My 16-year-old son, Anton, had gone to the local swimming hole． Most of the kids swim there, and there are plenty of rocks for them to use as safe harbors, so I had no fears for his safety．

    Still, the firefighter's first words "You need to come up here to the Stillwater River" made me catch my breath, and his follow-up words gave me relief: “Your son is OK．”

    When I got to the river, I immediately saw the firetruck, ambulance and Anton, wrapped with a towel about his shoulders, sitting quietly on a low platform of the fire engine．I hurried over to him． "You OK?"I asked．

    “Yeah,” was all he said． But my eyes begged for an explanation, I didn't get it from my son, however, who tends to play his cards close to his vest ．

    The story was this: A woman was being swept under water． Hearing the cries, Anton and his friend Tyler, without hesitation, swam out to her, and brought her safely to shore.

    In an age in which the word "hero" is broadcast with abandon and seemingly applied to anyone who makes it through the day, I realized the real thing in my son. The teens are stubborn and self-centered, but that didn't mean they have no desire to do good.

    Still shocked by my son's daring, I drove him home. Along the way, I tried to dig out some more information from him but he had precious little to say. The only words he said were, “What's for supper?”

    I spent some time alone that evening, thinking about the tragedy that might have been. The next morning, when Anton got up, I half expected him to tell me the story. But all he did was toast some bread, pull himself together, and head for the door to start a new day. Watching from the window, I was reminded that still water often runs deep.

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Why is pink or purple a color for girls and blue or brown for boys?

    The answer depends largely on cultural values as well as personal experiences. To the Egyptians, green was a color that represented the hope and joy of spring, while for Muslims, it means heaven. Red is a symbol of good luck in many cultures. In China, children are given money in a red envelope to bring good fortune in the New Year. For many nations, blue is a symbol of protection and religious beliefs. Greek people often wear a blue necklace hoping to protect themselves against evils（灾祸）.

    People's choice of colors is also influenced by their bodies' reactions （反应）toward them. Green is said to be the most restful color. It has the ability to reduce pain and relax people both mentally and physically. People who work in green environment have been found to have fewer stomach aches.

    Red can cause a person's blood pressure to rise and increase people's appetites（食欲）. Many decorators will include different shades of red in the restaurant. Similarly, many commercial websites will have a red “Buy Now” button because red is a color that easily catches a person's eye.

    Blue is another calming color. Unlike red, blue can cause people to lose appetite. So if you want to eat less, some suggest that eating from blue plates can help.

    The next time you are deciding on what to wear or what color to decorate your room, think about the color carefully.

    The weather is very important to farmers. The calendar might say “August”， but the weather's more like October. For some farmers the cool weather is a good thing. For others, it's a cause for concern.

    At Apple Hill, the cooler weather was giving the Boeger Winery a chance to concentrate on bottling instead of picking. “Things were really maturing, it has just been a welcome relief to have more time to prepare.” said Greg Boeger of Boeger Winery.

    But down in the Delta, the earlier hot weather has them two weeks ahead of schedule. Their harvest actually started on Tuesday, and this cooling trend is a worry. There have been no problems yet, but for each of the last two years heavy rain right after Labor Day was a problem, one that Don Pylman would not like to see repeated.

    “If it doesn't start raining, we're in good shape，” said Pylman. “If the sun comes out and clears up we can get right back to work, but if we do get rain, the rots will start.”

    The kind of grape makes a difference as well. Thin­skinned grapes like the chardonnay variety are much more sensitive to rain than some of the others. They're also more difficult to dry off.

    There has long been a notion （观念） that money buys happiness. However, although "we really, really tried that for a couple of generations, it didn't work," said Francine Jay, author of The Joy of Less, A Minimalist Living Guide: How to Declutter, Organize, and Simplify Your Life.

    Thanks to a travel inspired revelation （启发）, Jay has been happily living a simpler life for 12 years. "I always packed as lightly as possible, and found it exciting to get by with just a small carry on bag," she told CNN. "I thought if it feels this great to travel lightly, how amazing would it be to live this way？ I wanted to have that same feeling of freedom in my everyday life."

Jay decided to get rid of all her excess （额外的） possessions and live with just the essentials （必需品）. "I wanted to spend my time and energy on experiences, rather than things."

    Jay is a follower of a movement called "minimalism （极简主义）". Growing numbers of people have been attracted to this lifestyle all over the world. They share the same feeling of disappointment with modern life and a desire to live more simply. Minimalists are typically progressive and concerned about the environment, Leah Watkins, a lead researcher at Ota go University in New Zealand, told Stuff magazine in March.

    But many simply experienced unhappiness caused by owning too many possessions. Depression with the materialism of our world isn't new. English romantic poet William Wordsworth summed up how dispiriting （令人消沉的） this was back in 1802, at the beginning of the industrial age, when he wrote: "Getting and spending, we lay waste our powers". His preference was to go back to nature. Closer to our own times, the hippies （嬉皮士） of the 1960s also sought to "drop out" of modern life.

    And for many minimalists, their key is to unload. Without objects, they "believe people are forced more and more into the present moment and that's where life happens," wrote Stuff.

But does simplicity ever feel like a sacrifice （牺牲）？

    "It's eliminating the excess﹣unused items, unnecessary purchases﹣from your life. Well, I may have fewer possessions, but I have more space …Minimalism is making room for what matters most," said Jay.

    And "the real questions", according to Duane Elgin, US social scientist, are "what do you care about？" and "What do you value?"

    He told CNN: "It's important for people to realize minimalism isn't simply the amount of stuff we consume. It's about our families, our work, our connection with the larger world, our spiritual dimension. It's about how we touch the whole world. It's a way of life."

    How a few members of the animal kingdom handle the transition to adulthood?

    African elephants

These beautiful beasts come close to imitate teen rebellion. Calves spend a decade with their mothers in female-dominated groups —- and ladies stay there —- but adolescent boys leave mom for noisy crews of bros. In their 20s, they often downsize to smaller male groups.

    Orangutans (猩猩)

Slow metabolism allows these primates to survive food shortages —- times when weather makes ripe fruit scarce. But energy efficiency comes at a cost; growth and maturation take time. Orangutan mamas nurse their young longer than any other wild creature does.

    Orcas(逆戟鲸)

    Killer whales join their mother's familial group for life. This lasting-relationship seems to increase a pup's chance of survival; if mom dies  a young male (under 30) is three times more likely to die than a peer whose mother is alive. Risk of death post-mom-mortem rises as kids get older.

Harp seals

A harp seal's "childhood" lasts just 12 days. A pup's sole purpose during that brief period of coddling(宠爱) is to constantly nurse, gaining a fifth of its birth weight in blubber(鲸脂) every day. Once it's fat —- they become greater from 25 to 80 pounds —- it slides off the ice and takes on the sea.

    Wolf spiders

    Every parent knows that tired toddlers love to hitch a piggyback ride. The wolf spider straps all her babies (40 or 50, on average) onto her back at once, carrying the brood until they are capable of fully functional spider-hood. But luckily she only has to pull them for a few days.