ride. Driver and passengers chatted about projects they've completed for the time bank, and no one raised an eyebrow when Mary said she likes "to avoid the conventional economy."

    "The beauty of this is that you make friends," Mary Liepold said. "You don't just get services."

    The Silver Spring Time Bank formed in 2015 and has about 300 members, said co-founder Mary Murphy. Last year, she said, l,000 hours were exchanged for basic home repairs, dog walking, cooking and tailoring, among other services, without the exchange of money. "You get to save that money that you would have spent," she said. "You get to meet somebody else in your community and get to know that person. That's a bonus that's part of an exchange."

    A deal performed partly to make friends would seem to go against classical economics and one of Benjamin Franklin's most memorable sayings: "Time is money." To those at the forefront of modem time-banking, that is the appeal.

Last year, the Bureau of Labor Statistics reported that 55 million people in the U. S. are "gig workers" which is more than 35 percent of the U. S. workforce. That number is projected to jump to 43 percent by 2020.

People are drawn to gig work（零工）because it brings in a little extra income without a major time commitment. And recent technologies like Skype, Slack, and Dropbox have made the gig life a reality, giving you maximum freedom, an ideal work-life balance, and the chance to pursue your passions.

If you're thinking of joining the gig economy, it's never been easier. One of the great things about the gig economy is that you don't have a boss breathing down your neck. As a freelancer, you no longer have to cater to a company culture or work schedule that might cause physical or emotional stress. Instead, you get to choose the type of work you do and who you work with. But this degree of freedom requires a corresponding amount of discipline. With no boss to make sure you're on task, it's all on you.

A lot of gig workers start their careers by hopping on a project because the employer is desperate and in need of help. On the employer's end, it's tough to take on people for higher management positions when the pool of talent is full of gig workers who haven't been given an opportunity to improve their skills. Businesses have to evolve to learn how to account for an influx (涌入) of temporary workers. It is harder for gig workers to become skilled and get promoted.

The workforce is becoming more advanced and educated by the day. You have to keep learning and keep up with industry trends to maintain a competitive edge. This is true even for people in traditional office settings, but it's critical if you're your own boss.