People born in winter are more likely to suffer mental health disorders, according to a recent study carried out by researchers at Vanderbilt University in Tennessee.

    Researchers raised baby mice from birth to weaning (断奶) in either “summer” light cycles of 16 hours of light and 8 hours of dark or “winter” cycles of 8 hours of light and 16 hours of dark. A third group experienced 12 hours of light and 12 hours of dark a day.

    Then half the winter mice stayed in a winter cycle, while half switched to a summer schedule. The summer mice were similarly split. The mice raised in equal periods of light and dark were split into three groups, one of which stayed on the 12­hour schedule, one of which joined the winter group, and one of which joined the summer group.

    After 28 days, it turns out the summer­born mice behaved the same whether they stayed on the summer cycle or switched to winter. But among the winter­born mice, those stayed in winter kept their previous schedule, while those that switched to summer stayed active for an extra hour and a half, which indicates that mice born and weaned in a winter light cycle showed dramatic disruptions（破坏） in their biological clocks.

    The finding is the first of its kind in mammals, and it could explain why people born in winter are at higher risk for mental health disorders.

    “We know that the biological clock regulates(管理) mood in humans,” said study researcher McMahon. “If the mechanism (机制) similar to the one that we found in mice operates in humans, then it could not only have an effect on a number of behavioral disorders, but also have a more general effect on personality.”

Authors (作者)

    Alexandru Micu: Author

    ZME Science author profile | e-mail: alex@zmescience.com

    Main focus: technology, biology

    Curiosity (好奇心) is what drives Alex forward-his interest in learning more about the planet being matched only by his ability to discuss things with a light heart. Alex tries to make others more interested in special science and technology. He does things in his own way.

    Dragos Mitrica: Author

    ZME Science author profile | e-mail: dragos@zmescience.com

    Main focus: wheather

    Dragos loves nature, and does everything he can to understand it. This interest led him to many unexpected places in his life, and now, he mainly studies and understands how ancient (古代的) weather changed, and what this means for the future.

    Henry Conrad: Author

    ZME Science author profile | e-mail: henrykconrad@gmail.com

    Main focus: technology

    Henry Conrad is a game developer from Albuquerque, New Mexico. Whenever he's not working or reading the latest tech news, he enjoys writing about the latest inventions and technology, which benefits (有益) him a lot. It helps him find rich writing materials (材料).

    Mihai Andrei: Editor-in-chief

    ZME Science author profile | e-mail: andrei@zmescience.com

    Main focus: geophysics, environment

    Andrei has put a lot of sweat and tears into ZME Science ever since he was a student. He is always looking for the most interesting subjects, presenting them in a way that everybody can understand. He believes that education is the key towards a better future and he tries to persuade people to become better persons of the planet. His background is in Geology and Geophysics, but now, he focuses more on environmental studies.

Best Inventions

    Sun Power

    People who buy solar panels (嵌板）for their home hope to help the environment and save some money. But they end up with large metal boxes on their roof. Tesla, a car company, solved the problem. The solution is the Solar Roof. It is a series of tiles (瓦) made to look like traditional roofing material while using the power of the sun. Tesla developed it with SolarCity, a longtime provider of solar panels. It is now available to the public.

    Talking Tech

    Echo gives users the ability to talk to their tech. Apple's Siri and Microsoft's Cortana do that too. But in many ways，Amazon's version，Alexa, which is built into Echo，is more powerful. Alexa has grown since it was put on the market in 2014, and today, you can use it to turn on the lights, order a pizza, and more. Echo costs $ 180. Amazon recently developed a junior version, the $ 50 Echo Dot.

    Spin and Roll

    Goodyear is reinventing the wheel. It introduced its Eagle 360 spherical tire (球形轮胎) in March, 2016. The tires allow cars to move in many directions, including sideways, and at angles to handle slippery surfaces. The key is magnetic levitation (磁悬浮). Tires are fixed to cars, but Eagle 360s float beneath them. They're meant for self-driving cars of tomorrow.

    Cycle Safety

    Jeff Woolf had a serious bike crash. If he hadn't been wearing his helmet, he would have been badly hurt. He wondered why so many riders didn't wear helmets. That turns out it was mostly because helmets were big and hard to carry around. Woolf, an engineer, came up with Morpher. The helmet is made from interwoven plastics (交错编织的塑料). It is strong, but it's also flexible enough to fold almost totally flat. That makes it easy to carry. Morpher is priced at $ 119.

    The Spanish sculptor Isaac Cordal sees the city as his playground. He specializes in miniature, a street art often representing a social commentary as a critical observation on capitalism, power and so on.

    Cordal first models the sculptures in clay then reproduces them in cement(水泥)about 15cm in height.

    “As a material, cement seems very symbolic because it is one of our most recognizable footprints against nature.” he says. “Today we have been too used to cement city habitat.”

    For several years he's been working on the project, Cement Eclipses, referring to the state when a building covers the sun: “It's a critical reflection on the idea of progress.”

    These tiny cement figures have appeared in cities across Europe, found sitting on top of bus shelters or drowning in the grass land of the big city. “The street became a perfect setting in which I could find enough landscapes for them. Due to their small size and color, they go really well into the urban environment. They even normally go unseen by passersby. I'm very interested in that moment of surprise when someone accidentally discovers them.” he says.

    “Nowadays there is a fear of not being seen in the public area, so everything is always big and bold. We become a product of this and do not focus in as much. I think it is good to pay attention to small details. My work is a reward for those who do and it allows us to understand and change the world we have created in a different angle.”Cordal says.

    Have you ever fallen for a novel and been amazed not to find it on lists of great books? Or walked around a sculpture known as a classic, struggling to see why it is famous? If so, you've probably thought about the question a psychologist, James Cutting, asked himself: How does a work of art come to be considered great?

    The direct answer is that some works of art are just great: of inner superior quality. The paintings that win prime spots in galleries, get taught in classes are the ones that have proved their artistic value over time. If you can't see they're superior, that's your problem. But some social scientists have been asking questions of it, raising the possibility that artistic canons(名作目录)are little more than old historical accidents.

    Cutting, a professor at Cornell University, wondered if a psychological pattern known as the "mere­exposure effect" played a role in deciding which paintings rise to the top of the cultural league. Cutting designed an experiment to test his hunch(直觉). Over a lecture course he regularly showed undergraduates works of impressionism for two seconds at a time. Some of the paintings canonical, included in art­history books. Others were lesser known but of comparable quality were exposed four times as often. Afterwards, the students preferred them to the canonical works, while a control group liked the canonical ones best. Cuttings students had grown to like those paintings more simply because they had seen them more.

    Cutting believes his experiment casts light on how canons are formed. He reproduced works of impressionism today bought by five or six wealthy and influential collectors in the late 19th century. Their preferences given to certain works made them more likely to be hung in galleries and printed in collections. And the fame passed down the years. The more people were exposed to, the more they liked it, and the more they liked it, the more it appeared in books, on posters and in big exhibitions. Meanwhile, academics and critics added to their popularity. After all, it's not just the masses who tend to rate what they see more often more highly. Critics' praise is deeply mixed with publicity. "Scholars", Cutting argues, "are no different from the public in the effects of mere exposure."

    The process described by Cutting show a principle that the sociologist Duncan Watts calls "cumulative advantage": once a thing becomes popular, it will tend to become more popular still. A few years ago, Watts had a similar experience to Cutting's in another Paris museum. After queuing to see the "Mona Lisa" at the Louvre, he came away puzzled: why was it considered so superior to the three other Leonardos, to which nobody seemed to be paying the slightest attention?

    When Watts looked into the history of "the greatest painting of all time", he discovered that, for most of its life, the "Mona Lisa" remained in relative obscurity. In the 1850s, Leonardo da Vinci was considered no match for giants of Renaissance art like Titian and Raphael, whose works were worth almost ten times as much as the "Mona Lisa" It was only in the 20th century that "Mona Lisa rocketed to the number­one spot. What brought it there wasn't a scholarly re­evaluation, but a theft. In 1911 a worker at the Louvre walked out of the museum with the "Mona Lisa" hidden under his coat. Parisians were shocked at the theft of a painting to which, until then, they had paid little attention. When the museum reopened, people queued to see it. From then on, the "Mona Lisa "came to represent Western culture itself.

    The intrinsic (本质的) quality of a work of art is starting to seem like its least important attribute. But perhaps it's more significant than our social scientists admit. Firstly, a work needs a certain quality to reach the top of the pile. The "Mona Lisa" may not be a worthy world champion but it was in the Louvre in the first place, and not by accident. Secondly, some objects are simply better than others. Read "Hamlet" after reading even the greatest of Shakespeare's contemporaries, and the difference may strike you as unarguable.

    A study suggests that the exposure effect doesn't work the same way on everything, and points to a different conclusion about how canons are formed. Great art and mediocrity (平庸)can get confused, even by experts. But that's why we need to see, and read, as much as we can. The more were exposed to the good and the bad, the better we are at telling the difference.

    LaVonn was helping out in her dad's store when a little boy, about five or six years old, came in. He was wearing a brown and oversized coat with dirty, old clothes beneath it. His shoes were broken, and only one had lace (鞋带). The boy looked around the store, picked up several items, examined them one by one and then carefully put them back on the shelf.

    LaVonn's dad walked over to the child and asked if he could help. The little boy said, "I'm looking for a gift for my brother." After 20 minutes, the child picked up a toy airplane. He held it carefully in his hands as if it were made of glass and carried it to LaVonn's father.

    "How much is this?" he asked. "My brother loves airplanes." LaVonn's dad answered, "How much money do you have?" The little boy reached into his coat and pulled out some small change (零钱). He spread his money out on the table and began to count. "I have twenty-seven cents," he answered. Her dad picked up the coins and said, "The airplane costs exactly twenty-seven cents! Wait here and I'll pack it up for you."

    The little boy walked out of the store with the gift and a smile of total satisfaction on his face. LaVonn made her way back to the shelf and she found the plane was priced at $11.98.She never mentioned it to her father. Her father didn't say anything more about it either, but she realized later, "My best gift that Christmas was seeing my dad's love in action."